The ectodermal dysplasia (ED) was first described by Thurman1 and is characterized by abnormal development of certain tissues and structures of ectodermal origin such as hair, nails, skin and teeth.2 These disorders are relatively rare and occur in 1 in 10,000 to 1 in 100,000 births.3 ED can be clinically classified as -:
(1) Anhidrotic or hypohidrotic (Christ-Siemens-Touraine syndrome): Inherited as an X-linked form, characterized by the classical triad of hypodontia, hypohidrosis and hypotrichosis and characterized by dysmorphic facial features.
(2) Hidrotic (Clouston’s syndrome).4 Inherited as an autosomal trait, this form of ED usually spares the sweat glands, can affect the teeth, hair and nails.
Various gene mutations result in six different types of ED (Table 1).5,6,7 The objectives of prosthetic dental treatment in ED patients are to preserve alveolar ridges, early development of perioral musculature, speech and restoring normal facial characteristics. This facilitates normal emotional and psychological development.
Table 1: Different Types of Ectodermal Dysplasia and their Gene Mutations
A 3 year old boy reported to the Department of Pediatric and Preventive Dentistry, Bhojia Dental College and Hospital, Baddi, with the chief complaint of missing teeth. He was accompanied by his father who gave history of delayed eruption of three teeth in the upper arch at the age of 2 years and non eruption of other primary teeth. Patient had heat intolerance, hyperpyrexia and sweating was absent.
On examination, scalp had sparse and fine hair. The skin over hands was soft, dry and fragile. The reduced lower facial height led to senile facial experience. Hair over eyelashes and eyebrows were thin and scanty. Low set ears, everted lips, depressed nasal bridge and frontal bossing were other features in this patient (Figure 1A, B, C). Intelligence level was normal in the child according to his age.
Figure 1: (A) showing dry and fragile skin on hands; (B)(C) Showing frontal and lateral view with sparse hair, scanty eyelashes and eyebrows, frontal bossing,depressed nasal bridge, everted lips and low set ears.
Intra oral examination revealed completely edentulous mandibular arch and maxillary arch with erupted 51 55 and 65. Due to absence of teeth, alveolar ridges were atrophic and thin (Figure 2A, B). OPG revealed absence of any other primary teeth but maxillary permanent canines and all permanent first molars were present (Figure 3). HED was confirmed on the basis of the clinical features of hypohidrosis, hypotrichosis and hypodontia.
Figure 2: (A) and (B) showing edentulous mandibular arch and maxillary arch with one central incisor andsecond molars.
Figure 3: OPG showing presence of permanent canines in maxillary arch and permanent first molars in both arches.
Oral rehabilitation with removable partial denture in upper arch and complete denture in lower arch was planned for the child. This improves maxillomandibular relationship, phonetics, masticatory efficiency and positive self image which is prerequisite for normal psychological development of the child. Young age of patients and atrophic ridge makes ED difficult to be managed prosthodontically.
The child was familiarized with the materials and primary impressions were made using alginate for both upper and lower arches. Sharp and thin ridges were covered with a wax spacer. Acrylic custom trays were prepared and border moulded using green sick compound. Final impressions were made using Zinc Oxide Eugenol impression paste.
Occlusal rims were fabricated, and jaw relations were registered with increased vertical dimension at occlusion to establish better muscle tone and lip support. Acrylic teeth were selected and trimmed to the approximate dimensions of the primary teeth and teeth arrangement was done with bilateral balanced occlusion. Try-in was checked for retention, esthetics and phonetics. Dentures were processed using heat cure fibre reinforced acrylic resin. The processed dentures were finished and polished and inserted (Figure 4A, B). Post insertion instructions on denture wear, functions of speech, mastication, hygiene and maintenance were given. The facial profile and expressions improved significantly with complete dentures (Figure 5A, B). Recall appointments were scheduled after 24 hours, 1 week, 4 weeks and 6 weeks.
Figure 4a: Denture fabricated
Figure 4b: Denture inserted
Figure 5(A) (B): Showing frontal and lateral view post insertion of denture.
The patient was examined after 24 hours. Retention and stabilization of the dentures were clinically acceptable. Discomfort areas were relieved. Instructions were given to the parents for home care of the denture and replacement by new ones as growth occurs. The patient had no discomfort and seemed to be adapting well on the following weekly visits.
A multidisciplinary approach and knowledge of behaviour management is the prerequisite for rehabilitation of a child with Ectodermal Dysplasia. Prosthetic rehabilitation in children with HED depends on the degree of anodontia. In patients with partial anodontia, removable/fixed partial dentures and overdentures may be considered8 according to number of teeth present.Oral rehabilitation at an early age improves perioral muscle tonicity, delays alveolar bone resorption associated with the absence of teeth.9 The initial dentures at preschool stage helps in better adaptation by the child. As the child grows, the denture will have to be relined and replaced, in primary, mixed and permanent dentition till the growth is complete.If we do not rehabilitate the oral function, this will lead to class III malocclusion, which is caused byrotation of mandible anteriorly and represents as an upward and forward displacement of the chin, with a reduction in the lower facial height.1
Fixed prosthesis are rarely used exclusively in the treatment of ED because of the presence of least number of teeth and if prosthesis cross the midline, rigid connectors may cause interference with jaw growth.4
Osseointegrated implants are also an alternative to removable prosthesis. Overdentures with implants have an advantage of stability and retention but the dental implants in young children may get submerged when placed in development years.10 Infraocclusion may also result due to growth of the adjacent natural teeth11 and the dramatic growth changes of maxilla and mandible are not conducive to the maintenance of implants.12 This approachshould be postponed until 13 years of age because of possible implant movement caused by jaw growth.13 The use of implants in the anterior mandible may be routinely recommended in young patients14 and can be placed to support an overdenture from the age of around 6 years, when the median suture of the mandible is closed.15 As the lateral growth of the anterior mandible is usually completed by 3 years of age, implant placement can be considered if anodontia exists in this area. Soft tissue implants can be considered as an alternative.
ED patients need interdisciplinary approach for their special needs, which includes prosthesis at an early age with relining and replacement as growth occurs.
Early prosthetic treatment in cases of Ectodermal dysplasia improves physical and psychological growth of the child. It is recommended to rehabilitate the patient with dentures as early as preschool age and subsequent transition to fixed prosthesis/ implants once the growth is complete.