Hypodontia and delayed development of the second premolars in cleft palate children

Bilateral asymmetry of congenitally absent second premolars, the rate of tooth formation of the remaining second premolars and asymmetric development of paired second premolars were studied in 95 cleft palate children with congenital absence of one or more second premolars. The results were compared with a random sample of 60 children with clefts but without hypodontia, and with a random sample of 100 non-cleft children. Symmetrical hypodontia was found in the lower jaw in 75% of cases and in 49% in the upper jaw. In the hypodontia group, the development of the remaining second premolars was delayed from 0.4 to 1.4 years. There was a marked increase in the asymmetrical development of the paired teeth, and marked delay in development compared with the control group. Delayed mineralization and asymmetry in formation of the second premolars seem to have a common etiology.