Dentinogenesis imperfecta in the Brandywine isolate (DI type III): clinical, radiologic, and scanning electron microscopic studies of the dentition.

Teeth of seven patients from the Brandywine isolate who had dentinogenesis imperfecta (DI) type III were evaluated by clinical, radiologic, and scanning electron microscopic techniques. The deciduous and permanent teeth were opalescent, and there was marked attrition. Enamel pitting was present on some permanent teeth. Anterior open bites were found in all persons with complete permanent dentitions. Pulps of developing teeth were larger than normal during early development but rapidly became almost completely obliterated. There was increased constriction at the cementoenamel junctions. While radiolucencies were noted at the apices of teeth which had pulp exposures due to attrition, several patients had similar radiolucencies which could not be attributed to caries or attrition. Scanning electron microscopy showed a significant reduction in the number of dentin tubules on fractured dentin surfaces; calcospherites at the calcification front were either irregularly shaped or absent. A single tooth from a patient with DI type II was studied and had similar abnormalities on scanning electron microscopy, although tubules were easier to find and calcospherites at the calcification front were more regular than in DI type III. The findings in DI type III of enamel pitting, enlarged pulps early in tooth development, and radiolucencies at the apices of teeth without pulp exposures support the hypothesis that DI type II and DI type III are different disorders.