Genetic and environmental contributions to variation in human tooth size

Contributions of genetics and of the environment to variation in human tooth size are discussed. A significant effect of the environment shared by twins, uterine or early in life, was found for mesiodistal (MD) and buccolingual (BL) diameters of maxillary first molars. Significant non-additive genetic variation was seen in MD diameters of canines and first premolars. That would be consistent with selective pressures at some stage in human evolution.