Full-Mouth Rehabilitation of a Patient With Ectodermal Dysplasia With Dental Implants

Ectodermal dysplasia (ED) describes a large and complex group of disorders defined by the abnormal development of 2 or more structures derived from the embryonic ectodermal layer (ie, skin, hair, nails, nerve cells, sweat glands, and parts of the eye and ear).¹  The incidence of the disease varies between 7 in 10 000 and 7 in 100 000 live births.^1,2  Ectodermal dysplasia is classified as 2 major types: hypohidrotic, in which the sweat glands are absent or significantly decreased, and hidrotic, in which the sweat glands are normal. Hypohidrotic ED (HED) is the more common and severe form associated with dental defects.³  HED is inherited as an X-linked autosomal recessive disorder, whereas other forms of ED are inherited as autosomal dominant disorders.⁴  In addition to the complete absence of sweat glands, clinical features of HED include abnormal or missing teeth, absent or very thin hair, and abnormal nails. HED may also present with increased pigmentation around the eyes and mouth, saddle nose, fine-line wrinkles around the eyes, and heat intolerance. Children with the disease may have difficulty controlling fever. Mild illnesses can produce extremely high fevers due to lack of sweating and appropriate temperature control. At an adult age, the affected individual is usually unable to tolerate a warm environment and requires special measures to keep a normal body temperature.^5,6 

Clinical findings suggest that there may be an inflammatory process associated with the complications in ED. Oral characteristics include complete or partial hypodontia, anodontia, impacted teeth, loss of vertical dimension of occlusion, protuberant lips, malformed and widely spaced conical-shaped teeth, and underdeveloped alveolar ridges.^6–9  Absence of teeth as a result of hypodontia alters transverse bone growth and sagittal maxillary and mandibular growth, while vertical growth can be affected by reduced alveolar height.³  Thus, ED patients often require a multidisciplinary approach in dental treatment planning to restore function, esthetics, and comfort. Conventional prosthodontic treatment, including complete dentures, overdentures, or a combination of fixed and removable partial dentures, presents considerable problems in ED patients.¹⁰  The irregular distribution and the conical-shaped teeth often limit the integration of bridges and crowns in patients with ED.¹¹  Hypodontic mandibles of children with ED exhibit underdeveloped alveolar ridges,¹²  making it very difficult to gain adequate retention and support for conventional prostheses.¹³  Finally, progressive resorption of basal bone when the edentulous ridge is loaded at an early age may lead to prosthetic difficulties in later years.¹⁴  Therefore, there is a need for alternative therapeutic approaches beyond conventional dental techniques for restoring the function, esthetics, and phonation in patients with ED. Dental implants have been suggested as an important alternative for ED patients to support, stabilize, and retain the prosthesis.^{3,9,12,14–18}  The present report describes a severe case of HED and full-mouth restorations using osseointegrated dental implants.

A 22-year-old male patient with HED was referred to the Department of Periodontology, Faculty of Dentistry, University of Istanbul, with esthetic complaints and inability to eat properly. Extraoral examination revealed fine, sparse, thin hair; scant eyelashes and eyebrows; frontal bossing; a depressed nasal bridge; protuberent lips; a prominent chin; and a resultant concave facial profile (Figure 1a). The patient reported that he sought frequent medical care because of high fever and hydrated lesions on his skin due to a lack of sweat glands and was diagnosed with HED. He also reported absence of primary and secondary teeth and treatment with maxillary and mandibular over a denture prosthesis fabricated when he was 7 years old. The patient had never adapted to the removable dentures.

Intraoral examination revealed that all permanent teeth were missing except for the maxillary central incisors and mandibular right canine, and the vertical dimension of occlusion was increased because of the severe alveolar resorption of the jaws (Figure 1b). The patient had hypoplasia of the salivary glands and dry mucosa. Panoramic radiography (Cranex 3+, Ceph, Sorodex, Finland) and dental volumetric tomography (E-WOO Tecnology CL, Republic of Korea) were used to measure the bone density and to observe anatomic restrictions (Figure 1c). After a comprehensive clinical and radiographic examination and a detailed discussion of treatment options with the patient and his family, the treatment was planned as fabrication of mandibular and maxillary implant tooth–supported telescopic partial dentures. The patient declined implant prosthetic treatment for the maxilla. Therefore, the maxilla was rehabilitated with a tooth-supported telescopic partial denture while the mandible was restored with an implant and teeth-supported prosthesis as planned. Alveoloplasty was necessary due to the “knife-edge” morphology of the edentulous mandibular ridge prior to implant placement during the same surgery. Implants (Tapered Screw Vent, Zimmer Dental, San Diego, Calif) were placed in the mandible at the sites of right (3.7 × 13 mm) and left (3.3 × 13 mm) lateral incisor teeth using a torque of 50 N. Following implant placement, the remaining buccal bone dehiscence was filled with deproteinized bovine bone graft (Bio-Oss, Geistlich Pharma AG, Wolhusen, Switzerland) and covered by a resorbable collagen membrane (Bio-Gide, Geistlich Pharma AG). The patient was prescribed amoxicillin + clavulanic acid (1g, 2 × 1) for 1 week and chlorhexidine gluconate (% 0.2; 2 × 1) for 2 weeks. After a submerged healing period of 6 months, the implants were uncovered and healing abutment connections were placed. At the same time, free gingival graft was placed to increase the attached gingival tissue around the implants as an autogenous graft. The graft healed uneventfully (Figure 2a). In the maxilla, a frenectomy was performed between the upper santral incisors. To increase the keratinized mucosa and vestibular depth for preparation of the placement of partial dentures, bilateral soft-tissue grafting was planned. An acellular dermal matrix allograft (AlloDerm, Biohorizons, LifeCell Co, Branchburg, NJ) was used for simultaneous grafting of the right and left buccal aspects of the maxilla (Figures 2b and c) since the intraoral sites were not going to be sufficient for this procedure. A large wound was not favored at the donor sites.

After complete healing of the soft tissues in edentulous sites and around teeth and implants for 8 weeks, prosthodontic procedures were started. An impression of the abutments was made with polyvinylsiloxane impression material (Affinis Putty Soft, Coltène/Whaledent GmbH + Co KG, Langenau, Germany) using an open-tray technique. Primary and secondary copings of telescopic crowns were prepared with gold alloy because of its compatibility with gingival tissues and high-precision casting and retentive properties (Figure 3a). The patient was instructed to perform daily maintenance with an interdental brush (Curaprox Soft Implant Brush CPS508, CURADEN International, Istanbul, Turkey), superfloss (Curaprox Bridge & Implant Floss DF844, CURADEN International), and a single toothbrush (Curaprox Single CS 1009, CURADEN International).

A professional maintenance program was instituted with periodontal and peri-implant recall visits every 3 months following delivery of definitive restorations (Figure 3b). Periodontal and peri-implant conditions were stable over 12- and 24-month follow-up appointments, with no signs of attachment or bone loss associated with implants or the remaining teeth. Radiographic control was done with panoramic radiographs in the first and second year after the definitive prosthesis was placed (Figure 3c, d). To evaluate the qualitative as well as quantitative changes in the alveolar bone, dental volumetric tomography was repeated (Figure 4a, b). No signs of resorption were observed.

In this article, we report full-mouth restoration of a patient with severe ED. The treatment included a combination of dental implants and remaining natural teeth and telescopic partial dentures. The case was followed for 2 years. The patient has been highly satisfied with the outcomes with regard to the functional, esthetic, and phonation levels and has restored social acceptance and self-esteem. This case supports the notion that, using a multidisciplinary approach, severe cases of ED can be restored successfully and treated in the dental practice.

The most common complaint of childhood and adolescence in patients with ED is the concern about the dental anomalities and facial appearance.¹⁹  The treatment of choice is often a removable partial denture or complete denture since these can be easily modified during periods of rapid growth.^20,21  Early implant placement and fixed prosthesis were suggested as a good treatment option in ED cases with anodontia or hypodontia and with an uncooperative child,²²  although this has not been supported by strong evidence. Likewise, a recent review has recommended the insertion of implants in pediatric ED patients who suffer from syndromal hypodontia, suggesting that the most suitable site of insertion is the anterior mandible, while insertions in the maxilla should be avoided or at least should not cross the midline.⁹  Nevertheless, clinical evidence in implant treatment of young children with ED is still limited. Implant surgery in ED patients presents special challenges, mainly because of the small dimensions of the jaws and the dense cortical bone. Thus, such treatments should always include dental tomographic imaging and the use of small-diameter implants postponing the treatment until jaw size is sufficient.²³  In adult ED patients, dental implants have increasingly become the treatment of choice, because growth has stabilized by adulthood and the implants can be used to support, retain, and stabilize the prosthesis.^{3,12,18,24,25}  Implants placed in ED patients younger than 18 years have a higher risk of failure, but implant survival rates vary between 88.5% and 97.6% in adolescent ED patients.²⁶  Garagiola et al²⁷  suggested dental implants inserted successfully in ED patients in association with guided bone regeneration and bone grafts. In this report, we have used a similar approach to facilitate the placement of implants in a prosthetically guided position. The survival data for telescopic systems with both types of abutments used (ie, teeth and implants) have been comparable with that of prostheses supported solely by implants.²⁸  Therefore, we have combined the dental implants with retaining teeth and telescopic partial removable dentures. The strategy used in combination with soft-tissue grafting to increase the vestibular depth and keratinized gingival width has shown stability for 2 years, and patient satisfaction was achieved.

Dental treatment of ED has a marked financial effect on patients and their families and varies depending on the type and duration of treatment. In their study, Murdock et al²⁹  reported that costs ranged from $2038 to $3298 for those who received prosthodontic treatment only and from $12 632 to $41 146 for those who received a combination of prosthodontic, orthodontic, and implant treatment. This is a limiting factor and has also been the case in our patient. Advanced augmentation techniques and surgeries (sinus lifting, autogenous bone blocks from the iliac crest, distraction osteogenesis, etc) could not be performed because of financial limitations. Still, we were able to restore the dentition with the support of 2 dental implants and build a functional and esthetically acceptable prosthetic restoration. The main goal was to replace missing teeth and bone, establish the normal vertical dimension, and provide support for the facial soft tissues.²⁹  While the follow-up time was limited to 2 years, this was critical to detect any implant failures and alveolar bone resorption. During this period, no implants were lost, and there was no observable bone resorption.

In summary, the case report presented in this article demonstrates that the oral rehabilitation of an adult HED patient with a reduced number of teeth and underdevelopment of alveolar bone is possible. This treatment highly enhanced the patient's functional and esthetic status, significantly increasing his social confidence and self-esteem.

Abbreviations

ED

ectodermal dysplasia

HED

hypohidrotic ectodermal dysplasia