Interdisciplinary Management of Patients With Ectodermal Dysplasia

Ectodermal dysplasia is a well-recognized syndrome that affects appendages that arise from the ectoderm, including the skin, the hair, and, of interest to the dental profession, the teeth.1 Severity of tooth loss may range from multiple missing teeth (hypodontia) to loss of a relative few.2–5 Sweeney et al2 noted that the permanent teeth most likely to be present in the upper arch were the central incisors followed by the first molars and the canines, whereas in the mandible, the canines and the first premolars and the first molars were most likely to be found. Associated with the hypodontia is lack of development of the alveolar ridges, which results in a decrease in the volume of bone available to support implants or conventional prostheses.6 Hypodontia can have psychosocial implications for patients, necessitating early prosthetic management.7,8 Patients with ectodermal dysplasia can have accompanying skeletal discrepancies caused by underdevelopment of the jaws. The purpose of this paper is to present a patient with ectodermal dysplasia who required restorative, orthodontic, and oral and maxillofacial surgery to achieve a satisfactory result. The focus is on the interdisciplinary management of a patient with complex restorative needs.

A 15-year-old girl with ectodermal dysplasia was referred for restorative care to the General Practice Residency Program at the University of Kentucky. Her concerns included an inability to masticate well and poor esthetics with animation (Figure 1a and b, Figure 2). Clinical examination showed that the patient had coarse hair and a fine texture to the skin. Skeletal analysis of her lateral cephalogram showed both vertical and horizontal maxillary hypoplasia, resulting in an over-closed appearance (Figure 3). Analysis of the dental arches showed that the patient had hypodontia, with only permanent central incisors and first molars in the upper arch and permanent canines and first molars in the lower arch (Figure 4). Fifteen retained primary teeth were identified, some of which were submerged relative to the permanent teeth. Minimal bone height was noted between the floor of the maxillary sinus and the alveolar ridge in the premolar region (primary molars). A diastema was observed between the maxillary central incisors. In the lower arch, both permanent canines had drifted distally, more on the left side, in the position of the first premolar.

Consultations were obtained from staff in orthodontics and oral and maxillofacial surgery. After these consultations were conducted, a treatment plan with several stages was designed. Stage 1 would be a Le Fort I osteotomy and sinus augmentation surgery. At stage 2, the remaining primary teeth would be removed and 13 implants would be placed. At stage 3, orthodontic movement would achieve alignment of the remaining permanent teeth and would create space for 1 additional implant. An additional implant would be placed at stage 4. At stage 5, restoration of the case would be achieved. The General Practice Residency Program coordinated and interfaced in several parts of this patient's care, as will be discussed below.

During the first stage, the maxilla was advanced and rotated downward to correct the position of the maxilla relative to the mandible. Additionally, the maxillary sinus was augmented by lifting the membrane as described by Jensen, Leopardi, and Gallegos.9 The planed position of the maxilla was established by model surgery, and a temporary prosthesis was wired in place to the mandible (Figure 5). This was removed 6 weeks later (Figure 6). The second stage was completed at 3 months after maxillary surgery, with removal of the remaining primary teeth and placement of 13 ITI implants (Straumann ITI Implant System, Straumann USA LLC, Andover, Mass) of various heights and widths. Interim maxillary and mandibular prostheses were fabricated for esthetics and function until the remaining stages were completed (Figure 7). In the lower left arch, there was room for only 1 implant. It was placed in the second premolar region until stage 3 could be completed (Figure 8). Eight weeks after placement of the implants, stage 3 began with orthodontic movement of the remaining teeth (Figure 9). In the lower arch, provisional crowns were placed on the implants placed in the lower incisor position. These implants were used as maximum anchorage to move and align the canines mesial and to align the molars. In the upper arch, provisional crowns were placed on the implants in the first premolar regions to correct molar rotations and to coordinate the occlusion with the lower molars (Figure 10). Once the ideal lower cuspid positions were achieved, an additional implant (fourth stage) was placed in the lower left first premolar position (Figure 11). The final or fifth stage was the restorative stage. A diagnostic wax-up was completed and reproduced for fabrication of temporary prostheses. The remaining natural teeth—Nos. 2, 8, 9, and 15—were incorporated into the fixed prosthetic plan to optimize esthetics and occlusion. Standard solid abutments of various sites were used for the fixed single- and multiple-unit implant prostheses. Posterior occlusion was established initially, and the case was completed by seating the single-cut crowns for the natural dentition (Nos. 3, 8, 9, and 15) (Figure 12). Total time was 25 months from the initial consultation to cementation of the fixed prostheses. No implants were lost, and the patient is under maintenance therapy in the Division of General Practice (Figures 13 and 14). Frontal and profile photographs show that the increase in facial height and projection was maintained (Figure 15a and b).

Although implant restoration in patients with ectodermal dysplasia has become more common practice, multiple issues must be considered.1–6,10 Among these are the position of the maxilla and the mandible relative to one another, the remaining teeth in the arch and their positions, the volume of bone present, and the age of the patient. Kearns et al10 followed 6 subjects who had ectodermal dysplasia and osseointegrated implants placed for prosthetic rehabilitation. Of 41 implants, 40 were successfully integrated. One mandibular implant and 4 maxillary implants placed in a partially dentate younger patient became submerged as the adjacent alveolar bone developed. Bergendal et al4 followed a patient who had implants placed at age 6. Over the next 4 years, the denture that was constructed had to be modified to accommodate eruption of the permanent dentition. Bergendal, Ekman, and Nilsson5 noted a slightly higher failure rate in children with ectodermal dysplasia, which they attributed to the challenges caused by small bone volumes.

The patient presented in this case was treated at close to completion of growth, when minimal further alveolar growth would be anticipated. A number of practitioners had seen her before she was referred to the General Practice Clinic. Over the years, the patient had received several removable prostheses and had undergone some minor orthodontic tooth movement as part of her overall dental care. At the time of her referral, she was skeletally mature and ready for definitive restorative treatment.

Similar to many patients with ectodermal dysplasia, this patient exhibited underdevelopment of the alveolar ridges in both arches with maxillary hypoplasia. Her maxilla was positioned in space in accordance with standard orthognathic practice. Because of her hypodontia and over-closure, a splint was fabricated and secured to the lower arch at the proper vertical dimension of occlusion. Because of the minimal bone volume of the maxilla in the area of the premolars and molars, the patient required simultaneous augmentation, so that the implants would be successful and would be placed in ideal locations. Several papers have described performance of a Le Fort I osteotomy and simultaneous placement of implants.10–12 Li, Stephens, and Gliklich11 followed 20 patients who had 139 implants and were followed for an average of 33 months. Eighteen percent of their implants (25) were lost. Several difficulties were encountered involving a simultaneous Le Fort I procedure and placement of implants. These included management of the vascular supply to the segment and precise placement of the implants for ultimate restoration. Because the ultimate plan for the patient consisted of fixed restorations, staged procedures were chosen, with deficient regions of the maxilla grafted first. Jensen, Leopardi, and Gallegos9 described doing a Le Fort I osteotomy and bone grafting while maintaining the sinus mucosa. The present case was similar to theirs in that the maxilla was downfractured while the sinus lining was preserved, and the sinus floors were grafted. This was done to maintain good bone volume.

In many individuals with hypodontia, some of the remaining teeth will have drifted from their normal position. This occurred with both lower canines in the present case. Given the minimal anchorage opportunities afforded by the other permanent teeth, the permanent implants served as maximal anchorage to move the canines into the desired position. Both permanent and removal implants (temporary anchorage devices) have dramatically influenced the practice of orthodontics.13,14 When permanent osseointegrated implants are used for orthodontics, their position is dictated by the ultimate restorative goals. In this patient, a single implant was placed in the second premolar position in the lower left arch until the canine could be moved. Active orthodontic forces were initiated at 8 weeks after implant placement in coordination with restorative placement of provisional crowns on selected implants. Two months later, the final implant was placed in the first premolar position.

Patients with ectodermal dysplasia present to the dental practitioner with multiple restorative issues. Because of compromised dental status, these issues also have psychosocial implications. An integrated approach that addresses both skeletal and dental issues can provide superior results. In this case, restorative goals guided the overall treatment plan, requiring the integration of restorative services at several stages of care, which involved orthodontics and oral and maxillofacial surgery.