Dentinogenesis imperfecta

Dentinogenesis imperfecta is a hereditary defect of dentin that involves both the primary as well as the permanent dentition.

The disease occurs in several forms and the three most common among them are:

• Type I dentinogenesis imperfecta,
• Type II dentinogenesis imperfecta, and
• Type III dentinogenesis imperfecta.

The type I Dentinogenesis imperfecta is often associated with osteogenesis imperfecta and it involves the deciduous teeth more commonly.

Dentinogenesis imperfecta which is not associated with osteogenesis imperfecta comes under type-Il, and it involves the deciduous as well as the permanent teeth with equal frequency.

Type III Dentinogenesis imperfecta also known as the Brandy- wine type is an unusual form of the disease and it commonly shows multiple pulp exposures and periapical lesions in the deciduous teeth. Both dentitions are affected in this type.

Clinical Features

• Dentinogenesis imperfecta clinically presents the following features:
• The teeth exhibit an unusual opalescent or translucent hue, which is a characteristic feature of the disease.
• The enamel on the tooth surface appears normal but very often it is lost by fracturing away due to the abnormal dentinoenamel junction.
• Because of the early loss of enamel1 especially from the occlusal or incisal edges, the exposed dentin becomes attrited rapidly but the teeth do not show high caries susceptibility.
• The color of the teeth ranges from gray to brownish violet or yellowish brown.

Radiological Features

• In case of type I and type II Dentinogenesis imperfecta, the radio-graph shows obliteration of the pulp chamber and root canals by the deposition of dentin.
• The teeth often appear “bell-shaped” due to their abnormal constriction at the cervical area and the roots are short and blunted.
• In type Ill, the dentin appears very thin and the pulp chambers and the root canals are extremely large. Because of this, all the teeth appear as thin “shells” of enamel and dentin (shell tooth).

Histopathology

• The dentin shows less number of dentinal tubules and these are irregular and larger.
• Complete obliteration of pulp chamber and root canals by the deposition of dentin.
• The dentinoenamel junction appears smooth, instead of being scalloped.
• The enamel histologically appears normal.

Treatment
The treatment for Dentinogenesis imperfecta involves construction of metal crowns in the posterior teeth and jacket crowns for the anterior teeth.