Dental Ankylosis

A rare odontologic disorder characterized by the loss of the periodontal ligament space and orthodontic mobility.

Epidemiology

The prevalence is unknown.

Clinical description

In dental ankyloses, the tooth is in contact with the alveolar bone with obliteration of the periodontal ligament and can lead to submergence. It can affect both primary and permanent teeth and may occur at any time during eruption. Permanent molars are less frequently affected than deciduous molars. Varying numbers of teeth may be affected. After eruption, it halts any adaptive changes. In a growing child, an ankylosed tooth appears to 'submerge' as adjacent unaffected teeth and alveolar bone continue their normal pattern of growth occlusally. The disorder may result in loss of the retained molar and neighboring teeth due to caries and periodontal disease, and, in severe cases, deformation of the facial skeleton (reduction in the height of the lower face, relative mandibular prognathism, posterior open bite). Occasionally, dental ankylosis may be associated with fifth finger clinodactyly. Dental ankylosis exists in isolation or associated with other abnormalities as part of a syndrome.

Etiology

Etiology remains uncertain but a genetic predisposition, trauma, inflammation or infection may play a causative role.

Diagnostic methods

Clinical examination and X-ray are the main diagnostic methods for detecting ankylosis.

Differential diagnosis

Differential diagnosis includes mechanical obstruction, primary failure of eruption, and malocclusion.

Genetic counseling

Familial occurrence has been shown in several families, with autosomal dominance inheritance suggested.

Management and treatment

The recommended management includes removing the ankylosed tooth to ensure development and eruption of the permanent teeth, and surgery to expose, protect, or reposition the emerging tooth. Dental composites reestablish occlusion and improves esthetics. Decoronation is recommended in the incisal sector before vertical bone development is complete and the crown reaches a certain degree of infraocclusion. This permits preservation of the alveolar bone for eventual implants after completion of growth. Where primary teeth ankylosed, removal of the affected tooth is recommended to ensure development and eruption of the permanent teeth.

Prognosis

Ankylosed teeth have an unfavorable prognosis with risk of progression to replacement resorption.