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CE Credit: Interdisciplinary Approach for the Oral Rehabilitation of an Ectodermal Dysplasia Patient
This article offers 1.0 C.E. Credits. Test questions are available for review at the end of the article.
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AUTHORS
Konstantinos Chochlidakis, DDS, MS, is an associate professor and program director in the department of prosthodontics at the Eastman Institute for Oral Health at the University of Rochester, N.Y. He is a fellow of the American College of Prosthodontists. Conflict of Interest Disclosure: None reported.
Evangelia Lampraki, DDS, is a prosthodontist in private practice in Dubai, United Arab Emirates. She is a fellow of the American College of Prosthodontists. Conflict of Interest Disclosure: None reported.
Maria Gabriela Carranza, DDS, is an assistant professor at the Eastman Institute for Oral Health at the University of Rochester, N.Y. She is a fellow of the American College of Prosthodontists. Conflict of Interest Disclosure: None reported.
Carlo Ercoli, DDS, MBA, is a professor of prosthodontics and periodontics and the chair of the department of prosthodontics at the Eastman Institute for Oral Health at the University of Rochester, N.Y. Conflict of Interest Disclosure: None reported.
Theocharis Nikellis, DMD, is a resident in the department of prosthodontics at the Eastman Institute for Oral Health at the University of Rochester, N.Y. Conflict of Interest Disclosure: None reported.
Alexandra Tsigarida, DDS, MS, is an associate professor and program director in the department of periodontics at the Eastman Institute for Oral Health at the University of Rochester, N.Y. Conflict of Interest Disclosure: None reported.
ABSTRACT
Background: Ectodermal dysplasia is a rare genetic disorder with common oral and extraoral manifestations that require a medical-dental multidisciplinary approach.
Case description: Dental treatment is often complex, includes treatment in both jaws, starts in early childhood and involves the coordination of multiple treatment phases and specialists. The surgical and prosthetic rehabilitation of an individual with ectodermal dysplasia is presented.
Practical implications: Diagnostic and patient communication approaches, key treatment steps and prognostic indicators are emphasized in order to provide a clinically relevant protocol to the reader.
Key words: Ectodermal dysplasia, rehabilitation, implants, restorations
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Ectodermal dysplasia (ED) is a rare genetic disorder that affects the development and/ or homeostasis of two or more structures of ectodermal origin. [1] Reported prevalence is contradictory but is estimated to be 1 in 5,000–100,000 births. [1–3] Patients often present with a combination of clinical signs, such as nail malformations, hypotrichosis, sweat gland abnormalities, skin dryness and fragility and dentofacial malformations. [1–5]
The oral manifestations include dental abnormalities, such as anodontia, hypodontia or oligodontia and, especially in males, underdevelopment of the alveolar processes and tooth shape anomalies. [2,3] The latter are often evident with conical or tapered shapes of the maxillary and mandibular incisors and abnormal root formation of the molar teeth. [6] Moreover, maxillary hypoplasia, mandibular protrusion, short facial appearance and salivary flow reduction have often been reported. [2,3,7]
Orofacial impairment in ED patients affects mastication, swallowing, speech and socialization. [8] The oral healthrelated quality of life of affected individuals is low and psychological complications are common. [9–11] Due to the partial or complete edentulism, underdevelopment of the alveolar ridges is often present with resultant loss of vertical dimension. Due to the complex nature and multilevel manifestations of ED, consideration related to dental treatment should start in early childhood and include a multidisciplinary medicaldental team. Often, speech therapists and psychologists are necessary for the accomplishment of treatment goals. [12,13]
Depending on the severity and complexities of the patient’s dentofacial conditions, patient expectations and their physical and psychological growth, prosthetic treatment options range from removable dentures to implant-supported removable or fixed prostheses. [2,3,7,8,14,15] While dental implants are not ideally placed before the skeletal growth has been completed, [16] in ED patients with severe oligodontia or anodontia, the early placement of dental implants, especially in the anterior mandible, has been reported and shown to significantly improve the retention and stability of removable dentures. [16] Thus, the strategic use of dental implants for young, growing ED patients appears to be supported in the literature. From a prognostic standpoint, high implant and prosthesis survival rates have been reported in patients with ED, including zygomatic implants. [2,14,17]
Given the complexities of the treatment for ED patients, the collaboration of multiple specialists, the extended treatment time, the need to ensure adequate and effective communications among the involved clinicians and the patients and their families, it is important that the restorative dentist/prosthodontist be involved early in the care of an ED patient to coordinate the necessary steps with other clinicians to ensure a successful treatment outcome. For this purpose, the judicious utilization of digital technology during the diagnostic and planning phase can improve the surgical and prosthetic dental workflows and decrease the duration of the treatment. [18]
The purpose of this report is to describe the multidisciplinary dental treatment approach of an adult patient diagnosed with ED.
Case Report
A 32-year-old male patient presented at the University of Rochester Dental Faculty Group for comprehensive evaluation. The patient had been diagnosed with ectodermal dysplasia and was interested in improving his oral function and appearance (FIGURES 1 and 2).
Intraoral clinical examination revealed the absence of all permanent teeth except for the maxillary left second molar, left and right first molars, right first premolar and central incisors, mandibular first molars and mandibular lateral incisors (FIGURES 3 and 4). Several retained deciduous teeth were present, specifically the maxillary second molars, canines, lateral incisors and mandibular second molars, first molars and canines. Several teeth presented a conical shape, maxillary and mandibular arches appeared underdeveloped and the patient was diagnosed with severe malocclusion and loss of vertical dimension. Mandibular bilateral tori were observed. A cone beam computed tomography (CBCT) (i-CAT FLX, KaVo Kerr, Brea, Calif.) was taken and confirmed the intraoral findings (FIGURE 5). CBCT findings included vertical bone height of 5 mm in the sinus areas, and grafting would be required before any implant placement.
Initial alginate impressions were taken (Jeltrate, Dentsply Sirona, Charlotte, N.C.) and diagnostic casts fabricated. Centric relation was recorded in order to mount the diagnostic casts. Extraoral landmarks were used to fabricate a wax-up at an increased by 2 mm vertical dimension of occlusion (VDO). A composite resin mock-up was then made and tried in the patient’s mouth to evaluate aesthetics and phonetics at the new proposed VDO and to obtain the patient’s acceptance (FIGURE 6). An orthodontic consultation was sought and concluded that, for this patient, an adequate treatment outcome could be achieved without orthodontic treatment by the time the patient was satisfied aesthetically by the diagnostic mock-up.
The treatment plan included extraction of all deciduous teeth, bone augmentation procedures in four quadrants and the placement of 11 dental implants. The prosthetic treatment included all-ceramic, complete-coverage crowns and a fixed partial denture on the residual permanent teeth. Fixed implantsupported ceramic restorations were also planned for the implants placed in the edentulous sites.
Stereolithographic (STL) files of the mock-up were imported into a digital design software (Exocad, Darmstadt, Germany) (FIGURE 7); polymethylmethacrylate (PMMA) (Telio-CAD, Ivoclar Vivadent, Buffalo, N.Y.) full-arch provisional fixed partial dentures (FPDs) were then milled with a 5-axis mill (Roland DWX-51D, Roland DGA Corp., Irvine, Calif.) powered by a dedicated manufacturing software (Millbox, CIMsystem, Cinisello Balsamo, Italy). At the initial treatment appointment, tooth preparation of the maxillary and mandibular permanent teeth chosen as abutments was completed, deciduous teeth were extracted and surgical crown lengthening on the maxillary right first premolar was performed. The provisional PMMA prostheses were relined intraorally with self-polymerizing acrylic resin, finished, polished and delivered with a eugenol-based luting agent (FIGURE 8).
After two months of healing, bone augmentation procedures were carried out. Maxillary sinus augmentations were performed bilaterally via an indirect and direct approach on the right and left side, respectively, with a combination of xenograft (Bio-Oss, Geistlich Pharma North America, Princeton, N.J.) and allograft (Straumann Allograft, Straumann USA LLC, Andover, Mass.) materials.
Three months later, a new set of the provisional FPDs were milled, modified to serve as a surgical template (FIGURE 9) and used to guide the placement of 11 implants in the maxillary and mandibular arches (BLT, Straumann USA LLC) (FIGURE 10).
Three months post-implant placement, uncovering surgeries were performed and healing abutments placed. At the same visit, open tray implant impressions were taken with polyether material (Permadyne, 3M, St Paul, Minn.) and jaw relation records taken for the fabrication of a new set of implant-supported and teeth-supported fixed provisional restorations. These prostheses guided soft tissue contouring for the implant and pontic sites for two months and allowed the patient a final assessment of the aesthetics, phonetics and function ahead of the definitive prosthesis fabrication
(FIGURE 11). Final maxillary and mandibular open tray implant impressions were again made with polyether material (Permadyne, 3M). The definitive tooth-supported prostheses consisted of monolithic, zirconia (KATANA Noritake Zirconia STML, Kuraray America Inc., New York) single crowns for the four molars; feldspathic porcelain-veneered, zirconia (KATANA Noritake Zirconia STML, Kuraray America Inc.) bilayered restorations were chosen for the single crowns on the maxillary central incisors, first premolar and the fixed partial denture in the anterior mandible. For the implantsupported prostheses, a monolithic design was used for the screw-retained single implant-supported crown on the maxillary right second premolar while monolithic, screw-retained, splinted, fixed partial dentures were fabricated in the second, third and fourth quadrants (FIGURES 12 and 13). Screw retention was designed for all implant-supported prostheses with the utilization of screw channel, angled abutments (Variobase AS, Straumann USA LLC) to facilitate laboratory design and optimize the location of the screw channel. A maxillary PMMA occlusal orthotic was then fabricated. The patient was again instructed and motivated on self-performed plaque removal measures and enrolled in a six-month maintenance program. Patient was very satisfied with the final outcome and was compliant with oral hygiene at the follow-up maintenance appointments (FIGURES 14 and 15).
Discussion
Ectodermal dysplasia is a rare congenital disease that affects several ectodermal structures. Manifestations of the disease differ in severity and can involve teeth, skin, hair, nails and sweat glands. [19] Intraoral examination in an ED patient usually reveals hypodontia and oligodontia usually with peg-shaped teeth. Dental and alveolar process hypodevelopments with resultant malocclusion often compromise lip support and are responsible for a decreased lower facial height.
A multidisciplinary team effort involving oral and maxillofacial, orthodontic, periodontic and prosthodontic specialists is often required for the treatment of the dentofacial deformities presented by ED patients. [20] In this case report, though, orthodontic treatment was not included because the diagnostic mock-up showed that the position of the permanent teeth and the alveolar arch relationships could provide for an adequate projected prosthetic outcome.
While the treatment of ED patients is often complex and lasts several years, the restoration of adequate occlusion not only improves chewing function but also enhances the patient’s self-confidence and quality of life. [3] For children, removable dentures are generally considered an appropriate treatment option especially during growth, but fixed, implant-supported prostheses are often a treatment of choice for adults. [20,21]
A challenge related to the placement of dental implants may be constituted by the hypodevelopment of the alveolar processes in ED patients and the resultant need for bone grafting. While ridge augmentation grafting was successfully executed for this patient, the maintenance of the deciduous teeth had likely decreased the residual ridge resorption that could have otherwise been anticipated. It is therefore important during the early phases of treatment to retain healthy deciduous teeth until ridge augmentation and implant placement can be carried out. Once implants are placed, the implants may provide stimulation to maintain alveolar ridge dimensions. [22] An international Delphi study designed to establish clinical guidelines and consensus for the treatment approach in children with ectodermal dysplasia included the use of dental implants. [20] Even though moderately high implant failures (range of 9% to 24%) have been described in ED patients, there has been agreement that implant placement is an indicated treatment modality, even in the mandibular canine region, in 5- to- 10-year-old patients. [20,23–26] However, implant placement should be avoided adjacent to teeth until the completion of facial growth. [20] For the patient presented in this article, these considerations were moot, as the patient presented after the completion of his growth.
Regarding the design of the prosthetic restorations, a single implant was used on the maxillary right canine for a cantilever fixed partial denture on the maxillary lateral incisor. Due to the very resorbed ridge in the lateral incisor site and the challenges that a vertical augmentation could hinder, the cantilever option was chosen. A systematic review by Pjetursson et al. [27] has shown high implant and prosthesis survival for the cantilever FPDs after 10 years of followup. The survival rate of cantilever FPDs was 5% less than conventional implant FPDs, but this solution was something that was more predictable than placing narrow and short diameter implants due to bone width and distally inclined roots of the central incisors.
The implant FPDs that were used in the second, third and fourth quadrant were splinted instead of individual implant crowns. The patient was informed about the option of having individual implant crowns as compared to FPDs, and he chose to have the latter. The advantages that splinted crowns may offer are the easier fabrication process, decreased chairtime during the delivery of the prosthesis and better stress distribution in the implant/ abutment and cortical bone tissue. [28,29] On the contrary, patients with splinted crowns are not able to floss in between the crowns, which may make oral hygiene more difficult in these areas. A recent study by Yi et al. [30] showed that an implant splinted to both mesial and distal adjacent implant has a higher risk for peri-implantitis. Our patient had excellent oral hygiene throughout the treatment and was a good candidate for splinted implant crowns.
The restorative material chosen for the definitive restorations was zirconia. Due to the short clinical crowns and existing previous direct restorations on the remaining permanent molars and premolar, complete coverage instead of partial coverage crowns was the design of choice. Several studies have reported survival outcomes and biocompatibility for both teeth as well as implant zirconia restorations. [31–35] More specifically, monolithic zirconia crowns on teeth and implants with a five-year follow-up period have shown approximately 95% and 97% survival rates, respectively. [31,32] Even though the material of choice has a high survival rate, any patients with tooth- and implant-supported prostheses will need a high mechanical and biological maintenance and recall protocol for a successful clinical result. [36]
Conclusions
The diagnosis of ED is of the utmost importance for the early development of a comprehensive, interdisciplinary treatment plan. While dental and maxillofacial treatment of ED patients often takes several years, it is of paramount importance to design a team-based treatment approach that visualizes the planned outcome and is communicated to the patient and family early during the initial patient evaluation. Once treatment goals are identified and agreed upon, the rehabilitation of the ED patient can proceed toward an improvement of the aesthetics, phonetics and function and hopefully aid in increasing patient self-esteem and overall quality of life.
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C.E. CREDIT QUESTIONS
June 2021 Continuing Education Worksheet
This worksheet provides readers an opportunity to review C.E. questions for the article “Interdisciplinary Approach for the Oral Rehabilitation of an Ectodermal Dysplasia Patient” before taking the C.E. test online. To take the test, you must first be registered at cdapresents360.com. To take the test online, please go to https://www.cdapresents360.com/learn/course/internal/view/elearning/75/interdisciplinary-approach-for-the-oral-rehabilitation-of-an-ectodermal-dysplasia-patient. This activity counts as 1.0 of Core C.E.
1. The cause of ectodermal dysplasia is considered to be:
a. A virus
b. Trauma
c. Insufficient nutrition
d. Genetic
2. The oral manifestations of ectodermal dysplasia include:
a. Anodontia
b. Oligodontia
c. Hypodontia
d. All of the above
3. The reason for often observing loss of vertical dimension in an ectodermal dysplasia patient is:
a. Bruxism
b. Rampant caries
c. Underdevelopment of the alveolar ridges
d. None of the above
4. Implant supported fixed and removable prostheses are not indicated for the ectodermal dysplasia patients.
a. True
b. False
5. The use of implants for the treatment of the ectodermal dysplasia patient is indicated:
a. Only after the age of 21
b. Only for those who present with complete anodontia
c. Only if the patient is financially able
d. Even in young, growing patients
6. Manifestations of ectodermal dysplasia can also involve:
a. Skin
b. Hair
c. Nails
d. All of the above
7. Dentofacial deformities presented by ectodermal dysplasia patients can better be addressed by:
a. An endodontist only
b. An orthodontist only
c. A plastic surgeon
d. A multidisciplinary team
8. During the early treatment of an ectodermal dysplasia patient, it is important to remove the patient’s healthy deciduous teeth.
a. True
b. False
9. Lateral incisors often are replaced with a single canine implant cantilever prosthesis because:
a. Of finances
b. It is more predictable than placing narrow and short implants at the lateral position
c. It provides better aesthetics
d. The survival rate is far superior to a fixed partial denture
10. Excellent oral hygiene and follow-up is essential in the long-term prognosis of implant restorations placed during treatment of the ectodermal dysplasia patient.
a. True
b. False
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