[Verification of the method for estimating age-at-death using maxillary suture obliteration in Japanese]

The method for estimating age-at-death of human skeletal remains based on the morphological changes of maxillary sutures is widely accepted in Japan. This method is based on the work of Kamijo (1949), which describes the age-related alternations in the morphology of maxillary sutures in Japanese population. However, from the modern anthropological viewpoint, Kamijo's report has some serious flaws in the definition of the morphology of the sutures as well as in the quality and quantity of the samples. Despite these problems, no verification has been conducted for the validity of estimating age-at-death based on his data. Recently, Mann et al. (1991) published a new method for estimating skeletal age based on the progressive obliteration of maxillary sutures. However, there has been no report that verified the effectiveness of their method in Japanese. In the present study, we re-examined the age-related alternations in the morphologies of maxillary sutures in Japanese and assessed the effectiveness of the method of Mann et al. (1991) by using 375 (274 males and 101 females) Japanese skeletons of known sex and age. In all maxillary sutures, the morphological transitions from "no obliteration" to "partial obliteration" with age could be confirmed. However the transition from "partial obliteration" to "complete obliteration" with age could be seen only in the incisive suture and the posterior median palatine suture. Moreover the percentage of each morphology of suture to a total within each decade shows almost no change over fifth decade. By using the method of Mann et al., we could correctly estimate the age-at-death of only 36.9% for males and 25.7% for females of the Japanese samples, however, we seldom overestimated the age-at-death of these samples compared with their actual age. This finding suggests that this method is applicable to estimate the minimum age-at-death in Japanese population.