[Estimation of age from epiphyseal union degrees of the sternal end of the clavicle].

The sternal ends of right clavicles of Japanese aged 13-31 years (n = 54) autopsied during 1982-1992 were observed for determining degree of epiphyseal union to establish a criterion for age estimation. As the degree of union 5 stages (McKern and Stewart, 1957) were applied to samples: Stage 0; without any union between the trunk and the epiphyseal cap, stage 1; between stage 0 and stage 2, stage 2; half united, stage 3; between stage 2 and stage 4, and stage 4; completely united. As results, in females union appears to proceed faster than in males. There were cases in which union reached stage 4 in younger ages. As a criterion for age estimation it is proposed at present that in both sex, when union is in stage 0, age is certainly estimated to be less than 22 years old and in stage 4, more than 19 years old. Comparing the present data with the investigation about American males by McKern and Stewart (1957), in Japanese males union proceeds more fast than them. The authors realized that the correct criteria should be used in age estimation on a sample belonging to the same race and to the times. The clavicles in skeletal remains tend to be preserved outdoors and are suitable for estimating age from adolescence to about 30 years old. Therefore the present criterion would be very useful in districts such as Hokkaido where skeletal remains are commonly found.