Type I dentin dysplasia: report of two cases.

Dentin dysplasia is a rare developmental disturbance of dentin affecting approximately 1:100,000 people. It has been classified as an autosomal dominant disease. Two distinct forms of dentin dysplasia have been described. As more cases of dentin dysplasia were reported these categories seemed inadequate; subclassification of type I dentin dysplasia were proposed based on root length and the presence or not of a pulpal remnant. This paper presents two cases demonstrating the classic features of type I dentin dysplasia in the mixed and permanent dentitions and discusses the suggested subclassifications. The authors suggest that while differences in root length may be useful in determining treatment options, thinking of these variables as separate types of dentin dysplasia is not warranted at this time. Justification of a subcategory of type I dentin dysplasia should be based on a different disease process, different histology, significantly different symptoms, or different etiologies, and until researchers can clearly prove from a genetic or chromosomal standpoint that the subcategories are separate entities, we should accept, as we do for many other genetic disorders, that some patients are more severely affected than others.