Estimating the age at death in a group of historically unknown adults

Ten diaphysis specimens of femurs and humeri from a total of 4 bodies, three excavated from 14th-15th century graves. (Muromachi period) and one from a tomb of the 7th century (period of ancient burial mounds), were examined using histomorphological methods to estimate their ages. The estimation formula was established using humeri (72 specimen) and femurs (71 specimen) from Japanese aged between 26 and 75 years. The formula was prepared based on a multiple regression analysis of the following 3 items: number of osteons/mm2, mean diameter of osteons, and mean diameter of the Haversian canals. Four estimation formulas were established based on the humeri from all subjects, the femurs from all subjects, the humeri from subjects between 26 and 55, and the femurs from subjects between 26 and 53, respectively. Since the age of the excavated human bones was unknown, we used morphological age estimates (e.g. attrition of teeth, cranial suture closure and similar items) for comparison. Histological and visual estimates correspond in 2 of the 10 cases, but the histological age estimates were higher than the visual estimates in the other cases. In 4 of the 10 cases, age estimates produced by the formulas for younger ages were lower than those by the formulas for all age groups. Thus the formulas for younger ages were not so successful.