International Journal of Orthodontics - Fall 2016

VOLUME 27 | NUMBER 3 | FALL 2016

International Journal of

Orthodontics

Published Quarterly by the

International Association for Orthodontics In this Issue:

n ManageCost-Effective Management of Patients with Unilateral Congenitally Missing Second Maxillary Premolars

n Management of a Patient with Impacted

Maxillary Canine, Peg-Shaped Lateral Incisors and Transmigrated Mandibular Canine

n Bone Remodeling in Adults: Treatment of an

Adult Skeletal Class II, Division 2 Patient Using a Modified Bionator II Appliance

n HR Spring: A Simplified Approach to

Simultaneous Space Gaining and Derotation

n Management of Unusual Rotation of Maxillary Central Incisor with Impacted Mesiodens

n The ‘SOS activator:’ A Novel Functional Device Combined with Fixed Appliances for the Correction of Class II Malocclusion

n Volumetric MRI Evaluation of Airway, Tongue,

and Mandible in Different Skeletal Patterns: Does a Link to Obstructive Sleep Apnea Exist (OSA)?

n Esthetic versus Function in Early Treatment of Class III Malocclusion

n Oropharyngeal Airway: The Orthodontist Perspective

n Fixed Orthodontic Treatment in Mandibular Lateral Incisor-Canine Transposition

n Craniofacial Asymmetry: A Literature Review n Upper Arch Molar Distalization Appliances in Treatment of Class II Malocclusion

n Moving a Blocked-Out Bicuspid into the Arch Using the “Sleeze”

n Hypoplastic Canine: Would Treatment Decision be Different if the Diagnosis Were Made with Computed Tomography?

Orthodontics: Still the Best Kept Secret in Dentistry Today Visit the IAO online at www.iaortho.org

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changed my life! The knowledge and experience I gained has transformed my practice. The knowledge and experience I gained has transformed my practice. The Guided Growth Appliances and the Controlled Arch® system have allowed me to treat patients of all difficulty levels with a higher level of confidence and ease than I ever have before. I have practiced orthodontics for 13 years using various techniques and tricks and experiencing the same frustration of occasional lack in stability and finished product. After the Facial Beauty Institute opened my eyes to the critical importance of the airway and the correct way to diagnose and treat this makes finishing cases easy. They are telling the truth when they say they teach exceptional orthodontics!

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After seven years of extensive training and treating hundreds of patients, I was still very frustrated. Just like my specialist colleagues’ cases, my patients had straight teeth. But what about the health of their TMJ or airway? As general practitioners doing orthodontics we tend to have long term follow-up with our orthodontic patients. We get to see our “failures” in relapses, TMD complications, sleep disordered breathing all either caused or worsened by straightening teeth without considering the TMJ or the airway.

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Dharmesh Parbhoo, DDS AFAAID, FDOCS, IAO Senior Instructor,

Adjunct Clinical Instructor of Oral Rehabilitation and GPR/AEGD Program at the Georgia Regents University College of Dental Medicine. He is an active practitioner with a private practice with a focus on growth, orthodontics, sleep medicine and rehabilitation of the Orofacial complex.

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No truer statement reflects the profound and fulfilling contribution that Dr. Galella has made to my professional life and my ability to improve my patients’ lives. Helping TMD and sleep apnea patients is my calling but there was always a big elephant in the room – the airway was the problem but it was simply what was left over when the corruption of mid-face development had run its course. The Big 3 – nasal breathing, correct swallow and tongue posture and a lip seal mean the difference between correct expression of the genetic blueprint or its aberrancy. Dr. Galella taught me how to correct the foundation. How to stimulate growth and remodeling to create arches large enough to house the tongue and optimally positioned in the face to optimize the airway. No longer are my tools limited by the compromised arch form and size that the patient presents with. Being able to correct the foundation predictably and with excellence is the gift Dr. Galella has given me which enables me to play it forward to my patients and colleagues. If it is being done, it is probably possible.

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Anne-Maree Cole, BDSc, MScMed (Sleep Medicine), LVIM, MICCMO

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TABLE OF CONTENTS Editor Steve Galella, DDS, IBO Collierville, TN, USA E-mail: drsgalella@hotmail.com Medical Editor Annette S. McDevitt, PhD 2982 Woodland Ash Cove Lakeland TN 38002 E-mail: amcdevitt@att.net Managing Editor Tamiko L. Kinkade Communication & Publication Solutions, Inc. 1417 James Street, Springfield, IL 62703 Phone: 217/585-9065 Fax: 217/529-7178 E-mail: tk@tkcpsolutions.com

International Journal of

Orthodontics

FALL 2016 n VOLUME 27 n NUMBER 3

FEATURES

Cost-Effective Management of Patients with Unilateral Congenitally Missing Second Maxillary Premolars .................................................................................................................11

By Alla Dekterov, DDS Management of a Patient with Impacted Maxillary Canine, Peg-Shaped Lateral Incisors and Transmigrated Mandibular Canine ..................................................................................15

By Dipti Shastri, BDS,MDS; Gyan P Singh BDS,MDS; Pradeep Tandon BDS,MDS Consultants Bone Remodeling in Adults: Treatment of an Adult Skeletal Class II, Division 2 Patient Richmond Cheng, DDS, IBO, Vancouver, BC, Canada Using a Modified Bionator II Appliance ..................................................................................19 Anne-Maree Cole, BDS, LVIM, Strathpine, Australia By: Kristopher Krimi, BSc, DMD, IBO Rick Grant, DDS, IBO, Winnemucca, NV, USA HR Spring: A Simplified Approach to Simultaneous Space Gaining and Derotation..........27 P. Harikrishnan, BDS, MDS, FDSRCS, Chennai, India By Anubha Rathi, BDS; Rohan S. Hattarki MDS Yosh Jefferson, DMD, IBO, Mount Holly, NJ, USA Unusual Rotation of Maxillary Central Incisor with Impacted Mesiodens...........................29 Jean Noel Lavallee, DDS, IBO, MBA, Longueuil, QC,

By Vipul Kumar Sharma, BDS, MDS, FODS, IMS, BHU; Kirti Yadav, BDS, MDS Pradeep Tandon, Canada BDS, MDS; Gyan Singh, BDS, MDS Edmund Liem, DDS, Chilliwack, BC, Canada The ‘SOS activator:’ A Novel Functional Device Combined with Fixed Appliances for the Mike Lowry, DDS, IBO, Lacombe, Alberta, Canada Correction of Class II Malocclusion ........................................................................................33 Derek Mahony, BDS, MSc, DOrth, MDorth, IBO, Sydney Australia

By Sossani Sidiropoulou, DDS, PhD; Athina Chatzigianni, DDS, MSc, PhD Sylvan Morein, DDS, IBO, Glenside, PA, USA Volumetric MRI Evaluation of Airway, Tongue, and Mandible in Different Skeletal Reuel Owen, DDS, IBO, Galesburg, IL, USA Patterns: Does a Link to Obstructive Sleep Apnea Exist (OSA)? ...........................................39 Adrian Palencar, DDS, IBO, Thorold, ON, Canada

By Krishna Sharma, MDS; Sunita Shrivastav, MDS; Kavita Hotwani, MDS Jae Hyun Park, DMD, MSD, MS, PhD, Mesa, AZ, USA Esthetic versus Function in Early Treatment of Class III Malocclusion .................................49 Pierre Pellan, DMD, Quebec, QC, Canada

By Marlene Thompson, DDS Korrodi Ritto, DDS, PhD, Leiria, Portugal Oropharyngeal Airway: The Orthodontist Perspective ........................................................51 Brock Rondeau, DDS, IBO, London, ON, Canada

By Ashish Agrawal, MDS; T P Chaturvedi, MDS; Midhun Raghav, BDS, Post Graduate Student (MDS) Ankit Shah, BDS, MDS, MS, Irving, TX, USA Fixed Orthodontic Treatment in Mandibular Lateral Incisor-Canine Transposition ..........57 Cris Simmons, DDS, Seattle, WA, USA

By Alkan Özer, PhD; Yüzbaşıoğlu Betül, PhD; Kaya Yeşim, PhD Alfredo Valera, DMD, Quezon City, Philippines Craniofacial Asymmetry: A Literature Review .......................................................................63

By Judith Maria Medina-Rivera, DMD Upper Arch Molar Distalization Appliances in Treatment of Class II Malocclusion.............67

By Léonard Jacques, DMD Moving a Blocked-Out Bicuspid into the Arch Using the “Sleeze”........................................75

By Ahmed Masoud, BDS, MSc International Journal of Orthodontics, copyright 2013 (ISSN #1539-1450). Published quarterly (March, Hypoplastic Canine: Would Treatment Decision be Different if the Diagnosis Were Made June, September, December) by International with Computed Tomography? .................................................................................................77 Association for Orthodontics, 750 North Lincoln

By Giordani Santos Silveira, DDS, MD; Johnny Holanda de Gauw DDS, MD; José Nelson Mucha Memorial Drive, #422, Milwaukee, WI 53202 as a DDS, MD, PhD membership benefit. All statements of opinion and of supposed fact are published on the authority of the writer under whose name they appear and are not to be regarded as views of the IAO. Printed in the USA. Periodical postage paid at Milwaukee, WI and additional mailing offices. Subscription for member $15 (dues allocation) annually; $40 U.S. non-member; $60 foreign. Postmaster: Send address changes and all correspondence to:

International Journal of Orthodontics 750 North Lincoln Memorial Drive, #422 Milwaukee, WI, USA 53202 Phone 414-272-2757  Fax 414-272-2754 E-mail: worldheadquarters@iaortho.org

DEPARTMENTS Orthodontics: Still the Best Kept Secret in Dentistry Today ............................................................... 5

By Steve Galella, DDS, IBO Ortho Points: How to Run a Successful Orthodontic Practice ............................................................ 9

By Mark D. Paschen, DDS Lit Review ............................................................................................................................................83

By Michel Champagne, DMD, MAGD, IBO, CDE

ADVERTISERS Controlled Arch ................................................Inside Front Cover G&H Orthodontics.............................................................................4 T&S Therapy Centre Intl................................................................ 14 Murdock Laboratory...................................................................... 26

Visit the IAO online at www.iaortho.org

Rondeau Seminars ......................................................................... 32 Johns Dental Labs .......................................................................... 62 IAO Annual Meeting ...................................................................... 66 Dolphin Imaging Systems .......................................... Back Cover

AUTHOR’S GUIDELINES FOR THE INTERNATIONAL JOURNAL OF ORTHODONTICS POSTED ONLINE AT www.iaortho.org.

Past IAO publications (since 1961) available online in the members only section at www.iaortho.org.

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EDITORIAL Orthodontics: Still the Best Kept Secret in Dentistry Today

hether you are merely interested in basic concepts of orthodontics, or you want to add orthodontics to your practice, the time is right. To determine whether orthodontics is right for your practice, let us examine the current available information which may influence your decision.

Let’s look at it statistically. The Academy of General Dentistry (AGD) reported in 2003 that only about 10-20% of orthodontic problems were being diagnosed. It stands to reason that diagnosis and treatment planning for orthodontics could provide general dental practices with additional satisfaction and financial boosts. Today, depending on whom you ask, about 20% of general dentists are involved in comprehensive (i.e., bands and brackets) orthodontics. What’s more, recent results from the American Association of Orthodontists (AAO) survey suggest that more than 1 million adults in the U.S. are currently wearing braces, and adults account for 20% of all orthodontic patients. This means there is a significant lack of necessary orthodontic treatment available for the general public.

Contributing to the projected trend of increased demand for orthodontic care overall are patient education and an increasing desire for esthetics. Technological advancements enable dental professionals to offer orthodontic treatments more efficiently, over less time, and with more esthetic results.

Orthodontics and dentofacial orthopedics is a science, and science evolves through knowledge, evidence, and application.

We have seen changes — big changes in the last decade. Our profession claims it now has the means to treat orthodontic and dentofacial orthopedics patients faster and better, with less pain, and with better functional and esthetic results. I sincerely think this is true, and we can achieve better results than ever before. We talk professionally about philosophies, innovations in orthodontics and dentofacial orthopedics, advances of modern mechanics, and the ways that orthodontics and dentofacial orthopedics can increase both smile and facial balance. Orthodontics and dentofacial orthopedics is now a vital component in the treatment for straight teeth, facial growth, compromised airways, oral habits, sleep disordered breathing, temporomandibular dysfunction, and proper function of the stomatognathic system. Dentofacial orthopedics is more technologically sophisticated than ever before with the introduction of growth guidance appliances. Treatments are more individualized to each patient, and the therapeutic resources are exceptional.

Any practitioner should not expect to be able to treat effectively and provide quality orthodontics after only a couple IJO  VOL. 27  NO. 3  FALL 2016

Steve Galella, DDS, IBO Editor of weekend courses. Your first responsibility is to enroll in quality programs with responsible and knowledgeable instructors — a program that includes enough hours to get you to a high standard of care. You must evaluate the availability of long-term support from your instructor. The experience and knowledge of your instructor and willingness of your instructor to support you as your cases progress are essential to your success.

Although orthodontics and dentofacial orthopedics has a bit of a learning curve, your journey should be a pleasantly challenging experience. Your passion may lead you to move to more difficult and challenging cases, but take your time. The easiest thing in orthodontics is to start cases — the problems come as you try to finish them. You do not have to treat every case that comes your way. As you gain experience, cherry pick your early cases.

Knowledge is the key, when you do it right. Refer the cases that do not match your level of knowledge or experience. Develop harmonious relations with one local orthodontist (if there is one available). Find a trusted partner that you would send your children to, and refer him/her the cases that you do not want to treat. Enjoy your orthodontic education and plan it well.

Performing quality orthodontics enhances your practice in many ways.

The greatest quality of a professional resides in his or her willingness to learn, unlearn, and re-learn. Today’s truth may be laughed at tomorrow. Today, you have to adapt to change, and you will have to cope with new notions in a short time. Doctors, are you ready for this new challenge that our demanding world imposes?

Orthodontics is part of that future. Every book and dental magazine that I put my hands on seems to discuss a personal vision of what the future of the profession will be. The future of orthodontics varies depending on who has the vision.

In the years to come, the future of orthodontics is already traced; you only need to use your judgment to decide when to make the move to a more profitable practice. It will not come by itself, and it will take some effort. What is the future of 5

orthodontics? My thought is clear: the future of orthodontics is very bright. The best future includes: self-ligation, low friction and low force bracket systems, advancement in growth (understanding growth and modifying growth efficiently), 3-D imaging, computerized and individualized system designs for brackets and wires, mini-screw anchorage, easy data gathering, and collaboration with other professionals on the Internet, from office to office.

What orthodontists must understand is that by increasing the orthodontic knowledge of the GP community, they will receive more referrals from those GPs. I have never seen a good orthodontist (who usually is a very busy one) take the time to criticize the GPs in his or her area. Most of the ones who do it are often not too busy, and from my viewpoint, it means that they probably are not in the top of their group — I may be wrong, and that is for you to judge. They probably should remain silent and work on their images within their own profession and the public.

In my 35 years of practice, I have never seen a competent specialist (this includes orthodontics) who was afraid of his or her market. It has been my observation that those who fear are usually less knowledgeable, and their practices are marginally surviving. My position is very clear on this and has not changed for the last 20 years (I needed the first 15 years to get a position!). The ones who succeed in dentistry, including orthodontic specialists, are the ones who show advanced knowledge of their profession. The ones who see every fellow dentist as a threat are the ones who are often less knowledgeable, and in that sense, they do have good reason for concern.

As a clinician practicing orthodontics, the learning process continues the rest of your professional life--reading, studying, and evaluating input from different instructors. It is a fabulous field to be in, but you have to be willing to learn and study.

Our first responsibility, as students, is to get enough proof of effectiveness for any procedure we try for the first time. Has it proven its effectiveness over time, and is it well-documented?

Our clinical decisions must take into account the actual patient situation, the scientific data, and also our clinical experience and patient preferences.

6

We know that we are in a world of innovation. Innovation brings about improvement. As a GP starting in orthodontics, there is a code of ethics. In private practice, dentists are typically required to satisfy relevant legal standards, follow professional guidelines, and maintain ethical values. Innovation often refers to procedures that are so new that they seldom have been tried before in the context of patient care. If innovation equals experimentation, it is not the place to be as a general dentist.

As a GP practicing orthodontics, we must deliver the same quality of care as specialists do in orthodontics. Furthermore, we are more exposed to criticism because we are not in the big boys’ club (not being university-trained specialists). My recommendations are to start with easy cases (as long as you know what easy cases are) and avoid skeletally open cases.

To do that, you have to take the time to learn diagnosis.

Choose a Class I interception case as a starter. Stay with normodivergent cases until you have gained experience. Then you can move up to growing Class II mandibular retrusive cases.

Choose a case that is hypodivergent or normodivergent. Take a case that matches your comfort level. We all know the meaning of the learning curve in dentistry. The dictionary describes a learning curve as a graphical representation of the changing rate of learning (in the average person) for a given activity or tool. Typically, the increase in retention of information is sharpest after the initial attempts, and then gradually evens out, meaning that less and less new information is retained after each repetition.

The point is—orthodontics involves life-long learning. If you are interested in expanding your knowledge and offering quality orthodontic care to your patients, the time is right. This translates into personal fulfillment as well as financial success.

Most importantly, it means that you are in a position to offer the finest state-of-the art treatment for your patients. It is indeed an exciting time for our profession, so let’s move forward and be the best that we can be.

IJO  VOL. 27  NO. 3  FALL 2016

Pearls from Dr. Larry White

Reprinted with Permission

Larry W. White, DDS, MSD, FACD - www.larrywwhiteddsmsd.com Orthodontic Pearls, A Clinician’s Guide by Larry W. White, DDS, MSD can be purchased at: www.larrywwhiteddsmsd.com.

Watch for more Pearls in future issues of the IJO.

Dr. Lisa King of Albuquerque, NM contributed this idea for making smoother alginate impressions: Spray Pam (2 squirts) in the alginate-water mix and then spray over the loaded tray to create a surface that produces flawless impressions.

Tom Mulligan from Phoenix, AZ has been my mentor in biomechanics for more than 40 years, and he has some tremendous pearls. One of my favorites is the expanded .036 overlay that he uses to correct stubborn posterior crossbites. Dr. Mulligan combines this technique of crossbite correction with another equally valuable idea: removing the arch wires for a few weeks to test the stability of therapy prior to removal and retention.

Dr. Bill Wyatt of Glen Rose, TX has discovered a way of making the wax that clinicians give to their patients far more effective in protecting their mouths form the appliances they use. He flattens a small piece of wax, adds a small wisp of cotton and folds the wax over, thereby constructing a wax sandwich that adheres to the wires and brackets much more effectively than wax alone.

Small piece of wax

IJO  VOL. 27  NO. 3  FALL 2016

Flattened piece of wax with wisp of cotton

Wax folded to make sandwich 7

I discovered this pearl while working for Dr. Jim Moore of Garland, TX. Jim has developed a really quick and efficacious way of rebonding broken brackets that eliminates the air-water syringe, which often causes hemorrhaging and subsequent contamination of the bonding site. Dr. Moore’s technique also eliminates waste of etchant and sealant.

Removing residual composite with a diamond bur

Soak one end of a cotton roll with water

8

Wetting a micro-brush with a drop of etchant

Rinse the etchant with gentle pressure - but without rubbing - with the wet end of the cotton roll

Etch the tooth

Gently dry the tooth with the dry end of the cotton roll

Complete drying with warm air

Apply a drop of sealant to microbrush

Apply sealant with microbrush

Place bracket and light-cure composite IJO  VOL. 27  NO. 3  FALL 2016

PRACTICE POINTS

How to Run a Successful Orthodontic Practice - Part III Mark D. Paschen, DDS Abstract: This is the third in a series of articles outlining How to Run a Successful Orthodontic Practice. In the previous two articles, I emphasized the importance of the receptionist and the hygienist. In this article, I will concentrate on the treatment coordinator (TC). I had been practicing orthodontics for over 15 years before I even heard the term “TC.” Once I integrated a TC into my orthodontic practice and realized how integral she (or he) is to my success, in terms of freeing up my time and increasing my production, I have become a much more relaxed person and can concentrate more on treating my patients while the TC connects with the patients and covers the financials. The TC is the key to building a relationship with the new patient and ultimately achieving treatment acceptance.

ntroduction Treatment Coordinator: (I will refer to the TC as “she” even though there may be many very qualified and talented men out there serving in that role). There are five main responsibilities of the TC. They range from meeting the new patient to getting the new patient to accept treatment.

These responsibilities are: 1. Immediately connect with the new patient 2. Take any needed records, while still connecting 3. Go over the treatment plan with the parent and/or patient after the doctor has reviewed the records and performed the exam 4. Go over the financial options 5. Get the patient to book the treatment When new patients arrive for their orthodontic evaluations, it is important not to keep them waiting. Nothing is more negative than keeping a patient waiting--especially a new patient. My TC goes out to the reception area and personally greets any new patient. If the patient is a child, my TC gets down to the level of the child (kneels if necessary) and warmly welcomes them. The TC explains to the parent that a series of digital images will be taken first on their child, and then she will escort the parent into the room while photos and the exam by the doctor are performed. You need to schedule enough time for the new patient evaluation appointments so the TC can finish a previous appointment in plenty of time before her next one. We IJO  VOL. 27  NO. 3  FALL 2016

allow 80 minutes for a new patient evaluation in our office, and the time is divided as follows: First 30 minutes: Gather necessary records, digital images, photos, and connect. Notice I didn’t say impressions. We wait on the impressions until the patient commits to treatment.

Why subject a six year-old to impressions if we are going to wait another six months for the first molars to erupt before starting?

Impressions can also be a negative experience for some patients, and we want to keep this initial visit as positive as possible. For those of you who are novices to orthodontics, the impressions should be taken to better evaluate treatment needs. “Veterans” to orthodontics can usually dictate the treatment plan without models (and prior to a cephalometric tracing) but always caution the parent verbally and in writing on your treatment plan form that the treatment may change depending on growth factors which may be beyond our control. This allows for changes in the treatment plan.

Next 20 minutes: TC goes over records with doctor, gives doctor an idea on patient and parent personality, doctor performs the oral exam and dictates the treatment plan to the TC in front of the patient. It is important that the TC speak with the doctor before he or she examines the patient.1 A lot of insight can be gained as to the personality of the patient, needs and wants of the patients, and even the personality of the parent(s). For example: Will you be walking into an evaluation where the parents and child are 100% on board and ready to start treatment (recognize the problem), or is there a lot of negativity present and the teenage boy doesn’t want braces, and the parents are oblivious as to why they are even at the 9

appointment? It is helpful to know these things before walking into the evaluation. A well-trained TC can give the doctor that insight. We also have specific questionnaires for each age group which help us to connect better with the patients. These will be discussed in an upcoming article on marketing.

Last 30 minutes: TC goes over treatment plan. There are five parts to any treatment plan which should be incorporated,2 even for general dentistry procedures. They are: 1. Show what is wrong 2. Show what it should look like 3. Tell what would happen if nothing is done 4. Tell them the fee 5. Tell them what the next step would be (schedule the treatment) Number 3 above, beside the fee, is really what parents want to know. Basically, how will treatment benefit them? You should emphasize some sense of urgency, although you never want a patient to feel pressured into doing treatment or to have “buyer’s remorse.” Several reasons and scenarios should be given as to the importance of treatment. If this step is done well, the patient (parent) should be asking when they can start--even before getting the fee quoted.

The fourth step of the treatment plan process (#4 above) is often overemphasized. If the first three steps are done well, this step should be seamless. The keys to discussing fees are to give options for payment3 and to make sure the TC is comfortable discussing fees. I can’t emphasize that enough. At one point, I had two TCs who alternated days. I tracked their case acceptance, and one of them had a much higher acceptance than the other. I discussed scripting with them, and we roleplayed together. I finally discovered that one of the TCs was uncomfortable in discussing fees with patients. Not surprisingly, she was the one who had a much lower case acceptance rate.

My current TC is so comfortable in discussing fees that I have empowered her to make any special fee arrangements that she deems necessary. She gives the option of a higher down payment and low monthly payments, or a low down payment and higher monthly payments. We also give a 5% courtesy for payment in full.

10

Your TC should ask the parent (patient) what option would work best for them. Also, ask if there are any other concerns they may have before starting treatment. If not, the TC then gives options on booking the treatment. For example, it is stated, “We would love to welcome you into our orthodontic family. Let’s get your appointment scheduled. Would a morning or afternoon work best for you? Would a 1:00 PM or 4:00 PM fit into your schedule better?” Always make the appointment about THEM. Never state WE have a 1:00 PM or 4:00 PM appointment available.4 Having a personable, educated, and well-trained TC will make your life so much easier and will improve your case acceptance immensely. If you are to make any investment in your orthodontic practice, as far as practice management, definitely invest in training one of your auxiliaries properly to become a TC. The next article will focus on marketing your orthodontic practice. I will discuss internal marketing, which will involve very little financial commitment. You will learn how to connect better with your patients through customized new patient questionnaires, how to “jazz” up your office to get your general dentistry patients interested in orthodontics, some fun contests you can do for your existing patients, and other ideas to keep a steady flow of new patients coming to you for orthodontics.

References: 1.

2.

3.

4.

J Swift Consulting, Phoenix, AZ. Office visit Rick Pereira, Practice Management Consultant, Phoenix, AZ. Office visit Chase, L, “Yes to Treatment” 2012, Landy Chase, MBA, CSP Scheduling Institute, Alpharetta, GA. Telephone training module.

Dr. Mark D. Paschen graduated from the Marquette University School of Dentistry in 1983. His “passion” has always been practice management, giving his patients extraordinary service. After years of incorporating orthodontics into his general dentistry practice, his practice is now focused solely on orthodontics, TMD, and Sleep. He credits much of the success of his practice to not only furthering his clinical skills, but also to his close attention to practice management implementation. Dr. Paschen has lectured extensively in the United States and also in Sydney, Australia. He is a Senior Certified Orthodontic Instructor for the IAO.

IJO  VOL. 27  NO. 3  FALL 2016

FEATURE

This article has been peer reviewed.

Cost-Effective Management of Patients with Unilateral Congenitally Missing Second Maxillary Premolars

By Alla Dekterov, DDS

Abstract: Two case presentations are utilized to review the cost-effective treatment options in patients with unilateral congenitally missing second maxillary premolars. Once diagnosed, the dentist can either preserve or remove the respective primary molar. Preservation will lead to a tooth-size discrepancy. To limit the size of the second primary molar to the dimension of the contralateral premolar, and to allow the preservation of alveolar bone, removal of its mesio-distal aspect should be performed. Later on, the primary molar may become infraoccluded or lost, and it will be necessary to do a coronal built-up or a prosthetic replacement respectively. Any type of prosthetic replacement will significantly increase the total cost of treatment. Clinicians should aim for ideal occlusion and profile and take into account other orthodontic problems and propose the most appropriate treatment plan for each patient.

Keywords: hypodontia therapy, congenitally, missing teeth, orthodontics, dental implants.

ntroduction Congenital absence of maxillary second premolars is the fourth most frequent type of agenesis after the third molars, mandibular second premolars, and maxillary lateral incisors. 1, 2 Unilateral versus bilateral maxillary second premolar agenesis has been reported in up to 60% of all agenesis cases. 3 The objectives of this review are to direct the clinician through a diagnostic sequence of recognition and treatment planning for a unilateral congenitally missing second maxillary premolar in the most appropriate time and cost-effective way.

Implications: If the space will be left open for future restoration, it is important to create the correct amount of space and leave the alveolar ridge in an ideal condition for a future restoration. If the space will be closed, the clinician must avoid any detrimental effects on the occlusion and the facial profile.

Significance: Some early decisions that the clinician makes for a patient whose one maxillary second premolar is congenitally missing will affect his or her dental health for a lifetime. Therefore, the correct decision must be made at the appropriate time.

Purpose: In this article, we will present and discuss different treatment considerations for patients with unilateral congenitally missing maxillary second premolar. Two cost-effective options will be presented in a case-study format.

Hypodontia is the term used to describe the developmental absence of one or more primary or permanent teeth excluding the third molars.4,5 In Caucasian studies, the second maxillary premolar is the fourth most common congenitally missing tooth after the third molars, mandibular second premolars, and maxillary lateral incisors.6 Often management of congenitally missing teeth implies space management to accommodate future implants placement IJO ď Ž VOL. 27 ď Ž NO. 3 ď Ž FALL 2016

or other restorative options. Implant placement is absolutely the best treatment modality to replace congenitally missing teeth-also it is one of the most expensive options.7 The clinician must consider proximity to the maxillary sinus. If the primary tooth will be extracted, we always must evaluate the amount of available bone. Will bone grafting or a sinus lift procedure be required prior to the implant placement?

Therefore, the general dentist plays a key role in monitoring eruption and growth of young patients. With the knowledge and experience in all aspects of dentistry, we can preserve various treatment options in the future. If this is well-done, the final result will be esthetic, predictable, and affordable.

Regardless of which unilateral permanent premolar is congenitally missing, the clinician must make the proper decision at the appropriate time regarding management of the edentulous space and should ask the following questions: 1. Can the primary tooth be maintained in the arch preserving the alveolar bone for future implant and prosthetic restoration?

2. Can malocclusion be treated satisfactorily with keeping one permanent tooth on one side of the mouth and no corresponding permanent tooth on the other side?

3. Should the unilaterally present permanent tooth be extracted?

4. Should the space be opened in place of the missing unilateral permanent tooth?

5. Is it necessary to extract the other three corresponding permanent teeth?

As general dentists, we often encounter patients with congenitally missing teeth. We evaluate patients with missing teeth at an early age. An important factor in managing these patients at an early age is space maintenance. If the patient has no arch length deficiency and will not require extractions to treat 11

malocclusion, it is important to maintain the primary tooth as long as possible.8 However, the mesiodistal width of the primary second molar creates tooth-size excess that makes it difficult to achieve ideal interdigitation of the posterior teeth. A normal primary second molar is about 9.5 mm wide. Therefore, it is beneficial to reduce the mesiodistal width so that it is equal to the width if a second premolar is 7.5 to 8.0 mm. The crown of a primary second molar converges significantly toward the cervical region and allows us to reduce the crown width by 1.5 to 2.0 mm.9 After the tooth reduction has been completed, a thin layer of light-cured composite must be placed interproximally to cover exposed dentin. It is often necessary to build up the occlusal surface to establish adequate crown height and occlusal contact.

Occasionally, a primary second molar become ankylosed.

If ankylosis occurs while the patient is young and still growing, the tooth will become submerged relative to adjacent erupting permanent teeth. If this region will be restored with a future implant, the alveolar ridge can be compromised vertically and will require a bone graft. Vertical bone grafting is often unpredictable and adds expense for the patient.10 Therefore, extraction of ankylosed primary molars is recommended if the patient is missing the primary second molar, and the face is still growing.

The most reliable indicator of primary molar ankylosis is to evaluate the alveolar bone level between the primary molar and adjacent permanent first molar and first premolar. If the bone is flat, this indicates that the primary tooth and the adjacent teeth are erupting evenly. However, if the alveolar bone level becomes oblique, with the bone level located more apically around the primary tooth, this confirms ankylosis.11 The most common question after primary molar extraction is whether to place a space maintainer to preserve arch length. V.O Kekich and V.G.Kokich8,11,12 do not place a space maintainer in most situations, especially if the implant will be placed for restoring the edentulous space. If the edentulous space is not maintained, the adjacent permanent molar and first premolar should erupt together. During orthodontic treatment, the first premolar and six year molar will be pushed apart to create the implant space. As the roots of those teeth move apart, they deposit bone behind that equals the width of the premolar and molar. This process is called orthodontic implant-site development.12 Occasionally, the decision to extract an ankylosed primary maxillary second molar will be made too late, resulting in a narrow alveolar ridge with a vertical deficiency. Implant placement will require a bone graft to provide adequate ridge width and height. It has been suggested to push the first premolar into the second premolar position, thereby creating space for the implant in the first premolar location.13 Another alternative for treating a patient with unilateral congenitally missing maxillary second premolar is to simply close the space. If the patient has crowding or a protrusive facial profile, closure of the edentulous space will be advantageous.14 If the space will be closed, the clinician must avoid any detrimental alterations to the occlusion and the facial profile.

However, in a patient with no dental crowding and a normal facial profile, additional anchorage, i.e., extraoral 12

(protraction facemask) or intraoral (mini-screws and miniimplants) will be required to prevent an undesirable facial profile.15 Northway suggest another method of closing the edentulous space which is to hemisect the primary second molar at an early age and allow the permanent molar to erupt in a mesial direction.16 During treatment planning, the following factors should be considered and will increase the likelihood of extraction of the primary second molar and closure of the edentulous space:1 1. Large degree of crowding 2. Midline discrepancy 3. Antero-posterior molar discrepancy between right and left sides 4. Procumbence of the incisors on the underlying alveolar structures (double-dental protrusion) 5. Full facial profile requiring reduction in lip support 6. Increased vertical dimension of the lower face 7. Shallow overbite or anterior open bite Evaluation of panoramic and periapical radiographs may reveal unilateral congenitally missing second premolar before complete eruption of the first permanent molar. This allow us to monitor and guide eruption through selective primary tooth extraction. A definitive diagnosis of aplasia of the second maxillary molar in patients under 9 years of age can rarely be made. It has been suggested that in subjects with hypodontia, the second primary molars should be extracted early before 11 years of age to allow spontaneous space closure.15 Most patients with congenitally missing teeth require comprehensive orthodontic treatment. If the decision is made during treatment planning for the space to be closed, then the patient can avoid post-orthodontic restorative treatment.

We present and discuss two treatment alternatives for managing orthodontic patients with unilateral maxillary congenitally missing second premolars where the patients didn’t require further restorative treatment.

Case #1 A girl, age 6, has congenitally missing maxillary left second premolar #2.5 and 3 third molars #1.8;3.8;4.8(FDI numbers).

The decision was made to extract the primary second molar and close the edentulous space by moving the first permanent molar forward during eruption. Movement of both teeth #2.4 and #2.6 was noticed until age 12. Straight wire mechanics were applied at 12 years of age to resolve crowding and completely close the edentulous space on the upper left. Significant movement of the left first molar eliminated the need for extensive restorative dentistry without compromising the facial profile. Total treatment time was 15 month finishing with Class I cuspids on both sides, Class I molars on right side, and Class II molars on left side; maxillary and mandibular midlines were coincident with the facial midline (Figure 1).

Case #2 This 19 years old female was missing her right second premolar #1.5 and all third molars. There was a 3 mm maxillary midline shift to the right, posterior crossbite 2.5;2.6;2.7/3.4;3.5;3.6;3.7 as well as moderate maxillary and IJO  VOL. 27  NO. 3  FALL 2016

References 1.

2.

3.

4.

5.

6.

Figure 1: Top row from left to right, Girl 12 years old, congenitally missing left second premolar. Left primary second molar was extracted at age 6. Bottom row from left to right, significant mesial movement of left maxillary first molar eliminated need for extensive restorative treatment.

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Figure 2. Top row from left to right, Young 18 years old female was congenitally missing right maxillary second premolar.

Bottom row from left to right, maxillary second premolar was extracted, maxillary midline was moved to the left by 3 mm.

mandibular crowding. Molars were in Class II relationship. The decision was made to extract the maxillary left second premolar, move the upper midline to the left to have it coincident with the facial midline and resolve crowding. Combination of straight wire mechanics and maxillary Nitanium Palatal Expander2 (CerumOrtoOrganizers®) were used to achieve the above-mentioned goals. Total treatment time was 19 month finishing with Class I cuspids and Class II molars on both sides maxillary, and mandibular midlines are coincident with facial midline (Figure 2).

Conclusion In order to achieve the ideal occlusion and profile, the clinician should take into account other possible circumstances such as proximity of the maxillary sinus to the edentulous space, the degree of crowding, pre-existing upper and lower midline discrepancies, and the facial profile and accordingly propose the most appropriate treatment for each patient. Optimizing clinical outcome is one consideration, doing it cost-effectively is another increasingly important consideration during unstable economic times.

IJO  VOL. 27  NO. 3  FALL 2016

16.

Kennedy D. Orthodontic management of missing teeth. J Can Dent Assoc 1999; 65:548-50.

Baccetti T. Tooth anomalies associated with failure of eruption of first and second permanent molars. Am J Orthod Dentofacial Orthop. 2000 Dec; 118(6):608-10.

Ith-Hansen K, Kjaer I. Persistence of primary molars in subjects with agenesis of the second premolars. Eur J Orthod 2000 Jun; 22(3):239-43.

Fekonja A: Hypodontia in orthodontically treated children.

Eur J Orthod 2005; 27:457-460.

Larmour C, Mossey P, Thind B, Forgui A, Stirrups D: Hypodontia- A retrospective review of prevalence and etiology. Part I. Quintessence International 2005 Apr; 36(4): 263-270.

Nunn JN, Carter NE, Gillgrass TJ, Hobson RS, Jepson NJ, Meechan JG, Nohl FS: The interdisciplinary management of hypodontia: background and role of paediatric dentistry.

British Dental Journal 2003; 194(5):245-251.

Sabri R: Management of congenitally missing second premolars with orthodontics and single tooth implants. Am J Orthoped Dentofacial Orthop 2004; 125:634-642.

Kokich VO: Early management of congenitally missing teeth: Semin Orthod 2005; 11:146-151.

Valencia R, Saadia M, Grinberg G. Controlled slicing in the management of congenitally missing second premolars. Am J Orthod Dentofacial Orthop 2004 May; 125(5):537-43.

Ostler M, Kokich V. Alveolar ridge changes in patients congenitally missing mandibular second premolars. J Prostet Dent 1994; 71:144-9.

Kokich VG: Managing orthodontic-restorative treatment for adolescent patient, in McNamara JA, Brudom WL (eds): Orthodontics and Dentofacial Orthopedics. Ann Arbor, MI, Needham Press, 2001, pp 423-452.

Kokich VG, Kokich VO. Congenitally missing mandibular second premolars: clinical options. Am J Orthod Dentofacial Orthop 2006 Oct; 130(4):437-44.

Christou P, Kiliaridis S. Three-dimensional changes in the position of unopposed molars in adults. Eur J Orthod 2007; 29(6): 543-547.

Zimmer B, Schelper I, Seifi-Shirvandeh N. Localized orthodontic space closure for unilateral aplasia of lower second premolars. Eur J Orthod 2007 Apr; 29(2):210.

Angelopoulos G. What are the treatment options in patient with unilateral congenitally missing mandibular premolars?

Oral Health Group 2013 Sept 1; www.oralhealthgroup.com Northway W. Hemisection: One large step toward management of congenitally missing lower second premolars.

Angle Orthod 2004; 74:790-7.

Dr. Alla Dekterov has been a member of the IAO since 2007. She graduated from Minsk State Medical University, Belarus in 1985 and from University of Alberta, Canada in 2004. Dr.Dekterov held a position as a Clinical Instructor Faculty of Medicine and Dentistry at the University of Alberta from 2004 to 2007. She has completed extensive courses in orthodontics, implant dentistry and has graduated from Kois Centre for Advanced Dental Studies. Currently, Dr.Dekterov has a private practice in general dentistry in Stony Plain, Alberta with a focus on comprehensive dentistry including orthodontics.

13

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FEATURE Management of a Patient with Impacted Maxillary Canine, Peg-Shaped Lateral Incisors and Transmigrated Mandibular Canine: A Case Report

By Dipti Shastri, BDS,MDS; Gyan P Singh BDS,MDS; Pradeep Tandon BDS,MDS Abstract: To treat morphological abnormalities, impaction, and severe malposition of the teeth, the lateral incisors are sometimes extracted, followed by orthodontic space closure. This procedure often requires special consideration, not only with regard to esthetics but also for functional issues. However, thus far, few reports that have performed a functional evaluation in such cases. The purpose of this article is to report the successful treatment of a 23 year-old male patient with the complaint of irregular placement and abnormal shape of his teeth.

The patient had an impacted maxillary unilateral left canine, peg shaped lateral incisor, and transmigrated mandibular canine. Patient was treated with extraction of the upper lateral incisors and eruption of the impacted canines was guided to the place of the lateral incisor and extraction of the transmigrated mandibular canine.

Keywords: Impacted maxillary canine, peg shaped lateral incisor, transmigrated mandibular canine.

ntroduction Most patients seeking orthodontic treatment have a chief complaint of functional and/or esthetic deformities due to misalignment of the maxillary anterior teeth.

In such patients, the extraction of maxillary anterior teeth has generally been avoided, as it may create an esthetic problem associated with specific orthodontic considerations because of its relationship with malocclusion. The maxillary canines are important teeth in terms of esthetics and function. The likelihood of their failing to erupt or becoming impacted ranges between 1% and 3%1 The causes of canine impaction can correlate with other dental anomalies, and they can be due to local factors or a polygenetic, multifactorial inheritance. Local factors are tooth size-arch length discrepancies, prolonged retention or early loss of the deciduous canine, abnormal tooth bud position, alveolar cleft, dilaceration of the root, and idiopathic conditions with no apparent cause.2 The absence of the maxillary lateral incisors or small or peg-shaped lateral incisors correlates closely with maxillary canine palatal impaction (with an incidence 2.4 times higher than in the general population).3-5 Impaction in the mandibular arch is less frequent, and the incidence was reported to be 20 times lower than that for maxillary canines.6 Migration of a tooth across the midline is an even rarer anomaly.7-11There are so many treatment options for impacted canines: no treatment, surgical intervention, removal, transplantation, prosthetic or restorative treatment, or surgical exposure with or without orthodontic traction to align the malpositioned tooth.8 On the other hand, the maxillary lateral incisor is known to be one of the teeth that is most commonly congenitally absent,12 IJO  VOL. 27  NO. 3  FALL 2016

with 1.3% of the population lacking at least one of these teeth.13 Furthermore, orthodontists sometimes face situations where they are compelled to extract maxillary incisors for various reasons, such as the presence of peg-shaped, severely malpositioned, or impacted teeth, or because of root resorption due to ectopicallypositioned maxillary canines. In addition, there have been cases of incisor extraction followed by space closure.14,15 Orthodontic space closure, using the canines to replace the absent maxillary lateral incisors, is one of the common treatment options used to provide a better esthetic outcome. However, the substitution of canines for lateral incisors drastically modifies the functional occlusion, as there is no potential for canine guidance during jaw movement excursions. Consequently, treatment planning for patients with maxillary space closure requires consideration of both functional and esthetic aspects.7–10 There have been some reports of successful morphological or esthetic changes after eruption of impacted substitution in place of the lateral incisor,2,16,17 but no reports have described the impacted maxillary canine with peg-shaped lateral incisors and transmigrated canine.

The aim of this case report is to present an eruption of impacted canine as well as substitution of impacted canine in place of the peg-shaped lateral incisors and management of transmigrated mandibular canine.

Case Report A 23 year-old male came with the chief complaints of crowded incisors and crooked teeth (Figures 1a-1c). An intraoral examination showed that patient had an unerupted left canine and a peg-shaped lateral incisor on both side with end-on molar relationships on the right side and Angles Class 15

Figure 1: Pre-treatment photographs a-c: Intraoral photographs; d: Smile photograph, e: Orthopantomogram; f: Occlusal x-ray (maxillary); g: Occlusal x-ray (mandibular)

Figures 2 a-b. Surgical exposure of palatally impacted canine with open window technique; c. K-9 spring (017X025 TMA) ligated for the movement of impacted canine and lingual button bonded on palatal surface of maxillary left pre-molar ,elastic chain attached between lingual button and arm soldered on transpalatal arch; d. Left lateral view, e. Impacted canine erupted into the oral cavity (3.5 months).

Figures 3 a-d. 016 Cu NiTi ligated and extraction of right side peg shaped lateral incisor

Figures 4 a-c. Alignment progressing with the 018 NiTi 16

I on left side. Due to the irregular placement of the anterior teeth and impacted maxillary canine led to unaesthetic smile (Figure 1d). He also had a midline deviation due to an irregular placement of maxillary central incisors. Crowding was present in the mandibular arch, and rotation of the lower left lateral incisor and an unerupted lower left canine were noted.

Radiographic examination showed an impacted maxillary left canine and transmigrated mandibular left canine (Figures 1e-1g). The maxillary and mandibular left canine was impacted with complete root formation (Figure 1e). A maxillary occlusal radiograph confirmed the palatal position of the impacted tooth (Figure 1f ).

In this patient, the etiology of the impaction was probably the early loss of the deciduous canine, tooth size-arch length discrepancies, and malformed lateral incisor.

Treatment Objectives The goals were to expose and align the impacted left canine, and we decided to extract the peg-shaped maxillary lateral incisors and obtain anterior symmetry with bilateral canine substitutions. In the mandibular dentition, the objectives were to extract the transmigrated mandibular left canine. The occlusal objectives were to improve the intercuspation of the posterior teeth and esthetics in the anterior teeth.

The patient did not desire to have treatment of the mandibular arch. The benefit of this treatment plan was to avoid restoration of the maxillary lateral incisors. Furthermore, it is easier to achieve an esthetically pleasing result in the anterior region which would result in symmetrical tooth size and shape. Extraction of the peg-shaped lateral incisors facilitated the ideal intercuspation of the posterior teeth. A disadvantage might be in the final esthetics vis-àvis tooth shape, color, and size—factors that are often uncertain in canine-substitution cases.

To optimize the esthetic and functional occlusion, we planned to reshape the maxillary canines and bleach them after orthodontic treatment.

Treatment Progress Initially, molars of the maxillary arch were banded, and the transpalatal arch was placed. The remaining teeth were bonded with 0.022 x 0.028 inch pre-adjusted- edge wise appliance. The surgical exposure was done by creating a window (Figure 2a-2b) that has been carried out by the oral surgeon in this stage, and the attachment was bonded. The attachment was ligated to the K-9 spring, and the impacted tooth moved in IJO  VOL. 27  NO. 3  FALL 2016

the vertical direction initially (Figure 2c-2d).

As the impacted tooth moved vertically, the distal traction force was applied by cinch back of the K-9 spring. Impacted canine erupted into the oral cavity in 3.5 months (Figure 2e).

Following this, the extraction of the right lateral incisor was done. A 0.016 inch Cu-NiTi wire (Figure 3a-3d) was ligated and progressively activated to maintain a force of 60-90 g, and alignment progressed to a 018 Ni Ti wire (Figure 4a-4c). A lingual button was bonded on the palatal surface of the maxillary left canine, and an elastic chain* was attached to the arm soldered to the transpalatal arch (Figure 4c).

Simultaneousl extraction of the transmigrated mandibular left canine was done (Figure 5a-5b).

Alignment of the impacted canine was done with the extraction of the left lateral incisor, and a bracket on the labial aspect of the canine was inverted to correct the torque. This was ligated to the auxiliary 0.016 inch Cu Ni Ti ** overlay wire with stabilizing 017X 025 SS wire, and this progressively increased to 0.019 x 0.025 inch stainless steel wire; subsequently, finishing was done (Figures 6a-6c). To improve esthetics, we recommended recontouring and bleaching the maxillary canines and alignment of the mandibular arch, but the patient refused.

Otherwise, compliance was excellent, and treatment was completed in 18 months.

Results Overall, favorable esthetics and excellent occlusal results were obtained. Significant improvement in the patient’s smile was noted (Figure 7d) ,and we achieved a well intercuspated occlusion and acceptable overjet and overbite (Figures 7a-7c).

The peg-shaped lateral incisors were extracted, and the space was closed by substituting the canines. The impacted maxillary left canine could be aligned, and the mandibular labial vestibule showed uneventful healing after the extraction of transmigrated canine (Figure 7a). The post-treatment panoramic radiograph (Figure 7e) showed that the roots of the teeth in the maxillary arch were angulated and aligned, and the path traveled by the impacted canine was 19mm (Figure 7f ).

Discussion The maxillary canines are the most frequently impacted teeth (except for the third molars). According to Dewel,12 the maxillary canines have the longest development period as well as the longest and most tortuous route from the point of formation to their final destination in full occlusion. During their development, the IJO  VOL. 27  NO. 3  FALL 2016

Figure 5: a. Extraction of transmigrated mandibular canine; b. Hollow bone after removal of impacted canines and flap sutured back in place

Figure 6 a-c: Extraction of maxillary left peg shaped lateral incisor and alignment of maxillary left impacted canine with 016 Cu Ni Ti overlay wire with stabilizing 017X025 SS

Figure 7: Post-treatment photographs a-c. Intraoral photographs; d. Improvement seen in smile photographs. e. Orthopantomogram, F.Superimposition of palatally impacted canine on orthopantomogram (path traveled by canine = 19mm)

crowns of the permanent canines are intimately related to the roots of the lateral incisors. Thus, the absence of the maxillary lateral incisor and the variation in the root size of the tooth have been implicated as important etiologic factors of canine impaction.2 Treatment considerations for transmigratory teeth depend on the stage of development, distance of migration, and the symptoms. When the root apices are closed, if inadequate space for alignment of an impacted mandibular canine exists, than extraction is the only choice. Wertz (1994)18 reported that if the tip of the crown has migrated past the opposite incisor area, or if the apex has migrated past the apex of the adjacent lateral incisor root apex, it might be mechanically impossible to bring the aberrant canine into its normal place. In 17

this case, the root development of the transmigrated mandibular canine was already completed with resultant crowding in the mandibular arch. Therefore, surgical extraction was preferred.

Most clinicians agree that permanent canines are essential for functional occlusion and that they play a major role in an attractive smile. For this reason, an orthodontist’s main task is to align the impacted canines. Treatment duration, optimum dental hygiene, and perfect compliance are essential. It is of utmost importance to minimize undesirable reactive movements of the anchor teeth and to provide an optimum force system.2 With anchorage on the transpalatal bar and efficient buccal-segment wire, it is possible to control the intrusive effects on the adjacent teeth. The treatment plan included alignment of the impacted left canine, extraction of the peg-shaped lateral incisors with space closure, and an extraction of the transmigrated mandibular left canine.

There were no signs or symptoms of temporomandibular joint dysfunction. There was no evidence to support the belief that establishing a Class I canine relationship should be the preferred mode of treatment 19-21 Furthermore, the lingual surfaces of maxillary canine were reduced to remove excessive forces on the incisal edges of the mandibular lateral incisors during mastication. To optimize the esthetics (shape and color of the canine crown), we recommended recontouring and bleaching of the maxillary canines and the alignment of mandibular arch, but the patient refused.

Conclusions This case demonstrated that an impacted maxillary left canine with peg-shaped lateral incisors and a horizontallyimpacted transmigrant mandibular canine can be successfully treated without the risk of root resorption, periodontal, and pulpal damage. Patient was treated with extraction of the upper lateral incisors and eruption of the impacted canines was guided to the place of the lateral incisor and extraction of the transmigrated mandibular canine. Favorable esthetics and excellent long-term occlusal results were achieved. *OrthoOrganizers (San Marcos, California,USA) **Sentalloy TM,(GAC International,Central Islip,New York) References 1.

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Tuverson DL. Anterior interocclusal relations. Am J Orthod. 1980;78:371– 393.

Kokich VG, Nappen DL, Shapiro PA. Gingival contour and clinical crown length: their effect on the esthetic appearance of maxillary anterior teeth.

Am J Orthod. 1984;86:89–94.

Argyropoulos E, Payne G. Techniques for improving orthodontic results in the treatment of missing maxillary lateral incisors. A case report with literature review. Am J Orthod Dentofacial Orthop. 1988;94:150–165.

Robertsson S, Mohlin B. The congenitally missing upper lateral incisor.

A retrospective study of orthodontic space closure versus restorative treatment. Eur J Orthod. 2000;22: 697–710.

Cozzani M, Lombardo L, Gracco A. Class III malocclusion with missing maxillary lateral incisors. Am J Orthod Dentofacial Orthop. 2011;139:388– 396.

Al-Anezi SA. Orthodontic treatment for a patient with hypodontia involving the maxillary lateral incisors. Am J Orthod Dentofacial Orthop.

2011;139:690–697.

Wertz, R.A. (1994). Transmigrated Mandibular Canines. American Journal of Orthodontics and Dentofacial Orthopedics, Vol.106, pp. 419-27.

Robertsson S, Mohlin B. The congenitally missing upper lateral incisor.

A retrospective study of orthodontic space closure versus restorative treatment. Eur J Orthod 2000;22:697-710.

Nordquist GG, McNeill RW. Orthodontic vs. Restorative treatment of the congenitally absent lateral incisor—long term periodontal and occlusal evaluation. J Periodontol 1975;46: 139-43.

Zachrisson BU, Stenvik A. Single implants—optimal therapy for missing lateral incisors? Am J Orthod Dentofacial Orthop 2004; 126(6):13-5A.

Dr. Dipti Shastri, BDS MDS is an assistant Professor at the Department of Orthodontics and Dentofacial Orthopaedics, Faculty of Dental Sciences, King George’s Medical University, Lucknow, Uttar Pradesh, India

Dr. Gyan P. Singh, BDS, MDS is an Professor Junior grade, Department of Orthodontics and Dentofacial Orthopaedics, Faculty of Dental Sciences, King George’s Medical University, Lucknow, Uttar Pradesh, India.

Dr. Pradeep Tandon, BDS, MDS is Professor &Head ,Department of Orthodontics and Dentofacial Orthopaedics, Faculty of Dental Sciences, King George’s Medical University, Lucknow, Uttar Pradesh, India.

IJO  VOL. 27  NO. 3  FALL 2016

FEATURE

This article has been peer reviewed.

Bone Remodeling in Adults: Treatment of an Adult Skeletal Class II, Division 2 Patient Using a Modified Bionator II Appliance By: Kristopher Krimi, BSc, DMD, IBO Abstract: Revision of published facts about bone remodeling and re-evaluation of preconceptions about bony changes provide a renewed perspective on clinical decision-making in treatment options for adults. Bionator II appliances have been successfully used to treat Class II malocclusions in growing patients. In non-growing patients, however, these appliances have been mostly used as retainers. In this paper, a modified Bionator II is used to treat a Class II Division 2 malocclusion in an adult.

Keywords: Bone remodeling, adult orthopedics, skeletal imbalances bionator II, TMJ.

ntroduction Bone grows and models during active growth in response to physiological, hormonal, and mechanical responses of the body. In a nongrowing individual, bone re-models as a continuous process of bone maintenance. In treating adult patients with medical, dental, periodontal, neuromuscular, psychological, and skeletal complexities who often have aesthetic concerns, holistic and realistic objectives need to be considered. The possibility of manipulating bone morphology beyond what is genetically determined still fuels the debate between proponents and opponents of dentofacial orthopaedics. Some believe that local environmental factors ultimately determine the craniofacial skeleton, which could therefore be subjected to some regulation by changing its functional pattern.1 Others believe these alterations are strictly dentoalveolar and do not affect the basal bone. Therefore, the use of appliances for stimulating bone growth/modifications would only be temporary or insignificant, and the morphogenetic pattern would eventually prevail-- in so, only surgical intervention is the method for skeletal imbalance correction in adults. In this article, an attempt is made to outline published facts in non-surgical orthopaedic treatments in particular with respect to adult patient clinical treatments.

Bionator II is an orthopaedic appliance aimed at protruding a retruded jaw to stimulate its growth anteroposteriorly in actively growing patients. As such, its uses are mainly in the CVM3 growth stage,2 hence modulating the direction of condylar growth.

The ideal skeletal Class II treatment for an adult, particularly with a gummy smile, could include orthognatic surgery depending on the severity of the condition. Mandibular bone growth in adults remains rare and obscure mainly because of the lack of skeletal growth. 3 Division II malocclusions are known to be associated with some perioral muscular condition, as well as a discrepancy in the over jet/overbite ratios.4 Changes in bone structure require resorption and deposition of the affected bone. Moreover, bone volume remodels throughout life as a continuous means by which our IJO  VOL. 27  NO. 3  FALL 2016

bodies accommodate function and stress of the associated soft tissues, while maintaining the role of support and reservoir that bone has as an organ. The maintenance of bone happens in phases and cycles of 2-4 weeks, and basic multi-cellular units (BMUs) re-model in periods of 3-6 months.5 The following are characteristics of this process: • Lifespan of BMU: 6–9 months • Speed: 25 μm/day • Bone volume replaced by a single BMU: 0.025 mm • Lifespan of osteoclasts: 2 weeks • Lifespan of osteoblasts: 3 months • Interval between successive remodeling events at the same location: 2–5 years • Rate of turnover of whole skeleton: 10% per year 6,7 Function is the factor that maintains bone health via remodeling all through life. The remodeling cycle consists of three consecutive phases: resorption, during which osteoclasts digest old bone; reversal, when mononuclear cells appear on the bone surface; and formation, when osteoblasts lay down new bone until the resorbed bone is completely replaced. Bone re-modeling serves to adjust bone architecture to meet changing mechanical needs, and it helps to repair micro damage in bone matrix preventing the accumulation of old bone. It also plays an important role in maintaining plasma calcium homeostasis.

The regulation of bone re-modeling is both systemic and local.

The major systemic regulators include parathyroid hormone (PTH), calcitriol, and other hormones such as growth hormone, glucocorticoids, thyroid hormones, and sex hormones. Factors such as insulin-like growth factors (IGFs), prostaglandins, tumor growth factor-beta (TGF-beta), bone morphogenetic proteins (BMP), and cytokines are involved as well. As for local regulation of bone re-modeling, a large number of cytokines and growth factors that affect bone cell functions have recently been identified.8 The impact of medications on orthodontic treatments is also documented with a reduction in bone re-modeling that can prolong treatment time. In asthmatic patients with a chronic use of corticosteroids (use of bisphosphonates in osteoporosis, 19

for example), the rate of re-modeling decreases, thus increasing treatment time. Alcohol and smoking on the other hand, increase the rate of re-modeling by provoking osteopenia and reduction of alveolar crest by periodontal disease respectively.

The use of statins and anti-cholesterol medications increases bone volume, perhaps useful for retention of orthodontic results, is known to decrease bone re-modeling. Coffee intake, corticosteroids for chronic allergies or asthma, and antiinflammatories have also been documented to reduce bone re-modeling in clinical orthodontics.9 In the facial, head, and neck complex, proper functions of nasal respiration, swallowing, talking, and eating (occlusion) are the prerequisites to dentofacial balance and its maintenance.

Aberrant functions bring about a sequence of compensations-sequences that leads to instability in morphology.

Orthopaedic appliances used initially to modify growth in growing patients are used as an alternative for adult patients seeking non-surgical treatments. These appliances commonly modify growth in actively growing individuals by modifications which affect teeth, muscles, tongue, lips, cheeks, integuments, mucosa, connective tissue, nerves, blood vessels, airways, pharynx, tonsils, and adenoids to mention a few.10 In actively growing patients, orthopaedic appliances have an ideal timing of use as in CVM2 to modify the growth of the maxilla as an effective long-term use as in Bionator therapy for mandibular growth modification.11 Wolff ’s law describes the forces, intrinsic or extrinsic, which allow the adaptation of facial bones to maintain function during active growth.12 It is hypothesized that, locally, the surrounding soft tissue acts as a trigger or regulator, which determines the direction and pattern of change. In the same manner, the pharyngeal airway (nares to glottis) regulates the arch form of the orbits, the nasal and oral sides of the palate, the maxillary arch, the sinuses, and the zygomatic arches. In nasal breathers, these structures are aberrant, and their correction requires modification of function and changes in the soft tissues. Its function signals the remodeling of the concerned bony structures, in turn, bringing about the functioning of the two arches (maxillary and mandibular) into occlusion. Surprisingly, the mid-palatal suture (being opened with expanders) only plays a minor role in the lateral displacement of the maxillary alveolus. 13 Adult versus Growing Patients Dentoskeletal changes retain much better if treatments are done at younger ages.14 Maintenance of proper function can be best achieved, learned, and maintained if learned earlier in life. In the case of mandibular advancement in true Class II (skeletal) malocclusions, muscle adaptations, as in the case of the pterygoid muscle, occur to new forward positions of the mandible. The activity of the pterygoid muscle and forward position of the TMJ shows adaptation of muscular function with the Herbst appliance without which relapse is inevitable.15 The mechanism of action of this appliance ultimately is to alter the muscular function to a normal position, hence muscular activity that, in turn, brings about the observed skeletal bony changes. However, with respect to the mandible, ideal timing of Bionator usage coincides with the growth of the mandible CVM2-3, in Class II, D1 malocclusion. 2,5 As shown in adult rats, function, through mastication and jaw opening reflex, affects masticatory performance.5 Chewing 20

improves chronic, mild stress-induced bone loss in a murine model of senile osteoporosis in mice.16 The correlation between the oro-muscular influence and the link between the mentolabial muscle activity to the orofacial anatomy, as seen in Class I malocclusions, has been clearly shown to exist.4 Proper lip closure force is associated with Class I subjects with a proper overbite-overjet ratio. The Y-meter measurements have shown a strong link between lip incompetence and malocclusions.17 Significant numbers of children seeking orthodontics present oral myofunctional disorders requiring multidisciplinary treatments.18 The role of the function of muscles such as the masseter/temporalis, measured via EMG integrated electromyogram, shows a correlation between mandibular advancement and the enhanced activity of the above muscle, 19 one possible requirement for the success of mandibular advancement treatments. Stability obtained with rapid maxillary expansion (RME) in children also correlated with the stability of tongue posture.20 In actively growing patients, Herbst changes a posterior growth of TMJ to a more normal direction, and the amount of growth is enhanced as the functions are normalized. 21 Cone beam computed tomographic (CBCT) evaluation of young adults with Class II D1 malocclusions shows the remodeling of the condyle and glenoid fossa (widening the airways) after treatment with appliances such as Herbst. With the latter, the morphological changes after treatment are significant when comparing the post-treatment evaluations to the untreated controls.22,23 In adult orthopaedics, the initiation of change seems to occur through a modification in the neuromuscular pattern.

Using adult expanders to create missing space in the arches is common in adult orthodontic treatments.24 Appliance treatment with adults has been shown to improve aesthetics, improve nasal breathing, and to aid in sleep apnea when used in the right conditions. 3 In a severe skeletal Class III malocclusion, with a total anterior crossbite of an adult patient, orthognathic surgery as the primary treatment option remains inevitable. Some clinicians do not believe any pre-pubertal treatment is worth considering since a re-intervention would most likely occur in adulthood. Hence, with the exception of such true Class III skeletal discrepancies, orthopaedics in adults, through bone re-modeling, do give results once proper functional is established, and etiological factors are eliminated or controlled. Sometimes the treatment objective is the growth (or re-growth, since the patients usually have stopped growing) of a deficient maxilla. For compliance reasons, surgery is proposed more often, as well as in severely unfavorable skeletal patterns such as hyper-divergent or counterclockwise facial growth patterns.25 A study was conducted regarding growth changes of Japanese faces associated with mandibular prognathism over 3 years after pubertal growth peak. The investigation was based on the serial lateral cephalometric x-rays of prognathic and normal males and females, respectively. Maturational stages of the pubertal growth were determined individually via hand-wrist radiographs. Results indicate that the morphologic characteristics of mandibular prognathism, are established before the pubertal growth peaks and were strongly maintained during the study period. However, mandibular prognathism seemed to show a manner of growth change fairly similar to that of the norm after the pubertal growth peak ends.26 Symphysis has IJO  VOL. 27  NO. 3  FALL 2016

been shown to have particular morphological characteristics in true skeletal Class III malocclusion (which eventually requires orthognathic surgery), as well as relationships to the inclination of the long axis of the lower incisor. In both the surgical and normal occlusion groups, a significant correlation was observed between the inclination of the long axis of the lower incisors and symphysis inclination. In the basal bone region however, there was no significant correlation. These observations demonstrate that with respect to the basal bone, the tendency of change is less expected in true Class III skeletal patterns.

In another study, maximum bite force increased significantly over time and with age. Incisal forces peaked at 14.3 and 15.3 years of age for females and males, respectively.

Maximum molar bite force peaked at 16 years for both males and females. Subjects with normal occlusion were shown to have significantly higher bite force than subjects with malocclusions.

Malocclusion has a detrimental effect on bite force. Changes in maximum bite force are also due to age, sex, and repeated testing.27 A difference in dentofacial morphology between groups with malocclusions is thus expected.

Orthognathic surgery has long been the ultimate method for correction of severe skeletal dentofacial anomalies evaluated on an individual basis. Enhancing orthodontic methods of bone remodeling such as Propel ,laser, or ultrasound, seems to provide additional tools to further increase the speed of the process, thus attempting to reduce treatment time.

Importance of Local Anatomy Bone density of the maxilla and mandible are very different. In dentulous subjects, for example, the mandible is twice as dense as that of the anterior segment of the maxilla, and the posterior maxilla and hard palate are even less dense, respectively.28 In an adult, mandible bone remodeling can create enlargement of the bone, as in a deficient mandible.

Furthermore, condylar displacement / glenoid fossa displacement and bone remodeling should be distinguished ideally with CBCT pre- and post- treatments. Condylar growth after nonsurgical advancement in adults is documented after successful appliance treatment which advanced the mandible as observed by panoramic x-rays.29 The flattening and erosion of the condyles disappeared along with the TMJ symptoms, showing remodeling of the TMJ due to the environment, proper muscular activity, mastication, and swallowing.29 Condylar cartilage with dense undifferentiated mesenchymal and multipotential cells can respond to the environment: i.e.,elimination of occlusal disturbances, which dictates the mandibular movements such as mastication or other mandibular motions.

The gonial angle, traditionally known to be unchangeable, has a definite decrease with advancing age, with no correlation with gender. There is also an increase in gonial angle for edentulous subjects. This correlation is attributed to physiologic function of the mandible, hence a relationship between the complete loss of teeth and changes in the gonial angle.30 The change in bone morphology is thus achieved following the changes in the function. As an objective to reduce the gonial angle, mastication or chewing gum is encouraged or ordered.

Inversely, soft food could be ordered for skeletal deep bite patients to increase the lower facial height. In one experiment, mice were simultaneously subjected daily to one of the following stressors: water immersion, physical shaking, and flashing lights.

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Some of the ‘’stressed” mice were allowed to chew on a wooden stick during the experimental period. Chewing was found to improve chronic, mild stress-induced bone loss in murine senile osteoporosis.16 Other observations indicate that both blood supply and function influence the shape of the gonial region.

The gonial angle is capable of altering in shape through the proper response via remodeling as shown in monkeys induced by alterations of muscle length.31 The proper masticatory function and its quantity determine the activity of muscles and the gonial angle responses by its morphology to adapt to the requirements of function.

Bone is richly innervated with adrenergic and peptidergic nerve terminals that play important roles in bone remodeling.

A recent study confirmed a functional nerve-osteoblastic interplay by using an in-vitro co-culture model comprised of mouse osteoblastic cells and neurite-sprouting mouse superior cervical ganglia. This proves nerve-osteoblastic cell cross-talk indicating the dynamic regulation of local bone metabolism by the peripheral nervous system. Thus, in-vivo and in-vitro evidence exists, implicating peripheral neuron action in bone metabolism.32 The regulation of bone metabolism by the peripheral nervous system could be through function. In one experiment, 6-week-old male Wistar rats had a metal cap inserted between the maxillary and mandibular incisors to prevent the molars from biting. Cancellous bone mineral density, based on computed tomography, was shown to decline 4 weeks after the start of the experiment in the masticatory hypo-function group.

The functional adaptive response by the mandible to mechanical stress resulting from mastication occurs not only in the muscle insertion area but also in mandibular alveolar bone in the molar region.33 The maxilla is one of the causes in certain malocclusions, best documented as its proper correction by non-surgical expansions produces changes in function and stability of orthodontic treatment in adults.34 The crucial factor in retention of adults is particularly related to tongue posture along with the other crucial functions, such as nasal breathing and lip posture.

Vertical drift of teeth guides the teeth to a position of stable occlusion via intramembranous bone modeling, used as in Bionator 1 treatment. Stable occlusion is one of the retainers of the maxillomandibular complex.35 The optimal treatment time of skeletal problems can vary from one case to another, yet treatment results are still attainable through the same mechanism regardless of age.36 The modification in the neuromuscular pattern established before treatment can be different from case to case, rendering the times of treatment and the retention of modification variable in adults. Wear of appliances and behavioral modification can be challenging for adults.34 The floor of the nasal cavity, being resorptive in nature, causes a downward relocation of the palate when proper nasal breathing is initiated and maintained.37 Horizontal transverse expansion of maxillary tuberosity and the key ridge, via bone remodeling, widens the maxillary sinus, which allows for better nasal function.38 The functional matrix theory (Moss) suggests that the sum of all soft tissues operating in association with that bone determines skeletal morphology of that bone.39 In adults, mechanisms of actions of common appliances remain obscure and are not fully documented. Some act via neuromuscular modifications without the added action of 21

Figure. 1: Before and after profile photos: a 6 month orthopaedic appliance treatment with an objective to tip the 3 upper incisors and allow the mandible to shift forward, improving a retruded mandible into a more straight profile.

Figure 2: Pre-op intra and extraoral photos

growth; changes can be more dramatic (as in Class II Division 2 cases) with an added bonus of mandibular forward displacement as presented in Figure 1.

In this case, the dynamic motions of the jaw signals the fact that the maxilla could be placed further forward anteroposteriorly, and that the mandible is trapped by the lingually tipped upper incisors.

Our adult female patient showed lingually tipped upper incisors, minor lower incisor crowding, and a retruded mandible (Figure 2).

Closer examination revealed occasional (1/10) asymptomatic noise: crepitus of the left TMJ during opening or closing motions, as well as an aberrant dynamic movement: a posterior deflection on closing, close to maximum intercuspidation (Figure 3) possibly due to the lingually tipped upper incisors. She had a previous history of articular dislocation with reduction following her traumatic wisdom extractions. She had gone through interceptive orthodontic treatment with appliances at childhood.

Her chief concern was the position of her upper left lateral incisor , unpleasing to her future husband, and the fear that the TMJ condition could get worse. Her wedding date was to be determined soon, and she was seeking treatment without fixed braces. She was given a complete dental exam where it was judged to take records for an optimal treatment plan that could deal with her bad bite. Cephalometric analysis confirmed a retruded mandible, Class II skeletal malocclusion (Figure 4). It is noted that the lower midline is shifted to right, lower incisor crowding, upper incisors lingually tipped, and a Class II canine dental malocclusion. Her thin lips, strained perioral musculature, a mild gummy smile on wide smile, prominent nose, with a mandibular retrusion, it was felt that her convex profile could be improved .

A possible diagnosis of TMJ articular internal derangement was considered, with the lingually retruded upper incisor possibly blocking the lower jaw in a more posterior centric static position and dynamic motions; centric occlusion (C.O.) 22

Figure 3: Sagital representation of envelop of maximum opening / closing to maximum intercuspidation, note the posterior deflection just before teeth contact.

was abnormally posterior to the centric relation (C.R.). The discrepancy manifested as lower incisor crowding and lack of space of the lower arch is determined by Moyers space analysis (Figure 5).

Articulation of the casts in centric relation indicated that the lower arch require a 2.5 mm lateral expansion in the lower premolar regions for proper articulation of the posterior segments.

Several treatment options included observation and a referral to TMJ specialists, possibly with additional diagnostic tools such as TMJ 3-D imagery. Being asymptomatic, keen and cooperative as a patient, a removable appliance to correct the IJO ď Ž VOL. 27 ď Ž NO. 3 ď Ž FALL 2016

Figure 4: Pre- and post-op cephalometric analysis

etiology (the lingually positioned upper incisors, possibly through tense perioral muscular pattern) was proposed. The objectives were to:

IBO Cephalometric Data Sheet Area

Norm

Pre Tx

Post TX

6

6

Direction - Y Axis - Facial Axis

Stage 1-6 Epiphysis covers diaphysis Ossification of sesamoid To SN = 66° To FH = 59° 90° + - 3°

2-Airways Upper Airway Lower Airway

8-18 mm 10- 12 mm

18 6

19 8

3-Vertical – Skeletal FMA LAFH UFH/LFH SN – Go Gn

25° 58-72mm 45-55 % adult, 50-50% child 32°

38 67 44 56 39

35 72

77 103 26

81 103 22

90° Class 1 = 1 +- 1 mm Class 2 = +3 mm Class 3 = -3 mm Class 1 = 0-5 131o Class 2 > 5 – Class 3 < 5 103o -1 to 3mm

99 1

99 2

127 5 90 4

124 4 97 3

-2mm +/- 2mm 96-118 degrees Do they have one?

Mx and Mn lips even to line

-4 -2 118 Y 0 +1

-5 -4 120 Y -2 -2

1-Growth Stage - CVM - Hand Wrist Radiograph

4-Sagittal –Skeletal Length Max Mnd Cond to A Cond to Gn Difference: By Age 5-Dental IMPA Witts

Interincisal Angle ANB Mx incisor to SN Mn incisor to A-Pog 6-Soft Tissue Rickett’s esthetic Line Naso-labial angle Lip seal Steiner’s S-Line

1.

75 74 80

72 83

74

2.

3.

43 56 37

Age 6 – 9 – 12 – 14 - 16

17 - 20 – 23 -25 - 27

With a lingual arm labialize the lingually tipped upper incisors force being to the cinguala of the upper incisors Disarticulate with (hard) acrylic full teeth coverage Expand by 3 mm the lower arch laterally in the pre-molar region.

A protruded bite corresponding to the final expected closure position of the mandible was taken. The correction of the C.O.-C.R. discrepancy is done with the correction of the lingually tipped upper incisors.

It was also stressed that lingual surfaces of the lower incisor should have no contact with the appliance to avoid any labial tipping since these teeth were already labially tipped. Prognosis was determined as being reasonable mainly because of the patient’s favorable expected cooperation. It was stressed that final dental alignment and occlusal stability (finishing) could require other orthodontic treatments.

Active treatment was 5 months with minor activation of the lingual arm to labialize the upper incisors, done every month allowing the mandible to shift forward to a more favorable closing position, hence correcting the “trapped” mandible. The appliance was worn 12-14 hours a day (evening and night). Intrusion of the alveolar ridges was as well attempted by mastication

Figure 5: The available space for the lower anterior sextant and the sum of mesio distal dimension of the lower incisors (red) shows a lack of space of 2.5 mm.

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23

Figure 6: Modified Bionator II for the correction of dentofacial anomaly. a)Maxillary view with the lingual labializing arm (pink arrow) and a labial bow(yellow arrow)for stability. b) mandibular view :with the expander: the ruler used to measure the acquired expansion. The upper and lower segments bonded on a protruded bite.

Figure 7: Post-op intra and extra oral photos April 2015

October 2015

after meals with sugar-free gum. The patient was instructed to nasal breathe at all times, and perioral closure exercises were also given.

Every two days, the patient expanded the appliance by ½ turn, with weekends off. It was also necessary to wear the appliance 3 hours prior to activation (Figure 6).

The upper and lower segments bonded on a protruded bite. Progress was monitored, by monthly visits, measuring the expansion and by evaluating the motivation and progress (Figure 6b) along with occasional visits to a chiropractor/ massotherapy. The activation of the lower expansion screw allowed for a slow orthopaedic expansion of the lower arch to fit the upper arch in a new more forward intercuspidation position, as well as correcting the aberrant dynamic motions.

Surprisingly, the crowding of the lower incisor autocorrected, with no influence in their torque position (Figure 4, post op) and a more straight profile, making a very satisfied patient (Figure 7).

The superposition of the two cephalometric x-rays tracings (Figure 8) of April 2015 and October 2015 shows the orthopaedic advancement of the mandible, a change in the form of the head of the condyle to the ramus (Figure 9), position of the condylar fossa, size of the maxilla and the Rickett’s E line, an improvement in the ANB angle and the facial and Y axis (Figure 4).

This adult patient’s desire to embark in minimally invasive and cost-effective correction of her aesthetic and functional problems was met by correcting her malocclusion.

Conclusion In adults, evaluation of dentoskeletal disharmony takes into account the patients’ main complaints and their relation to overall health and dental situation, the imbalances, their causes (etiologies), and the instability of the orofacial complex. Psychological, aesthetic, medical and dental history play a crucial role in treatment planning.

Muscles, through function (neuromuscular or cartilage mediated), and behavior modification are responsible for bone remodeling, as the mechanism in action in all the changes and results obtainable in adult orthopaedic treatments.

The mechanism of action is through modification of the neuromuscular matrix; change in morphology is attainable with proper diagnosis of etiologies.

Interdisciplinary concerted treatment

Figure 8: Pre-op / post-op cephalometric tracing traced on digital x-rays 24

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4.

5.

6.

7.

8.

9.

Figure 9: The superposition of the tracings on the S-N Line of the Figure 8 x-rays shows the translation of the condylar fossa (blue arrow), the condyles, the effective change in the Rickett’s E line (blue lines), and the closeup of the latter superimposition showing the positive changes in dental structures (red vs black).

options and patient cooperation bring positive changes if appliances are successfully used. Options for aesthetic surgery could be proposed along with the associated risks which are justifiable, particularly in severe dentoskeletal abnormalities.

Multitudes of specialized therapies such as maxillofacial and cosmetic surgeons, speech and myo-facial therapists, posturists, osteopaths, physiotherapists, allergy and ENT specialists, or neurologists help diagnose the systemic, musculoskeletal predisposing etiologies that may hinder the treatment results, and/or its retention. Extraction and implant replacement are sometimes an option. As an interdisciplinary approach, specialized consultations are often encouraged. Psychological reinforcing methods to motivate the patient cooperation are essential for success.The use of clear aligners, removable appliances, TADs, or surgery-assisted methods are recommended to achieve positive alveolar changes and reduce fixed appliance treatment time.

Bony changes in the morphology of the condyle and ramus have been reported following successful treatment of a TMJ symptomatic patient.29 The treatment of our patient was successful because an etiological-based treatment planning method was used. The facial skeletal disharmony was identified, and the patient’s main concern was addressed. The objectives and options were clearly planned and carried out with patient cooperation. Retention and stability will depend on maintaining proper functions and habits. She must wear the passive (regarnished) plate at night indefinitely, and final alignment of the dentition can be done with further fixed or removable orthodontic treatments for better stability. Future x-rays are needed to show the durability of remodeling and its stability of this short treatment for long term results.

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Jung M-H, Yang W-S, Nahm D-S., Y-meter used to effectively show the force of perioral muscles in adults. Effects of upper lip closing force on craniofacial structures. A J Orthod Dentofacial Orthop. 2003, 123;58-63.

Van Lierde KM1, Luyten A, D’haeseleer E, Van Maele G, Becue L, Fonteyne E, Corthals P, De Pauw G, Articulation and oro myofunctional behavior in children seeking orthodontic treatment. Oral Dis. 2015 May;21(4):483-92.

Du X, Hagg U., Gradual advancement of mandible affects masseter, role of muscles as the determinants of development. Angle Orthodontist. Vol 73, #5, 2003.

Tyag U F-T, Oglu M, Atug-Atac AT. Lowe., A stability of maxillary expansion and tongue posture. Angle Orthod. 2009;79.

Pancherz H, Fischer S., Amount and direction of TMJ growth changes in Herbst treatment; A cephalometric long-term investigation. Angle Orthodontist, Vol 73, No. 5 2003.

Savana M., Raveli D B, Santos-Pinto A D, Raveli T B, Gomez S.P., Computed Tomographic evaluation of a young adult treated with the Herbst appliance. J Orthod, 2010 Sep Oct, 15 (5): 130-6.

Lowry M., Expand your practice=adult expansion IJO Vol 18, No.1 Spring 2007.

Mitani H. Sato K., Junji Sugawara J., Growth of mandibular prognathism after pubertal growth peak. Am J Orthod Dento Ortho 1993;104:330-6.

Nojima K1, Nakakawaji K, Sakamoto T, Isshiki Y., Relationships between mandibular symphysis morphology and lower incisor inclination in skeletal class III malocclusion requiring orthognathic surgery. Bull Tokyo Dent Coll.

1998 Aug;39(3):175-81.

Roldán SI1, Restrepo LG2, Isaza JF3, Vélez LG4, Buschang PH5, Are maximum bite forces of subjects 7 to 17 years of age related to malocclusion? Angle Orthod. 2015 Sep 8.

Devin H, Horner K, Ledgerton D, A comparison of maxillary and mandibular bone mineral densities, J Prosthect Dent 1998, March: 79 (3), 323-7.

Cuccia A M, Caradonna C., Condylar growth after non-surgical advancement in adult subject: A case report, Head Face Med, July 2009:5:15.

Hendricksen RP, McNamara JA Jr, Carlson DS, Yellich GM., Changes in the gonial region induced by alterations of muscle length. J Oral Maxillofac Surg. 1982 Sep;40(9):570-7.

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Togari A1, Control of bone remodeling by nervous system. Regulation of bone metabolism by peripheral nervous system. Clin Calcium. 2010 Dec;20(12):1831-8.

Sato H1, Kawamura A, Yamaguchi M, Kasai, Relationship between masticatory function and internal structure of the mandible based on computed tomography findings. Am J Orthod Dentofacial Orthop. 2005 Dec;128(6):766-73.

Handelman CS, Wang L, BeGole EA, Haas AJ., Nonsurgical rapid maxillary expansion in adults: report on 47 cases. Angle Orthod.

1999;70:129-144.

Azuma M, Enlow DH, Fine structure of fibroblasts in the periodontal membranes and their possible role in tooth drift and eruption. Japan J Orthod 1977;36;1.

Stuart DA1, Wiltshire WA., Rapid palatal expansion in the young adult: Time for a paradigm shift? J Can Dent Assoc. 2003 Jun;69(6):374-7.

Kahn DM, Shaw RB, Aging of the bony orbit: A three-dimensional CT study. Aesthet Surg J 2008;28;258-264.

Galella S, Chow D, Jones E, Enlow D, Masters A. Guiding atypical facial growth back to normal Part 1, Understanding facial growth. IJO, Vol 22,No.4 Winter 2011.

Ranly DM, Craniofacial growth. Dental Clinics of North America 2000,44:457-470.

Dr. Krimi holds a BSc in Microbiology and Immunology and Biochemistry from McGill University, and DMD from Laval University. He holds certifications in DFO from FORCE , IDI, two orthodontic mini-residencies at the Montreal Childrens Hospital. He is a Diplomate, examiner, Master senior of the Instructor for the IAO, a member of the international association of healthcare professionals, the International Association of Dentists, and International Board of Orthodontics. Nominated for the leading physicians of the world award, he is in private practice in Montreal Quebec.

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IJO  VOL. 27  NO. 3  FALL 2016

FEATURE

This article has been peer reviewed.

HR Spring: A Simplified Approach to Simultaneous Space Gaining and Derotation

By Anubha Rathi, BDS; Rohan S. Hattarki MDS

Abstract: A simple and easy spring design is introduced in this article for simultaneous space gaining and derotation. The technique is explained with the help of a clinical case to align a severely rotated lower central incisor.

Keywords: Derotation, Space gaining

ntroduction Correction of rotation during the stage of aligning is one of the most important procedures in orthodontic treatment. If any of the anterior teeth are rotated then for correction of these teeth, space should either be available or created orthodontically. This entire procedure is usually done in two steps, that is, space gaining and then derotation and takes a lot of time and is responsible for prolonging the duration of orthodontic treatment.

In this article, a simple technique is described for simultaneous space gaining and derotation of a lower incisor tooth with the help of a spring made of TMA wire(0.017”x0.025”). Following is the method of its fabrication: 1. Form a helix with a sectional 0.017”x0.025” TMA wire such that its two arms are parallel to each other (Figure 1).

2. Bend one arm at a 90 degrees angle at the level of the bracket slots such that helix should lie approximately 3-4mm gingival to the cervical margin of the teeth. This arm goes into the slots of the teeth to be distalized to gain space. The length of the arm should be enough to engage these teeth. The other arm is bent such that it is parallel to the facial surface of the tooth to be derotated. (Figure 2).

3. Activation: a. For space gaining- open the two parallel arms of the spring to form a V shape and then bend the horizontal space gaining arm upwards such that it lies along the bracket planes (Figures 3a and 3b). b. For derotation- the derotating arm is bent such that it lies parallel and in one plane with the other arm (Figures 4a and 4b).

4. In the present case, since there was no space for a bracket to be bonded onto the rotated tooth, a multipurpose attachment1 was bonded for securing the spring, and two adjacent incisors were bonded on the right side. The arms of the spring are secured tightly in the bracket slots with the help of ligature ties or elastomeric modules (Figures 5a and 5b).

5. For reactivation, the spring is removed from the teeth, the helix is reopened to expand the V, the horizontal IJO  VOL. 27  NO. 3  FALL 2016

Figure 1: 0.017”x0.025” TMA wire with helix

Figure 2: Pre-activation bends

Figure 3a: Helix opened for activation for space gaining & b Compensatory bend of the horizontal arm

Figure 4a: Activation for derotation. b: Activation for derotation (top view)

27

Figure 5 a: Spring placed in patient’s mouth (front view). b: Spring placed in patient’s mouth (occlusal view)

Figure 6 a: Progress of the treatment after 2 weeks. b: Progress of the treatment after 4 weeks. c: Progress of the treatment after 6 weeks

space gaining arm is again bent upwards to maintain the level with the plane of the brackets. The derotation arm is bent in the same way as done during activation.

6. The reactivation procedure is repeated every 2 weeks until the desired correction is achieved (Figures 6a, 6b, and 6c).

7. After complete derotation, a continuous archwire can be placed for final levelling, aligning, and torque expression.

In the presented case, complete procedure of space gaining and derotation took 10 weeks.

Mild gingival recession was seen after alignment for which periodontal therapy is planned along with circumferential supracrestal fibrotomy after completion of treatment (Figures 7a and 7b).

Advantages a. Simple, economical b. Can be used for severely rotated teeth c. Simultaneous derotation and space gaining can be achieved d. Reduces treatment time Reference 1.

Vashi NS, Vashi BN.: A multipurpose attachment (MPA), J. Ind. Orthod. Soc. 35:89-93, 2002.

Dr. Anubha M. Rathi, BDS, is currently undergoing post graduate training at the KLE VK Institute of Dental Sciences, Belgaum India.

Figure 7 a: Space gaining and derotation completed after 10 weeks(frontal view). b: Space gaining and derotation completed after 10 weeks(occlusal view)

Pre-treatment OPG & IOPA

Dr. Rohan S. Hattarki, completed his BDS at SDM College of Dental Sciences Dharwad and his MDS from KLE VK Institute of Dental Sciences KLE university, Belgaum, India. He is currently working as a Reader in KLE VK Institute of Dental Sciences KLE University, Belgaum, India

Post-treatment OPG & IOPA 28

IJO  VOL. 27  NO. 3  FALL 2016

FEATURE

This article has been peer reviewed.

Management of Unusual Rotation of Maxillary Central Incisor with Impacted Mesiodens: Case Report

By Vipul Kumar Sharma, BDS, MDS, FODS, IMS, BHU; Kirti Yadav, BDS, MDS Pradeep Tandon, BDS, MDS; Gyan Singh, BDS, MDS Abstract: Supernumerary teeth are frequently found in the maxillary anterior region, largely in permanent dentition (rare in deciduous dentition). Shape of the supernumerary teeth may vary from conical, tueberculate, supplemental to odontome. Mesiodens is a conical type of supernumerary teeth located in the maxillary central incisor region and is generally unerupted. Presence of mesiodens may result in rotation, uneruption, or malalignment of adjacent maxillary incisors. In this article, we present a case report of unusual rotation of maxillary central incisor with impacted mesiodens.

Keywords: Supernumerary teeth, Mesiodens, Rotation ntroduction The prevalence of hyperdontia has been reported in the literature1-3 between 0.15% and 3.9%.

Supernumerary teeth are frequently found in the maxillary anterior region, largely in permanent dentition (rare in deciduous dentition). The shape of the supernumerary teeth may vary from conical, tueberculate, supplemental to odontome.

Mesiodens is a conical type of supernumerary teeth located in the maxillary central incisor region and is generally unerupted.4 These teeth are frequently associated with various craniofacial anomalies, including cleft lip and palate, Gardner’s syndrome, and cleidocranial dysostosis.5 The most widely accepted cause of supernumerary teeth is hyperactivity of dental lamina.6 Another reason is attributed to genetics, as they have been frequently present in twins, siblings, and sequential generations of a single family. Autosomal dominant inheritance7 with incomplete penetration and sex-linked pattern4 (male to female ratio 2:1) has been proposed in genetic theory. Presence of mesiodens may result in rotation, uneruption, or malalignment of adjacent maxillary incisors.8 Based on rotation of the distal margin of incisors, it is called winging (labial rotation) or counter- winging (lingual rotation.)9 Winged or rotated and malformed teeth have often been found to be associated with other dental anomalies.4 In this article, we present a case report of unusual rotation of the maxillary central incisor with impacted mesiodens.

Diagnosis An 18 year-old male patient reported to the Orthodontic Graduate clinic with a chief complaint of a rotated upper front tooth. Facial profile was convex with competent lips. On intraoral examination, the left maxillary central incisor was rotated at 90 degree. Other findings include Angle’s Class I canine and molar relationship with an overjet of 2 mm and an overbite of 4 mm. Maxillary dental midline was shifted towards the left side by 2 mm. Mild crowding was present in the lower arch. On radiographic examination, impacted supernumerary tooth resembling mesiodens was observed in relation to the apex of maxillary left central incisor (Figure 1).

IJO  VOL. 27  NO. 3  FALL 2016

Treatment objectives were to surgically remove the supernumerary tooth, align and level the maxillary anterior teeth, correct the rotated teeth, and retain the achieved results.

Treatment Plan and Progress Orthodontic treatment was initiated with a non-extraction treatment approach. Maxillary teeth were bonded with 0.022inch, preadjusted edgewise appliance (Roth prescription). Initial alignment and leveling was done using 0.016 inch stainless steel (SS) multiple loop archwire. After three months, 0.018 x 0.025 inch SS archwire was ligated to the maxillary teeth, and a NiTi open coil spring (0.010”x0.030”) was compressed between the maxillary right central and the left lateral incisor to create space for a rotated incisor (Figure 2). Mesiodens was surgically removed (Figure 3) At this point, the patient was involved in an accident, resulting in injury to the maxillary anterior region.

Mobility (between grade 1 and grade 2) was observed in relation to the maxillary right central and lateral incisor. Active forces were removed, and it was decided to halt the orthodontic treatment for three months. The maxillary right central incisor did not respond to vitality testing, and a periapical radiograph revealed pulpal and periapical changes. Endodontic treatment of the maxillary right central incisor was then advised. Two months after endodontic treatment, orthodontic treatment was resumed. The rotated central incisor was aligned using pure couple in the next four months (Figure 4). In order to enhance the stability of the rotated tooth, recontouring followed by a papilla split procedure was done. A porcelain-fused-to-metal crown was fabricated for the maxillary right central incisor. After fifteen months of treatment, fixed appliances were removed, and a bonded retainer (3-3) was given for the maxillary arch (Figure 5).

Discussion On extraction of the impacted supernumerary tooth, it resembled the conical shaped mesiodens which was the possible cause of rotation of the maxillary left central incisor. If diagnosed at an early age, there is normal eruption of ectopically erupted 29

incisors after extraction of supernumerary teeth.10 A positive correlation, though weak, is found between increased tooth rotation and bone loss. Severity of bone loss increases beyond 20 degree rotation.11 Despite maintenance of good oral hygiene, there was an apical shift of bone interdentally due to the cervical line being more apical on the labial and lingual sides as compared with the mesial and distal sides.12 Pure couple mechanics for derotation was applied to avoid any other unwanted movement like tipping, translation, or extrusion. After an injury, usually a three-month waiting period is recommended before any orthodontic treatment is resumed.13 CO2 pulp testing was used to check the vitality of the injured teeth and is the preferred method of vitality testing in the presence of orthodontic bands and brackets.

Two months after endodontic treatment of the affected tooth, orthodontic treatment was resumed as after 1-2 months of root canal treatment, the exudate (liquids) and the Figure 1: Pre-treatment photographs (A-H) and radiographs showing inflammatory infiltrate (cells) are absorbed and impacted mesiodens (I) Orthopantomogram (J) Intraoral periapical migrate from the site.14 Endodontically-treated radiograph (K) Maxillary occlusal x-ray teeth usually respond normally to orthodontic forces and do not in any way affect orthodontic tooth movement.15 Permanent retention was given because supracrestal gingival fibers contain elastin fibers that take around 232 days to reorganize and cause most of the rotational relapse.16 Six weeks prior to debonding, sectioning of the supracrestal fibers was done by a papilla split procedure to enhance the stability of the rotated tooth. This is an alternative procedure to circumferential supracrestal fiberotomy (CSF) in which there are more chances of gingival recession.17,18 Interdisciplinary treatment allowed us to successfully bring the rotated teeth into the arch without any undesirable tooth movement sequelae.

Figure 2: Alignment and leveling followed by space creation and correction of midline. (A-B) 016 SS multiple loop archwire, (C-D) 018x025 SS with open coil spring

Conclusion Problems like ectopically-erupted and rotated maxillary central incisors should be treated with careful diagnosis and treatment planning. Clinical examination should be augmented with radiographic examination to rule out any impacted supernumerary teeth. Although there is a weak, positive correlation between rotation and bone loss, periodontal status of the affected tooth should be carefully monitored during treatment.

Figure 3: Surgical exposure and extraction of impacted mesiodens. A) Elliptical incision and elevation of full mucoperiosteal flap. B) Extracted mesiodens (14 mm x 6 mm dimension) Figure 4: Correction of rotation (A) and (B) 30

IJO  VOL. 27  NO. 3  FALL 2016

Figure 5: Post-treatment photographs (A-G) and radiographs (H) Orthopantomogram (I) Intraoral periapical radiographs (J) Maxillary occlusal x-ray

References 1.

2.

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Bergstrom K. An orthopantomographic study of hypodontia, supernumeraries and other anomalies in school children between the ages of 8–9 years. An epidemiological study. Swed Dent J 1977; 1(4):145–57.

Brabant H. Comparison of the characteristics and anomalies of the deciduous and the permanent dentition. J Dent Res 1967; 46(5):897–902.

McKibben DR, Brearley LJ. Radiographic determination of the prevalence of selected dental anomalies in children. ASDC J Dent Child 1971; 28(6):390–8.

Sykaras SN. Mesiodens in primary and permanent dentitions. Report of a case. Oral Surg Oral Med Oral Pathol 1975; 39(6):870–4.

Gorlin RJ, CM, Hennekam RC. Syndromes of the head and neck. 4th ed.

Oxford University Press; 2001.

Primosch RE. Anterior supernumerary teeth- assessment and surgical intervention in children. Pediatr Dent 1981; 3(2):204–15.

Marya CM, Kumar BR. Familial occurrence of mesiodentes with unusual findings: case reports. Quintessence Int 1998; 29(1):49–51.

Tay F, Pang A, Yuen S. Unerupted maxillary anterior supernumerary teeth: report of 204 cases. Journal of Dental Child 1984; 51(4): 289–294.

Dahlberg AA. Analysis of the American Indian dentition. In: Brothwell DR, ed. Dental Anthropology. New York, NY: Pergamon;1963:149–177.

Ashkenazi M, Greenberg B.P, Chodik G, Rakocz M. Postoperative prognosis of unerupted teeth after removal of supernumerary teeth or odontomas. Am J Orthod Dentofacial Orthop 2007; 131:614-9.

Peretz B, Machtei EE. Tooth rotation and alveolar bone loss. Quintessence Int 1996, 27:465-468.

Nelson SJ, Ash MM. Wheeler’s Dental Anatomy, Physiology and Occlusion. 9th ed. Saunders Elsevier.2010:99-105.

Kindelan SA, Day PF, Kindelan JD, Spencer JR, Duggal MS. Dental trauma: an overview of its influence on the management of orthodontic treatment. Part 1. J Orthod 2008;( 35): 68–78.

Consolaro A, Consolaro RB. Orthodontic movement of endodontically treated teeth. Dental Press J Orthod. 2013;18(4):2-7.

Esteves T, Ramos AL, Pereira CM, Hidalgo MM. Orthodontic root resorption of endodontically treated teeth. Journal of Endodontics 2007; 33:119-22.

Riedel R. Retention and relapse. J Clin Orthod 1976;10:454-72.

Edwards JG. A surgical procedure to eliminate rotational relapse. Am J Orthod. 1970; 57: 35–46 Edwards JG. Soft-tissue surgery to alleviate orthodontic relapse. Dent Clin North Am 1993;37:205-225.

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Dr. Vipul Kumar Sharma is Assistant Professor in Orthodontics and Dentofacial Orthopaedics Division, Faculty of Dental Sciences, IMS, BHU, Varanasi. He has completed his Undergraduate & Postgraduate (Orthodontics) in King George Medical University , Lucknow, UP.

Pradeep Tandon, BDS, MDS, Professor and Head Professor &Head ,Department of Orthodontics and Dentofacial Orthopaedics, Dean, Faculty of Dental Sciences, King George’s Medical University, Lucknow, Uttar Pradesh, India.

Gyan P. Singh, BDS, MDS, Associate professor Associate Professor, Department of Orthodontics and Dentofacial Orthopaedics, Faculty of Dental Sciences, King George’s Medical University, Lucknow, Uttar Pradesh, India

Dr. Kirti Yadav (BDS, MDS) is Senior Resident in Department of Periodontology Faculty of Dental Sciences, KGMU, Lucknow (U.P).

31

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FEATURE

This article has been peer reviewed.

The ‘SOS activator:’ A Novel Functional Device Combined with Fixed Appliances for the Correction of Class II Malocclusion

By Sossani Sidiropoulou, DDS, PhD; Athina Chatzigianni, DDS, MSc, PhD Abstract: The aim of this paper is to present a new functional appliance named 'SOS activator.' It is a modified removable headgearactivator type of appliance, which is indicated in growing skeletal Class II cases with mandibular retrusion and can be combined with banded (Quad-Helix, Hyrax, TPA) and bonded fixed appliances in the upper arch. This device can concurrently correct sagittal, vertical, and transversal discrepancies allowing the active expansion of the upper dental arch and the alignment of the upper teeth, while providing maximum anchorage or even distal movement of the upper first molars and exerting a restraining effect on the maxilla. The use of this appliance eliminates the need for a first phase of therapy and shortens treatment duration. In clinical praxis the 'SOS activator' has been used until now for the treatment of hundreds of patients and seems to be a reliable method of choice for the correction of Class II malocclusions with a retrognathic mandible, while presenting many advantages compared to other functional appliances. In this paper, the technical characteristics, the construction details, and the method of action of the new device are analyzed. Furthermore, a treated case with this method is presented.

Keywords: SOS activator; modified functional appliance; Class II malocclusion; retrognathic mandible; combination with fixed appliances.

ntroduction Functional appliances have been predominantly used to correct the mandibular deficiency in growing children.1-4 There are a number of different intraoral removable devices under the term ‘functional appliances’ designed to alter the mandibular position sagittally and vertically, resulting in an alteration of the muscular forces.5-8 In Class II malocclusion cases, the forward mandibular repositioning transmits forces to the dentition, the periosteum, and basal bone. This produces a restraining effect on the forward growth of the maxilla while stimulating the mandibular growth and causing dentoalveolar adaptations, resulting in the correction of the Class II malocclusion.

Although the influence of functional appliances (especially on mandibular growth) is a controversial issue,4 the mandibular protraction appliances remain a device of choice for the correction of Class II deformities with a retrognathic mandible.

The common functional appliances are used in a phase of treatment where an orthognathic relationship of the jaws should be achieved, whereas the alignment and perfect interdigitation of the teeth are performed with fixed appliances, prior or after the functional appliance treatment. 9, 10 In clinical praxis, Class II division 1 cases with mandibular deficiency may also present a narrow maxilla with a constricted upper arch that needs expansion and, in some cases, also distalization of the upper molars. In Class II division 2 cases, a correction of the inclination and over-eruption of the upper front teeth may be additionally needed. Thus, the use of a functional appliance which would enhance the mandible, retain or distalize the upper molars in a way of a headgear effect, and allow maxillary expansion and alignment of the teeth with the concurrent combination of fixed appliances on the upper jaw would be desirable.

IJO  VOL. 27  NO. 3  FALL 2016

The ‘SOS activator’ (Figure 1) is designed to cover this need of simultaneous use of fixed appliances in the upper jaw and functional appliances in the lower jaw for the correction of the retrognathic mandible in the initial phase of treatment.

The appliance’s name, ‘SOS activator,’ has its origin from its inventor’s first name and expresses also the emergency requisite of the direct use of the appliance concurrent with fixed appliances in age-limited borderline cases concerning skeletal growth where maturation is about to be completed. It is worth mentioning that except for its useful application on patients where growth is almost terminated, this appliance is widely used during the circumpubertal growth period like common functional appliances.

Indications The use of the ‘SOS activator’ is indicated in the following cases with a retrognathic mandible: 1. In Class II division 1 malocclusion cases 2. In Class II division 2 malocclusion cases 3. In low angle cases 4. In growing individuals The appliance is not indicated in high angle cases. It must be mentioned that the correction of skeletal retrognathia with the ‘SOS activator’ is followed in most cases by a second phase of treatment, which includes fixed appliances in the lower arch for the refinement of the occlusion and the finishing of the treatment.

Clinical Management And Appliance Design The ‘SOS activator’ consists of acrylic and wire (Figure 1).

It is a complete intraoral device without any extraoral part or traction bands. The upper first molar bands have to be banded as the upper wire parts of the appliance fit into the headgear tubes 33

bilaterally. The ‘SOS activator’ could be considered as a development of a headgear activator-type of functional device, since when the appliance is placed in the mouth in a protruded mandibular position, it simultaneously applies distal forces to the upper molars (Figure 2).

Figure 1: The ‘SOS activator’

Figure 2: Alteration of the postural position of the mandible, producing forces of the retractor muscles that are transmitted to the upper molars

Figure 3: a, b) Example of study models and c) construction bite

Figure 4: a) Straight upper buccal wire endings during fabrication and b) construction of the HG-type bayonet bends mesial to the molar bands during clinical application

Figure 5: a, b) The upper buccal wires configuration

Figure 6: Reactivation of the appliance by opening the loops of the buccal wires bilaterally 34

Impressions and Work Models An accurate reproduction of the upper and lower dentition and the associated soft tissues, especially of the lower lingual region, is important because the acrylic base is fitted in this area. At the time of impressions, the upper first molar bands should already be banded with no necessity to be transferred to the stone models. Alternatively, the upper molar bands can be transferred to the work models in cases where a Quad-Helix or transpalatal arch (TPA) should be fabricated in combination with the ‘SOS activator.’

Construction Bite The wax construction bite is made directly intraorally as usual. A 5-10 mm thickness of medium hard wax is used to orient the upper and lower dental arches in all three planes of space.

The construction bite is taken by advancing the mandible from 3-5 mm depending on the anteroposterior discrepancy. In general, the mandible is repositioned forward until, if possible, a Class I canine relationship is confirmed. The vertical opening between the incisors should be 2.0 to 2.5 mm to allow enough space for the acrylic cap to cover the mandibular incisors and avoid proclination (Figure 3).

Acrylic Fabrication Before the acrylic fabrication, a wax relief is applied to the lingual surface of the lower incisor region. This will prevent the acrylic from coming in contact directly with the lower anterior teeth and applying undesirable labial pressure to the incisors, due to the force of the retractor muscles of the advanced mandible. The ‘SOS activator’ is fabricated as a single unit fitted in the lower arch, resembling a lower removable appliance with posterior occlusal blocks and an acrylic cap covering the lower incisors. The interocclusal acrylic is constructed so that the maxillary posterior teeth touch a flat occlusal acrylic , while the mandibular posterior teeth are in contact with and covered entirely from the acrylic (Figure 4).

Wire Fabrication a. Upper buccal wires: The ‘SOS activator’ is composed by two upper buccal wires with loops, one on each side, which fit into the molar band tubes and secure the device in its proper position (Figure 5). The upper buccal wires consist of IJO  VOL. 27  NO. 3  FALL 2016

strong stainless steel .045” wire, similar to the inner bow of the headgear and are embedded into the interocclusal acrylic. The loops of the wires are extended upwards approximately 5-7 mm above the gingival margin distal to the upper canine area (Figure 4). The wires come straight along the upper posterior teeth in a distance of about 2-3 mm parallel to the occlusal plane and are inserted into the molar band tubes with a bayonette bend similar to the inner bow bend of the headgear (Figure 4). b. Lower labial wire: The lower labial wire is bent in a Hawley configuration from .036” stainless steel wire. The labial bow guides the lower anterior teeth at their midpoint.

Control of the Posterior Eruption If a vertical eruption of the posterior teeth is desired, the interocclusal acrylic covering the lower posterior teeth can be removed as in the common activator allowing an unimpeded eruption of the teeth. In this way, the curve of Spee can also be improved. The lower incisors are covered with an acrylic incisal cap that prevents the vertical eruption and proclination of these teeth and stabilizes the activator in the mouth.

Reactivation In cases with a large overjet, the initial appliance can gradually enhance protrusion by activation of its loops (Figure 6). After bilateral loop widening, a more forward position of the mandible is established. A step-wise overjet reduction is indicated in large overjet cases, where an extreme mandibular advancement would produce tension in the craniomandibular musculature and cause patient discomfort and non-compliance. Moreover, the upper buccal wires can also be activated in the transverse direction, resulting in expansion in the upper molar region.

Method of Action The correction of Class II malocclusion using the ‘SOS activator’ is accomplished resulting in alterations in both jaws and dental arches. The appliance advances the retrognathic mandible and corrects the mandibular position in the same way other functional appliances do. Furthermore, the appliance produces a distal effect on the maxilla and its dentition.

The muscular forces generated by the forward mandibular positioning, as the muscles attempt to return the mandible to its original position, are being transferred to the maxillary molars through the maxillary buccal wires that are secured into the headgear tubes (Figure 2). These forces applied to the upper molars have a distalizing effect on the teeth or the upper dental arch and a restraining effect on the forward growth of the maxilla, depending on the management of the upper fixed appliance.

Further dentoalveolar adaptation, which contributes to the bite correction and vertical eruption, comes from proper trimming of the interocclusal acrylic covering the lower posterior teeth. More protrusion of the mandible can be achieved by activation of the maxillary vertical loops.

Optimal Treatment Timing Like common functional appliance, the appropriate patient’s age for ‘SOS activator’ application is around the circumpubertal growth period of a child. Optimal timing IJO  VOL. 27  NO. 3  FALL 2016

depends on the skeletal maturation level of each individual, and up to now, the most popular available methods to determine peak mandibular growth are the hand-wrist (HW)11,12 radiograph method and the cervical vertebrae maturation method (CVM).13,14,15 Advantages The ‘SOS activator’ is designed to transcend the variety of common removable functional appliances currently described in the literature, and compared to those, it features the following advantages: 1. Can be used in combination with fixed appliances on the upper jaw 2. Can be combined with expansion or other palatal devices such as the Quad-Helix, transpalatal arch (TPA), Hyrax, Pendulum appliance, and others 3. Shortens treatment duration due to the concomitant use of fixed appliances 4. May have a headgear effect on the upper maxillary molars providing maximum anchorage or even distal movement of those teeth 5. May have a restraining effect on the upper jaw and the maxilla 6. Could be potentially used with fixed appliances on the lower jaw 7. May eliminate the need of a first phase of treatment in Class II division 2 cases The SOS activator is a removable functional appliance and is not designed to be compared to the fixed-functional appliances currently available, such as the Jasper-Jumper, the Herbst, the Forsus etc., which are rigid and were developed for a noncompliance orthodontic treatment.

Clinical Application The ‘SOS activator’ has been successfully used during the past years for the orthodontic treatment of hundreds of orthodontic patients seeking treatment at the private orthodontic practice of the two authors and at the postgraduate clinic of the University Orthodontic department under the supervision of the first author. The clinical effectiveness of the device together with the dental and skeletal alterations produced by the appliance will be presented in a clinical trial in a future study. In the present paper, one typical case report with Class II division 1 malocclusion treated with the ‘SOS activator’ is presented.

Case Report A 10 year-old girl with Class II division 1 malocclusion is shown in Figure 7(a-h). The intraoral examination revealed an Angle Class II canine and first molar relationship, a large overjet of 9mm, deep bite with traumatic occlusion, a narrow maxilla and constricted upper arch, proclination of the upper incisors, and increased curve of Spee. The extraoral view showed a convex profile with posterior positioned mandible.

The cephalometric analysis confirmed the Class II skeletal discrepancy with a retrognathic mandible. The treatment was performed with functional jaw orthopedic therapy using the ‘SOS activator’ and fixed appliances in combination with an 35

a.

b.

d.

c.

e.

f.

g.

h.

Figure 7: Pre-treatment: a, b) Frontal view, c) profile view, d-h) intraoral view

a.

d.

b.

c.

e.

f.

Figure 8: a-e) The ‘SOS activator’ in combination with fixed appliances in the upper arch and f) in combination with the Quad-Helix

a.

d.

b.

e.

c.

f.

Figure 9: After ‘SOS activator’: a, b) Frontal view, c) improved profile view, d, f) correction of the overjet and overbite, e) distal movement of the maxillary arch 36

expansion device on the upper jaw to correct the anteroposterior, vertical, and transverse problem (Figures 8 a-f ). The ‘SOS activator’ was secured in the headgear tubes as described before and distal forces were applied to the upper dental arch, bringing the mandible in a more forward position, while the Quad-Helix delivered the proper upper arch expansion (Figure 8f ). The ‘SOS activator’ wear time was 13-15 hours daily for a treatment period of about 11 months. The ‘SOS activator’ treatment phase together with fixed appliances only on the upper jaw, resulted in the correction of the sagittal, vertical, and transverse discrepancies and established a Class I canine and molar relationship (Figures 9a-f ).

The distal movement of the maxillary arch can be seen at the end of the ‘SOS activator’ treatment where a space is created between the right lateral incisor and the canine (Fig. 9e). After that, fixed appliances were bonded on the lower arch for the refinement of the occlusion (Figures 10a-d).

Progress intraoral and extraoral photographs together with lateral radiographs were obtained after each treatment phase in order to confirm the dental and skeletal correction of the discrepancy.

The Viewbox 4® cephalometric software was used for cephalometric analysis (Viewbox 4, dHAL Software, Kifisia, Greece). Superimpositions and analysis of initial, after SOS activator, and final tracings are shown in Figure 13(a-c) and show the forward repositioning of the mandible and the headgear effect on the maxilla. The ‘SOS activator’ treatment resulted in the reduction of ANB and Wits appraisal values and increased the SNB, SNPog values together with other skeletal improvements (Table 1). As seen on the maxilla superimposition, the upper first molars were retained in their position during treatment while dental relations were normalized.

Discussion The ‘SOS activator’ appliance can be used in skeletal Class II cases with mandibular retrusion concurrent with fixed appliances in the upper jaw from the initial phase of the treatment. The appliance advances the retrognathic mandible, corrects the mandibular position, while at the same time exerting distal forces on the upper dental arch. The ‘SOS activator’ causes mandibular advancement, stabilization or distal movement of the maxillary molars while at the same time it allows refining of the occlusion with banded and bonded fixed appliances on the maxillary dentition. Patients with large overjet will also benefit from a step-wise overjet reduction by reactivation of its loops.

Considerations may arise with regard to patients presenting a retruded mandible together with a IJO  VOL. 27  NO. 3  FALL 2016

Table 1: Variables of cephalometric analysis before and immediately after ‘SOS activator’ treatment

a.

c.

d.

Figure 10: a-d) Bonding of the lower arch following ‘SOS activator’ treatment

a.

before

after ‘SOS activator’

mean

SD

SNA

78.2°

77.6°

81.8°

3.7°

SNB

73.7°

76.7°

79.2°

2.3°

ANB

4.5°

1.5°

2.6°

2.4°

Skeletal

b.

b.

c.

WITS

4.9°

1.7°

0°

1.8°

SN-Pog

76.2°

79.6°

80.2°

2.5°

Facial angle

88.1°

85.6°

84.8°

3.5°

NA-Apog

3.8°

1°

1.7°

4.7°

H angle

20.5°

12.8°

11.8°

3.1°

SN-SGn

66.2°

66.7°

65.7°

3.4°

SN-NL

8.9°

8.8°

6.9°

2.8°

SN-ML

23.8

25.1°

31°

5.2°

Ar-Go-Me

112°

115,7°

125.6°

5.9°

SGo:Nme x100

72.7°

73°

66.8°

4.4°

1s-NL

127.8°

115.8°

112°

6°

1i-ML

105°

106.1°

92.6°

6.7°

1i-Apog

0.5°

2,6°

1.3°

2.2°

1s-1i

109°

120.3°

132.1°

9.8°

1s-SN

118.9°

107.1°

104°

6°

96.9°

105.8°

109°

8°

2

-1.9

-1

2

Dental

d.

e.

f.

Soft tissue g. h.

Figure 11: Post-treatment: a, b) Frontal view, c) improved profile view, d-h) intraoral view

Nasiolabial angle Lower lip to E-plane (mm)

a. b. c.

Figure 12: Cephalometric radiographs: a) Pre-treatment, b) after ‘SOS activator’, c) Post-treatment

Figure 13: Superimposition: a) Of the craniofacial complex, b) of the maxilla, c) of the mandible IJO  VOL. 27  NO. 3  FALL 2016

37

normal maxilla, where there is a lack of necessity to intervene on a distal direction with the ‘SOS activator.’ Nevertheless, unless an extraoral traction is applied, the mandible cannot be moved forward without a maxillary anchorage unit. All available functional appliances include a part that is attached on the maxilla. Classical activator has a labial arch on the upper front teeth or Adam hooks on the molars, Fraenkel II consists of acrylic and wires that cover the upper and lower arch, Twin Block is constructed not only with a mandibular, but also with a maxillary part. A systematic review on the effect of functional appliances on maxillary growth has shown a slight inhibitory effect on the sagittal growth of the maxilla in the short term.

The minimal reduction of SNA was found to be -0,61° per year which is clinically insignificant.16 Possible skeletal effects of the ‘SOS activator’ should be analyzed in a sample of treated patients to draw more precise conclusions.

Regarding the timing of ‘SOS activator’ application, it is primarily used like all available functional devices at the circumpubertal growth period but can be also used in borderline cases regarding skeletal maturation where growth ceases, as it condenses the phases of orthodontic treatment gaining valuable treatment time. A common general problem associated with the optimal time for functional therapy is the identification of the period of maximum facial growth. The most popular methods that have been used until now are a) the assessment of hand-wrist (HW) radiographs11, 12 and b) the evaluation of cervical vertebrae maturation (CVM). 13, 14, 15 These methods identify ossification stages of the bones of the hand and the wrist and changes on cervical vertebrae morphology and correlate maturational stages with facial growth. However, controversies have arisen about the validity of the latter, and the best method to determine the timing of mandibular growth peak remains unclear.17, 18 In the future, clinical trials with ‘SOS activator’ therapy will be presented in order to describe the effects of this new functional appliance on skeletal and dentoalveolar characteristics. The sample should be ideally divided according to the maturational stage of the individuals in order to detect differences in mandibular and maxillary response.

Conclusions The ‘SOS activator’ can concurrently correct sagittal, vertical, and transversal discrepancies allowing the active expansion of the upper dental arch and the alignment of the teeth using fixed appliances and auxiliaries such as the Quad-Helix, Hyrax, or TPA. It is easily fabricated, removable, comfortable, and well-accepted by patients. In clinical praxis, this apparatus, when indicated, seems to be a reliable method of choice for the correction of Class II malocclusions with retrognathic mandible, while presenting many advantages compared to other functional appliances.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

Bishara SE, Ziaja RR. Functional appliances: A review. Am J Orthod Dentofac Orthop 1989; 95(3): 250-258.

Bimler HP. Dynamic functional therapy. The Bimler appliance. Trans Eur Orthod Soc 1973; 49: 451-456.

Fränkel R. Technik und Handhabung der Funktionsregler. VEB Verlag Volk und Gesundheit, Berlin; 1976.

Teuscher U. Direction of force application for Class II Division 1 treatment with the activator-headgear combination. Krips Repro Meppel, Studieweek, The Netherlands; 1980: 193-203.

Van Beek H. Overjet correction by a combined headgear and activator. Eur J Orthod 1982; 4(4): 279-290.

McNamara JA Jr, Brudon WL. Orthodontic and orthopedic treatment in the mixed dentition. Ann Arbor, MI; Needham Press; 1993.

McNamara JA Jr, Peterson JE Jr, Alexander RG. Three dimensional diagnosis and management of Class II malocclusion in the mixed dentition. Semin Orthod 1996; 2(2):114-137.

Houston WJB, Miller JC, Tanner JM. Prediction of the timing of the adolescent growth spurt from ossification events in hand-wrist films. Br J Orthod 1979;6:145–152.

Fishman LS. Radiographic evaluation of skeletal maturation. A clinically oriented method based on hand-wrist films. Angle Orthod 1982; 52: 88–112.

OpenUrlLamparski DG. Skeletal Age Assessment Utilizing Cervical Vertebrae. Thesis, University of Pittsburgh;1972.

Baccetti T, Franchi L, McNamara JA Jr. The cervical vertebral maturation (CVM) method for the assessment of optimal treatment timing in dentofacial orthopedics. Sem Orthod 2005;11:119–129.

Baccetti T, Franchi L, McNamara JA Jr. An Improved version of the cervical vertebral maturation (CVM) method for the assessment of mandibular growth. Angle Orthod 2002;72:316–323.

Nucera R, Lo-Giudice A, Rustico L, Matarese G, Papadopoulos MA, Cordasco G. Effectiveness of orthodontic treatment with functional appliances on maxillary growth in the short term: A systematic review and meta-analysis. Am J Orthod Dentofacial Orthop 2016 May;149(5):600-611.

Chatzigianni A, Halazonetis DJ. Geometric morphometric analysis of cervical vertebrae shape and its relationship to skeletal maturation. Am J Orthod Dentofacial Orthop 2009 Oct;136(4):481.e1-9.

Engel TP, Renkema AM, Katsaros C, Pazera P, Pandis N, Fudalej PS. The cervical vertebrae maturation (CVM) method cannot predict craniofacial growth in girls with Class II malocclusion. Eur J Orthod 2015;8:1-7.

Dr. Sossani Sidiropoulou is Associate Professor in the Department of Orthodontics, Faculty of Dentistry, Aristotle University of Thessaloniki, Greece. She is the inventor of the appliance named ‘SOS activator.’

Also, she has published a number of papers and given lectures, she is a reviewer in international orthodontic journals and has been president of the Orthodontic Society of Northern Greece.

Dr. Athina Chatzigianni is a Specialist Orthodontist, DDS, MSc and Dr.med.dent. of the University of Bonn, Germany. Currently she works as clinical instructor and lecturer in the Department of Orthodontics, Faculty of Dentistry, Aristotle University of Thessaloniki, Greece. She has received awards and honorary distinctions and has completed a number of research projects. Additionally, she reviews papers in orthodontic journals.

References 1.

2.

3.

38

Andersen V, Häupl K. Funktions-Kieferorthopädie. Hermann Meusser, Berlin; 1936.

Harvold EP. The activator in interceptive orthodontics. The CV Mosby Company, St. Louis, MO; 1974.

Vargervik K, Harvold EP. Response to activator treatment in Class II malocclusions. Am J Orthod 1985; 88(3): 242-251.

IJO  VOL. 27  NO. 3  FALL 2016

FEATURE

This article has been peer reviewed.

Volumetric MRI Evaluation of Airway, Tongue, and Mandible in Different Skeletal Patterns: Does a Link to Obstructive Sleep Apnea Exist (OSA)?

By Krishna Sharma, MDS; Sunita Shrivastav, MDS; Kavita Hotwani, MDS Abstract: Background/Objectives: Craniofacial disharmony has been long debated as an important predisposing factor in the development and progression of sleep-disordered breathing and OSA. The present study was aimed to determine and compare whether a direct correlation occurs between the airway volume, mandibular dimension, and tongue volume in different craniofacial growth patterns.

The objectives were the 3D MRI assessment and comparison of airway volume, mandibular dimensions, and tongue volume in Class I normodivergent, Class II hyperdivergent, and OSA group. Materials/Methods: Study population included 45 patients (12-18 years). Soft tissue volume estimation for airway [oropharyngeal (OP), nasopharyngeal (NP)] and tongue was carried out using MRI and DICOM image processing software(Osirix® v5.6).Mandibular dimensions were characterized on MRI, and derivations were made using the Pythagoras theorem. Subsequently, 3D reconstructions were carried out. The mean and standard deviation were obtained. Kruskal-Wallis and Wilcoxon rank sum test were used. Multiple regression analysis was performed for OP and NP volumes using BMI, mandibular area, and tongue volume as predictors for the complete sample. Results: It was found that in overall sample, mandibular length showed a positive correlation with OP, NP, and tongue volumes. For both OP and NP, glossomandibular area, and tongue volume were found to be statistically significant predictors. Conclusions/Implications: A direct correlation was confirmed between the airway volume, mandibular dimensions, and tongue volume in different craniofacial growth patterns. The present knowledge can be utilized on patients for treatment of reduced airway space using the derived formula for mandibular dimensions, and the regression equations can be used as a diagnostic aid in determining the OP and NP volume for any individual using 2D radiographs in orthodontics.

Keywords: Obstructive sleep apnea, Oropharyngeal volume, Nasopharyngeal volume, Mandibular dimensions, glossomandibular area, craniofacial risk factors

ntroduction In recent times, the orthodontic perspective on obstructive sleep apnea(OSA) has arguably demanded eclectic discussions and propositions.

Sleep-disordered breathing (SDB) varies in severity; ranging from snoring, upper airway resistance syndrome (UARS) and, the most severe, obstructive sleep apnea (OSA). The pediatric population experiences these disorders in association with hypertrophy of tonsils and adenoids, allergies, frequent colds, and mouth breathing.1,2 In this regard, the main link is thought to be impaired nasal breathing or pharyngeal insufficiency. This leads to unfavorable dentofacial growth in association with OSA. Comprehension of this syndrome has increased not only because of its high rate of incidence but also because orthodontists and oral surgeons are beginning to play a more significant role in treating OSA syndrome with the use of intra-oral devices and/or orthognathic surgery.

Craniofacial disharmony can also be an important predisposing factor in the development and progression of sleep-disordered breathing and OSA.3 Several studies in the past have demonstrated that children with partial or complete airway obstruction have a different dentofacial morphology when compared with those without any obstruction.4-8 Thus, evaluation of upper and lower airway space which should be an integral part of diagnosis and treatment planning to achieve functional balance, and stability of the results is essential.

IJO  VOL. 27  NO. 3  FALL 2016

We presume that atypical or aberrant airway may be associated with facial growth compensation and if the size and posture of mandible as well as tongue is also altered, it may increase the risk of reducing the airway dimension-- hence increasing the risk of snoring which may later on manifest as OSA. In order to better understand this correlation between airway, pharyngeal space, jaw morphology, and their probable risk factors which predisposes to OSA and other breathing disorders, the present study was undertaken with an attempt to determine and compare whether a direct correlation exists between the airway volume, mandibular dimension, and tongue volume in different craniofacial growth patterns.

Materials and Methods The main objectives of the present investigation were the three-dimensional assessment of airway volume, mandibular dimensions, and tongue volume in Class I normodivergent cases (control group), Class II hyperdivergent group, and obstructive sleep apnea group. The University Ethical Committee of Datta Meghe Institute of Medical Sciences (DU) approved the study protocol. An informed written consent was obtained from the patient or their parents (in the case of a minor) prior to the study. Selection to homogenize the sample with respect to age, sex, BMI, and ethnicity was specifically performed. A total of 30 patients of an age group ranging from 12-18 years without any previous history of orthodontic treatment were randomly 39

selected from the OPD of patients visiting the Department of Orthodontics. Based on their clinical findings as a routine procedure, a pre-treatment lateral cephalogram was taken.

All lateral skull radiographs were taken with a cephalometric radiograph unit (Planmeca Proline® Oy Asentajankatu Helsinki, Finland) using a standard technique.

Based on the cephalometric findings they were classified as: Group I: 15 patients (8 males, 7 females) with Class II skeletal relation with average growth pattern (normodivergent) which were used as the control group.

Group II: 15 patients (8 males,7 females) with Class II skeletal relation and vertical growth pattern (hyperdivergent) which were used as an experimental group.

The following cephalometric measurements were used to classify the randomly selected cases into three groups as follows: Group 1 mean 81- 83° 79-81° 2- 4° 1 to 2 mm 27-34° 22-28° 31 - 32° 125 - 130° 24 - 26° 88 - 92° 85 - 89°

Parameter SNA SNB ANB angle Wits appraisal Beta angle FMA SN – Go Gn Gonial angle Basal plane angle Facial axis angle Facial depth Lower anterior facial height

Group 2 mean 80- 83° 74 -79° 4 -7° 3- 7mm 20 - 25° 30 - 37° 33 - 38° 130 - 140° 27 - 32° 85 - 88° 80 - 85 °

Group 3 mean 79- 84° 72 -80° 1- 8° 1 – 8 mm 19 - 35° 24 - 38° 30 - 37° 127 – 139° 24 - 33 ° 84 - 91° 83 - 86°

65- 68 mm 68 - 74 mm

65 - 70°

Group III was comprised of 15 (8 males,7 females) patients diagnosed and admitted for obstructive sleep apnea syndrome in the I.P.D. (Sleep Apnea Ward) Department of Pulmonary Medicine. AVBRH, DMIMS (DU) were used as an experimental group. Overnight PSG and other relevant investigations such as electroencephalography, electrooculography, submental electromyography, and electrocardiography using surface electrodes, percutaneous arterial oxygen saturation using a finger pulse-oximeter (PULSOX®-M24; TEIJIN Co., Tokyo, Japan) were recorded in all the obstructive sleep apnea subjects. The predominant sleep stage was determined according to the criteria established

by Rechtschaffen and Kales.34 Arousal responses were identified according to the criteria of the American Sleep Disorders Association.

Criteria for OSA AHI /RDI index

>20

Blood O2 saturation

80-90 %

MRI Procedure All the subjects selected underwent a MRI scan at the Department of Radiology A.V.B.R.H Sawangi, DICOM images were procured using a 1.5 Tesla magnetic resonance imaging scanner(BrivoTM MR355 1.5T; General Electric, Waukesha, WI, U.S.A.). Since head and neck position may alter upper 40

airway soft-tissue configuration and upper airway geometry, subjects were aligned in the Frankfort plane prior to the scanning. Foam pads were placed between the patient’s head and each side of the receive-only volume neck coil (General Electric Medical Systems) to ensure that head movement did not occur during the MRI scanning. All studies were performed during wakefulness. Contiguous sagittal T1-weighted 3D gradient echo MR images were acquired centered about the mid-sagittal plane through the long axis of the airway. Axial sections (TR = 24 ms, TE = 9 ms, 250 × 250 matrix, FOV = 249 mm, 4-mm slice thickness, imaging time = 4 min) of the pharynx were gathered perpendicularly to the tangent of the posterior pharyngeal wall spanning from the top of the nasopharynx to the epiglottis.

Soft Tissue Volume Estimation Using MRI Image Processing and Anatomic Measurements Measurements from MR images were made with DICOM image processing software (Osirix® v5.6, Biomedical Visualizers Geneva, Switzerland). Airway, soft tissue, and bony structure segmentation were performed by manual tracing.

Computation of Oropharyngeal (OP) and Nasopharyngeal (NP) Volume The oropharyngeal airway was defined as being bounded anteriorly by the soft palate or tongue, laterally by the tonsils, and posteriorly by the pharyngeal constrictor muscle. At this level, a series of linear measurements were performed along a vertical line bisecting the apex of the nasal septum in the axial slice. This vertical line was used as a reference line for orientation of all MR slices (Figure 1).

Mandibular Dimensions and Glossomandibular Area The mandibular measurements of length and width were assessed to determine the dimensions of the lower portion of the mandible. Three mandibular measurements were assessed to determine the dimensions of the lower portion of the mandible.

The coordinates for the most anterior–inferior point of the mandible (gnathion) and the most posterior–inferior points of the mandible (left and right gonion) were identified on the corresponding frontal/coronal MRI slices. Mandibular body length (ML) was measured as the average distance from the gnathion to the left and right gonion, and mandibular width (MW) was measured as the distance between the left and right gonion. Mandibular depth (H) and glossomandibular area were derived using the measurements as per the Pythagoras theorem (Figure 2).

Tongue Volume (TV) The volume of the tongue was calculated from the MRI tracings. A semi-automatic calculation of the borders permitted virtual reconstruction of the tongue (Figure 3).

Volume Computation The described airway and tongue volumes were directly computed using OsiriX software (Figure 4). The software allows the user to designate ROI (Region of Interest) in each slice. These individual ROIs were then merged to evaluate and compute the volume of the desired anatomical unit. The OsiriX® software allowed us to “sculpt out” the desired airway IJO  VOL. 27  NO. 3  FALL 2016

Figure 1a: Method employed for estimation of nasopharyngeal volume

Figure 1b: Method employed for estimation of oropharyngeal volume Reference plane 1: Vertical line bisecting the apex of nasal septum in the axial slice. This vertical line was used as a reference line for orientation of all MR slices. The sagittal slice, so obtained (after reference orientation) was used for computing OP volume. OP volume was defined as the volume of the pharynx that is between the palatal plane (ANSPNS) extending to the posterior wall of the pharynx and the plane parallel to the palatal plane that passes from the most antero-inferior point of the epiglottis. The inferior limit of the NP airway was defined as the superior limit of the OP airway, and the superior limit was defined as the last slice before the nasal septum fused with the posterior wall of the pharynx.

IJO  VOL. 27  NO. 3  FALL 2016

41

3D reconstruction A curved MPR (curved multiplanar reformation) image was rendered from a 3D dataset which was obtained using OsiriX® software by fusing 3 dimensional MPR images of the oropharynx, nasopharynx, and tongue.

Figure 2: Method used for assessment of madibular dimensions. The coordinates for the most anterior-inferior point of the mandible (gnathion) and the most posterior-inferior points of the mandible (left and right gonion) were identified on the corresponding frontal/coronal MRI slices. Mandibular body length (ML) was measured as the average distance from the gnathion to the left and right gonion, and mandibular width was measured as the distance between the left and right gonion. Mandibular width (MW) was measured as the distance between the left and right gonion. Mandibular depth(H) and glossomadibular areas were calculated as per Pythagoras theorem. A triangular representation of the area is shown in above. To determine the area, H was estimated using Pythagorus theorem as:

Thus, the area of triangular region was obtained as:

Figure 3: Method used for estimation of tongue volume. The tongue was defined as all of its intrinsic muscles plus the entire genioglossus and hyoglossus muscles since sagittal orientation gave greater resolution than frontal orientation, only sagittal views were used for tongue volumne calculation.

and tongue volume from the rest of the structure, and, by adjusting the brightness and opacity values, the unwanted voxels were removed before calculating the volumes. The OsiriX® 3D engine uses a ray-tracing algorithm. There is no distortion or statistical errors introduced during this process. It is fully reproducible. In all reconstructions, the 3D measurements were computed as a whole, correlating all the views together. The sagittal view was utilized for marking the boundaries for tongue, but real time correlation in other view was simultaneously carried out for volume computation.

42

Statistical Analysis The data generated on various anatomical factors as well as demographic and biological variables were analyzed using appropriate statistical techniques. To determine the accuracy of data collection, all physical measurements were repeated at the interval of 2 weeks by the same observer, and Dahlberg’s formula was used to quantify the error in different measurements. The mean and standard deviation for airway volume, tongue volume, and mandibular dimensions were obtained. Kruskal-Wallis test was used to evaluate the statistical significance across the three groups for each parameter; and upon finding significance, the Wilcoxon rank sum test was used to obtain pair-wise significance. Multiple regression analysis was performed for OP and NP volumes using BMI, mandibular area, and tongue volume as predictors for the complete sample.

Results As per Dahlberg’s formula, overall there was very strong evidence indicating an agreement between the measurements. Descriptive statistics for biological parameters (age, BMI) were obtained, and it was found that the mean age for the normodivergent group was 12.73 ± 1.86 years, the hyperdivergent group was 13.33 ± 2.09 years, and the OSA group was 12.8 ± 1.82 years. The difference in the means was statistically insignificant. The mean FMA (Frankfort-mandibular plane angle) in the normodivergent group was 24.60 ±1.68; the Hyperdivergent group was 33.71 ±1.96; and the OSA group was 27.47±1.75.

The mean and standard deviation for airway volume, tongue volume, and mandibular dimensions were obtained as shown in Table 1. KruskalWallis test was used to evaluate the statistical signficance across the three groups for each parameter; and upon IJO  VOL. 27  NO. 3  FALL 2016

finding significance, the Wilcoxon rank sum test was used to obtain pair- wise significance. Table 1 shows that each factor differed significantly across three groups (p < 0.05). To ascertain which groups differ significantly, pair-wise analysis was carried out with the results shown in Table 2.

With respect to the Class I normodivergent group, the OP and NP volume as well as mandibular length, width, and glossomandibular area were found to be the highest amongst all the groups, whereas tongue volume was found to be the lowest. With respect to the Class II hyperdivergent group, mandibular width was found to be the lowest amongst all the three groups. In the OSA group, OP, and NP volumes and mandibular length were found to be the lowest amongst all groups, whereas tongue volume was found to be the highest (Table 1).

It was found that in the overall sample, mandibular length showed a positive correlation with OP, NP, and tongue volumes. A positive correlation was evident for OP and NP with the glossomandibular area. A negative correlation was found between mandibular length and the tongue volume.

Tongue volume was also negatively correlated with the glossomandibular area.

In the hyperdivergent group, a negative correlation of mandibular width with

Class I Normodivergent

Class II Hyperdivergent

Obstructive sleep apnea

Figure 4a: 3-Dimensional reconstruction model of airway

Class I Normodivergent

Class II Hyperdivergent

Obstructive sleep apnea

oropharyngeal volume existed. In the OSA group, mandibular length and width showed negative correlation with tongue volume (Table 3,4,Scatter plot 1, 2).

Multiple regression analysis was performed for OP and NP volumes using BMI, mandibular area, and tongue volume as predictors for the complete sample. The data was log-transformed and the results obtained are shown in Table 5. For both OP and NP, glossomandibular area and tongue volume emerged as statistically significant predictors.

The percent of variation explained by the set of predictors in these models were 52.1% and 56.1% respectively, which was reasonably good.

A test sample of 15 (5 cases from each group) was considered, and the data on OP, NP, and tongue volume, mandibular length and width along with BMI were obtained. The data was used for validation of the above two expressions, with the results obtained as shown in Table 6.

The predicted values for each sample based on log transformed BMI, area and tongue volume were obtained. It was found that glossomandibular area and tongue volume seemed to be good predictors of OP and NP volume. Glossomandibular area and tongue volume were found to be good predictors of OP and NP volumes (Table 6).

The models derived from this analysis are as follows: logOP = 0.451 + 0.065 logBMI + 0.864 logArea – 1.421 logTV …(1) logNP = 1.234 + 0.117 logBMI +0.738 logArea – 1.597 logTV …(2) Discussion The relationship between airway volume

Figure 4b: 3-Dimensional reconstruction model of tongue

Table 1: Descriptive statistics for estimation of airway volume, tongue volume, and mandibular dimension in three study groups Normodivergent (n=15)

Hyperdivergent (n=15)

OSA (n=15)

P-value*

Oropharyngeal volume (cm3)

5.93±0.45

3.73±0.41

3.32±0.26

< 0.0001 a

Nasopharyngeal volume (cm )

6.91±0.38

4.64±0.54

3.96±0.29

< 0.0001a

Mandibular length (mm)

73.73±6.18

66.70±3.11

65.23±3.01

0.0001b

Mandibular width (mm)

71.23±4.36

64.33±3.15

68.13±2.97

< 0.0001a

82.07±4.97

86.43±4.22

91.73±5.88

0.0005b

2295.78±279.37

1873.81±122.07

1897.12±162.04

< 0.0001a

Characteristic

3

Tongue volume (cm3) Glossomandibular area (mm ) 2

*Kruskall-Wallis test; a: Highly significant; b: Significant at .05 level IJO  VOL. 27  NO. 3  FALL 2016

43

Table 2: Pair-wise significance of mean levels of risk factors between different groups Comparisons* Anatomical Risk Factor

Normodivergent vs.

Hyperdivergent

Normodivergent vs.

Obstructive Sleep Apnea

Hyperdivergent vs.

Obstructive Sleep Apnea

Oropharyngeal volume (cm3)

< 0.0001a

< 0.0001 a

0.0027 b

Nasopharyngeal volume (cm3)

< 0.0001 a

< 0.0001 a

0.0001 b

Mandibular length (mm)

0.0004b

0.0002 a

0.3079c

Mandibular width (mm)

< 0.0001 a

0.0451 b

0.0019 b

0.0504 c

0.0004 b

0.0132 b

< 0.0001a

0.0004 b

0.8357 c

Tongue volume (cm3) Glossomandibular area (mm2)

*Statistical significance tested using Wilcoxon rank sum test. a: Highly significant; b: Significant at 0.05 level; c: Statistically insignficant (P> 0.05)

Table 3: Bivariate correlation between anatomical risk factors Anatomical risk factors Anatomical factors / Groups

BMI

Mandibular length

Mandibular width

Correlation (P-value)* Oropharyngeal volume

Table 4: Correlation between area of glossomandibular area and anatomical risk factors Anatomical factors / Groups

Area

Oropharyngeal volume Normodivergent

-0.327 (0.234)

Hyperdivergent

-0.205 (0.462) 0.075 (0.790)

Normodivergent

-0.073 (0.795)

-0.197 (0.479)

-0.288 (0.296)

OSA

Hyperdivergent

0.334 (0.223)

0.097 (0.729)

-0.707 (0.003)

Overall

OSA

0.262 (0.344)

0.198 (0.477)

-0.097 (0.731)

Nasopharyngeal volume

Overall

0.135 (0.373)

0.577 (< 0.0001)

0.181 (0.233)

Normodivergent

0.112 (0.689)

Hyperdivergent

0.096 (0.732)

Nasopharyngeal volume

0.492 (0.0005)

Normodivergent

0.189 (0.498)

0.226 (0.416)

-0.200 (0.474)

OSA

-0.248 (0.371)

Hyperdivergent

0.007 (0.979)

0.142 (0.611)

0.180 (0.520)

Overall

0.505 (0.0004)

OSA

0.307 (0.265)

-0.211 (0.449)

-0.270 (0.331)

Tongue volume

Overall

0.124 (0.417)

0.554 (<0.0001) 0.209 (0.166)

Tongue volume

Normodivergent

0.158 (0.573)

Hyperdivergent

-0.293 (0.288)

Normodivergent

0.510 (0.051)

0.189 (0.497)

-0.218 (0.433)

OSA

-0.694 (0.004)

Hyperdivergent

0.416 (0.122)

-0.361 (0.185)

-0.338 (0.217)

Overall

-0.503 (0.0004)

OSA

0.091 (0.748)

-0.636 (0.011)

-0.818 (0.0002)

Overall

0.227 (0.132)

-0.498 (0.0005)

-0.351 (0.018)

*Spearman’s rank correlation

and the stomatgnathic system is still not clear and has been a reason for controversy in the last century. According to the functional matrix theory,9 there is a close interrelationship in the function of swallowing and breathing. It is also contemplated that dysfunction of the airway can cause skeletal deformation in growing children, and conversely, craniofacial malformation can negatively impact the airway.

There are limited methods which can be employed to evaluate the airways, most being 2-dimensional using a lateral cephalogram10 or are based on animal studies, but it 44

does not gives an accurate measurement of a 3-dimensional structure.11,12 In the present study, MRI was used which is a 3-dimensional procedure and takes images with the patient in the supine position which is helpful in understanding breathing obstruction during sleep. It also images the soft tissues, so the role of soft tissues structures in causing airway obstruction can be evaluated.13-16 In the present study, technically, a spatial resolution of slice thickness of the MRI scans was 4mm. This was done in order to improve the spatial resolution. Also, the imaging voxels were more isotropic, and the 3-dimensional visualization and reconstruction of the data were found to be much better. The use of 4mm slices also was advantageous, as these are less susceptible to partial volume effects. Conversely, the MRI scan procedure did require more time, as the slice thickness was less.

IJO  VOL. 27  NO. 3  FALL 2016

The primary goal of the present investigation was to determine the anatomic risk factors for the sequelae of obstructive breathing disorders, using the state-of-the-art volumetric MRI methods. The core of the present study analysis was formed on the belief that craniofacial anomalies, including mandibular or maxillary retrognathism, short mandibular body, and clockwise rotation of the mandible may lead to reduction of the pharyngeal airway passage. The decreased space between the mandibular corpus and the cervical column may lead to more posterior posture of the tongue and soft palate, which may impair respiratory function during the day and may predispose to possible nocturnal problems such as snoring, upper airway resistance syndrome, and obstructive sleep apnea. Thus, we

performed volumetric and area measurements for airway, tongue, and mandible in different skeletal patterns to find anatomical risk factors from an orthodontic perspective. This would enable orthodontists to recognize potential craniofacial risk factors in patients seeking routine orthodontic treatment who may be at risk to OSA development. It is understood that these measurements cannot detect structural alterations at specific locations, as patients with obstructive sleep apnea have characteristic dentofacial features, but the sites of obstruction differ greatly. Nevertheless, these structural alterations in OSA could be variable; however, the end result, i.e. development of OSA, would be predominant.

Table 5: Multiple regression analysis for OP and NP considering samples from three groups Dependent variable

Independent variables

B Coefficient SE (B)

t-value

P-value

Oropharyngeal volume

BMI

0.065

0.161

0.407

0.686

0.252

3.434

0.001

Area

Nasopharyngealvolume

0.864

Tongue volume

-1.421

0.388

-3.664

0.001

Constant

0.451

1.304

0.346

0.731

BMI

0.117

0.149

0.791

0.434

Area

0.738

0.233

3.172

0.003

Tongue volume

-1.597

0.358

-4.458

< 0.0001

Constant

1.234

1.205

Adjusted R2

0.521

0.561

0.312

Table 6: Prediction of OP and NP using respective regression models* Study group Normodivergent

Hyperdivergent

OSA

Oropharyngeal volume

Nasopharyngeal volume

BMI

Area

Tongue

(kg/m2)

(mm2)

volume (cm3)

Observed

Predicted

Residual

Observed

Predicted

Residual

1.150

3.275

1.881

0.801

0.683

0.118

0.774

0.782

-0.008

1.337

3.351

1.944

0.765

0.670

0.096

0.797

0.758

0.039

1.324

3.322

1.929

0.799

0.666

0.133

0.841

0.759

0.081

1.122

3.346

1.886

0.792

0.734

0.058

0.790

0.822

-0.031

1.426

3.419

1.924

0.776

0.763

0.013

0.760

0.851

-0.091

1.085

3.253

1.869

0.538

0.676

-0.138

0.678

0.777

-0.099

1.167

3.257

1.919

0.565

0.614

-0.048

0.615

0.709

-0.094

1.258

3.271

1.881

0.510

0.686

-0.176

0.622

0.792

-0.169

1.260

3.301

1.881

0.552

0.712

-0.160

0.625

0.814

-0.189

1.300

3.299

1.949

0.583

0.616

-0.033

0.677

0.708

-0.031

1.164

3.366

1.908

0.561

0.723

-0.161

0.509

0.806

-0.297

1.211

3.317

1.954

0.601

0.619

-0.018

0.563

0.703

-0.140

1.242

3.229

1.964

0.536

0.531

0.006

0.520

0.626

-0.106

1.136

3.299

1.919

0.573

0.648

-0.075

0.592

0.737

-0.145

1.419

3.318

1.903

0.594

0.706

-0.112

0.496

0.810

-0.313

Mean

-0.033

-0.106

SD

0.104

0.110

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Scatter plot 1: Correlation between mandibular length and oropharyngeal volume

Scatter plot 2: Correlation of mandibular region area with OP, NP and Tongue volume

The present study was undertaken in order to better understand the correlation between airway, pharyngeal space, jaw morphology, and their probable risk factors which predisposes to OSA and other breathing disorders. For example, a patient seeking routine orthodontic treatment is found to have retrognathia or micrognathia may be at risk for OSA development, as it may result in posterior displacement of the tongue, an inferior position of the hyoid bone, and narrowing of the airway. In this case, truly, volume and area measurements cannot detect structural alterations at specific locations.

However, it can give a direction to the orthodontist towards suspecting airway insufficiency and subsequent referral.

In our study, the pharyngeal dimensions were not affected by sex in any group; this agrees with the findings of Solow, et al.,17 Ceylan and Oktay,18 Linder-Aronson and Woodside,4,19 and Handelman and Osborne.20 CBCT findings have shown that pharyngeal volume and area increases sharply in both sexes during childhood.21 The subjects in the age range of 12–18 years were selected to observe airway differences in growing adolescents with different skeletal patterns. According to Schendel, et al,22 airway dimensions increase until age 20 years; after this, moderate stability is observed. Nearly 90 % of the maxillary and mandibular growth is completed by 12 years of age, so most of the formation or deformation occurs by that age. Between 14 and 18 years, a quiescent period for pharyngeal structures, has been reported whereas growth slowed significantly by adulthood. No growth was discernible in 3-dimensions during adulthood.23-26 In the present study, based on these data, the most stable time period to evaluate mature OP and NP regions seems to be between 12 and 18 years of age.

Uniformity in BMI for each group was matched because obstructive breathing disorder may occur secondary to obesity, and it was necessary to rule out its role. The volumetric analysis confirmed that a significant difference exists between the dimension of pharyngeal volume seen in the Class II hyperdivergent and the OSAS groups as compared with Class I normodivergent cases. We presume that a relatively short and/or posteriorly-placed mandible might force the tongue and the soft palate back into the pharyngeal space, causing a reduction in OP volume, which was evident in the present study.

Our findings for these parameters was similar to the findings of Kerr27 and Kim, et al.,16 whereas, Mergen and Jacobs28 reported that the midsagittal nasopharyngeal area and the nasopharyngeal depth are significantly larger in subjects with normal occlusion

as compared to the Class II malocclusion.

The findings of our study were in contrast to the observations of Ceylan and Oktay18 who reported that the pharyngeal structures were not affected by changes in the ANB angle. Ono, et al 29 reported that in the upright position male patients with Class I OSA showed the most atypical craniofacial and upper airway structures. However, these findings were 2-dimensional and were observed in Western OSA patients, and it is doubtful whether these characteristics are applicable to Indian OSA patients.

46

IJO  VOL. 27  NO. 3  FALL 2016

Another important parameter analyzed in the present study was tongue volume. This has been of considerable interest, as it plays a central regulatory role in the craniofacial complex development. Song and Pae30 in their animal studies suggested that enlarged tonsils increase the upper airway resistance, which might facilitate the activity of the oropharyngeal muscles (genioglossus, mylohyoid, etc.) through mechanoreceptors in the upper airway. This action would bring the tongue forward and downward, opening the mouth for better respiration.

In the present study, the largest mean of tongue volume was found to be in the OSA group. With our findings, we can presume that increased tongue volume can probably be a craniofacial anatomic risk factor for development of breathing disorders and OSA. But this does not rule out that patients with smaller tongue volumes relative to oral cavity size may not have other (e.g. non-anatomic) factors predisposing to breathing disorders and apnea. This possibility warrants further investigation. A larger tongue for a given oral cavity size has been demonstrated in patients with breathing disorders, and it is believed that this situation contributes to increased upper-airway collapsibility by airway narrowing and increased extra luminal tissue pressure. Numerically, an obvious finding is agreed upon, i.e., a big tongue and normal mandible will probably give the same statistical outcome, as will a normal tongue and a small mandible. However, the tongue is a dynamic muscular organ, and hence we cannot directly say that findings are self-evident.

Our findings also confirmed that due to an increased tongue volume, more tongue mass would occupy the upper airway space, and this in turn could make the upper airway more prone to obstruction. This can be true as vice versa also. These findings were in affirmation with the findings of Kondo, et al.31 Our study also evaluated the mandibular dimension, and as per our findings, it was evident that mandibular deficiency is frequently associated with a narrower pharyngeal pathway.

We believe that a retrognathic mandible and decreased space between the cranial column and the mandibular corpus might lead to a posteriorly-postured tongue and soft palate, increasing the chances of impaired respiratory function and possibly causing nocturnal breathing problems. This also supports our hypothesis that in patients with skeletal Class II with vertical growth pattern, as there is retrognathic mandible, this group might be a particularly at risk group for breathing disorder development like snoring and OSA. There is further increased risk if associated with large tongue volume. Cumulatively, these might be considered as risk factors in this population for OSA development.

Adding another dimension to the present investigation, we derived the mandibular area measurements according to the Pythagoras theorem. Use of such derivations has not been reported in the literature in the past. Mathematically, when applied to cases of congenital deformities of the mandible, this theorem does not hold well as the calculations would be extraneous. However, our sample did not include such cases, and hence this theorem was utilized successfully. This derivation was done, primarily, to find out the effect of the glossomandibular area on the development of respiratory dysfunction. It was observed that this area was reduced in the Class II group as well as in the OSA group. This region could be considered as a key craniofacial factor, which needs future attention. We understand IJO  VOL. 27  NO. 3  FALL 2016

that tongue volume for any patient is anatomically determined; however, the mandibular dimensions control the area available for tongue mass to be occupied in the craniofacial complex. This reflexive posture of tongue, mandible, and head can be explained very well with the help of Zipf ’s principle.32 The tongue adjusts physiologically to this area with the help of alterations in position as well as posture. Hence, this area is a crucial determinant of the tongue position, which in turn, would affect the oropharyngeal and nasopharyngeal airway, as discussed earlier.

According to our results, it was evident that an increase in the mandibular length increases the nasopharyngeal and oropharyngeal volume. However there was a negative correlation of mandibular length with the tongue volume. Similarly group wise analysis showed that any increase in mandibular width was associated with smaller oropharyngeal volume in the hyperdivergent group and in the OSA group. Also, a smaller mandibular length and width were significantly associated with larger tongue volumes. We presume that the position of the mandible with respect to the cranial base contributes to the size and volume of the oropharynx.

Recent evidence suggests that the mechanisms underlying apnea are highly variable, with some patients having primarily an anatomic problem. It has been shown that in addition to individual anatomic factors, relationships between softtissue and bony enclosure size are altered, a concept termed anatomic balance.33In an attempt to analyze this balance, we carried our regression analysis to generate a model so as to derive a diagnostic equation for the orthodontist concerned with the airway problems. We presume that this predictive equation might be helpful as a screening aid for orthodontic patients who are at risk for development of OSA. Our data suggests that the size of the mandible, rather than the maxilla or angular measurements, may be a more important risk factor for obstructive disorder and OSA. Anthropologically, some of the findings of the present investigation may be explained by topographical relationships. Differences in craniofacial morphology within and between populations of different backgrounds are a result of complex interactions between genetic and environmental factors that exert their influences during formation and growth of the skull. It is agreed that the function of mastication, which is influenced by the diet, adopted by different population groups, may influence the dimensions of the facial structures as observed by marked differences particularly in the maxillary and mandibular regions. Thus, in order to fully accept the results of the present investigation, it is imperative to compare the same in different ethnic groups and at the same time analyze the anthropological variations.

Also, the inclusion of Class I hyperdivergent subjects and CL II normodivergent subjects in the present study could give a deeper insight into OSA link to orthodontics. However, within the limitations of the current study design, the authors included only Class II hyperdivergent subjects based on extensive review of the literature.

The present knowledge can thus be utilized clinically for treatment of reduced airway space using the derived formula for mandibular dimensions, and also the regression equations can be used as a diagnostic aid in determining the oropharyngeal and

47

nasopharyngeal volume for any individual using 2-dimensional radiographs. Thus, it was concluded that a direct correlation exists between the airway volume, mandibular dimensions, and tongue volume in different craniofacial growth patterns. Also, the Class II hyperdivergent group was found to be at risk for OSA development according to craniofacial risk factors.

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Dr.Krishna Sharma, MDS, is an Assistant Professor, Orthodontics and Dentofacial Orthopaedics at Sharad Pawar Dental College, Wardha. Dr. Sharma has received his certificate from Academy of General Dentistry, USA. Fellowship Cleft Orthodontics Smile Train USA 2013 and 3M Incognito Lingual Certification 2014. He has many published articles.

IJO  VOL. 27  NO. 3  FALL 2016

FEATURE

This article has been peer reviewed.

Esthetic versus Function in Early Treatment of Class III Malocclusion

By Marlene Thompson, DDS Abstract: A comparison of two Class III malocclusion cases corrected with a modified tandem appliance reveals the importance of critical esthetic concerns in diagnosing and developing a treatment plan. Because the device employs a rapid palatal expander, it creates interproximal spaces in the case of narrow tooth morphology or size discrepancy.

Keywords: Modified Tandem Appliance; Class III Malocclusion; Interceptive Orthodontics; Early Treatment; Tooth Morphology

ntroduction In solving a case of Class III malocclusion, there is more to consider than routine diagnostic treatment.

Two cases are presented--similar in every respect except for tooth morphology. In the first case, Class I occlusion was achieved with good esthetics: the size and width of teeth are in harmony. In the second case, Class I occlusion was achieved; however, regarding esthetics, the patient’s mesio-distal width is too narrow relative to her profile. This resulted in interproximal spaces in the anterior segment.

Case 1 In the first case, an eight year-old boy, the chief complaint involved lower front teeth displacement. The patient was diagnosed with developing deep anterior overbite Class III malocclusion. The objective for him was to increase the size of the maxilla by forward movement and reduce the growth and size of the mandibular, and thereby improve facial esthetics. This would correct the anterior cross-bite and reestablish functional occlusion. I proceeded with a rapid palatal expander in order to

correct the size of the maxilla.1 The upper section of this device is fixed and consists of a maxillary banded hyrax appliance with buccal arms soldered with two hooks for Class III elastics, mesial to the first primary molars. The lower section is similar to a removable retainer with lower bows, which insert into a buccal tube in the acrylic in the area of the first permanent molars with occlusal bite blocks. Good function and occlusion were achieved as well as a healthy TMJ and a well-balanced face. 2 Case 2 In the second case, a thirteen year-old female, the chief complaint was also lower tooth displacement but primarily on the right side. The first objective was to correct the anterior cross-bite; this would improve her facial profile and the skeletal jaw relationship. Again, the modified tandem appliance was employed ; however, her upper frenum needed to be excised before treatment in order to achieve closure of the anterior teeth.

The objectives were met and in half the time required in the first case. Her cross-bite was corrected; her facial profile was improved, and she had a healthy TMJ and functional occlusion.

Because of the expansion in her maxilla, however, her tooth size discrepancy caused interproximal diastemas in the anterior segment. In order to achieve complete esthetics in this case, porcelain or composite veneers for the anterior segment were proposed.

Figures 1-3: Pre-treatment extra-oral photographs

Figures 4-6: Pre-treatment intra-oral photographs Figure 9 -11: Pre-treatment extra-oral photographs

Figures 7 and 8: Post-treatment extra-oral photographs IJO  VOL. 27  NO. 3  FALL 2016

Figure 12-14: Pre-treatment intra-oral photographs 49

The Literature In the critical review article, “The Myth of Instant Orthodontics,”3 decisions about achieving occlusion versus esthetics are considered within an ethical framework. The practice of bypassing orthodontic methods and surgically achieving esthetic results often causes other problems including nerve damage, high sensitivity, and temporary discomfort.

Certainly orthodontic methods alone do not achieve perfect esthetics but in the majority of cases can achieve function and beauty. The author concurs with my finding in the second case: “Interproximal space may result from tooth-arch-size discrepancies in which the size of the anterior teeth is small in comparison with the size of the alveolar ridge, from an anterior-tooth-size discrepancy in which the maxillary anterior teeth are small in comparison with the mandibular anterior teeth or from adjacent teeth with divergent crowns.” 3 In order to achieve beauty, which is often the underlying motivation of my patients, I have found that orthodontic treatment may need to be supplemented with cosmetics. Although I might be satisfied with functional achievements, such as a healthy TMJ or functional occlusion, the patient will expect more, particularly esthetically; and, I need to be sensitive to and try to balance our different conceptions of beauty.

Other clinicians might approach these Class III cases with other appliances, such as a RPD with posterior bite planes and facemask protraction.4 This is considered a very aggressive treatment. Another approach is using a petit facemask therapy with reverse pull headgear in combination with or without RPD.5 I find facemasks to be uncomfortable, and this often results in patient non-compliance, inhibiting our objectives.

A third device is a reversed twin block, a less powerful means of achieving maxilla development . 6 This is better for milder cases of pseudo Class III malocclusion. Even if these types of treatment had achieved the desired functional objectives in Case 1 and Case 2 above, it would not have solved the esthetic problems of Case 2.

50

Conclusion I have presented these two cases as examples of the complexity of the decision-making involved in interceptive orthodontics. There is in most cases a tension between the esthetic and functional concerns. This is complicated by differences of opinion regarding beauty among the dentist, the patient, the orthodontic community, and society in general. Finally, all decisions have both monetary and ethical components. The appliances used in interceptive orthodontics achieve excellent results in maxillary and mandibular corrections; nevertheless, cosmetic dentistry is sometimes required.

References 1.

2.

3.

4.

5.

6.

Kempler L. Early treatment of skeletal Class III open bite with tandem appliance. JCO 2011; 308-316.

Champagne M. Esthetics and ethics in orthodontics. IJO 2002; 13(3) 3: 5-6.

Jacobson N, Frank CA. Critical review. The myth of instant orthodontics.

An ethical quandary. JADA 2008; 139: 424-433.

Kumar A, Rohilla A, Tandom P, Nager A. Early treatment of Class III malocclusion. IJO 2014; 25: 41-45.

Aileni KR, Rachala MR. Early treatment of class III maloclussion with petit facemask therapy. IJO 2011; 22: 41-46.

Kumar A, Tandom P, Singh GP. Management of pseudo Class III malocclusion—Synergistic approach with fixed and functional appliance.

IJO 2013; 24(2): 41-44.

Dr. Marlene Thompson received a dental degree from San Martin de Porres University, Lima, Peru. She is currently practicing dentistry in Escondido, California. She enjoys helping young people achieved their orthopedic goals.

IJO  VOL. 27  NO. 3  FALL 2016

FEATURE

This article has been peer reviewed.

Oropharyngeal Airway: The Orthodontist Perspective

By Ashish Agrawal, MDS; T P Chaturvedi, MDS; Midhun Raghav, BDS, Post Graduate Student (MDS)

Abstract: Dentofacial morphology can be altered by nasorespiratory obstruction depending on the magnitude, duration, and time of occurrence. More recent findings suggest that nasal-oral breathing per se is not necessarily harmful to craniofacial growth. However, in instances where the nasopharyngeal or oropharyngeal airspace is small, exaggerated postural responses in obligatory mouth breathers may be detrimental to craniofacial growth. Extended head posture which was observed in mouth breathers is found to influence the position of the mandible. Deviated nasal septum , allergies , chronic infection , hypertrophied inferior turbinates, adenoidal pad, and faucial tonsils hypertrophies are the common etiological factors affecting the pharyngeal airway. The orthodontist will be the first clinician to attend the child to observe any change in the breathing pattern such as mouth breathing during examination or during the treatment. The cause of nasal obstruction in children can usually be determined by a thorough history and physical exam. The goals of the evaluation are to determine specific causes of problems, the severity of the obstruction, and the presence of associated medical complications. Rapid expansion exerts its effect by dilating the anterior nares, through the preferential expansion of the anteroinferior aspect of the nasal cavity. A mean decrease in nasal resistance has been demonstrated after surgical maxillary impaction. Airway can be evaluated by physical examination, functional examination, and different imaging techniques such as CT, MRI, cephalometry, acoustic reflection, nasal pharyngoscopy, and fluoroscopy. A multidisciplinary approach involving orthodontist, oral and maxillo facial surgeon, ENT surgeon, and sleep study researchers is needed for management.

Keywords: Oropharyngael Airway;Craniofacial Devolopment;Orthodontic Appliance

ntroduction The position of the maxilla and mandible with respect to the cranial base and soft tissue covering it determines facial morphology. The pharyngeal airway, which has a role in shaping facial morphology, has been the area of interest to the orthodontist for decades. The manner in which the airway affects morphology and malocclusion is a controversial issue. Some authors 1-3 believe that the airway has an important role to play in shaping facial morphology, whereas others4 say it does not have any relationship with it. Genetic and environmental factors (posture of the tongue, breathing patterns) are some of other factors responsible for the aberrant growth pattern of the dento-facial complex.5 Any change in the respiratory pattern, such as mouth breathing, can provoke a deviation in normal posture of the head, jaw, and tongue. The altered position changes the equilibrium of pressures within and outside the oral cavity which manifests as malocclusion.

According to functional matrix theory, growth of the face occurs as a response to functional needs and is under neurotropic influences which are mediated by the soft tissues in which the jaws are embedded.6 De Frietas,7 Muto,8 and Anegawa9 have analyzed the dimensions of the upper airway in patients with different sagittal and vertical skeletal discrepancies using lateral cephalograms.

These studies evaluated the airway in 2-dimensional (2D) cephalograms which provided limited data such as linear and angular measurements for a complex 3-dimensional structure.10 In the lateral head film, measurements are taken from specific IJO  VOL. 27  NO. 3  FALL 2016

cephalometric landmarks, superimposition makes it difficult to identify and measure. Moreover, due to variations in 3D airway anatomy such as protrusion of the inferior turbinate into the nasopharynx, it becomes difficult to exactly measure in 2D techniques11 (Figure 1).

Anatomy (Orthodontics Perspective) The pharynx is a tube-shaped structure formed by the muscles, bony housing, cartilage, and the soft tissue covering it.

Its length is approximately 12-14 cm. It is located behind the nasal and oral cavities and the larynx, and it extends from the cranial base to the level of the sixth cervical vertebrae and the lower border of the cricoid cartilage. The pharynx is divided into three parts: nasopharynx, oropharynx, and laryngopharynx.

The nasopharynx forms the upper part of the respiratory system and lies above the soft palate and behind the posterior nares, which allows free respiratory passage between the nasal cavities and the nasopharynx. The adenoid is a median mass of mucosaassociated lymphoid tissue, which is situated on the roof and posterior wall of the nasopharynx. The nasal and oral parts of the pharynx communicate through the pharyngeal isthmus which lies between the posterior border of the soft palate and the posterior pharyngeal wall. The palatine tonsils are present in the oropharynx and are dense, compact bodies of lymphoid tissue that are located in the lateral wall of the oropharynx.

The isthmus extends from the 2nd cervical vertebrae to the 4th cervical vertebrae. The laryngopharynx is situated behind the entire length of the larynx and extends from the superior border 51

Figure 1

Figure 2

Figure 3 52

of the epiglottis, where it is delineated from the oropharynx by the lateral epiglottic fold12 (Figure 2).

Allergies, enlarged adenoids and tonsils, and deviated nasal septum can be a few reasons for altered breathing habits. However, it has been seen that mouth breathing can also be present in the absence of the above etiologies; therefore, it is imperative to find out whether mouth breathing is habitual or obligatory. The change from nasal to oral breathing occurs when the nasal cross-section area13 is < than 0.4cm. However, this is not a universal finding, as we know that the dimension of the nasal airway changes with growth and varies widely among individuals.

There are controversies about the growth of the adenoids-- few studies suggest that the adenoids grow gradually until 10-12 years of age, and then they regress; other investigators believe it to be maximum in size in an age range of 2-7 years and then regress. If the etiology of mouth breathing is due to enlarged adenoids, this has to grow about 2 -3 mm for it to obstruct the oronasal isthmus.14 However, changes in the soft tissue lining the oropharyngeal airway (OPA) alone can cause changes in the pattern of breathing. These are dynamic erectile tissues whose thickness can be altered by the amount of fluid and blood flow in it. A longitudinal study done by Linder -Aronson and Leighton15 showed that the growth of soft tissue of the oronasal airway shows dual pattern, i.e. initially there is gradual increase in size until 5 years and then decreased after 5 years and until 10 years; thereafter the size increases in thickness until 11 years of age which is due to increase in the lymphatic. However, there is a general consensus among investigators that the size of the oronasal airway decreases pre-pubertally which can be due to the effect of changes in levels of sex hormones within the soft tissue. These sex hormones (gonadotropins) include luteinizing hormone (LH), follicle stimulating hormone (FSH), estradiol (E2), and testosterone (T).

The head position has a profound effect on the pharyngeal airway (especially the lower pharyngeal airway16 ) and therefore, it is important to orient the patient properly in the cephalostat. Studies have shown that natural head position can alter in the same individual at different point in time and may also vary among individuals.17 Diagnosis Equilibrium theory gives an insight into the balance of forces between muscles which are believed to influence the position and stability of the dentoalveolar complex. Solow and Krieborg18 IJO ď Ž VOL. 27 ď Ž NO. 3 ď Ž FALL 2016

Table 1: Factors Compromising the Airway CONGENITAL: Down Syndrome

Poorly developed bridge of nose, macroglossia

Treacher-Collin syndrome, Goldenhar’s syndrome Articular and ocular defect, Malar and mandibular hypoplasia Pierre-Robin syndrome

Micrognathia, macroglossia, cleft soft palate

ACQUIRED DEFECTS: Infections

Ludwig’s angina, supraglottis, Abscess (intra oral or retropharyngeal)

Arthritis

Rheumatoid and ankylosing arthritis

Benign tumors

Cystic hygroma, lipoma, adenoma, goiter

OTHER FACTORS INCLUDES: Facial injury

Hematoma, unstable fracture of maxilla and mandible

Obesity

Short and thick neck, redundant tissues of oropharynx

Acromegaly

Macroglossia, prognathism

Acute burns

Edema of airway

put forward their “soft tissue stretch theory” in which they suggested that the obstruction of the airway is a major causative factor in determining the facial morphology; therefore, airway evaluation is of the utmost importance. The airway can be evaluated by physical examination, functional examination, and different imaging techniques such as CT, MRI, cephalometry, acoustic reflection, nasal pharyngoscopy, and fluoroscopy.

Anatomical Assessment: (Orthodontic Importance) The Mallampatti test19 is a relatively simple test that can be routinely done during orthodontic examination procedures.

It is a test which correlates the size of the tongue in regard to pharyngeal tissues. The test is performed with the patient in the sitting position, head in a natural position, mouth open, and tongue protruding to its maximum. The patient should be told not to make any vocal sound while protruding the tongue. The assessment is made on the extent to which the base of the tongue can mask the pharyngeal structures: Class 1: Visualization of soft palate, fauces, uvula, anterior and posterior pillars Class 2: Visualization of soft palate, fauces, and uvula Class 3: Visualization of soft palate and base of uvula Samsoon and Young20 added Class IV: Class IV: Only hard palate is visible, and soft palate is not visible Physical Examination Physical examination mainly focuses on pharyngeal anatomy including the lateral wall, soft palate, uvula, and tongue volume. There are different chair side methods to assess the mode of respiration which includes water holding test, mirror condensation test, and cotton whip test.

Radiological Examination 1. Lateral cephalogram: Although the pharynx is a three dimensional structure, a cephalogram is a useful tool in the hands of an orthodontist. It is important to orient the patient in a natural head position. Measuring different region IJO  VOL. 27  NO. 3  FALL 2016

of the pharyngeal airway and correlating it to the various morphological structures is a method of studying the airway and its effects on skeletal structures. Various measurements include the position of the mandible and maxilla relative to the cranial base, position of the hyoid bone, measurements at various levels of the pharyngeal airway, and anterior and posterior facial height orientation on the mandibular plane, etc. Lateral x-ray is an important tool in predicting post-operative results of uvulopalatopharyngoplasty (UPPP).21 2. Computerized Tomography (CT): The images can be generated in all the planes (especially in the retropalatal and retrolingual regions which can be clearly visualized). A 3D model can be generated (Figure 3). Volumetric analysis of both the tongue and airway can be assessed and compared.

Any pathological condition such as nasal polyp, deviated nasal septum, or tumors can be diagnosed. CT imaging has been widely used in sleep apnea studies, but the major disadvantage of it is high radiation and poor resolution.

3. Magnetic Resonance Imaging (MRI): MRI helps in detecting lateral narrowing of the pharyngeal airway, especially in obstructive sleep apnea (OSA) patients. The major axis is abnormally oriented in the anterior and posterior dimension and could increase the airway collapsibility.22 Dynamic MRI has also been used to evaluate upper airway during sleep for research purposes in order to explain the patho-physiology of airway constriction.

Rhinomanometric examination23 is the most objective way for assessing the nasal airway. Simultaneous recording of transnasal pressure and airflow is done. There are three different methods by which rhinomanometric can be done: anterior, posterior, and postnasal rhinometry. The measurements can be recorded on strip charts, x- y plotters on computer, or oscilloscope. SNORT (simultaneous nasal and oral respiratory technique) is a highly reliable technique for recording respiratory modes. Both oral and nasal respiration can be recorded and calibrated simultaneously.

53

Etiology And Effects Of Deranged Airway On Facial Morphology Chronic respiratory obstruction can be produced by prolonged inflammation of the nasal mucosa associated with allergies or chronic infection (Table 1). It can also be produce by mechanical obstruction anywhere within the naso-respiratory system. The pharyngeal tonsils or adenoids normally are larger in children, and partial obstruction from this source may contribute to mouth breathing in children.6 The nasopharynx and oropharynx have significant location and function because both of them form a part of the unit in which respiration and deglutition are carried out, and they include lymphoid tissues in their structures. Nasal obstruction secondary to hypertrophied inferior turbinates, adenoidal pad hypertrophy, and hypertrophy of the faucial tonsils can cause chronic mouth breathing, loud snoring, and obstructive sleep apnea.24 In this situation, a number of postural changes, such as open mandible posture, downward and forward positioning of the tongue, and extension of the head can take place. If these postural changes continue for a long period, especially during the active growth stage, dentofacial disorders at different levels of severity can be seen, together with inadequate lip structure, long face syndrome, and adenoid facies.2, 3 Norland25 through his “compression theory” says that in mouth breathing patients there is constriction of the maxillary arch which is responsible for the lowered position of the tongue in order to facilitate breathing. A lowered tongue is less capable of balancing the lateral pressure of the cheek muscles of the maxillary arch thereby bringing about changes in facial structures.

It has been postulated that a functional adaptation, which facilitates mouth breathing, occurs where there is difficulty with nasal breathing. In order to breathe through the mouth, it is necessary to lower the mandible and tongue and extend the head. If these postural changes were maintained, face height would increase, and posterior teeth would supra erupt; unless there were an unusual vertical growth of the ramus, the mandible would rotate down and back, opening the bite entirely and increasing the overjet--an increased pressure from the stretched cheeks might cause a narrower maxillary dental arch.3,6 Solow and Krieborg 18,26 suggested that any change in the craniofacial skeletal structure from its natural position will induce a stretch or tension on the soft tissues which covers the skeletal part—this ultimately results in variation in orofacial morphology. In patients with nasal obstruction, the soft tissues will rotate the mandibular body in a downward and backward fashion, thus increasing anterior facial height. There will be a change in the position of the hyoid bone, and this will lead to a lowered tongue position.

Obstructive sleep apnea is a syndrome characterized by a constellation of signs and symptoms related to arterial oxygen desaturation and sleep fragmentation caused by pharyngeal obstruction during sleep.27 A small upper airway can be caused by the relative positions of the maxillofacial skeletal structures and of the dental arches to one another and to the cranial base.28 The importance of this obstruction in the development of many childhood problems is increasingly recognized. OSA in children is associated with excessive daytime sleepiness, hyperactivity, attention deficit disorder, poor hearing, physical debilitation, and failure to thrive.29 54

Various Orthodontic Treatment Modalities and Their Effects on Oropharyngeal Structures The assessment of the pharyngeal structures should be included with the orthodontic diagnosis and treatment planning as functional, positional, and structural assessment of the dentofacial pattern. Orthodontists play a significant role in the management of potential irregularity results from the impaired pharyngeal airway.

Maxillary expansion has been shown to decrease upper airway obstruction during sleep in young adults with mild or moderate obstructive sleep apnea.30 Garib et al31 suggested that the improvement of nasal breathing after rapid maxillary expansion (RME) occurs due to the anterior and inferior dislocation of the maxilla. Whereas, according to Langer et al,32 RME does not influence the nasopharyngeal area or nasal airway resistance in long term evaluation.

The effects of headgear treatment on the upper airway space seem to be limited to the nose, nasopharynx, and retropalatal area. Although the principal idea of headgear treatment is to restrict forward growth of the maxilla, treatment does not restrict the growth of the palatal plane. The cervical headgear treatment increases the retropalatal airway space, but it does not significantly affect the rest of the oropharynx or hypopharynx in children with Class II malocclusion without retrognathia.30 Face masks affected both the maxilla and mandible. Elastic forces applied to the upper dentition stimulated forward growth of the maxilla and moved the maxillary teeth forward, while the reciprocal forces acted on the mandible and caused a rotational clockwise effect. Class III patients treated with reverse pull headgear show an increase in nasopharyngeal airway volume and improved respiratory function in patients with maxillary hypoplasia.33, 34,35 Orthodontic patients with severe sagittal discrepancies may require surgical management as well. Mandibular distraction osteogenesis in a micrognathic mandible increases mandibular volume and advances the hyoid bone and upper airway volume. This will reduce airway obstruction and thus eliminate symptoms of OSA.36 Whereas, according to Hamada et al,37 mandibular distraction osteogenesis in Class II patients does not change the volume of the upper airway, but it shows an enlarged velopharynx associated with treatment. Surgical maxillary expansion can be done in two ways: maxillary transverse distraction osteogenesis or segmental Lefort I osteotomy. The expansion produced by Lefort I osteotomy is very limited, but maxillary distraction osteogenesis can produce as much as 12 mm of expansion thereby increasing the upper airway space.

Transverse bimaxillary distraction osteogenesis followed by maxilla-mandibular advancement significantly reduces OSA symptoms and increases upper airway volume.38 The advantage of bimaxillary distraction osteogenesis is that dental occlusion can be controlled because both jaws are being moved. Another surgical option is uvulopalatopharyngoplasty where a part of the soft palate and surrounding oropharyngeal tissues are surgically resected to prevent them from obstructing the pharyngeal airway space.39 The mandibular protraction appliance is used in patients with retrognathic or retro positioned mandibles who are not candidates for orthognathic surgery or continuous positive airway pressure therapy. The mandibular protruding device is a IJO  VOL. 27  NO. 3  FALL 2016

removable orthodontic appliance; it brings the mandible forward along with the soft tissue structures associated with the mandible such as tongue, pharyngeal dilator muscles, and indirectly the soft palate leading to increase in the oropharyngeal airway.39,40,41 Discussion Hakan et al,1 Mcnamara,2 and Kerr3 investigated and demonstrated that there are statistically significant relationships between the pharyngeal structures and development of craniofacial structures. Hakan et al1 observed that the oropharyngeal and nasopharyngeal airway volume in Class II patients is significantly lower than other patients. He also found that mandibular position with respect to the cranial base has an impact on the oropharyngeal airway whereas Ceylan et al24 investigated that there are no appreciable variations of pharyngeal size in different skeletal morphologies.

Tomonori et al29 carried out a study on pharyngeal airway space and found that children with Class III malocclusion had significantly larger oropharyngeal airways compared with those with Class I malocclusion. In that, 84% of children with Class I malocclusion had a square OA, 70% of the children with Class III malocclusion had a flat-shaped one.

The oropharyngeal airway volumes of Class II patients were smaller when compared with Class I and Class III patients.

It was observed that mandibular position with respect to the cranial base had an effect on the OP airway volume. The only significant difference in the NP volume was among the Class I and Class II groups.1,7,8,30,42 The mid-sagittal nasopharyngeal area observed in young subjects with Class II malocclusions was found to be smaller than the corresponding area in subjects with normal occlusion. The number of concavities and convexities of the posterior pharyngeal wall observed in the two groups also differed significantly--more concavities were found in the Class I group than in the Class II group.43 Conclusion It is important to correctly diagnose and determine the exact etiology of an orthodontic patient suffering from an abnormal breathing pattern during functional examination. A multidisciplinary approach involving an orthodontist, oral and maxillo facial surgeon, ENT surgeon, and sleep study researchers is needed for its management. The pharyngeal airway volume of retrognathic maxilla or mandible patients is significantly smaller than that of patients with normal sagittal and transverse skeletal relationships. There are different modalities of treatments in orthodontics which do have a profound effect in altering the volume of the oropharyngeal airway. Judicious selection of a treatment modality will not only correct the skeletal derangement but will also have a positive effect on the pharyngeal airway.

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Kaygısız E, Balos B¸ Tuncer S, Yuksel, C Tuncer,. Effects of Maxillary Protraction and Fixed Appliance Therapy on the Pharyngeal Airway. Angle Ortho. 2009; 79(4):660-667.

Rachmiel A, Aizenbud D, Pillar G, S. Srouji M. Bilateral mandibular distraction for patients with compromised airway analyzed by threedimensional CT. Int. J.Oral Maxillofac. Surg. 2005; 34: 9–18.

Hamada T, Takashi O, Otsuka R, Honda E, Harada K, Kurabayashi T, Ohyamag K.. Mandibular distraction osteogenesis in a skeletal Class II patient with obstructive sleep apnea. Am J Orthod Dentofacial Orthop 2007; 131:415-25.

Conley RS, Legan HL.Correction of severe obstructive sleep apnea with bimaxillary transverse distraction osteogenesis and maxillomandibular advancement. Am J Orthod Dentofacial Orthop. 2006; 129:283-92.

Haskell JA, McCrillis J, Haskell BS, Scheetz JP, Scarfe WC, Farman AG. Effects of Mandibular Advancement Device (MAD) on Airway Dimensions Assessed With Cone-Beam Computed Tomography. Semin Orthod 2009; 15:132-158.

Acar M, Saylisoy S, Turhan S, Cingi C, Yazgi A, Karabag A, Türkcan I. .Comparison of the effects of mandibular protruding devices on obstructive sleep apnea patients and healthy volunteers. Journal of CranioMaxillo-Facial Surgery 42 (2014) 1465e-1468.

Tsuiki S, Lowe AA, Almeida FR, Fleetham AJ. Effects of an anteriorly titrated mandibular position on awake airway and obstructive sleep apnea severity. Am J Orthod Dentofacial Orthop 2004; 125:548-55.

Alves M, Franzotti ES, Baratieri C, Nunes LKF, Nojima LI,. Ruella ACO: Evaluation of pharyngeal airway space amongst different skeletal patterns.

Int. J. Oral Maxillofac.Surg. 2012; 41: 814–819.

Jacobs M. The size of nasopharynx associated with normal occlusion and class II malocclusion. Angle Ortho.1970; 40(4):342-6.

Dr. Ashish Agrawal, BDS, MDS (Orthodontics and Dentofacial Orthopedics) is an Assistant Professor, Faculty of Dental Sciences at Banaras Hindu University, Varanasi India.

Dr. T. P. Chaturvedi, BDS, MDS (Orthodontics and Dentofacial Orthopedics), PhD (IIT, BHU) is a Professor and Faculty of Dental Sciences Banaras Hindu University, Varanasi India.

Dr. Midhun Raghav, BDS, Post Graduate Student (MDS), Orthodontics and Dentofacial Orthopedics is a member of the Faculty of Dental sciences Banaras Hindu University. Varanasi India.

IJO  VOL. 27  NO. 3  FALL 2016

FEATURE

This article has been peer reviewed.

Fixed Orthodontic Treatment in Mandibular Lateral Incisor-Canine Transposition

By Alkan Özer, PhD; Yüzbaşıoğlu Betül, PhD; Kaya Yeşim, PhD

Abstract: Transposition, which is a dental anomaly, is defined as a positional interchange of two adjacent permanent teeth found on the same dental arch. In this case report, we present the outcomes of fixed orthodontic treatment in a patient with unilateral mandibular lateral incisor-canine transposition. Following orthodontic treatment, transposed teeth were placed into their normal anatomical positions on the mandibular dental arch by applying mild orthodontic forces, and smile esthetics was restored with ideal, Angle’s Class I occlusion.

Keywords: Fixed orthodontic treatment, transposition.

ntroduction Transposition, which is characterized by a positional interchange of two adjacent permanent teeth found in the same dental arch, is quite a rare dental anomaly.1,2 Dental transposition is defined in two different ways: as complete transposition and incomplete transposition, according to the positions of the crown and root of the involved teeth.1 In cases with complete transposition, both crowns and roots of the teeth are in transposed position. In incomplete transposition cases, while crowns of the teeth are in transposed position, root apices are in their normal positions.1,3 In transposition cases, five maxillary4 and two mandibular2 transposition types have been identified in the classification system based on the involved teeth.

The etiology of dental transposition remains unclear.1,5,6 However, positional changes during the development of permanent teeth germs, traumas in early childhood, early loss of deciduous teeth, delayed root resorption of deciduous teeth, physical barriers to eruption pathways of permanent teeth, and genetic factors have been asserted as possible etiological factors for transposition. 2,5-8 The mean prevalence of dental transposition has been reported to be 0.33%.9 No difference was found between genders in the prevalence of dental transposition. However, maxillary and unilateral transposition was found to be more common than mandibular and bilateral transposition, respectively. 9 In cases with Mn.I2.C dental transposition, the prevalence has been reported to be just 0.03%.10 Distal tipping, distal displacement, and rotation were determined in mandibular lateral incisors that show deviation from the normal path of eruption, whereas mesial transposition was detected in mandibular canines.1,2,11 In this case report, the outcome of fixed orthodontic treatment performed in a patient with unilateral Mn.I2.C dental transposition, which is quite rare, is presented.

IJO  VOL. 27  NO. 3  FALL 2016

Case Presentation A 13 year-old female patient was admitted to our clinic with esthetic concerns about her teeth. The patient had good oral hygiene; clinical examination revealed a convex profile, Angle’s Class I molar relationship, 6 mm overjet, 5 mm overbite, and 2 mm deviation of the mandibular midline to the left. Severe crowding was observed in the mandibular and maxillary arches along with unilateral complete transposition of 32 and 33 (Figures 1 and 2). In model analysis, there was a 7 mm lack of space in the maxillary and a 5 mm lack of space in the mandibular dental arches (Figure 2). Panoramic radiograph demonstrated that all permanent teeth were present including the third molar teeth. Moreover, there were amalgam restorations in 46 and 47 and dilaceration of the root of 12.

In cephalometric analysis, a growth model of perpendicular direction and skeletal Class II relationship, compensated with the protrusion of the lower incisors, were noted (Figures 3 and 4).

Treatment Objectives The goals of fixed orthodontic treatment with planned extraction of 4 premolar teeth were based on the analysis of orthodontic material collected at the beginning of treatment.

The treatment objectives were: 1. Elimination of the severe crowding in the mandibular and maxillary dental arches 2. Placement of the teeth, which were located in unilateral Mn.I2.C transposition in the mandibular arch, into their normal anatomic positions 3. Restoration of smile esthetics with Angle Class I occlusion by correcting increased overjet and overbite Treatment Alternatives There are different options for orthodontic treatment of dental transposition cases. These therapeutic options include preventive treatments that can be performed when dental 57

transposition is diagnosed early in the 6- 8 year age group;12 leaving involved teeth in the transposed position and then reshaping of the teeth by conservative restoration after orthodontic treatment;3,5,12-14 orthodontic correction following the extraction of one or two transposed teeth due to crowding or tooth decay;5,12,14 and, placement of transposed teeth into their correct anatomical positions in the dental arch by means of orthodontic tooth movements. 3,5,12-14 While planning treatment, factors such as position and development stage of root apices of transposed teeth, tooth morphology, current occlusal situation, facial esthetics, and duration of treatment need to be evaluated.12

Figure 1: Pre-treatment facial and intraoral photographs

Figure 2: Pre-treatment dental cast photographs

Figure 3: Pre-treatment radiographs and the panoramic radiograph show a developing transposition 58

Treatment Progress Alignment of the transposed teeth into their normal positions in the arch, which is considered to be a more difficult treatment approach due to the esthetic concerns of the patient, was preferred.

After the planned extraction of 4 premolar teeth, 018 fixed slot brackets were used. Round Niti archwires, which apply a mild force, were used during the leveling phase of treatment, and laceback placements were performed for canines.

Tooth number 33, which was one of the transposed teeth in the mandible, was moved in the distal direction towards the extraction space using open coil, and the rotated tooth 32 was corrected by applying a force couple using an elastic chain. At 8 months of orthodontic treatment, after providing adequate space for 32, which had serious distal tipping and displacement, it was moved towards its ideal anatomical position with mild orthodontic forces (Figure 5). Over the course of active treatment, which lasted for 3 years and 1 month, the patient was scheduled for control visits at 3-4week intervals. Essix plates were used in the upper and lower dental arches in the retention phase of the treatment.

Treatment Results When the orthodontic material collected at the end of treatment was evaluated, it was determined that the severe crowding in the upper and lower dental arches was eliminated, both crowns and roots of teeth in Mn.I2.C transposition in the unilateral mandibular arch were placed in their normal positions with mild orthodontic forces, increased overjet and overbite were corrected, and smile esthetics was improved

by Angle Class I occlusion. This suggests that fixed orthodontic treatment performed with the extraction of 4 premolar teeth achieved the specified goals (Figures 6 and 7).

Panoramic radiographs taken at the end of the treatment revealed that dental roots IJO ď Ž VOL. 27 ď Ž NO. 3 ď Ž FALL 2016

were parallel to each other, and periodontium and surrounding tissues were healthy. After fixed orthodontic treatment, no pathological condition such as resorption was observed in the roots of the transposed teeth. Data of cephalometric analyses performed pre-treatment, post- treatment, and one year following the retention period are demonstrated in Table I (Figures 8, 9, and 10).

Figure: 4. Pre-treatment lateral cephalometric radiograph with tracing

Figure 5: Biomechanics used to correct transposition

Table 1. Cephalometric measurements Pre-treatment

Post-treatment

Post-retention

(T0)

(T1)

(T2)

SNA (°)

82.2

83.0

83.0

SNB (°)

73.0

74.6

74.6

ANB (°)

9.2

8.4

8.4

SN-MP (°)

37.6

40.6

40.6

FMA (°)

30.1

33.0

33.0

1 to SN (°)

92.2

88.6

88.6

1 to NA (°)

9.9

5.6

5.6

1 to NA (mm)

0.9

-2.4

-2.3

1 to NB (°)

29.0

27.5

27.5

1 to NB (mm)

5.2

4.2

4.2

1 to MP (°)

91.6

90.0

90.0

Upper Lip to E-Line (mm)

2.0

0.5

0.5

Lower Lip to E-Line (mm)

3.9

1.2

1.2

Measurements

IJO  VOL. 27  NO. 3  FALL 2016

Discussion Canine teeth, which are located in the normal anatomical position on the dental arch, are of great importance for both smile esthetics and mastication function.2,3,15 On the contrary, it has been observed that eruption problems in canine teeth are more prevalent when compared to other teeth during the eruption period, due to undefined etiology.1,3 Transposition of teeth, which is just one of these problems, is quite rare and is also defined as ectopic eruption.2 It has been reported that tooth transposition cases are multifactorial including both genetic and environmental factors.16 It has been stated that Mn.I2.C tooth transposition develops due to deviation of the permanent lateral tooth from its normal path of eruption after early loss of the first molar deciduous tooth. It then moves towards the distal through the lingual aspect of the lateral deciduous tooth and the canine deciduous tooth and erupts over the first permanent premolar tooth. 2,5,17 It has been reported that the incidence of mandibular tooth transposition, which is known to be less than 1%, is lower than the maxillary type.2,9 Increased mandibular bone density has been considered to be responsible for this situation in tooth transposition.12 This case report demonstrates the outcomes of orthodontic treatment in a typical Mn.I2.C unilateral transposition case, as described

by Peck, 2 and this is not often encountered.

While planning treatment for transposition cases, patient’s age, periodontal supportive tissues, occlusion, estimated duration of treatment, and patient cooperation should be precisely evaluated.

In addition, position and slope of the roots of transposed teeth and surrounding bone tissue should be evaluated.3,15,18 In order to obtain ideal outcomes from orthodontic treatment in terms of esthetics and function, placement of the transposed teeth into their normal anatomical positions is recommended.3,13,15 However, as this is not practical and not always possible, Mn.I2.C tooth transpositions can be orthodontically treated by various therapeutic options.3,5,13,19 Protective orthodontic treatment should be initiated if transposition, which develops as a dental anomaly, is recognized early between the ages of 6-8 years.1 First, the persistent deciduous tooth is extracted in order to guide the path of the eruption of the ectopic permanent tooth to its normal position in the dental 59

Figure 6: Post-treatment facial and intraoral photographs

Figure 7: Post-treatment dental cast photographs

Figure 8: Post-treatment radiographs 60

arch. The space needed for mandibular canine tooth should be preserved over the course of the eruption process.1,3,5,17 It has been reported that placement of transposed teeth into their ideal positions might cause a number of pathologies in the transposed teeth and the surrounding periodontal tissues in cases with mandibular transposition involving permanent canine teeth eruption. In such cases, leaving the teeth involved in the transposed position and reshaping the teeth by conservative restoration after orthodontic treatment is the method commonly preferred.1,3,13,19 It was stated that, in the case of transposition and crowding, one of the transposed teeth-generally the lateral incisor in the lingual location--is extracted, and the canine tooth is placed in the location of the lateral tooth; posterior teeth are placed respectively in the location of the canine tooth.5,13,19,20 When the results of these different therapeutic options used for the treatment of cases with transposition are evaluated, it has been stated that more successful treatment outcomes can be obtained when coupled with good force-control if the transposed teeth are aligned in their own anatomical positions, even though its clinical applicability is quite difficult.15 Based on the evaluation of patient records at the beginning of treatment, it was decided that extraction of 4 first premolar teeth is inevitable for the elimination of severe maxillary and mandibular crowding.

It was thought that using the space that would be gained by the extraction of the first premolar tooth instead of one of the transposed teeth in the mandible in order for the placement of transposed teeth in their own anatomical positions would be quite important for providing intra-arch symmetry and integrity. It was stated that more pathological situations can be encountered in dental and periodontal tissues since the mechanics that would be used in this therapeutic option are more complicated, and the duration of treatment is longer.13,14 At the beginning of treatment, the patient and her guardian were informed about problems that could be encountered, and an informed consent form was obtained. Fixed mechanical orthodontic appliances, which took the transposed canine tooth into the extraction hole by mild orthodontic forces and placed the lateral tooth in its own anatomical position in the arch, were removed 3 years IJO ď Ž VOL. 27 ď Ž NO. 3 ď Ž FALL 2016

Figure 9: Post-treatment lateral cephalometric radiograph with tracing

Figure 10: Superimposition of pre-treatment and post-treatment lateral cephalometric tracings

Figure 11: Post-treatment intraoral photograph and post-treatment periapical radiograph of transposed teeth

and 9 months after the treatment started.

It was observed that the active treatment period was longer than normal orthodontic treatments. Evaluation of the duration of treatment in cases in which transposed teeth were placed into their own anatomical locations revealed that treatment duration is closer to the inferior limit of 2 years and 11 months;19 3 years and 8 months;5 3 years and 9 months;3 4 years;14 4 years and 9 months;15 and, 5 years and 5 months.13 Possible pathologies in the roots and surrounding periodontal configurations of transposed teeth appear to be the main problems which can be encountered during orthodontic treatment of tooth transposition.13-15 Panoramic and periapical radiographs obtained at the end of the treatment demonstrated no pathological condition in the roots or surrounding periodontal tissues of the mandibular lateral incisor and canine teeth. Gingival hypertrophy, which was noted in the lateral tooth during periodontal evaluation, was treated with gingivectomy and gingivoplasty procedures, and the gingival margin was reshaped. No periodontal problem was encountered in the 12th month of retention phase of the treatment (Figures 10-12).

Conclusions In order to obtain better esthetic and functional outcomes in the case with mandibular transposition during the permanent dentition period, we preferred placing the transposed teeth into their own anatomical positions. With the therapeutic option used in the present case, we demonstrated that successful treatment outcomes can be obtained using accurate force systems without causing any pathology in the transposed teeth or in the surrounding periodontal tissues.

References 1.

2.

3.

4.

5.

Shapira Y, Kuftinec MM. Tooth transpositions: A review of the literature and treatment considerations. Angle Orthod 59: 271-276, 1989.

Peck S, Peck L, Kataja M. Mandibular lateral incisor-canine transposition, concomitant dental anomalies, and genetic control. Angle Orthod 68: 455-466, 1998.

Shapira Y, Kuftinec MM. Maxillary tooth transpositions: characteristic features and accompanying dental anomalies. Am J Orthod Dentofacial Orthop 119: 127-134, 2001.

Peck S, Peck L. Classification of maxillary tooth transposition. Am J Orthod Dentofacial Orthop 107: 505-517, 1995.

Doruk C, Babacan H, Bıçakçı A. Correction of a mandibular lateral incisor-canine transposition. Am J Orthod Dentofacial Orthop 129: 65-72, 2001.

Figure 12: Intraoral photographs after 10 months of retention IJO  VOL. 27  NO. 3  FALL 2016

61

6.

7.

8.

9.

10.

11.

12.

13.

14.

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Cannavale R, Matarese G, Isola G, Grassia V, Perillo L. Early treatment of an ectopic premolar to prevent molar-premolar transposition. Am J Orthod Dentofacial Orthop 143: 559-569, 2013.

Chattopadhyay A, Srinivas K. Transposition of teeth and genetic etiology.

Angle Orthod 66: 147-152, 1996.

Hatzouidi M, Papadopoulos MA. Prevalence of tooth transposition in Greek population. Hell Orthod Rev 9: 12-22, 2006.

Pappadopoulas MA, Chatzoudi M, Kalamanos EG. Prevalence of tooth transposition. Angle Orthod 80: 275-285, 2010.

Jarvinen S. Mandibular incisor-cuspid transposition: a survey. J Pedodent 6: 159-163, 1982.

Peck S, Peck L, Kataja M. Concomitant occurrence of canine malposition and tooth agenesis: Evidence of orofacial genetic fields. Am J Orthod Dentofacial Orthop 122: 657-660, 2002.

Ciarlantini R, Melsen B. Maxillary tooth transposition: Correct or accept?.

Am J Orthod Dentofacial Orthop 132: 385-394, 2007.

Giacomet F, Tirre M, Arau S. Orthodontic correction of a maxillary canine-first premolar transposition. Am J Orthod Dentofacial Orthop 136: 115-123, 2009.

Nishimura K, Nakao K, Aoki T, Fuyamada M, Saito K, Goto S. Orthodontic correction of a transposed maxillary canine and first premolar in the permanent dentition. Am J Orthod Dentofacial Orthop 142: 524533, 2012.

Maia FA, Maia NG. Unusual orthodontic correction of bilateral maxillary canine-first premolar transposition. Angle Orthod 75: 266-276, 2005.

Ely NJ, Sherriff M, Cobourne MT. Dental transposition as a disorder of genetic origin. Eur J Orthodontics 28: 145-151, 2006.

Manjula M, Sreelakshmi N, Thabitha RS. Early orthodontic treatment of unilateral mandibular left lateral incisor-canine transposition: A case report. Annals and Essences of Dentistry 2: 40-43, 2010.

18.

19.

20.

Babacan H, Kiliç B, Biçakçi A. Maxillary canine-first premolar transposition in the permanent dentition. Angle Orthod 78: 954-960, 2008.

Canoglu E, Kocadereli I, Turgut MD. Alignment of transposed mandibular lateral incisor and canine using removable appliances. Australian Dental Journal 54: 266-270, 2009. Öztoprak MO, Demircan Ç, Arun T. Correction of a maxillary canine-first premolar transposition using mini-implant anchorage. Korean J Orthod 41: 371-378, 2011.

Dr. Özer Alkan is a graduate of the University of Gazi and received his PhD in Orthodontics from the University of Gazi. Dr. Alkan is currently assistant professor and Chairman of the Department of Orthodontics at the University of Yüzüncü Yıl.

Dr. Betül Yüzbaşıoğlu is a graduate of the University of Ege and received her PhD in Orthodontics from the University of Yüzüncü Yıl.

Dr. Yeşim Kaya is a graduate of the University of Ege and received her PhD in Orthodontics from the University of Yüzüncü Yıl. Dr. Kaya is currently assistant professor at the University of Yüzüncü Yıl.

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IJO  VOL. 27  NO. 3  FALL 2016

FEATURE

This article has been peer reviewed.

Craniofacial Asymmetry: A Literature Review

By Judith Maria Medina-Rivera, DMD

Abstract: Craniofacial asymmetry is a very common finding. Possible etiologies include genetic and environmental factors or a combination of both. There is no age or gender preference for the development of craniofacial asymmetries in general, except for the postural plagiocephaly, which has been more frequently found in male babies. Craniofacial asymmetries have been identified before birth in presumably normal fetuses. Congenital and non-congenital craniofacial asymmetries have been related to certain types of pathology. One or more of the different structures of the cranial, dentoalveolar, and/or mandibular areas may be involved in the existing asymmetry. Assuming there is good function, soft tissue may camouflage an existing skeletal craniofacial asymmetry. No correlation has been established between craniofacial asymmetries and malocclusion. However, a correlation between soft tissue dysfunction and postural changes has been established and may account for a chain of compensatory effects that may include the development or the amplification of an existing craniofacial asymmetry.

Key words: craniofacial growth; development;genetic factor expression; skeletal asymmetry; function; physiology; congenital facial deformity; plagiocephaly; soft tissue; mandibular growth; temporomandibular joint dysfunction; mastication; dentoalveolar growth; muscle hypertrophy; soft tissue stretching; musculoskeletal imbalances; craniocervicomandibular system.

ntroduction During the embryonic development, the formation of the face is described as a merging of several processes and prominences to form one single unit. Merging involves the swelling of the processes with the elimination of a trail between them. 1 Moreover, fusion, which occurs in the union of the palatal processes, involves the breakdown of surface epithelium. The face develops during the fourth to seventh prenatal weeks. 1 During this period of time, environmental factors may easily affect the facial development since women are usually not aware that they are pregnant. The resulting defects on facial development will generally involve asymmetries that may vary in severity from mild to very severe.

After birth, the development of the craniofacial complex is mostly influenced by functional patterns.2 The oral system’s function arises from a neural excitation. If this excitation is physiological, it will produce physiological function and development, but if it is pathological, the developmental response will also be pathological.3 Habitual or chronic unilateral chewing due to occlusal interferences or other pathological reasons will create a mandibular shift towards the ipsilateral side with increase of the mandibular size on the opposite side by traction excitation.2,3 Establishing physiological functions like nasal breathing, correct tongue-resting position, correct swallowing patterns, and an equilibrated mastication are fundamentals for optimal craniofacial development and therefore minimize the development of asymmetries.

Literature Review Craniofacial asymmetries in humans have been described in the literature as a very common finding.4-9 Some authors have classified them according to their possible etiology including genetic and environmental factors. 7,8 Genetic conditions IJO  VOL. 27  NO. 3  FALL 2016

like multiple neurofibromatosis, which is transmitted as an autosomal dominant trait or may also represent a neo-mutation, is associated with different degrees of facial asymmetry.7,8,10, 11 Also some forms of clefts of the lip and palate are genetically influenced and result in facial deformity.7,8 Syndromes such as hemifacial microsomia, craniosynostosis, and craniofacial clefts, in which asymmetric growth occurs, have also been associated with a number of genes and factors. 5,7,8,10,11 Though there is no single gene that could be identified as a sole cause of these and other skeletal abnormalities ,5,9 nonetheless, Meng, et al found that some protein factors were highly expressed in specific regions of the condylar cartilage in patients with condylar hyperplasia, a condition in which skeletal facial asymmetry is present.5,12 A congenital but not genetic-related condition that can be associated with cranio-facial asymmetry is plagiocephaly, which is a unilateral flattening of the skull.

13,14 There are two types to distinguish: plagiocephaly resulting from fusion (synostosis) of a coronal or lambdoid suture in which the deformity of the cranium is visible from birth. The second type is the positional or postural plagiocephaly, in which the flattening is secondary to a pre- or post-natal mechanical pressure on the skull. According to Littlefield, et al, this form of plagiocephaly is more common in boys (71% of cases) and in twins. 14 Hollier, et al also found an association of plagiocephaly with congenital torticollis in 37% of cases.15 Although this positional plagiocephaly is most commonly a posterior flattening of the skull and only rarely affects its anterior aspect, it is a good example of how either prenatal and postnatal posture can influence the form of the body. Rossi, et al16 included different developmental stages groups from fetuses to adults in their study. They reported the presence of facial asymmetries in all age groups. This study included presumably normal infant and fetus skulls, and these were actually the two groups 63

that presented the largest degree of asymmetry. Their findings confirm that prenatal genetic and environmental factors may indeed be involved in the development of facial asymmetries and that craniofacial asymmetry is independent of the developmental stage of the subject. Other conditions associated with the development of craniofacial asymmetry are various forms of pathology that are not necessarily congenital, including ostoechondroma of the mandibular condyle, trauma, and certain forms of infections.7,8 Asymmetries can be classified according to the structures involved, whether they are skeletal, dentoalveolar, or muscular.

Mild skeletal facial asymmetries are very common, and it has been suggested that they are an intrinsic characteristic of humans and are present even in aesthetically pleasant faces. 4,5,7-9 Skeletal asymmetries of less than 3% are not clinically discernible as the soft tissue cover may mask the underlying skeletal imbalances.4,9 It has been suggested that normal functional adaptation in the dentoalveolar and mandibular regions of the face may compensate for the cranio-facial asymmetry resulting in symmetry of the lower part of the face. 6,9,16,17 Sanders, et al5 suggested that the proper function and regulation of the genes and factors related to facial development are likely to promote symmetric growth, but additional research is needed in order to identify what influences the expression of the genes and factors involved in the development of facial asymmetry. Moderate and severe skeletal asymmetries are usually related to congenital or genetic factors, pathology, or trauma, as discussed previously in this work. One or multiple bone structures of the skull and/or face may be involved in any skeletal asymmetry.5-9,16,17 Dentoalveolar asymmetries are mostly associated with tooth size discrepancies, premature loss of primary teeth, congenitally missing teeth, loss of tooth structure due to pathology, trauma, or abrasions, and dysfunctional oral habits such as thumb sucking and other postural habits.7,8 Midline shifts are associated with temporomandibular joint dysfnction (TMD) and/or dysfunction of the masticatory apparatus.6-9,17 RamirezYañez,et al17 supported the hypothesis that the mandible grows at different sites and adjusts its angles adapting to functional demands, while tooth development is not affected. 17 Years earlier, Shah and Joshi9 reported that facial asymmetry does not necessarily interfere with the occlusion and that asymmetry of the face may result at the cost of maintenance of the dental midlines, for instance. The forces of mastication transmitted from the teeth to the bones may influence craniofacial growth and therefore, the upper part of the face is larger in the ipsilateral side of the habitual mastication. On the other hand, in a case report by Katsetos,18unilateral mastication was related to the development of reactive temporalis muscle hypertrophy causing pain and muscular facial asymmetry in the absence of skeletal asymmetry.

Solow and Sandham19 found evidence that the differences in craniofacial morphology could be explained in terms of forces that the soft tissue exert on the skeleton also known as the soft tissue stretching hypothesis. Evidence of these forces were reported by Hellsing and L’Estrange20 in their experiment where they used a pressure transducer on the surface of an upper central incisor and recorded the difference in pressure exerted by the lips when the subjects tilted their head 5 degrees up and 64

down from their natural head posture. With this experiment, they demonstrated that the changes in head posture can easily influence the dentofacial and skeletal development.19,20 Based on these results, the following question can be formulated: could facial asymmetries also result from the differences of the soft tissue forces that are exerted on the two hemispheres of the face?

There are differences among the authors about the predominance of the sides of the face as well as what segments of the face are more affected by asymmetry. Also, different techniques have been used to quantify the presence of facial asymmetry in controlled studies such as tri-dimensional cone–beam computed tomography analysis, photographs, tridimensional photographs, postero-anterior cephalograms, and panoramic radiographs.4-7,9,16,17 The differences in assessment techniques to evaluate facial asymmetry may be an important variable to consider. Sanders,et al5 found a mild right predominance or left deficiency in the auriculo-temporal and condylar regions using a tri-dimensional cone-beam computed tomography assessment. Previously Ferrario4 also found that in average the right side of the face was larger than the left regardless of the gender. For the assessment, they used a system of two cameras that photographed the subjects and real time hardware for the recognition of markers and software for the tridimensional reconstruction of landmarks. Also, Shah and Joshi9 found that the right side of the face was larger than the left, and the assessment tool was standardized traced posteroanterior radiographic cephalograms. However, Vig and Hewitt6 reported that the cranial portion of the head exhibited a larger right side, but in the face, the left side was frequently larger than the right in the zygomatic and maxillary areas. The method of assessment was randomly selected cephalometric radiographs traced by one of the authors. Ramirez-Yañez et al17 found that the left side of the mandible was predominantly larger in their subjects. For this study, linear and angular measurements on digitally-scanned panoramic radiographs were used to evaluate dentoalveolar and mandibular asymmetry. Based on the results of all these studies, the prevalence of craniofacial asymmetry is independent of the age and gender of the subjects. In addition either side of the face may be larger than the other and the asymmetrical growth may occur at different areas of the face.

Conclusion In general, moderate and severe craniofacial asymmetries are mostly related to genetic and congenital conditions or other pathologies. Mild craniofacial asymmetries are commonly found in normal individuals and are believed to be part of the developmental differentiation between the two hemispheres of the brain. Some of the authors on this review found that even with the presence of a cranial asymmetry, the face could still look symmetric and pleasant with the assumption that a normal muscular function contributes to mask the underlying skeletal asymmetry.4,6,9 On the other hand, facial asymmetries of unknown etiology can be related to the presence of musculoskeletal imbalances resulting from dysfunctional habits. Unilateral mastication, sleeping, and other postural habits like resting the face over one of the hands have been related to the development of an asymmetrical face and unilateral temporomandibular joint disorders in otherwise IJO  VOL. 27  NO. 3  FALL 2016

healthy individuals. 7,8 Although craniofacial asymmetry has not been related to the presence of malocclusion, it could be part of a functional compensation of the craniocervicomandibular system. Dysfunctional-breathing patterns play a major role in the craniocervical postural compensations that will result in softtissue stretching and could affect the maxilla and the mandible growth. 19 It is still unknown if this same mechanism may account for the development and/or prevalence of post-natal facial asymmetries.

14.

References

18.

1.

2.

3.

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Chetty M. Embriology of the Head and Neck - Chapter 2: Embriology of the head, face and oral cavity (module video) University of Western Cape, www.oerafrica.org.

Ramirez- Yañez, GO. Early Treatment of Malocclusions, Prevention and Interception in Primary Dentition. Cucutá, Colombia: J. Ramirez Press; 2009: 5-19.

Planas, P. Rehabilitación Neuro-oclusal. Barcelona, España; AMOLCA 2008: 1-26.

Ferrario VF, Sforza C, Miani A, Serrao G A three dimensional evaluation of human facial asymmetry. Journal of Anatomy 1995; 186:103-110.

Sanders DA, ChandhokeT, Uribe FA, Rigali PH, Nanda R Quantification of skeletal asymmetries in normal adolescents: cone-beam computed tomography analysis. Progressive Orthodontics 2014; 15(1):26.

Vig PS, Hewitt AB Asymmetry of the human facial skeleton. The Angle Orthodontist 1975; 25(2): 125-129.

Cheong YW, Lo LJ Facial asymmetry: etiology, evaluation and management. Chang Gung Medicine Journal 2011; 34(4): 341-350.

Bishara SE, Burkey PS, Kharouf JG Dental and facial asymmetries: a review. The Angle Orthodontist 1994; 64(2): 89-98.

Shah SM, Joshi MR An assessment of asymmetry in the normal craniofacial complex. The Angle Orthodontist 1978; 48(2): 141-148.

Sigillo R, Rivera H, Nikitakis NG, Sauk JJ Neurofibromatosis type 1: a clinicopathological study of the orofacial manifestations in six pediatric patients. Pediatric Dentistry 2002; 24(6): 575-580.

James PL, Treggiden R Multiple neurofibromatosis associated with facial asymmetry. Journal of Oral Surgery 1975; 33: 349.

Meng Q, Long X, Deng M, Cai H, Li J The expressions of IGF-1, BMP2 and TGF-beta in cartilage of condylar hyperplasia. Journal of Oral Rehabilitation 2011; 15(1): 34-40.

Arnaud E, Marchand D, Renier D Diagnosis of facial and craniofacial asymmetry. Annales de Chirurgie Plastique Esthétique 2001; 46(5): 410-423.

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Littlefield TR, Kelly KM, Pomatto JK, Beals SP Multiple birth infants at higher risk for development of deformational plagiocephaly. Journal of Pediatrics 1999; 103(3): 565-569.

Hollier L, Kim J, Grayson BH, Mc Carthy JG Congenital muscular torticollis and the associated craniofacial changes. Journal of Plastic Reconstructive Surgery 2000; 105(3): 827-835.

Rossi M, Ribeiro E, Smith R Craniofacial asymmetry in development: an anatomical study. The Angle Orthodontist 2003; 73(4): 381-385.

Ramirez-Yañez GO, Stewart A, Franken E, Campos K Prevalence of mandibular asymmetries in growing patients. European Journal of Orthodontics 2010 doi:10.1093/ejo/cjq057 (from the author) University of Manitoba Libraries.

Katsetos CD, Bianchi MA, Jaffery F, Koutzaki S, Zarella M, Slater R Painful unilateral Temporalis muscle enlargement: reactive masticatory muscle hypertrophy. Head and Neck Pathology Journal 2014; 8(2): 187193.

Solow B, Sandham A Cranio-cervical posture: a factor in the development and function of the dentofacial structures. European Journal of Orthodontics 2002; 24: 447-456.

Hellsing E, L’Estrange P Changes in lip pressure following extension and flexion of the head and changed the mode of breathing. American Journal of Orthodontics and Dentofacial Orthopedics 1987; 91: 286-294.

Dr. Judith Medina Rivera is a general dentist graduated in 2001 Magna Cum Laude from the University of Puerto Rico School of Dental Medicine, Pierre Fauchard Academy merit distinction and a GPR from the Veterans Administration Hospital in San Juan. She is a Fellow and Certified Senior Instructor of the International Association for Orthodontics, and member of the Academy of General Dentistry and of the Institute for Functional Medicine. Her current practice in Austin, Texas is limited to Myofunctional Orthodontics.

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FEATURE

This article has been peer reviewed.

Upper Arch Molar Distalization Appliances in Treatment of Class II Malocclusion: A Critical Analysis

By Léonard Jacques, DMD Abstract: The number of new upper molar distalization appliances keeps climbing since the headgear’s appearance at the end of the 60s.

The aim of this critical review of the literature is to list and explore current upper arch molar distalization appliances in treatment of Class II malocclusion available in the market to this day. This article critically analyzes their benefits as well as their side effects and limitations.

Keywords: upper molar distalization, Class II malocclusion, intraoral appliances, tooth movement

ntroduction Since more than 75% of cases observed and treated in my cabinet are Class II malocclusions, it was not shocking to notice that an extremely large percentage of the orthodontic field of research is dedicated to this treatment. With the constant improvement of dentistry and orthodontics, the correction of Class II malocclusion is often a non-extraction or non-surgical treatment, conserving the patient’s dentition. To avoid extractions, treatments usually require maxillary molar distalization by means of intraoral or extra oral forces (this paper will not present the muscular forces associated with the upper molar distalization). Lack of space available in the upper arch for such a major movement is a significant disadvantage of such treatments. Patient’s request for non-extraction treatment generated a need for orthodontic appliances that could enlarge the upper arch in a transversal and distal direction. The main issue in distalization was, and is still, the loss of anchorage during the treatment. The anchorage control (concentration of desired force and dissipation of reactionary force) is a capital concern in designing such appliances. As addressed below, many appliances were unable to provide such control, and only a few were sufficiently effective.

anchor or external support for the appliance passing through the patient’s mouth and secured to the teeth.” Back then, the headgear was a helmet and was covering the whole patient’s head. Today, a lot of patients reject this option for obvious reasons of aesthetics, discomfort and social acceptance, even though it is much more discreet and does not require wearing a helmet.

Today’s literature counts three different types of headgear for Class II classified by their point of attachment, direction of pull, and the targeted treatment.3 The cervical headgear (Figure 1-A) presents an extra oral anchorage at the back of the neck with a cervical pull. It is easy to wear with minimal exterior show. However, it often causes extrusion of the upper first molars creating an open bite. 4 The high pull headgear’s (Figure 1-B) anchorage is at the back of the head. It will not extrude upper molars, but it presents more hardware for patients, and it is more difficult to achieve posterior forces on the maxilla.3 The combination headgear has been discarded over the years for obvious reasons such as lack of control on the force. Side effects of headgear are substantial. Studies often report unwanted extrusion forces on the maxillary molars and distal tipping of

Extra Oral Forces Traditional techniques imply the use of extra oral strengths with cervical, occipital, or combined anchoring. Although this category of appliance has shown its benefits, these techniques mainly rely on patient cooperation, and it is no secret that the patient compliance is a key factor in obtaining successful results.

Furthermore, these devices have a considerable effect on the cervical column.1 Headgear In 1969, Frank Nelson published a paper introducing his new invention: the orthodontic headgear.2 He enhanced the problem that “orthodontists have been handicapped by the lack of suitable external head-engaging fixtures to provide an IJO  VOL. 27  NO. 3  FALL 2016

Figure 1 67

molars. Moreover, it is undisputed that the main issue with this device is the need for patient compliance. A pilot study in 2003 investigated the compliance rate of headgear use and the role of timing headgear as a motivator.4 The headgears were equipped with time recorders without the participants knowing it. Among their conclusions, it was determined that the mean actual hours of daily wear relative to the providers’ requirements was 56.7%.

The acknowledgement of the monitoring regarding the wearing time is known to increase the patient’s cooperation to 62.7%. In conclusion, a headgear successful treatment depends on patient compliance and tolerance. That’s why it is not the most efficient treatment.

Intraoral Forces Looking for less interference of patient compliance and tolerance with the treatment, orthodontists have invented a vast number of intraoral appliances for upper molar distalization: these appliances are simple to construct and use, and they are a good alternative for non-cooperating patients.

Pendulum® Hilgers5 first described the Pendulum® appliance in 1992. It consists of a palatal Nance component with rests that are bonded to the occlusal surface of the first and/or second premolar teeth (Figure 2). It is designed to provide consistent and dependable upper molar distalization and rotation without the need for patient cooperation. Interestingly, this device does not require any coil mechanics. Research evaluating the distal molar movement using the Pendulum® appliance showed that it moved the molars distally without creating dental or skeletal bite opening and with little incisor anchorage loss.6 However, important molar tipping was noticed. Other studies have compared the Pendulum® appliance7 to other intraoral appliances (Distal Jet,® headgear) and the subjects.8 The standard Pendulum® appliance was then modified by integrating a distal screw into its base and by special preactivation of the pendulum springs. The springs have an adjustment loop that can be manipulated to increase molar expansion, rotation, and distal root tip.

Pend-X Appliance® Then came the Pendex appliance,®5 which is actually a Pendulum® appliance but incorporates an expansion screw in the design to allow both molar distalization and expansion. It is similar in nature to the Pendulum® and uses the expansion screw to widen the upper palate, correcting class II malocclusions and the patient’s bite.

Other modifications of Pendulum® appliances were also created through the years: • M Pendulum®, Scuzzo, 19999 • Franzulum Appliance,® Buyoff, 200010 • Modified Pendulum with removable arms,® Scuzzo, 200011 • Bone anchored pendulum appliance,® Byloff, 200612 Jones Jig® The Jones Jig® (Figure 3) is a sectional archwire coil spring device. It is fixed and uses palatal anchorage with an applied force of 70-75g delivered by a NiTi spring to move the maxillary first molars distally, reaching a Class I molar relationship. Studies compared the effects of the Jones Jig® to the Pendulum,®13, 14 and both concluded that the Jones Jig® appliance is creating mesial tipping, mesial angulation, and extrusion of the maxillary second premolars. It was also shown that there does not seem to be any particular advantage in using the Jones Jig® as a noncompliance appliance. Indeed, a randomized clinical blinded study15 compared two groups of patients to measure the effectiveness of an upper removable appliance (URA) and the Jones Jig’s:® twelve patients were randomly allocated to URA treatment and 11 patients to a Jones Jig.® The results revealed that the amount of tooth movement from using these two types of appliance was small, and both type of appliances were equally effective.

They concluded that the amount of distal molar movement with a Jones Jig® or URA was non-significant. Furthermore, other studies16 have reflected the equivalency of the results using a Jones Jig and many other appliances (Herbst appliance®, Wilson mechanics,® Repelling magnets,® Pendulum,® cervical headgear), concluding that the Jones Jig® does not stand out regarding efficiency or major advantage.

Figure 2 Figure 3

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Sliding Jig® The Sliding Jig® (Figure 4) is mainly a 2-inch length of 0.22 stainless steel wire in which one part is sliding over the main archwire and the distal part inserted in the buccal accessory tube of the first molar. It is activated by Class II inter arch elastic. It has proved most helpful in certain light wire treatment to convey distal elastic force to the molar on one side only.17 It can easily be added to the current fixed appliance and quickly constructed at chair side.

Distal Jet® The Distal Jet®18 (Figure 5) is considered to be among the devices that present good control over tooth movement and creates minimum loss of anchorage for treatment of Angle class II. The studies on Distal Jet® demonstrated advantages, including the relatively short duration of treatment (4 in 9 months).1 The disadvantage of this appliance mainly comes with the necessity to reactivate frequently the compression of the palatine spring. Even though is it a more controlled appliance, and the loss of anchorage is limited, the results of other studies pointed out that loss of anchorage is inevitable and is to be expected.19 With all those identified key components that could be upgraded, Carano and Testa20 reviewed their appliance and applied some changes to develop a more effective and practical tool. They completely redesign the lock and changed the manufacture of the lock from a machining process to a casting process. Their modifications reduced chair time, improved patient comfort, and enhanced treatment efficiency and reliability without changing the biomechanical foundation of the Distal Jet.®

Figure 5

Figure 6

Figure 7 Figure 4

NiTi Distalizer – DNT Inspired by the success of Distal Jet,® Dr. Michel Champagne introduced in 2003 the NiTi Distalizer.®21 Later in 2011, Dr. Patti and his team1 combined the principle of guiding tubes located near the center of resistance while modifying the drawing of NiTi springs (Figure 6) to minimize and even eliminate the need for reactivation. The technology is focused on the distalized tooth’s center of resistance, and it allowed him to develop an appliance that requires no patient compliance and reduces the so called inevitable molar tipping effect. They elongated the tubes to allow the insertion of longer NiTi springs that would not require any reactivation. Once the backward movement are achieved, the springs are deactivated. The major difference with this appliance is that the guiding tube is slightly distoapicaly angled (2-3 degrees) in order to control the molar tipping. Other variations of the NiTi Distalizer® are known as Gonzalez Distalizer,® C.D. distalizer,® and Inman distalizer.® IJO  VOL. 27  NO. 3  FALL 2016

Fast Back Expansor Appliance® Fast Back Expansor appliance® (Figure 7) is also called the fastback molar distalizer® (3 versions FB1, FB2, FB3).

This was created in 2000. It is now definitely one of the most popular appliance for molar distalization in the orthodontic field. The Fast Back Expansor® is based on the principle of placing constant forces on the molars by incorporating Memoria springs® delivering between 200g-300g on the molar to be distalized.22 This spring- activated device provides bodily distalization of the upper molars, and once distalization has begun, activation should be carried out, on average, every 30-45 days. It allows for delivery of continuous forces, and the direction of the spring is determined by the arm on the expansion appliance and does not require the cooperation of the patient during treatment because it is activated by the dentist.

Recent research showed that the Fast Back® was as effective as the Pendulum.®23 69

Temporary Anchorage Devices® – TADS Also referred as mini-implants or mini-screw in the literature, TADS®24, 25 are small skeletal anchors: They provide maximum anchorage,26 minimizing the side effects of traditional orthodontic technologies. Before their use, many cases reported dental tipping, bite opening, anterior anchorage loss, and thus they were invented to overcome anchorage limitations encountered with devices cited below. They are biocompatible devices fixed to the bone and removed once the distalization is completed. Studies have shown that TADS® allow a much more stable anchorage. However, this no anchorage loss has a price: there are several problems related to these mini-implants: the screw can fracture, and risks of infection around the screw are significant.26 PSM Medical Solution27 offers three types of temporary anchorage devices that represent most commonly used TADS.® The Benefit System® is particularly effective for molar anchorage and distalization as well as anchorage for the retraction of anterior teeth and space closure.27 It is a palatinal anchorage, and it can be placed in any area of the maxilla or mandibule for aligning teeth prior to prosthodontics. A Beneslider®28 can be anchored to one or more Benefit mini-implants® in the anterior palate to create distalization. For enhanced stability, “the Mentoplate System® provides a special orthodontic bone anchored plate for intraoral fixation in the maxilla and the mandible.”27 To minimize and prevent lingual tipping during the space closure process, a T-wire can be employed, or a Mesialslider® can be used as a direct anchorage device.29 It is attached to the mini-implants anchored in the anterior palate.

Finally, the Quattro System® (Figure 8) is designed to replicate an orthodontic bracket and buccal tube. It is the only system you can use exactly like a bracket on a tooth or a tube on a molar band.27 A very large study30 investigated 904 implants TADS® in 455 patients with different clinical with different clinical diagnoses including malocclusions (333/455), jaw deformities, etc. The aim of this retrospective study was to determine factors that might cause complications in use of TADS® (plate type and screw type). The measurement of implant mobility or implant loss was observed in only 62/904 implants. Both screw and plate type implants had a high success rate, and the overall results showed 90% rate of successful treatment.

The number of publications on implants in the orthodontic literature is constantly rising. Among those, Crismani, et al.31 published a meta-analysis evaluating 14 reports of clinical trials published before September 2007 with at least 30 mini-screws.

All 14 reports described success rates sufficient for orthodontic treatment.

TADS® (Figure 9) can be used in combination with almost every appliance creating a multitude of possibilities. No matter what, in each variation of their use, they offer ultimate anchorage and almost non-existent loss of anchorage when inserted accurately.

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Figure 8

Figure 9

Keles Slider® The Keles Slider® (Figure 10) was created to avoid distal tipping of maxillary Class II first molars. It was assembled with NiTi coil spring and screws. The Keles Slider® is a very effective fixed device to distalize molars bodily.32 It was also tested with bilateral distalization,33 and the anchorage loss was not significant. Other studies reported that the Keles Sliders® demands regular reactivation of the coil springs and that it presents several limitations.34

Figure 10

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First Class Appliance® – FCA The First Class Appliance® introduced by Fortini and his team35 consists of four bands, a vestibular side, and a palatine side. It is a screw-based appliance with forces generated by a telescopic screw mechanism. It is reported to be an efficient non-compliance appliance to distalize molars in mixed dentition without distal rotations. However, it is associated with distal molar tipping as well as anchorage loss of the anterior teeth.36 A modified version of the First Class Appliance® called the First Class Leone® (Figure 11) produces a rapid distalization of the first and second molars and does it with bodily movement without producing any tipping effect. Moreover, it was reported that the appliance was not producing any loss of anchorage or changes in the vertical dimension.37

Wilson’s Appliance:® Rapid Molar Distalization William L. Wilson created a treatment called “rapid molar distalization”® also known as the Wilson bimetric distalizing appliance® or Wilson 3D appliance.®40 Wilson’s “rapid molar distalization appliance”® (Figure 13) was created in 1978 to move the upper molars back without changing the position of the front teeth.41 It consists of compression springs positioned mesial to the maxillary first molar and class II elastics. A study showed that paired with elastics, the Wilson bimetric distalizing arch® provided efficient and simple Class II mechanics.

However, there is a serious risk of anterior undesirable movement of the premaxila if the elastics are not worn. Another study showed that the distal tipping of the maxillary first and second molars, and first and second premolars and canines were statistically significant.42 One advantage of the Wilson appliance® is that delayed bracketing of the premolars and second molars minimizes friction within the appliance which could allow for more rapid bodily movement of the molars.43

Figure 11

Intraoral Bodily Molar Distalizer® – IBMD The intraoral bodily molar distalizer®38 is composed of two parts: the anchorage unit and the distalizing unit (Figure 12).

The anchorage unit is a wide acrylic Nance button, and the active unit consists of TMA distalizing springs. “The springs distalize the maxillary first molars towards the direction in which the springs are inactive, exerting a distalizing force of 230g. It enhances molar distalization by discluding the posterior teeth.”39 It achieved bodily distal movement of maxillary molars and also eliminated the need for patient cooperation and did not require headgear wear for molar root uprighting.

Figure 13

Carriere Distalizer Appliance® The Carriere Distalizer® device44 (Figure 14) consists of a fixed functional appliance for Class II treatment. It was designed to create a Class I molar-canine relationship. It allows distal movement of the canine along the alveolar ridge without tipping and provides a hook for the attachment elastics. With this device, you have to carefully choose the source of anchorage, depending on the patient’s skeletal and neuromuscular pattern.

One limitation of this device is that brachyfacial patterns respond better to treatment; dolichofacial types are less responsive.44

Figure 12 Figure 14 IJO  VOL. 27  NO. 3  FALL 2016

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Simplified Molar Distalizer® (also called The Frog Appliance®) To date, very few studies have evaluated the efficiency of the recently developed intraoral Frog appliance.® An interesting comparative study45 evaluated the single use of the Frog appliance® (Figure 15) to its use combined with the high pull headgear worn at night. This study concluded that the Frog appliance® does indeed distalize the upper molars, but the movement is (like with a lot of other intra oral appliances) associated with undesirable changes such as tipping of molar axes, but nothing more than the typical tipping expected with the Pendulum® and the Distal Jet.® The results showed that both treatments combined improved the distalization time and also improved the ratio of maxillary molar distalization movement relative to the overall opening space between the first maxillary molars and second premolars. In 2011, the Skeletal Frog,®46 which is a modified version of the Frog® appliance, was created to eliminate the need for dental anchorage and its unfavorable effects on the anterior arch. It is an innovative mini-implantsupported molar-distalization appliance that requires no dental support or acrylic palatal button. One major contribution of this modified version is that it reduces treatment time because the alignment of the maxillary arch and the distal movement are occurring simultaneously.

the incisors, and a finger spring at the mesial aspect of the first molar. With the combined use of headgear, it was more likely to create bodily movement of the molar. At the beginning of the century, a study reported a bodily movement only in 9% of patients, and a distal crown tipping was found in 70% of treated cases.49 Lokar Molar Distalizing Appliance® The Lokar Molar appliance® is a recent appliance, and more studies are needed regarding its effectiveness. It is inserted into the molar attachment with a rectangular wire and a compression spring that is activated by a sliding sleeve50 (Figure 17). This appliance presents advantages like minimal breakage and ease of activation and insertion. Still there is a lack of data on this appliance to objectively discuss its efficiency on molar distalization.

Figure 17

Figure 15

Cetlin Appliance® The Cetlin Transpalatal Arch® (TPA) is a fixed appliance (Figure 16). It is the same appliance as the ACCO®47 but does not have headgear loops. It was developed by Dr. Norman Cetlin, and it utilizes a removable appliance intraorally to tip the crowns distally and then uses an extraoral force to upright the roots.48 Today, this appliance is rarely used in practice.

Reppeling Magnets® Magnetic devices introduced by Gianelly, et al in 198851 consisted of distalization by means of samarium-cobalt repelling magnets® (SmCo5). “The system consists of two repelling magnets per side, one anchored to the molar to move posteriorly, the other connected to the premolar or deciduous molar of the same quadrant, which is in turn anchored to a modified Nance holding arch extended until the palatal surface of the maxillary incisors to reinforce the anchorage”52 (Figure 18). As the molar distalization is achieved in a relatively short period, occlusal adjustment, including uprighting and derotation of the maxillary molars as well as post-treatment retention, seems recommendable.53 Revivew of the literature showed that these were tested and compared to many other intraoral molar distalization procedures. They were reported less effective than coil springs54 in terms of movement achieved, less efficient in maxillary molar distalization in individuals with Class II malocclusion, deeper bite than superelastic coils,55, 56 and were less effective than the NiTi appliance® for distal bodily movement of maxillary molars.57

Figure 16

The Acrylic Cervical Occipital Appliance® – ACCO The Acrylic Cervical Occipital Appliance® is a removable appliance that consists of an acrylic palatal section to create disclusion, Adams Clasps on the first premolar, labial bow across 72

Figure 18 IJO  VOL. 27  NO. 3  FALL 2016

K-Loop Molar Distalizer® The K-Loop appliance® (Figure 19) developed by Dr. Kaltra58 is used to distalize molars in a more bodily way. One of the most important characteristics of the K-Loop® is the special V-bend in the K-Loop® that moves both the crown and the root distally.59 It is made of TMA wire, and the legs of the K are inserted into the molar tube and the premolar bracket. This appliance provides minimum tipping.

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Fixed Piston Appliance® This device was first described by Raphael Greenfield in 1997. Its purpose is to distalize bodily without creating tipping of the crown and without loss of posterior anchorage. It consists of stainless steel wires and tubing banding the first maxillary molar and first bicuspid together. The force is applied by nickel titanium open-coil springs. This appliance has proved its efficiency in that it causes less posterior anchorage loss.60 In a comparison study of various distalization appliances,61 tip was reported to be of 6.5° (+/- 6.6°) in an average distal movement of 3.9 mm.

Conclusion All appliances mentioned above are able to create distalization movement of the upper posterior molar. Although some appliances create more undesirable side effects such as loss of anterior anchorage, mesial drift of anterior anchorage, tipping of the molar during movement, and opening of the bite caused by molar extrusion--most of these disadvantages (mainly anchorage lost) can be in part or totally neutralized by modifying the appliances with supplementary TADs anchorage.

Tipping and opening of the bite depend more on the nature of the mechanic used in the appliance and the intrinsic design of the appliance. Therefore, they are more difficult to bypass.

Appliances that depend more on patient cooperation have shown less predictable results. Choice of appliance may also be guided by the fact that the patient is already into treatment, and full bracketing has already occurred.

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Adriano G, Bertl MH, Čelar AG, Bantleon HP, Burstone CJ. Miniscrews in orthodontic treatment: Review and analysis of published clinical trials.

AJO-DO, 2010; 137(1): 108-113.

Keles A. Maxillary unilateral molar distalization with sliding mechanics: A preliminary investigation. European Journal of Orthodontics. 2001; 21: 507-515.

Keles A. The Keles slider appliance for bilateral and unilateral maxillary molar distalization. Chapter 19, 2011.

Kinzinger G1, Diedrich P. Biomechanics of the Keles Slider appliance for maxillary molar distalization-in-vitro analysis of force systems. J Orofac Orthop. 2008 Sep; 69(5): 365-72.

Fortini A, Lupeli M, Guintali F, Franchi L: Dentoskeletal effects induced by rapid molar distalization with the first class appliance. Am J Orthod. & Dentofacial Ortho. 2004; 125 (6): 697-705.

Papadopoulos AA,, et al. Noncompliance maxillary molar distalization with the First Class Appliance: A randomized controlled trial. American Journal of Orthodontics and Dentofacial Orthopedics. 2010 May; 137(5): 586.e1-586.e13.

Fortino A, Lupoli M. First Class Leone: A new appliance for rapid molar distalization. Ortho News. 2000 Mar; 1(20).

Keles A, Sayinsu K. A new approach in maxillary molar distalization: intraoral bodily molar distalizer. Am J Orthod Dentofacial Orthop. 2000 Jan; 117(1): 39-48.

Papadopoulos, M. Skeletal Anchorage in Orthodontic Treatment of Class II Malocclusion. Mosby Elsevier, 2015.

Wilson W.L, Wilson R.C. Multidirectional 3D functional class II treatment. J. Clin. Orthod. 1987; 21: 186-189.

Wilson, WL. Modular orthodontic systems part 1. J Clin Orthod.

1978;12:259–278.

Uçem TT, Yüksel S, Okay C, Gülşen A. Effects of a three-dimensional bimetric maxillary distalizing arch. Eur J Orthod. 2000 Jun; 22(3): 293-8.

Wilson W, Wilson R. Modular3D lingual appliance. PartI–Quad–Helix.

JClinOrthod.1983Nov; 161-166.

Carrière L. A new Class II distalizer. J Clin Orthod. 2004 Apr; 38(4): 224231.

Burhan AS. Combined treatment with headgear and the Frog appliance for maxillary molar distalization: a randomized controlled trial. Korean J Orthod. 2013 Apr; 43(2): 101-109.

Ludwig B, Glasl B. Kinzinger G, Walde K, Lisson, J. The Skeletal Frog Appliance for Maxillary Molar Distalization. Journal of clinical orthodontics: JCO. 2011 Feb; 45(12).

Cetlin NM, Ten Hoeve A. Nonextraction Treatment. J Clin Orthod. 1983; 17: 396-413.

Indian Dental Academy. Molar distalization – current trends. Molar distalization / certified fixed orthodontic courses. Feb 2014.

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Singhal A. Ambedkar B, Garg R. Molar Distalization by Intraoral Appliance: A Review. Heal Talk- 5th Anniversary. 2013 Sept-Oct; 6(1).

Gianelly AA, Vaitas AS, Thomas WM, Berger DG. Distalization of molars with repelling magnets. J Clin Orthod 1988; 22: 40–4.

Sfondrini MF, Cacciafesta V, Sfondrini G. Upper molar distalization: a critical analysis. Orthod. Craniofacial Res. 5, 2002; 114–126.

Bondemark, Kurol J. Distalization of maxillary first and second molars simultaneously with repelling magnets. Eur J Orthod. 1992 Aug; 14(4): 264-72.

Erverdi N, Koyutürk O, Küçükkeles N. Nickel-titanium coil springs and repelling magnets: a comparison of two different intra-oral molar distalization techniques. Br J Orthod. 1997 Feb; 24(1): 47-53.

Bondemark L. Orthodontic magnets. A study of force and field pattern, biocompatibility and clinical effects. Swed Dent J Suppl. 1994; 99: 1-148.

Bondemark L, Kurol J, Bernhold M. Repelling magnets versus superelastic nickel-titanium coils in simultaneous distal movement of maxillary first and second molars. Angle Orthod. 1994; 64(3): 189-98.

Bondemark L. A comparative analysis of distal maxillary molar movement produced by a new lingual intra-arch Ni-Ti coil appliance and a magnetic appliance. Eur J Orthod. 2000 Dec; 22(6): 683-95.

Kalra, V. The K-Loop Molar Distalizing Appliance. J. Clin. Orthod. 1995; 29: 298-301.

Kalra V. Aparato de asa en K para distalizer molares. J. Clin. Orthod. 1997; 3: 14-17.

Greenfield RL. Fixed piston appliance for rapid Class II correction. J Clin Orthod. 1995 Mar;29(3): 174-83.

Furgueson, et al. A Comparison of Two Maxillary Molar Distalizing Appliances with the Distal Jet. World Journal of orthodontics. 2005 ; 6(4): 1-9.

Dr. Jacques Léonard has been practicing dentistry for the past 24 years. He graduated from Université Laval in Québec city in 1992 and he became American Board certified in 1992. And, recently received an IAO Senior Instructor designation. To date, he has attended more than fifty conferences about orthodontics around the world that were lead by the greatest specialists in the field. He is constantly abroad, searching for new technologies and techniques to improve his practice.

IJO  VOL. 27  NO. 3  FALL 2016

FEATURE

This article has been peer reviewed.

Moving a Blocked-Out Bicuspid into the Arch Using the “Sleeze”

By Ahmed Masoud, BDS, MSc

Abstract: Dental crowding can frequently result in a tooth becoming palatally blocked-out. When the tooth is displaced too far, tying the tooth to the archwire can become unfeasible. A modified “slingshot” technique is presented to bring a blocked-out bicuspid into the arch. The elastomeric chain acted as a “sling shot” squeezing the bicuspid in, hence the name “sleeze.”

Key words: Slingshot; blocked-out teeth; biomechanics; crowding

ntroduction Dental crowding can frequently result in a tooth becoming palatally blocked-out. When the tooth is displaced too far, tying the tooth to the archwire can be unfeasible.1 This problem can be solved by using a relatively stiff base archwire engaged in all but the blocked-out tooth. The blocked-out tooth can then be pulled towards the archwire by any of the following devices: elastomeric thread or chain, cantilever spring, or a nitinol auxiliary (piggyback) wire.2 Additional techniques include: using heat-activated nitinol wires, ligating an elastomeric chain to the two adjacent teeth to act as a “slingshot” (Figure 1), using acrylic plates that incorporate a pushing mechanism such as a finger spring, and progressively engaging a nitinol wire using a stainless steel ligature wire.

The techniques stated above often need the creation of space by means such as open coil springs, before or while the blocked-out tooth is being moved towards the wire. However, when the adjacent teeth are severely rotated (Figure 2A), the bracket cannot be positioned in the proper position, and some practitioners would prefer to create some space to allow positioning the bracket properly rather than reposition it later.

Moreover, in the case below, the patient had a gum-scratching habit at the location of the blocked-out tooth and attempts to place a ceramic bracket, a metal bracket, and a metal button on

Figure 1 IJO  VOL. 27  NO. 3  FALL 2016

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International Journal for Orthodontics Quarterly

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Tamiko Kinkade

International Journal for Orthodontics 750 N. Lincoln Memorial Drive, Suite 422 Milwaukee, WI 53202-4020

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Same as above Dr. Michel Champagne 44 Patch Brome, Quebec, Canada J0E 2K0

Steve Galella, DDS, IBO Suite 16, 875 W Poplar Ave, Collierville, TN 38017

Tamiko Kinkade 1417 James Street Springfield, IL 62703

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750 N. Lincoln Memorial Drive, Suite 422 Milwaukee, WI 53202-4020

International Journal for Orthodontics

the upper left first bicuspid (UL4) have all failed because of it.

For that reason, a palatal approach was chosen. Alternatively, a bicuspid band could have been used.

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Technique A button was bonded to the palatal surface of the UL4, and an open coil spring was used between the upper left canine and the upper left first molar (UL6). An elastomeric chain was then tied from the button to the palatal surface of the band on the UL6, acting as a slingshot to push the upper left second bicuspid (UL5) buccally (Figure 2A). The side effects on the UL4 were to rotate it and pull it mesially, thus creating space distally. One of the greatest thrills for an orthodontist excited about biomechanics is when the side effects of the mechanics used work in the orthodontist’s favor, which was the case here.

The elastomeric chain acted as a “slingshot,” squeezing the UL5 in, hence the name “sleeze.”

In three months, about 4mm of space was created (Figures 2B, 2C, 2D). A bracket was bonded to the UL4, and an open coil was used between the UL4 and UL6 while still continuing the slingshot technique (Figures 2D and 2E). Once the UL5 was close enough, an elastomeric chain was used to bring it more buccally (Figure 2F). This was followed by fully engaging a nitinol wire to finish the case (Figure 2G). The transpalatal arch was already in place to correct a dental posterior crossbite at the UL6. Nonetheless, having it in place prevented unwanted side effects on the UL6 and is advisable.

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References 1.

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Park JH, Sanchez DJ. Dual approach for moving a blocked-out tooth into the arch. J Clin Orthod. 2008 Jun;42(6):356-7.

Proffit WR, Fields, HW, Sarver, DM. (2007) Contemporary Orthodontics.

Fourth ed., St. Louis, MO: Mosby Elsevier.

Dr. Ahmed Masoud is a faculty member in the Department of Orthodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia. He also serves as a Clinical Assistant Professor, Department of Orthodontics, College of Dentistry, University of Illinois, Chicago, Illinois and is a PhD candidate, Graduate Program in Neuroscience, University of Illinois, Chicago, Illinois.

Corresponding author: Ahmed I. Masoud can be reached at: +966503602125 or via e-mail: aemasoud@kau.edu.sa.

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IJO  VOL. 27  NO. 3  FALL 2016

FEATURE

This article has been peer reviewed.

Hypoplastic Canine: Would Treatment Decision be Different if the Diagnosis Were Made with Computed Tomography?

By Giordani Santos Silveira, DDS, MD; Johnny Holanda de Gauw DDS, MD; José Nelson Mucha DDS, MD, PhD

Abstract: This article discusses the orthodontic treatment of a girl, 9 years old, who presented with Class II malocclusion, bimaxillary protrusion, anterior open bite, and congenital absence of the right lower premolar, in which a severe hypoplasia on right maxillary canine was only noted after the extractions of the first maxillary premolars.

Key words: Hypoplasia;Orthodontics;Cone Beam Computed Tomography;Dental Extraction

case of a patient subjected to orthodontic treatment with dental ntroduction extractions associated with an open bite, dental bimaxillary In orthodontics, decision-making relies largely protrusion, agenesis of a mandibular second premolar, and a on a correct diagnosis based on vital information maxillary permanent canine with enamel hypoplasia. obtained through a clinical examination of the patient as well as complementary tests comprising casts of the Case Report dental arches, photographs, dental and facial x-rays, and/or A female patient aged 9 years and 1 month old presented at computed tomography (CT).1,2 the orthodontic clinic accompanied by her legal guardian. Her It is often that during orthodontic planning, orthodontists chief complaints were anterior open bite, protruding teeth, and are faced with a thorny dilemma which has haunted finger sucking habit (Figure 1). orthodontics since the dawn of its history, i.e., to extract or not Clinical examination disclosed a convex facial profile to extract.1,3-5 The key factors in favor of extracting teeth for with moderate protrusion of the lips, increased lower third, orthodontic purposes are related to the aesthetic improvement of symmetrical face, competent lips, and low exposure of the the face like bimaxillary protrusion, addressing a lack of spaces maxillary incisors on smiling. The intraoral aspect revealed in the dental arches, and correcting certain malocclusions such mixed dentition, two canines on the right side of the upper as open bite and Class II in adults.1,6,7 dental arch, Angle Class II, 6 mm anterior open bite, and 5 The teeth more commonly extracted are the first mm overjet. The permanent teeth exhibited white spot lesions premolars.8 Under certain circumstances, however, teeth can be throughout the crown. There were no anatomical changes, extracted due to carious injuries, root resorption, bone loss, or cracks, or enamel discontinuity with underlying dentin extensive or inadequate restorations.6 exposure, which suggested mild generalized enamel hypoplasia Dental development disorders, be it related to number (Figure 1). (agenesis), form (microdontia, macrodontia), or structure (enamel hypoplasia), can also influence the choice of the tooth to be removed. However, exercising orthodontic movement control can prove more challenging in these cases.6 Enamel hypoplasia is manifested as patches, grooves, surface defects, and irregularities in the tooth enamel of mild-to-severe intensity. The causes may range from systemic factors, as in the case of nutritional deficiency and excess fluorine, local factors, by trauma or infection, or hereditary factors (amelogenesis imperfecta).9 This change can be found clinically by direct visualization of the teeth affected and may not always be identified by x-ray examination.9 The purpose of this study is to discuss the diagnosis as well as the decision-making process and alternate treatment approaches by reporting the Figure 1: Intraoral and facial photographs (at age 9 years and 1 month) IJO  VOL. 27  NO. 3  FALL 2016

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Radiographic examination showed a missing right mandibular second premolar, a right maxillary supernumerary primary canine, and a right maxillary permanent canine showing some rotation (Figure 2). Further information obtained from a profile radiograph and data from cephalometric analysis can be seen in Figure 3. Medical and dental history revealed no systemic changes or noteworthy findings.

Treatment Goals The major goals were as follows: 1. achieving a Class I relationship 2. establishing proper overjet and overbite by closing the anterior open bite 3. correcting the dental and labial bimaxillary protrusion as well as achieving proper occlusal contacts in all teeth, efficient anterior and lateral disclusions 4. resulting stability Treatment Alternatives for a Missing Mandibular Premolar 1- Maintaining a primary tooth: In a study10 which evaluated 41 individuals aged 13.6 to 31.8 years, all presenting with agenesis of one or both mandibular second premolars, and the presence of primary second molars, it was found that only 2 of 59 teeth showed exfoliation. Five of these were extracted, and 2 were replaced by third molars. None of the patients who were over 20 years old lost any tooth whatsoever. Therefore, apparently, the teeth that managed to survive until this age seem to have a good prognosis for long-term survival.

2- Restoration of the primary tooth: Performed primarily to restore stable occlusal contacts.11 3- Slicing or hemisection of a primary tooth: Slicing of primary molars in patients aged 8 and 9 years promotes a relatively controlled mesial movement of the first permanent molars with minimal rotation or inclination.12 Removal of the distal half of the primary second molar can provide space closure in stages. Then closure of the remaining space can be carried out after removing the mesial half of the primary second molar.

Hemisection cases compared with cases involving extraction of the first or second premolars showed significant movement of the molars toward the anterior region, thus facilitating the relationship with the maxillary molars while improving facial aesthetics.13 4- Extraction of a primary tooth and spontaneous space closure: The early removal of primary molars favors the mesial movement of the first permanent molar, with minimal inclination.14 In the event that lateral incisors and mandibular second premolars are missing, the early extraction of the primary teeth and replacement of the lateral incisors with the canines through closure of lower space are recommended.15 Likewise, in cases where the mandibular second premolars are missing, excellent results can be achieved without compensatory extractions in the maxillary arch.16 In cases presenting with ankylosis and submersion of the primary molar, the latter can be removed to allow the eruption of the other teeth and the concurrent closure of the space in order to remove the bony defect. Space closure may

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Figure 2: Panoramic radiograph showing specifically the congenital absence of the right mandibular second premolar and the supernumerary maxillary primary canine (at age 9 years and 1 month)

Figure 3: A. Lateral cephalometric radiograph, BCephalometric tracing and measurements (at age 9 years and 1 month)

be considered a successful alternative, even in cases where the mandibular second premolars are missing unilaterally.17 5- Orthodontic space closure18 6- Autograft: Studies evaluating the replacement of missing mandibular second premolars with autograft attained success rates that ranged from 82% to 92% within a four-year period.19-21 Autograft features a good prognosis in growing patients as it allows the vertical development of the alveolar bone while providing a permanent solution to agenesis cases.19-21 7- Replacement of implants and the prosthetic solution: In cases where multiple teeth are missing and involvement of the maxillary premolars occurs, this may be the best alternative.22 Primary molars should be removed as near as possible to the time when the implant is placed to avoid reducing the buccolingual bone volume. Implants seem to be a good alternative in adolescents with extensive aplasia provided that the craniofacial growth has ceased or is nearly complete.23 Treatment Progress and Treatment Performed At the age of 9 years and 1 month old, only these steps were followed: (1) Extraction of the mesial-most primary canine to assist in correcting the midline, which was slightly deviated, and thereby ensure more space for closing the bite; (2) referral to a speech therapist to assist in eliminating the finger sucking habit; and, (3) waiting for the occlusion to develop, which might include the possibility of late development of the left mandibular second premolar.

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Figure 4: Intraoral and facial photographs (at age 10 years and 11 months)

The patient returned for reassessment at the age of 10 years and 11 months old. Clinical details can be seen in Figures 4 and 5. Despite some progress being made in the dentition, the panoramic radiograph basically revealed the missing right mandibular second premolar and right maxillary permanent canine with a mild rotation (Figure 6). The dental and skeletal condition in profile radiography and cephalometric analysis remained much the same (Figures 7 and 8).

It was decided that it was too early to start treatment, but the plan defined at this time, as agreed with the legal guardians, was the extraction of: (1) first maxillary premolars, (2) mandibular primary second molars, and (3) left mandibular second premolar, which resulted in the closure of spaces in the mandibular arch without the need for further procedures in the region of the missing mandibular second premolar.

The patient returned at age 11 years and 7 months old, and a new panoramic radiograph was taken (Figure 9) which revealed that the occlusion had indeed evolved as the first maxillary premolars erupted, exhibiting the same characteristics noted above, i.e. a missing mandibular second premolar and right maxillary premolar while the right permanent canine showed a mild rotation.

The extractions were performed, and the patient returned at age 12, when the orthodontic treatment was started. Fixed orthodontic appliances were bonded to all teeth on both dental arches. The bracket system was Standard Edgewise with 0.022”x0.028” slots.

After the eruption of the right mandibular canine, a severe enamel hypoplasia ensued (Figure 10) which had not been hitherto identified by either the orthodontist or the radiologist

Figure 5: Dental casts (at age 10 years and 11 months)

Figure 6: Panoramic radiograph showing specifically the congenital absence of the right mandibular second premolar (at age 10 years and 11 months)

Figure 7: A. Lateral cephalometric radiograph, BCephalometric tracing and measurements (at age 10 years and 1 month) IJO  VOL. 27  NO. 3  FALL 2016

Figure 8: Cephalometric superimposition of the tracings at ages 9 years and 1 month, and 10 years and 11 months

Figure 9: Panoramic radiograph (at age 11 years and 7 months) 79

Figure 10: Sagittal (A) and occlusal (B) views of severe enamel hypoplasia in the right maxillary canine

Figure 11: Intraoral and facial photographs at the end of treatment (at age 14 years and 4 month)

in their various diagnostic reports. Slicing had to be carried out on the lingual part of this canine to improve its relationship with the lower teeth given that there had been changes in the form; and, as a result, some of the contacts were no longer functional.

In order to correct the malocclusion, 0.014”, 0.018” and 0.019”x0.025” NiTi Thermoset alignment archwires were used, as well as working and finishing 0.019”x0.025” stainless steel archwires. The stainless steel archwires had delta loops between the lateral incisors and canines to allow the use of intermaxillary elastics.

Correction of the molar relationship and overjet was performed with the aid of Class II elastics, from the mandibular second molar tube to the delta loops between the lateral incisors and canines, thereby favoring the movement toward mesial of the mandibular molars and toward distal of the maxillary anterior teeth with an approximate force of 300 to 350 grams each side.

To assist in correcting the open bite, square elastics were used in the delta loops between the lateral incisors and canines in both the maxillary and the mandibular arches. The patient was instructed to use these elastics as long as possible, totaling an average of 14 to 16 hours per day.

Treatment Results All treatment goals were achieved, and the results, when the patient was 14 years and 4 months old, can be seen in Figures 11-15.

Post-treatment Follow-Up Two years and 7 months after treatment, when the patient was 16 years and 9 months old, the results remained stable with no major changes or modifications in the hypoplastic canine, which was still performing its functions properly (Figures 16).

Figure 12: Post-treatment dental casts (at age 14 years and 4 months)

Figure 13: A. Lateral cephalometric radiograph, B- Cephalometric tracing and measurements (at age 14 years and 4 months) 80

Discussion Although all the aesthetic and functional treatment results can be classified as appropriate, a severe enamel hypoplasia was detected in one of the teeth, which had not been identified in the radiographs and should therefore be addressed.

Likewise, the anterior open bite correction strategy also deserves reflection.

The treatment of choice for anterior open bite should take into consideration the major contributing factor to the clinical situation observed beyond the morphological changes brought about by this malocclusion. When the skeletal architecture is the key issue (e.g. hyperdivergent cases with short mandibular rami, increased gonial angle, and increased mandibular plane) orthognathic surgery emerges as a treatment option worthy of consideration.24,25 IJO  VOL. 27  NO. 3  FALL 2016

Open bite correction is favored by the space closure that results from extracting the premolars followed by incisor uprighting, thus reducing the interincisal angle and favoring the closure of the mandibular plane (thanks to the mesial movement experienced by the posterior teeth). Furthermore, open bite correction stability with extractions can be considered superior to stability in cases treated without extractions.26 In this clinical case, dental and labial bimaxillary protrusions were sufficient to justify per se an indication to perform extractions in both dental arches. Therefore, in light of the results, the decision to extract was highly justifiable.

The mandibular second premolar homologous to the missing tooth was extracted with the purpose of preserving the Figure 14: Superimposition of cephalometric tracings at symmetry of the arch, thus facilitating orthodontic mechanics. ages 11 years and 7 months, and 14 years and 4 months Moreover, in the maxillary arch, despite the finding of a more severe manifestation of hypoplasia in the enamel of the right canine after removal of the first premolar, this approach proved correct. Symmetry was maintained in the maxillary arch as well as improved control of the movement of the maxillary anterior teeth distally (anchorage control).

Even if the buccal surface of the right canine was affected by the most severe manifestations of hypoplasia, today’s restorative and/or prosthetic resources could circumvent satisfactorily any adverse effects that might interfere with the aesthetics of the crown.24 Periodontal aesthetics with appropriate gingival contour and canine eminence are naturally obtained when a canine root with normal shape and size is present.

In the event that one decides to extract this canine, the movement towards mesial of the right first premolar poses a daunting mechanical challenge (by increasing treatment time 15:Panoramic radiograph after orthodontic treatment (at and possibly extending the need to use temporary anchorage age 14 years and 4 months) devices) as well as aesthetic challenge, which would likely not yield results as favorable as those observed in the present report. Obtaining symmetry in the gingival contour and in the anatomy of the crown with the presence of the natural canine on the other side would require the intrusion of this premolar and subsequently an extensive restoration.27 In a hypoplastic canine, one can note some dentin exposure resulting from anatomical recontouring, which may eventually require the restoration of this tooth. However, compared with the alternative option of replacing the canine with the first premolar, the need for restoration would be immediate, and one could expect limitations in gingival aesthetics.

It may come as a surprise to the orthodontists, patients, and all those responsible for identifying the problem when they first notice the eruption of the right maxillary canine. The question to be asked at this point is whether it would be possible to foresee it before it actually happens. The answer is yes, if a cone beam CT scan is taken ahead of time.

There is still heated debate in the scientific community regarding the use of cone beam Figure 16. Intraoral and facial photographs of the patient 2 years and 7 computed tomography for diagnostic purposes in months after treatment (at age 16 years and 9 month) orthodontics. Nevertheless, the current consensus IJO  VOL. 27  NO. 3  FALL 2016

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seems to be that this type of examination should not be used as a standard part of the orthodontic records.28 Given that the radiographic image only suggested that this tooth was slightly rotated, there would be no support to justify the patient’s additional exposure to x-ray radiation with a CT scan.

No doubt, one could consider that if the Cone Beam Computed Tomography (CBCT) had been performed ahead of time, the decision to preserve the canine – and, if necessary eventually, to restore the tooth – would be the same decision reached through conventional radiography due to the aesthetic and functional reasons that would justify either the maintenance of the canine, or the proper restoration of the remaining root.

Conclusions Despite the fact that no early perception of the canine hypoplasia occurred prior to the extraction of the 3 premolars, the results achieved by taking advantage of the hypoplastic canine seem to have constituted the best possible solution.

In orthodontics, CBCT scans can contribute to the diagnosis but should not be trivialized. Even when CBCT images are used, the decision to preserve the canine, as illustrated in this clinical case, would not change.

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Sabri R. Management of congenitally missing second premolars with orthodontics and single-tooth implants. Am J Orthod Dentofacial Orthop 2004;125(5):634-42.

Thilander B, Odman J, Lekholm U. Orthodontic aspects of the use of oral implants in adolescents: a 10-year follow-up study. Eur J Orthod 2001;23(6):715-31.

Ramos AL, Pascotto RC, Iwaki Filho L, Hayacibara RM, Boselli G. Interdisciplinary treatment for a patient with open-bite malocclusion and amelogenesis imperfecta. Am J Orthod Dentofacial Orthop 2011;139(4 Suppl):S145-53.

Nahoum HI. Anterior open-bite: a cephalometric analysis and suggested treatment procedures. Am J Orthod 1975;67(5):513-21.

Janson G, Valarelli FP, Beltrao RT, de Freitas MR, Henriques JF. Stability of anterior open-bite extraction and nonextraction treatment in the permanent dentition. Am J Orthod Dentofacial Orthop 2006;129(6):76874.

Rosa M, Zachrisson BU. Integrating esthetic dentistry and space closure in patients with missing maxillary lateral incisors. J Clin Orthod 2001;35(4):221-34.

Turpin DL. British Orthodontic Society revises guidelines for clinical radiography. Am J Orthod Dentofacial Orthop 2008;134(5):597-8.

Dr. Giordani Santos Silveira is a Specialist in Orthodontics and MD. He obtained his MD at the Fluminense Federal University in Niterói, RJ, Brazil, and is currently in private practice in Belo Horizonte, MG, Brazil. His practice specializes in Orthodontics.

Dr. Johnny Holanda de Gauw is a Specialist in Orthodontics and MD. He obtained his MD at the Fluminense Federal University in Niterói, RJ, Brazil, and is currently PhD student at Rio de Janeiro Federal University in Rio de Janeiro, RJ, Brazil.

Dr. José Nelson Mucha is MD and PhD. He obtained his MD and PhD at the Rio de Janeiro Federal University, Rio de Janeiro, RJ, Brazil, and is currently Professor and Chair at Fluminense Federal University in Niterói, RJ, Brazil.

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LIT REVIEW Reviewer: Michel Champagne DMD, MAGD, IBO, CDE

Corticotomies and Orthodontic Tooth Movement: A Systematic Review Patterson BM, Dalci O, et al: J Oral Maxillofac Surg; 2016;74 (March): 453-473.

It has been suggested that the corticotomy elicits a temporary acceleration of the processes involved in alveolar bone healing by releasing cytokines, which allows roots to move more rapidly through bone. This article will evaluate the available evidence concerning the corticotomy procedure’s effect on orthodontic tooth movement and on tooth and supporting tissue health.

The authors searched electronic databases for published and unpublished literature that investigated the effects of the corticotomy procedure on orthodontic tooth movement and on the periodontium, root resorption, and tooth vitality. Only randomized clinical trials (RCTs) and controlled clinical trials (CCTs) on humans were eligible for inclusion. Fourteen articles (6 RCTs and 8 CCTs) were selected for inclusion in the review.

The studies included 175 patients who underwent corticotomy and 170 control subjects. The evaluated corticotomy techniques appeared to generate a statistically meaningful short-term increase in the rate of tooth movement that ranged from 1.5 to 4.0 times the normal rate. The 2 studies that examined the rate of tooth movement at regular intervals reported that the rate slowed after a few months and was similar to the control at 4 months. There were no apparent adverse effects on the periodontium, root length, and tooth vitality associated with the corticotomy procedures. Because of the wide variations in the studies, it was not possible to quantitatively analyze the data in the meta-analysis form. The evidence in the assessed studies was judged to be of low quality because of high bias risks, heterogeneity, and other multiple methodological issues.

The authors concluded that corticotomy procedures can accelerate orthodontic tooth movement to a statistically and clinically meaningful level in the short term. The corticotomy procedure does not appear to increase the risk for adverse side effects to the teeth and supporting tissues. Additional highquality RCTs are needed to allow more definitive conclusions.

Reviewer’s Comments: The results of this review should be interpreted with caution because of the low quality of the available evidence on the effects of corticotomies on orthodontic tooth movement. There are more clinical impressions in the literature than real data, but real data exist from different studies. The most important aspect is not to forget that with corticotomies, the window of action for tooth movement is near 4 months.

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Clinical Application of TADs in Orthodontics: Part 2 of 2.

Michael P. Chaffee, DDS, MS. Orthodontics - May 30, 2016 Vol. 30 - No. 12 Temporary anchorage devices (TADs) can be an adjunct in correcting orthodontic problems in all 3 planes of space: anteroposterior (AP), vertical, and transverse. Absolute anchorage can be achieved with TADs, and dramatic corrections have been achieved in class II and class III malocclusions.

Posterior Teeth Eruption: The idea that a patient’s Frankfort mandibular angle (FMA) can be reduced by moving molars forward out of the wedge in extraction treatment is a fallacy. Lower molar eruption over 30 months is greatest with extraction treatment (average eruption, 3.2 mm) followed by nonextraction treatment (2.2 mm) and nontreatment (1.5 mm). If TADs are used to control posterior teeth eruption during space closure, molars move forward along the maxillary and mandibular occlusal planes. In this scenario, clinically retrognathic patients who require extractions can have enhanced chin projection and FMA reduction. Even in nongrowing patients, chin projection and FMA reduction can occur if lower molar eruption is prevented and the upper molar is intruded as the maxillary space is closed.

Vertical Maxillary Excess: Miniscrews placed between maxillary anterior teeth can enhance upper incisor intrusion in deep-bite patients with excessive gingival display. Maxillary TADs can help intrude the entire maxillary dentition in patients with vertical maxillary excess. Anterior open bites can be closed effectively using TADs to intrude maxillary posterior teeth. If only maxillary intrusion is accomplished, lower molars will erupt more than usual to compensate for the upper molar intrusion.

Because of potential compensatory eruption, usually upper and lower TADs are indicated for severe anterior open bites. Because of probable intrusion relapse, over-intrusion of posterior teeth to close an anterior open bite is recommended. When correcting anterior open bites with miniplates, the average relapse rates are 27% on lower first molars and 30% on lower second molars.

In dolichofacial patients who undergo anterior open-bite correction via TADs plus a maxillary intrusion splint, maxillary molar relapse ranges from 0.5 mm to 1.5 mm. In patients who have anterior open bites that show the proper amount of upper incisor display, segmental mechanics can be used for posterior intrusion while avoiding any unwanted upper incisor extrusion.

Miniscrews placed palatally between maxillary first and second molars and facially between first and second premolars can effectively intrude the posterior maxillary segment. If miniscrews are placed between first and second molars only, tipping of the posterior segment can occur by extrusion of first premolars.

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Maxillary Expansion: In young adolescents, traditional rapid palatal expansion (RPE) results from about 50% skeletal and 50% dentoalveolar expansion. Several studies have shown that the effectiveness of sutural expansion is similar for TADsupported and traditional RPE. However, in an unpublished thesis at Saint Louis University, Helmkamp has some slightly more encouraging findings. Hyrax® tooth-borne rapid maxillary expansion (RME) demonstrates the expected 50% sutural and 50% dentoalveolar expansion, while implant-supported RME shows 66% sutural and 34% dentoalveolar expansion.

Treatment Effects of Fixed Functional Appliances in Patients With Class II Malocclusion: A Systematic Review and Meta-Analysis.

Zymperdikas VF, Koretsi V, et al: Eur J Orthod; 2016;38 (April): 113-126.

Since most previous studies examining the effects of treatment with fixed functional appliances have demonstrated varied patient responses in terms of skeletal compared to dental changes, the authors wanted to survey the existing literature to determine the cephalometric changes associated with orthodontic treatment using fixed functional appliances.

A total of 18 electronic databases were searched with relevant terms for studies published up until October 2014. Following Cochrane Collaboration guidelines, researchers screened for articles of prospective controlled trials involving Class II patients treated with fixed functional appliances compared to untreated Class II patients. Two authors independently summarized the data and conducted a meta-analysis to assess the outcome of angular measurements from lateral cephalometric analyses based on changes from the time of functional appliance placement to immediately after its removal. Subsequent subgroup analysis based on patient and appliance-related factors was also performed. The initial search of the literature and subsequent assessment resulted in 9 studies fulfilling all inclusion criteria.

The total combined sample included 244 treated patients with a mean age of 13.5 years compared to 174 untreated controls averaging 12.8 years in age. The consolidated findings for statistically significant treatment effects were normalized per year in treatment and included an increase in SNB angle of 0.87° and a reduction in SNA angle and ANB angle of 0.83° and 1.7°, respectively. Dental effects included a reduction in upper incisor proclination of 7.3° and proclination of the lower incisor by 8.0°. There was a wide degree of variation in treatment effects between patient age and appliance designs; however, due to significant heterogeneity between studies, no definitive recommendations could be drawn. They concluded that the short-term treatment effects of fixed functional appliances include little change to skeletal variables but a predictable uprighting of maxillary incisors and proclination of mandibular anterior teeth.

Reviewer’s Comments: The review was well-conducted and involved a large number of studies; it is clear that fixed functional appliances result in little clinically significant skeletal change but rather provide a treatment effect through dentoalveolar changes to the upper and lower dentitions.

Sometimes this approach is a valid one mainly when the patient refuses orthognatic surgery.

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Evaluation of Corticotomy-Facilitated Orthodontics and Piezocision in Rapid Canine Retraction.

Abbas NH, Sabet NE, Hassan IT: Am J Orthod Dentofacial Orthop; 2016;149 (April): 473-480.

Have you ever encountered a patient that does not wish a shorter treatment? Are corticotomy or piezocision actually better to increase the rate of tooth movement? The authors wanted to compare the rate of canine retraction of corticotomyfacilitated canine retraction versus piezocision. 20 patients who had their maxillary first premolars extracted prior to orthodontic treatment were included. The subjects were subdivided equally into 2 experimental groups. One group received canine corticotomies and the other piezocision. In each group, the contralateral first premolar was extracted, as would typically be done for orthodontic treatment, and acted as a control.

Immediately post-surgery, Nitinol coils were used to retract the maxillary canines, and the rate of canine retraction was measured for 3 months after the start of canine retraction. The rates of canine-crown tip were greater in the experimental sides than the control sides in both groups. There were no differences between the experimental and control sides or the 2 experimental sides in canine inclination, canine rotation, or molar movement, and no differences in any of the periodontal readings in either the corticotomy or the piezocision groups as measured before the start of canine retraction and 3 months after canine retraction.

The authors concluded that both corticotomy and piezocision increased the rate of canine retraction.

Reviewer’s Comments: Clearly both corticotomy and piezocision increase the rate of orthodontic tooth movement.

The question is whether patients are willing to endure the additional hard and soft tissue insults that result from these 2 procedures in order to save some overall treatment time. Studies should be done for more limited interventions and their effect on tooth movement.

Gingival Labial Recessions and the Post-Treatment Proclination of Mandibular Incisors.

Renkema AM, Navratilova Z, et al: Eur J Orthod; 2015;37 (October): 508-513.

We have always read that mandibular incisor proclination is an often undesirable side effect of orthodontic treatment, particularly in Class II patients. Excessive proclination of incisors is thought to lead to bone dehiscence and gingival recession over time. The authors decided to assess and compare gingival recession in patients with and without incisor proclination following orthodontic treatment who were retained with a fixed lingual retainer. The records of a university-based dental clinic were retrospectively reviewed for patients aged 11 to 14 years at baseline, who had dental casts and lateral cephalographs available from pre- and post-treatment as well as 5 years of retention with a fixed lingual retainer. Based on the post-treatment inclination of the mandibular incisors relative to the mandibular plane, the patients were separated into non-proclined (<95.0°) and proclined groups (>100.5°). Incisor recession was determined by measurement of the clinical crown heights of the dental casts, and the extent and number of recession sites were recorded and compared between groups. The study sample consisted of 57 patients in the non-proclined group, with an average postIJO  VOL. 27  NO. 3  FALL 2016

treatment incisor angle of 90.8°. A total of 60 patients with a post-treatment angle of 105.2° formed the proclined group.

The rate of extraction was similar between groups, though the amount of proclination from treatment was greater (6.6° vs 1.3°) in the proclined group, which also corresponded to a greater treatment increase in crown height (0.1 mm vs –0.12 mm). The mean increase of clinical crown heights of mandibular incisors from baseline to the end of the 5-year retention period ranged from 0.75 to 0.83 mm in the non-proclined and proclined groups, respectively. This difference between groups was not statistically significant, nor was the number of teeth scored with recession. The authors found that proclination of mandibular incisors during orthodontic treatment did not increase the risk of gingival recession at 5 years post-treatment.

Reviewer’s Comments: The results of this study support the notion that proclination alone is not associated with gingival recession. The authors did not research the gingival biotypte of the patients. Are thin gingival tissues more at risk, a question that needs an answer.

Clinical Application of TADs in Orthodontics: Part 1 of 2.

Michael P. Chaffee, DDS, MS. Orthodontics - April 30, 2016 Vol. 30 - No. 11 Temporary anchorage devices (TADs) have created a paradigm shift by facilitating the correction of multiple orthodontic problems. We must assess different points for better understanding.

Miniscrew Placement: When using miniscrews as TADs, their practicality depends on proper placement and adequate cortical bone thickness. (Resource: Park J, Cho HJ. Am J Orthod Dentofacial Orthop. 2009; 136 [September]: 314.e1-12.) The clinician must select an inter-root space that will accommodate placement of 1.5-mm miniscrew without having root contact.

For example, for a molar intrusion, a good buccal location is between the second premolar and first molar where the interroot space is 2.4 mm. If buccal bone anatomy allows, insert the screw in an apically directed angle, allowing the space to be an average of 3.3 mm at 9.0 mm apical to the cementoenamel junction (CEJ). On the palatal aspect, miniscrew placement between the first and second molar is practical, with about 3 mm of inter-root space at 7 mm apical to the CEJ. In the lower arch, the inter-root spaces practical for miniscrew placement are between the lower second premolars, first molars, and second molars. Cortical bone thickness varies between locations and is a factor in initial miniscrew stability. Ideal vertical location of miniscrews depends on personal preference and varying patient anatomy. Screws placed too coronally can encroach on the alveolar crest, leading to increased failure risk. Even under ideal circumstances, some screw failure must be expected: the average failure rate is about 15%.

Class III Correction: Dramatic orthopedic Class III correction has been achieved with the timely use of bone plates and De Clerck mechanics while avoiding dental compensation.

Class III elastics off of maxillary and mandibular bone plates result in orthopedic correction by both maxillary protraction and inhibition of mandibular projection. Bone-anchored orthopedic traction also closes the gonial angle, but any further IJO  VOL. 27  NO. 3  FALL 2016

forward projection is offset by glenoid fossa remodeling at the anterior eminence and bone resorption at the posterior wall. As a result, the maxilla and midface move forward, but the mandible does not rotate backward and downward as seen with facemask therapy.

Class II Correction: TADs are also effective for Class II correction, but the mechanics differ depending on whether the patient is brachyfacial or dolichofacial. In low angle Class II cases in growing patients, correction is a combination of mainly mandibular growth and some maxillary distalization. While AP correction is the goal, high angle Class II correction involves using TADs to control the vertical dimension. With functional appliances, most Class II corrections involve dental movement rather than condylar growth. But TADs can help control 2 increments of vertical facial growth by controlling the upper and lower posterior teeth. By doing so, condylar growth will likely be greater than vertical facial growth, resulting in greater chin projection.

Evidence-Based Dentistry: An Outline of How to Proceed.

Michael T. Goupil, DDS, MEd, MBA: Special Presentation.

Orthodontics - Evidence-Based Dentistry 2016 - Vol. 31 - No. 1 How do we perceive evidence-based dentistry (EBD)?

Should it be a patient-centered treatment approach that balances the patient’s needs and preferences with the latest scientific evidence and the clinician’s expertise? How does one go about incorporating EBD into the treatment planning process?

Patient Assessment: First, in most cases, the patient’s condition can be easily assessed through (1) clinical examination and review of the medical history and (2) information captured through earlier questionnaires. Pointed questions about what the patient is looking for regarding his or her health, in general, and his or her oral health, specifically, will help assess the patient’s desires and values, which can be further expanded as treatment options are discussed during the informed consent process.

Clinician’s Expertise: For the most part, you know your own clinical experience and expectations. Nonetheless, from time to time, you need to objectively review your treatment experiences and outcomes. Our success rates may not be as high as we want to believe.

Scientific Evidence: Incorporating scientific evidence into EBD is a little trickier. With practice, this step need not be time-consuming. “Scientific evidence” is frequently interpreted as only that which is published in current literature. This is partially true, but you also must consider what you learned in school, in professional meetings, and during discussions with peers and colleagues. You should also incorporate current standards of the American Dental Association and those of your specialty and community. These are only a few resources that you must use when looking for scientific evidence. None of these resources can be considered absolutely true and must be evaluated using a systematic, critical thinking approach.

Scientific Literature: Getting and/or staying updated with the scientific literature can be intimidating. To make this task less daunting, take an active approach in staying abreast of the scientific literature. I recommend that you set aside a few minutes each day to read the current dental literature.

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I recommend the Journal of the American Dental Association (JADA), which frequently updates us as to important changes in the standards of our profession. I also recommend Dental Abstracts, which supplies easy-to-read summaries of potentially relevant articles from a wide variety of journals that are generally not part of our routine reading.

Numerous online resources are available to help identify current literature and other scientific resources. While Google is a good search engine, you may also try SUMsearch, PubMed, and the Trip database.

Practical Acquisition of Scientific Evidence: Textbooks and Online Search Engines.

Michael T. Goupil, DDS, MEd, MBA: Special Presentation.

Orthodontics - Evidence-Based Dentistry 2016 - Vol. 31 - No. 1 In your practice, you will encounter patients with disease entities and/or are receiving medications for which your knowledge base is weak. At other times, you will need answers about appropriate treatments. Numerous scientific resources are available to help answer your questions. Numerous online resources are available to help identify current literature and other scientific resources. While Google is a good search engine, you may also try SUMsearch, PubMed, and the Trip database.

Textbooks: Although you need to use current sources, textbooks are one frequently overlooked resource. Remember that textbooks may already be outdated when published, yet you should consider using them when searching for more general information or more comprehensive in-depth information to help build or refresh your baseline knowledge.

Search Engines: When performing a literature search, the more specific the question, the more likely it is that the results are applicable to your need. However, if your question is too specific, the search engine may not locate any resources.

Therefore, the response from your search engine depends on how you set the sensitivity. The type of question you ask and the kind of information for which you are searching will determine the best place to start your investigation.

Medical History: For questions about information in a patient’s medical history, you may need only a drug app on your phone. A simple Google™ search in which you enter only the drug name or medical condition may suffice. Yes, even Wikipedia may give you the wanted information.

SUMsearch.org: For a number of years, the University of Texas at San Antonio has championed evidence-based practice in a real-world environment. They recognize the value of your time and, through their search engine at SUMsearch.org, they attempt to make this method of evidence-based research as easy as possible. SUMsearch.org is an excellent search engine for obtaining good-quality literature returns. This search engine is designed to readily accept your PICO questions (Patient/ Population; Intervention; Comparison; Outcome).

Other Engines: If your question does not readily adapt to using a PICO statement, a number of other databases are available, such as PubMed (http://www.ncbi.nlm.nih.gov/ pubmed/) and Google. Another recommended search engine is Trip database (www.tripdatabase.com), which also provides established practice guidelines that can help you in the decisionmaking process.

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Another Approach: Another way to formulate your search question is through the use of the “When, With, Where” type of questions used in problem-based learning pedagogy. What is the nature of …? What is the significance of …? What is the relationship of …? Select the most applicable question and then fill in the blank at the end of the question. For example, you might ask “What is the relationship of diabetes and periodontal health?”

Quick Assessment of Information Sources: Level of Evidence, Age, Methodology.

Michael T. Goupil, DDS, MEd, MBA: Special Presentation.

Orthodontics - Evidence-Based Dentistry 2016 - Vol. 31 - No. 1 When you practice evidence-based dentistry, you seek out the latest information to help answer questions and inform treatment-related decisions. Various resources are available, such as online search engines. Once potential articles are identified, you need to assess the articles and studies to determine whether the scientific evidence they provide is reliable. To quickly assess the reliability of an article, check the level of evidence, publication date, sample size, and follow-up duration. Look carefully for potential sources of publication bias.

Level of Evidence: The “level of evidence” is a rating system meant to help clinicians conduct their own rapid appraisal of the evidence provided by a study. In this system, evidence is ranked from strongest (Level 1) to weakest (Level 5). Level 5 evidence indicates an editorial or opinion paper; Level 4 indicates a case report; Level 3 indicates a case-control study; Level 2 indicates a cohort study; and Level 1 indicates a randomized controlled trial and/or meta-analysis systematic review. Several search engines allow you to designate the level of evidence for which you are searching. While Level 1 evidence is preferred, that type of evidence will not always be available. In most situations, you must settle for a lower level of evidence, but at least the search engine can help you identify current resources with the best level of evidence available.

Publication Date: Several search engines allow you to designate the range of publication dates that you would like searched. Although historical literature may have its place, it may not be the best resource for determining treatment options for your patient. Generally, I recommend searching for articles published ≤5 years ago. Remember the adage: once an article is published, it is already outdated by as much as 18 months.

You need to base your decisions on the best and most current literature available.

Publication Bias: Just because something is in print, this does not make it true. In addition, studies whose results show a statistically significant difference are more likely to be published than are studies without a statistically significant difference.

Therefore, be mindful that what you are reading is already a result of publication bias.

Study Methodology: Check the article’s “Methods” section.

Is the sample size large enough to indicate whether a statistical difference is valid? I prefer studies with a power analysis conducted to ensure an appropriate sample size. If test groups are compared over time, was the time interval long enough? A difference noted initially may be statistically significant, but when the study population undergoes a longer follow-up, that difference disappears.

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Author Guidelines

International Journal of Orthodontics MANUSCRIPT SUBMISSION Manuscripts are to be submitted electronically at http://www. editorialmanager.com/iaortho. If the manuscript is written in a language other than English, the author(s) must submit an English translation. The author may also submit a copy in his or her native language that will published in the online version only with a mention in the printed issue that the article is available online in his or her own language. The manuscript must be original and submitted exclusively to IJO. The Journal invites authors to submit: n Clinical reports n Technique articles n Review articles n Case reports MANUSCRIPT FORMAT Abstract. Must include a short abstract no more than 50 words that describe the significance of the article.

Keywords. Must include keywords to help categorize the article.

Length. Manuscript should be no longer than 15 doublespaced pages, excluding figures and illustrations.

Tooth Numbering. The numbering of teeth should be international numbering. (US numbering can be added and put in parentheses.)

Non-English Manuscripts. Authors are encouraged to submit the manuscript in languages other than English for posting on the IAO website. A mention will be added to the English version published in the International Journal of Orthodontics, directing readers online for other translations.

Illustrations. Images must be available electronically as separate files. High quality digital images must be presented in one of the following formats: .tiff, .eps, or .jpg with resolution of a minimum 300 dpi. Images must not be imbedded in software programs such as Word or Power Point. The names on the digital files for photo/illustration files should match the manuscript reference.

For example, if manuscript copy references Figure 1, electronic file should be titled Figure 1.jpg. No more than 16 photographs, figures, & illustrations are recommended; if greater than 16, IJO has the right to select and limit the number if necessary. Figures must be clearly referenced as to their placement in the manuscript. Brief captions for the figures, identified by number, must be provided. All images must be titled. Radiographs must be of superior quality.

References. References must be included in the article and authors are responsible for the accuracy of references. Manuscripts without them will be returned. Cite references in the text as endnotes and number them consecutively. Citations must be referenced in the following style: Periodical: 1. Sim JM, Jefferson Y, Dillingham SE, & Keller DC. Diagnosing an orthodontic patient using three different analyses. IJO 1990; 1(4):101-106.

Book: 2. Fonder AC. The Dental Physician. 2nd ed. Rock Falls, IL; Medical Dental Arts; 1985:25-82.

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Revised Spring 2016

World Wide Web site: 3. Health Care Financing Administration. 1996 statistics at a glance. Available at: http://www.hcfa.gov/stats/stathili.htm”.

Accessed Dec. 2, 1996.

Products: Any products mentioned in the manuscript should be footnoted disclosing the company name and address.* *XYZ Orthodontic Co., 123 Main St., Los Angeles, CA 90000.

REVIEW AND EDITING PROCESS Editor. Articles will initially be reviewed by the editor. If author fails to adhere to the guidelines set forth, manuscript will be returned to the author for revision and correction.

Peer review. Articles in IJO are subject to an anonymous peer review process. Reviews may take up to eight weeks to complete.

Decision. Once the reviewing consultants have completed their critiques, the editor examines their comments and makes a decision to accept, accept with minor revisions, revise and resubmit, or reject.

Editing. IJO reserves the right to edit manuscript for conciseness, clarity, and stylistic consistency. The author has final approval before publication.

AUTHOR RESPONSIBILITIES Copyright transfer. IAO holds the copyright for all editorial content published in the journal. All accepted manuscripts become the permanent property of the International Association for Orthodontics, and may not be published elsewhere in full or in part, in print or electronically, without written permission from the International Association for Orthodontics.

Reprint permission. The author is responsible for obtaining written permission from the publisher, or the person or agency holding the copyright for any material that is reproduced from a published source.

Consent forms. Any patient who is clearly identified in the article must sign a form indicating his or her consent to be thus depicted in the article. It is the author’s responsibility to confirm consent.

Author’s photo and bio. The author(s) must submit a headshot (preferably professional) and current biographical sketch. If author holds a teaching position, the title, department and school should be included. Any position or relationship with a dental manufacturer must be identified. The sketch should include rank or title and station of authors who are in federal service, and should be limited to 60 words or less.

Conflict of interest. The author will identify any conflicts of interest upon submission of any articles.

REPRINTS The International Journal of Orthodontics provides the corresponding author a final electronic copy of the journal in which the article appears as well as an electronic copy (.pdf ) of the pages where the article appears. Requests for individual reprints of the article should be directed to Tamiko Kinkade, Managing Editor, 217-585-9065 or at tkcps@comcast.net.

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3D Dolphin 3D Digital Study Models

The 3D Digital Study Model software module is designed for doctors who want to work with 3D study model data in addition to 2D patient data. What you can do: • Store and organize 3D digital study model files • Display models in various surface and volume views • Take various 3D measurements • Run traditional 2D arch-length-discrepancy analyses A patient CBCT is not required to store 3D model data. Supports standard .STL and .OBJ file formats from existing intraoral and study model scanners. Seamless integration with CEREC Omnicam and CEREC Ortho Software. Available in the Cloud. For more information, visit www.dolphinimaging.com/3dstudymodel.

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