Although most cases of cleft lip and palate are free of other developmental defects, children with isolated cleft lip/palate are at enhanced risk of delayed growth and reduced final size. Three variables were assessed in the permanent dentition away from the cleft site: congenital absence by tooth type (which ranged from 0 to 7%) asymmetry in developmental staging (3 times more common in cleft lip/palate than in controls), and dental age (with a mean delay of 0.9 yr in cleft lip/palate relative to controls). The pervasive nature of these measures of reduced growth potential and developmental control, which were greatest in teeth forming during infancy, suggests that the cause of the compromised growth is the adverse early postnatal environment rather than conditions intrinsic to the individual.