Japanese Specific Bone Age Standard on the TW2

Abstract

Japan has been experiencing ever more rapid socioeconomic development and changes in life style, especially for children, since the end of the Second World War. With these developments and changes the physical size of Japanese children has increased, but this secular trend has attained a plateau in the past 10 years.This phenomenon indicates that now Japanese children are growing in the nearly best conditions and their present physical conditions, for example, bone age, are thought to be specific and characteristic for the Japanese.The secular trend of linear growth since the end of the War is discussed, using the data of height in the annual reports of the school health program by the Ministry of Education, and the standardized TW2 bone age estimation method for Japanese children and adolescents is presented.