Normal ages of pubertal events among American males and females.

This study identifies the mean and standard deviations of the chronological age of the attainment of a variety of important events of puberty in American males and females. The information is based on longitudinal observations at 6-month intervals with the first observation of each particular pubertal characteristic being documented within 6 months of its appearance. The mean (+/- SD) ages of pubic hair and genital or breast stages, and onset of peak weight gain, peak height velocity, acne and axillary hair are given for both sexes. Menarche is documented for females, and gynecomastia, voice break and change, and facial hair for males. These data show the range of individual age variation of normal pubertal events. Puberty may begin from age 8.0 to 14.9 years for females and from age 9.7 to 14.1 years for males and is complete by age 12.4 to 16.8 years for females and by age 13.7 to 17.9 years for males.