Reconsidering the sex differences in the incidence of pubertal disorders.

The age range of normal puberty is determined statistically; therefore, a similar percentage of boys and girls should present early or late puberty. However, far more girls present with precocious puberty and more boys with delayed puberty. We suggest that the gender differences in the incidence of pubertal disorders may be due to the following: The signs of puberty are more readily detected in girls, whereas male genitalia may not be examined during a physical examination. The description of the onset of puberty in boys is not uniform. The secular trend towards earlier pubertal maturation is more intense in girls than in boys. Therefore, there may be a fall in the age that correspond to the 3rd and 97th centiles for onset of puberty in girls while the ages at these centiles remain practically unchanged in boys. The high ratio of males to females with constitutional delay of puberty may also be attributed to the late appearance of the pubertal growth spurt in boys. The sex differences in the incidence of pubertal disorders may be due to gender dimorphism in the secular changes of pubertal maturation, to the difficulty of detecting the onset of puberty in boys and to the physiological sex differences in the timing of the pubertal growth spurt.