Forensic age-at-death estimation from the sternum in a black South African population

Age-at-death estimation is a crucial component of any forensic anthropological analysis. Despite a variety of research in this field, uncertainties still exist when estimating adult age. The sternum is an under-considered element in terms of adult age estimation. Previous research on an Indian population suggested that this may be a usable region of the skeleton, although results were ambivalent. This study observed the fusion phases of 461 sterna from a black South African population in an attempt to match true age of an individual with the different phases of synostosis of the manubrio-sternal and the sterno-xiphoidal junctions. The results demonstrated that the majority of sterna remain unfused throughout adult life, with complete fusion observed both in young (25 year-old) and old individuals. Significant differences were identified amongst male and female sterna, with males presenting no transitional fusion of the segments, while female sterna demonstrated fusion to a lesser extent. Overall, logistic regression results demonstrated low accuracies (62.5%) for age estimation even when the two sexes were considered separately (male = 63.9%; female = 61.8%). The synostosis of both junctions is hence considered highly variable and deemed unreliable for adult age-at-death estimation in the black South African population.