Variability of discrete cranial traits in the skulls of Lithuanian children.

The data on the frequencies of discrete cranial traits in the skulls of 480 children and 2,681 adults are compared. The occurrence of 59.5% of the traits in children differs significantly from that in adults. The extent of age dependency is diverse in various kinds of traits: 100.0% of hypostoses, 90.0% of hyperostoses, 50.0% of sutural and fontanel ossicles as well as additional and irregular sutures and only 30.0% of various openings are age related. Separate trait categories show a different pattern of age variation: hypostotic characters are common in children, and their frequencies decrease in adults; hyperostotic traits change in an opposite direction; various openings, sutural and fontanel ossicles as well as additional and irregular sutures demonstrate mixed age dynamics. Possible reasons and mechanisms of age dependency of discrete cranial traits, as well as suitability of non-adult sculls for interpopulation phenetical comparisons are discused.