Assessing the Occipital Condyles for Age Estimation of Non-Adults

Abstract

Objectives New methods for assessing age of non-adult remains are frequently sought to improve the ability to correctly identify individuals in for forensic and archaeological purposes. Especially when faced with comingled remains, it is helpful to have a bone appropriate tool for age estimation. Research was carried out to assess the usefulness of the occipital condyles for aging non-adult individuals using metric and morphology analyses. The research population included occipital condyles, both fused and unfused, of individuals of known age at death non-adult from the from the Hamann-Todd Collection, Museum of Natural History, Cleveland, Ohio, USA (N=69); Colecção Esqueletos Identificados, Natural History Museum, University of Coimbra, Portugal (N=113); Museu Bocage, National Museum of Natural History, Lisbon, Portugal (N=60). Length and width measurements were taken then regression was used to analyse the datasets. Three morphological factors were observed including, level of fusion at the synchondrosis intraoccipitalis anterior, presence/absence of billows and presence/absence of depressions. Results Accuracy based on the metric model ranged between 37-71%. The morphological model showed fusion present as early as 3-years of age, with all non-adults over 8-years showing 100% complete fusion. Only individuals below 13-years of age displayed billows or depressions present; presence not absence of the morphological variables can be used to estimate age with a 92% accuracy rate. Conclusion The metric model does not reach an acceptable level of accuracy for use in aging non-adults. Morphology of the occipital condyles do not follow a specific age progression but can be used as a quick age assessment guide; if these morphological features are present the individual very likely between 3-13-years of age.