There are ethnic differences in the timing of sexual maturation. However, averages of sexual maturity rating (SMR) for Korean adolescents were not available until recently. The purpose of this study was to determine averages for the SMR of
adolescent
girls and boys in Korea.
The study population included 3,249 boys and 3,337 girls. The sample comprised 2,406 from the Seoul area, 2,441 from a medium-sized city and 1,739 from rural areas. Data were obtained through questionnaires and physical examinations for SMR given
by
pediatricians from 1991 to 1992. Sexual maturity was graded using the Tanner scales. This was a cross-sectional study.
In boys, the first growth of the testes (SMR 2) was observed at a mean age 12.7 years (from 10.4 to 15.1 years of age for 95% of them). SMR 3 and SMR 4 of genitalia were 14.2± 1.4, 15.4± 1.3 years of age, respectively. Adult genitalia (SMR 5)
was
observed from 14 to 18.2 with a mean age of 16.1 years. SMR 2 of pubic hair was at a mean age of 13.2 years, and SMR 3,4, and 5 were 14.4 ±1.4, 15.6 ±1.2, 16.0± 1.0 years of age, respectively. In girls, the mean age for breast budding (SMR 2)
was
11.0 years with a range of 8.9 years to 13.1 years for 95% of them. SMR 3,4, and 5 for breast were 12.6 ±1.4, 14.2 ±1.5, 15.7 ±1.1 years of age, respectively. SMR 2,3,4, and 5 for pubic hair were 12.9 ±1.8, 14.5± 1.5, 15.1± 1.3, 16.0± 1.0
years
of age, respectively. Tanner stages for breast and pubic hair in girls, and genitalia and pubic in boys did not agree well within one ordinal rank. Average length of time from SMR 2 to 5 was 3.3 years for boys and 5.0 years for girls. Mean age of
menarche was 12.8 years (from 10.8 to 14.8 years of age for 95% of them). Mean of menarcheal age was significantly different, geographically (12.6 years Seoul, 12.9 medium-sized city, and 12.9 rural area) (P<.0001). Menarche occurred 1.7% on
breast
SMR
2, 41.5% on SMR 3, 85.9% on SMR 4, 99.3% on SMR 5.
In conclusion, this findings might be interpreted as providing averages of SMR for Korean girls and boys in adolescence.
|