Age determination, using the spheno-occipital synchondrosis; medical end of the clavicle; and S1-S2 fusion, on a South African population

Abstract

Forensic Anthropologists are often tasked with establishing an osteo-demographic profile for a set of unknown skeletal remains. Estimating age is only one such demographic which needs to be established. Complete skeletal maturation occurs when three developmental markers completely fuse: spheno-occipital synchondrosis, medial end of the clavicle, and sacral elements S1 and S2. The aim of this study was to establish the age at which these developmental markers begin and complete fusion in a South African Black sample. Males and females from the Raymond A. Dart Collection of Human Skeletons were included. It was observed that the spheno-occipital synchondrosis begins fusion as early as 12 years in females and 15 years in males; while all individuals over the age of 20 years displayed complete fusion. No significant differences between the left and right clavicles, and staging score was observed (p=0.9). The mean age of partial union for the clavicle in males and females was 26.7 (±6.0) and 26.4 (±5.0), respectively. While complete union of this skeletal element was regularly noted in individuals above 30 years. The mean age of partial union for sacral elements S1 and S2 was established to be 29.1 (±7.0) years in males and 30.7 (±9.2) in females. Complete union of this skeletal element was observed more commonly in individuals over 35 years of age. The results obtained in this study demonstrate the importance of developing population-specific criteria – especially in a diverse, multi-cultural population such as South Africa