Age Estimation from the Rib by Phase Analysis: White Males

The determination of age at death is an important part of physical and forensic anthropology. Techniques now in use vary from direct observation of a bone to microscopic examination of a given segment. This study introduces the sternal end of the rib as a new site for age estimation by direct observation. The sample consisted of 118 white male ribs of verified age, sex, and race. The ribs were assigned to one of nine phases (0 through 8) based on changes noted at the costochondral junction. These included the formation of a pit, its depth and shape, configuration of the walls and rim surrounding it, and the overall texture and quality of the bone. Statistical analysis indicated that these changes were age related. It was further revealed that metamorphosis was most rapid and uniform from the mean age of 17 to 28 years (Phases 1 through 4). The rib morphology was more varied after age 39 (Phase 5) resulting in a wider range for the predicted age. Our study concluded that the sternal rib end may yield a similar degree of accuracy to the public symphysis and perhaps better than that for cranial sutural closure. Our technique also enables the forensic scientist to use the rib for corroboration with age estimations obtained by traditional methods.