Dentin dysplasia: review of the literature and a proposed subclassification based on radiographic findings.

The literature is reviewed to determine the radiographic appearance of the reported cases of dentin dysplasia. The sometimes confusing nomenclature is rationalized. Four distinct forms of dentin dysplasia type I and one form of dentin dysplasia type II are identified. There seems to be no need to identify more than two distinct types of this relatively rare inherited defect of human dentin, but a proposed subclassification of type I dentin dysplasia could make identification of the two types easier.