Late elongation of the cranial base.

A single logistic curve was fitted to serial data for three cranial base lengths (S-N, Ba-N, and Ba-S) in 33 boys and 26 girls. Elongation during pubescence plus adolescence is greater in boys than girls for each length. The maximum rate of pubescent elongation occurs earliest in Ba-N. There are no consistent sex differences in the maximum rates of elongation but they occur considerably earlier in girls. Similarly, girls reach 95% of their adult lengths at younger ages than boys.