The prevalence of developmental anomalies of teeth and their association with tooth size in the primary and permanent dentitions of 1650 Japanese children.

The prevalence of microdontia, macrodontia, peg-shaped tooth, Carabelli's tubercle, protostylid, paramolar tubercle, central tubercle and palatal accessory cusp were examined in Japanese children. This study included 905 children with primary dentitions (mean age 4 years 7 months) and 745 high-school students with permanent dentitions (mean age 16 years 8 months). Microdontia, macrodontia, Carabelli's tubercle, protostylid and paramolar tubercle were more frequent in the primary dentition, whereas peg-shaped tooth, central tubercle and palatal accessory cusp were more frequent in the permanent dentition. The association between the presence of developmental anomalies and the size of the remaining teeth was significant in permanent dentitions. Both the literature and this study indicate that developmental anomalies of tooth number, size and morphology should be studied as a group rather than as isolates.