[Degree of sexual maturation as an index of biological age]

Attempt was made to establish some characteristics of sexual maturation, depending upon chronologic and biologic age. A total of 1277 girls from 8 to 17 years of age in the city of Sofia are included in the study. There were no cases of precocious of considerably delayed pubertal development. Essential differences were found in the body dimensions, in connection with the increase in the degree of sexual maturation in one and the same chronologic age. The importance of biologic age for the individual approach to teen-agers girls and boys is emphasized.