Anodontia

An extreme developmental dental anomaly characterized by the complete absence of all teeth.

Epidemiology

The prevalence is unknown but it is extremely rare and usually only occurs as part of an associated syndrome such as X-linked hypohidrotic ectodermal dysplasia (X-linked HED; see this term).

Etiology

Genes found to be responsible for HED include EDA and EDAR and EDARADD.

Diagnostic methods

Clinical examination along with a panoramic radiograph (and intra-oral X-rays if needed) is performed when teeth eruption is delayed and teeth are then thought to be missing. In normal conditions all primary teeth and crypts of permanent first molars are visible on radiography at birth and permanent teeth crowns (except third molars) at 6 years of age. A diagnosis of anodontia is given when all teeth are missing.

Management and treatment

Treatment involves full fixed dentures or, in suitable candidates, dental implants. Early mandibular implants therapy is indicated in these severe phenotypes of anodontia. A marked alveolar bone hypotrophy is generally associated with anodontia and requires CT exams of the mandible and 3D reconstructions for implants surgical planning. Maxillary rehabilitation based on osteointegrated implants and prosthodontics is indicated at the end of the skeletal growth. Bone grafts such as onlay autogenous grafts and maxillary sinus floor augmentation procedures are often necessary. Before completion of growth a removable maxillary denture should be used.