The Skeletal Development of the Children in Tokyo

Abstract

Two kinds of the age of the children in Tokyo were assessed by two different methods of assessement respectively ; the standards of SUGIURA and NAKAZAWA's method (SUGIURA's method) was derived from the children in the central Japan (Shizuoka and Aichi Prefecture), and those of TANNER-WHITEHOUSE-HEALEY's method (TANNER'S method) was derived from the British children.The ages of 284 healthy boys and 368 healthy girls, aged from 4 to 12 years, were assessed and observed (Table 1).1. The age of the Tokyo boys assessed by both methods had a tendency to be under-estimated, and that of the Tokyo girls to be over-estimated.2. For assessement of the age, SUGIURA's method was more applicable to the Tokyo boys aged from 4 to 8 years and to the Tokyo girls aged from 8 to 12 years than TANNER'S method. And at the other ages, TANNER'S method was more applicable to the Tokyo boys and girls.3. The development of the Tokyo boys retarded remarkably than that of the boys in the central Japan from 9 years of age. At the age of 12 years, the Tokyo boys were about 15 skeletal months behind the boys in the central Japan in their maturity. On the contrary, the development of the Tokyo girls was superior to that of the girls in the central Japan after 9 years of age. At the age of 12 years, the Tokyo girls advanced about 5 skeletal monthsthan the girls in the central Japan in their maturity (Table 2, Table 3 and Fig. 2).4. The development of the Tokyo boys retarded than that of the British boys during the age period from 6 to 10 years, and at the age of 10 years, the gap was about 10 skeletal monthsin their maturity. But at the ages of 11 and 12 years, both maturity was equal. The development of the Tokyo girls were superior remarkably to that of the British girls after 8 years of age, and at the age of 9 years the maturity of the Tokyo girls advanced about 10 skeletal months than that of the British girls. In pre-puberty, the development of the Tokyo girls showed a tendency to close to that of the British girls, and at the age of 12 years the Tokyo girls advanced about only 3 skeletal months than the British girls in their maturity (Table 2, Table 3 and Fig. 2).5. The development of the children in the central Japan retarded than that of the British children in the Pre-school period. At the age of 7 years, the boys in the central Japan were lagging behind the British children about 5 skeletal months, and at the age of 5 years the girls in the central Japan were about 7 skeletal months behind in their maturity. But in the early school period, the development of the children in the central Japan advanced than that of the British children. At the age of 9 years, the maturity of the boys in central Japan advanced about 3 skeletal months than that of the British boys, and the gap between these two increased to about 12 skeletal months at the age of 12 years. The maturity of the girls in the central Japan advanced about 7 skeletal months than the British girls at the age of 9 years, but after 10 years of age the gap began to decrease, and at the age of 11 and 12 years both were equal. (Table 4, Fig. 3 and Fig. 4).6. Comparing with the development of the children in three populations, i, e., Tokyo, Central Japan and England, the retardation of the maturity of the Tokyo boys and the British girls in the early school period, and the acceleration of the maturity of the Tokyo girls after 8 years of age and of the boys in the cental Japan after 9 years of age were observed peculiarly in this report.