Investigation of Second, Fourth, and Eighth Sternal Rib End Variation Related to Age Estimation

Estimating age at death accurately can be invaluable in answering important questions in fields such as paleoanthropology, bioarchaeology and forensic anthropology. Sternal rib ends have received a great deal of research attention as an area that uniformly changes with age. The most popular methods developed in this area were developed by Iscan and coworkers (1984, 1985) using the right, fourth rib. However, the accuracy of this method has been called into question using different ribs (Yoder et al., 2001). The right, second, fourth and eighth ribs from the William M. Bass Donated Skeletal Collection were examined using the Iscan et al. (1984, 1985) methods. Wilcoxon rank sum tests demonstrate that there is a significant difference between scores obtained using the right, fourth rib and the second and eighth ribs. In order to better understand these differences, a transition analysis was performed. This analysis showed that the second rib was significantly over-aged using the Iscan methods, while the eighth rib was consistently under-aged, although in some cases not significantly.