ALTHOUGH the dental defects in mongolism have not been systematically analyzed, scattered observations are recorded. Nash1 reported that the teeth of his mongoloid patients, three to thirty-five years of age, were frequently missing, abnormally shaped or smaller than normal.2 In a study of 3 mongoloid skulls, Greig3 observed irregularities of the teeth that were more pronounced in the upper than in the lower jaw. In 1 skull, showing congenital absence of the nasal bones, there was a congenitally absent right upper lateral incisor (Fig. 1A); in the second skull the same tooth was markedly dwarfed, and the left upper . . .