Maxillary excess( A-P and Vertical)
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INDIAN DENTAL ACADEMY
Leader in continuing dental education www.indiandentalacademy.com
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Excessive growth of the maxilla in children with class II malocclusion often has a vertical as well as an anteroposterior component (downward and forward growth) The effect is to prevent mandibular growth from being expressed anteriorly
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The goal of the treatment is to restrict growth of the maxilla while the mandible grows into a more prominent and normal relationship with it
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Although the application of extra oral appliance is the obvious approach, Functional appliance can be used in excessive vertical growth
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Principles in the use of head gear
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Development of head gear
Extra oral force in the form of head gear was used by the pioneer orthodontists of the late 1800s By 1920 angle and his followers stopped using head gear ( class II elastics) It was after world war II, Silas Kloehn’s impressive results with head gear treatment of Class II malocclusion www.indiandentalacademy.com
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The greatest and most significant changes occurs in the Zygomaticotemporal and Zygomaticomaxillary sutures
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Compressive force inhibit sutural growth by producing resorption at the sutural bony margins www.indiandentalacademy.com
In pre-adolescent child, extra oral appliances are always applied to the first molar
To be effective should be worn regularly for at least 10-12 hrs per day
Early evening to next morning
Current recommended force 12 to 16 ounces or 350 to 450 gms per side www.indiandentalacademy.com
INDICATIONS
Anteroposterior maxillary excess, or maxillary protrusion.
Normal mandibular skeletal and dental morphology
When there is continued active mandibular growth, primarily disposing the mandible in a forward, rather than downward direction. www.indiandentalacademy.com
Selection of head gear type 1.
Head gear anchorage location
2.
Head gear attachment to dentition
3.
Bodily movement or tipping of teeth or maxilla is desired
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The length and position of the outer head gear bow and the form of anchorage determine the vector of force and its relation to the center of resistance of the tooth
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Selection of head gear
P. Parietal, O. Occipital, C. Cervical www.indiandentalacademy.com
Long face (skeletal open bite) vertical maxillary excess Two major diagnostic criteria ď Ź
Short mandibular ramus
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Rotation of the palatal plane (more posterior growth) Most common Restraining maxillary vertical development& Encouraging antero -posterior mandibular growth www.indiandentalacademy.com
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Children with excessive face height generally have normal upper face and elongation of max and mand posteriors
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Unfortunately, vertical growth extends into the adolescent and post adolescent years Active retention
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Hierarchy of effectiveness in long-face class II treatment HP Headgear to functional with biteblocks Bite blocks on functional appliances High-pull headgear to maxillary splint High-pull headgear to molars www.indiandentalacademy.com
Spontaneous correction of Class II malocclusion ď Ź
Traditionally, clinicians viewed class II malocclusion as primarily a saggital and vertical problem
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Most Class II malocclusion in mixed dentition patients are associated with max constriction. (max width less than 31mm)
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Mandible
Maxilla
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Reichenbach and Taatz used the example foot and shoe www.indiandentalacademy.com
Class II Problems in Adolescents(12-15yrs)
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Four major approaches 1. 2. 3. 4.
Growth modification with head gear or functional appliances Distal movement of maxillary molars, and eventually entire upper dental arch Retraction of maxillary incisors into a premolar extraction space, and A combination of retraction of the upper teeth and forward movement of the lower teeth www.indiandentalacademy.com
Growth modification in adolescents ď Ź
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Growth modification would be more successful when more growth remains As a general guideline, even in the most favorable circumstances it is unlikely that half of the changes needed to correct Class II malocclusion in an adolescent would be gained by differential growth ( 3-4mm from differential mandibular growth ) www.indiandentalacademy.com
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Head gear is compatible with fixed appliances but most functional appliances are not. If a functional appliances is desirable for adolescent treatment, often a fixed functional that allows brackets on the incisor teeth is the best choice.
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Fixed Vs Removable functional appliance
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There are very few studies that have evaluated the effectiveness of removable and fixed function appliances that have followed the effectiveness of removable and fixed functional appliances to completion with fixed appliance (Phase 1 and Phase 2).
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Kevi’ O Brien et al (AJO 2003) compared twin block and herbst appliance The results of this study revealed Phase 1 treatment (O’Brien 2003) is more rapid with Herbst but overall duration of treatment is similar to that with Twin Block
There are no differences in the dental and skeletal effects of treatment between the two appliances
The
skeletal effects with both the appliances were clinically insignificant www.indiandentalacademy.com
one phase Vs two phase treatment
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To examine whether functional appliances are effective in human patients prospective randomized clinical trials were undertaken at the university of Florida, Pennsylvania and north Carolina by Timothy wheeler, Joseph Ghatari and Cemillet Tuloch respectively.
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Florida study (AJO DO-1998) Keeling, wheeler et al ď Ź
Children aged 9 years at the start of treatment was randomly assigned to control, Bionator and Headgear with Biteplates. Cephalograms were obtained initially, after cl I molar was obtained or 2 years had elapsed. The data revealed that both Bionator and headgear treatment corrected cl II molar relationship; reduced overjet and apical base discrepancies. The skeletal changes that occurred were stable; however the partime retention protocol used in this study was not effective in preventing dental relapse www.indiandentalacademy.com
The
same patients were followed through phase II treatment and in the fine report in 2003 (AJO DO-2003) There
was no significant differences in the final score when patients who wore their headgear or bionator as a retention appliance between phase 1 and phase 2 treatment were compared with patients who did not wear any appliance during this period Most
of the changes in PAR scores came from the finished results achieved regardless of the protocol or initial severity of the malocclusion. Patients
who undergo 2 phase orthodontic treatment do not achieve better results than patients who undergo 1 phase treatment. www.indiandentalacademy.com
University of Pennsylvania study – Ghatfari et al AJO DO 1998 ď Ź
Ghatari et al conducted a prospective randomized clinical study to compare the treatment effects of headgear versus Frankel functional regulator in early treatment of cl II div/ malocclusion in prepubertal children. The results revealed that both headgear and functional regulator were effective in treatment of cl II div/ malocclusion. The headgear had a distal effect on the maxilla and first molars but not the maxillary incisors. The functional regulator retrained the growth of the maxilla and resulted in retroclination of the maxillary incisors, a more forward position of the mandible and a proclination of the mandibular incisors. There were no significant differences in the mandibular length when the two appliances were compared. www.indiandentalacademy.com
University of North Carolina study
Tulloch, profit, Philip et al initiated a randomized controlled clinical trial in1997 in growing patients with cl II malocclusion. Patients were randomly assigned to one of the three groups. Group I received headgear treatment, Group 2 received functional appliance Group 3 received no treatment. www.indiandentalacademy.com
The significant findings of this study widely publishing between 1997 and 2004 are as follows There was no difference between the groups in the
ANB angle either at start or after phase 2 treatment.
There was no differences in the quality of dental occlusion between the children who had early treatment and those who did not
There was approximately the same distribution of successes and failures with and without early treatment.
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Early treatment did not reduce the percentage of children needing extraction of premolars or other teeth during phase 2 treatment.
Early treatment did not influence the eventual need for Orthognathic surgery.
There
was very little differences in the time both groups spent wearing fixed appliances.
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In conclusion there is very little evidence in the literature to suggest the two phase treatment can significantly modify growth or eliminate the need for protracted phase two treatment nor can it be justified to result is fewer extractions or avoidance of orthognathic surgery. Early phase one treatment is beneficial in reducing the incidence of incisors trauma and may be useful in correction of eruption disturbances. www.indiandentalacademy.com
Correction by tooth movement
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1.
Distal movement of maxillary molars, and eventually entire upper dental arch
2.
Retraction of maxillary incisors into a premolar extraction space, and
3.
A combination of retraction of the upper teeth and forward movement of the lower teeth www.indiandentalacademy.com
2) MOLAR DISTALIZATION
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Indications for Molar distalization ď Ź
End on molar relationship with mild to moderate space requirement
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Cases with less than a full cusp class II molar relationship
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Indications for Molar distalization
Good soft tissue profile
Borderline cases
Mild to moderate space discrepancy with missing 3rd molars/2nd molars not yet erupted
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Indications for Molar distalization
Axial inclination : Mesially angulated upper molars
Normal or Hypodivergant growth pattern
Late mixed dentition with mild crowding of anteriors
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Treatment timing :
Perhaps best time to initiate distalization is late mixed dentition and it may be too late after eruption of second molar.
Canines and premolars follow molars as they moved distally.
Vertical growth helps : it is much easier to tip a molar distally if it can extrude at the same time www.indiandentalacademy.com
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In the absence of vertical growth the most successful way to move first molar distally is by extraction of 2nd molar
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Extraction of 2nd molar can successfully correct moderate class II ( not more than 4mm)
The ideal patient for distallization is one who has less than a full cusp class II molar relation www.indiandentalacademy.com
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Main drawback of extra-oral approach is patient compliance.
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This pit fall has been overcome by the intra-oral appliances but are not effective as extra-oral appliances.
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Various appliances used for Molar Distalization :
Headgears Wilson Bimetric arch design ACCO Crozat appliance Crickett appliance Modified Nance Lingual appliance Non-extraction treatment Schmuth and muller double plates Molar distalization with magnets www.indiandentalacademy.com
Various appliances used for Molar Distalization
Use of Super elastic NiTi Jones Jig The Pendulum appliance Clasp ring Removable molar distalization splint Fixed piston appliance The K-loop appliance The distal jet Using Implants Fixed functional appliances www.indiandentalacademy.com
3) Retraction of maxillary incisors into a premolar extraction space
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A straight forward way to correct excessive over jet is to retract the protruding incisors into the space created by extracting the maxillary first premolar (more than 4mm)
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With out lower extractions , class II elastic use would have to be minimal, and extra oral force might be needed ( or lingual arch with button) www.indiandentalacademy.com
Class I
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Class II
4) Extraction of maxillary and mandibular premolars
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Class II Problems in Adults (more than 16yrs)
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Two possibilities of treatment
Camouflage
Surgery
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TVL (True vertical line) drawn through subnasale with natural head posture
0 57
Color codes used with the Arnett soft tissue cephalometric analysis
4
2 64 -5
-3
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Black Green Blue Red =
= within 1 SD = within 2 SD = within 3 SD more than 3 SD
TVL
TVL
0 57
64
4
-5
TVL
0 57
64
4
-1
0 57
64
4
2
-12
-8
-5
-11
-6
-3
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TVL
TVL
0 57 64
3
63
0 3
-1
59
1
-8
-6
-6
-5
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TVL
57
64
TVL
-2
0 71
3
53
-5
-1
-3
-12
-9
-11
-9
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TVL
57
64
0 3
-5
TVL
0 57
64
4
2
-12
-5
-11
-3
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Camouflage
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The
objective of the treatment is to correct the malocclusion while masking the underlying skeletal problem less apparent Skeletal
class II problems can be camouflaged rather well (mild to moderate) Camouflage
works better in late adolescents
( extrusive nature of orthodontic mechanics ) Camouflage
is not successful treatment for vertical max excess www.indiandentalacademy.com
Orthognathic Surgery
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Development of orthognathic Surgery
Surgical treatment for mandibular prognathism began early in the twentieth century Trauner and Obwegeser’s introduction of the sagittal split osteotomy in 1959 marked the beginning of the modern era in orthognathic surgery In 1960 Lefort I down fracture was introduced by Epker and Bell Progress in orthognathic surgery has occurred quite recently (1980s and 1990s) www.indiandentalacademy.com
CLASS II DENTOFACIAL DEFORMITIES 1.
Mandibular deficiency
2.
Vertical maxillary excess
3.
Combination The decision to operate on the mandible ,maxilla or both jaws is based primarily on the vertical and antero-posterior position of the maxillary incisor www.indiandentalacademy.com
Early vs later surgery Orthognathic
surgery should be delayed until growth is essentially completed in patients who have problems of excessive growth For
patients with growth deficiency, surgery can be considered earlier ,but rarely before adolescent growth spurt
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Class II Dentofacial deformity secondary to Mandibular deficiency
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Mandibular advancement (BSSO)
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Pre-surgical orthodontic treatment Extraction of 5 5 4 4
Reduce upper and lower incisor proclination and maintain class II molar relation www.indiandentalacademy.com
Immediate pre surgical planning
Surgical cephalometric prediction tracing
Model surgery
Occlusal splint construction
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Surgical cephalometric prediction tracing
Horizontal osteotomy of BSSO Vertical osteotomy of BSSO To properly position proximal segments
Genioplasy
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Model surgery and Occlusal splint construction
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BSSO
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Mandibular advancement with advancement genioplasty
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Immediate pre surgical planning
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Mandibular advancement with reduction genioplasty
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Class II Dentofacial deformities secondary to vertical maxillary excess
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Majority of individuals with class II vertical max excess can be treated with or with out advancement genioplasty ď ŹTwo
basic techniques for superior repositioning of the maxilla Le Fort I max osteotomy Total max sub apical osteotomy www.indiandentalacademy.com
Le Fort I max osteotomy
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Conclusion
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There
is no one ideal method for treating ClassII malocclusion.
Following
clinical examination ,a precise analysis of cephalometric radiographs and dental casts should be undertaken to identify the components of the malocclusion that deviate from “normal” Then
clinician can select the appropriate treatment regimen from among a no. of options. www.indiandentalacademy.com
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