Age estimation from soft x-ray finding of the rib

The estimation of age at death is an important part of medicolegal identification. Techniques now in use vary from direct observation of a bone or a tissue to microscopic examination of a given specimen. A simple, rapid and reliable soft X-ray technique is developed for age estimation based on alteration of the sternal end of the rib, using either skeletonized or fresh human ribs from 142 individuals autopsied. Variables were ascertained from epiphysial line, upper- and lower-rimb and trabecula of the ribs. The changes of these parts were arbitrarily graded into 4 or 5 groups by the difference of soft X-ray findings and were indicated to be related with age by statistical analysis. Using the results obtained from 85 adult male individuals ranging in age from 17 to 69 years of age, partial regression coefficient and estimated score for adult males were calculated by means of multiple regression analysis and quantification theory model I analysis. Ages of the samples can be quantitatively estimated with a fairly high reliability. The result of the quantification theory model I analysis was more reliable than that of multiple regression analysis, though the difference between the two methods was almost negligible. When the age of the specimen is younger than 16 years or older than 70 years, the methods presented in this study cannot be used, and in such a case, other methods should be employed. (author)