Age estimation of immature human skeletal remains using the post-natal development of the occipital bone

Abstract

Whenever age cannot be estimated from dental formation in immature human skeletal remains, other methods are required. In the post-natal period, development of the skeleton provides alternative age indicators, namely, those associated with skeletal maturity of the cranium. This study wishes to document the age at which the various ossification centres in the occipital bone fuse and provide readily available developmental probabilistic information for use in age estimation. A sample of 64 identified immature skeletons between birth and 8 years of age from the Lisbon collection was used (females = 29, males = 35). Results show that fusion occurs first in the posterior intra-occipital synchondrosis and between the jugular and condylar limbs of the lateral occipital to form the hypoglossal canal (1-4 years), followed by the anterior intra-occipital (3-7 years). Fusion of the post-natal occipital does not show differences in timing between males and females. Relative to other published sources, this study documents first and last ages of fusion of several ossification centres and the posterior probabilities of age given a certain stage of fusion. Given the least amount of overlap in stages of fusion, the closure of the hypoglossal canal provides the narrowest estimated age with the highest probability of age.

Introducing Computed Tomography Standards for Age Estimation of Modern Australian Subadults Using Postnatal Ossification Timings of Select Cranial and Cervical Sites,

“…Interestingly, Queensland age parameters for the anterior and PIOS mirror the standards provided by Redfield (8) on a Yugoslavian (dated 1405-1475 AD) archaeological sample of unknown chronological age, and Scheuer and Black (3) and Cardoso et al (11) utilizing the Lisbon Collection (individuals born between 1908 and 1984). There may be evidence that the basicranium has a strong genetic predetermination (44) and may be resilient against environmental influences as head growth is frequently spared from severe malnutrition (45).…”

Ontogeny of the spheno‐occipital synchondrosis in a modern Queensland, Australian population using computed tomography

“…Using this extended analysis, we are able to determine the likely age of individuals who would currently be assigned to any given stage, as opposed to the transition analysis, which has a primary goal of estimating the average age at which individuals transition from one stage to the next. A Bayesian statistical approach was utilized to compute robust parameters for age estimation; the theoretical basis of the application of Bayes Theorem in the context of age estimation is discussed extensively in the literature (Cardoso, 2008;Konigsberg et al, 2008;Kimmerle et al, 2008;Langley-Shirley and Jantz, 2010;Cardoso et al, 2013;Lottering et al, 2013). Posterior density tables of age for a given stage of fusion were constructed to provide a comprehensive insight into the age variation in maturation of the synchondrosis that can be used for age estimation of adolescents.…”

The ossification pattern in paediatric occipito-cervical spine: is it possible to estimate real age?

“…4,9 However, the pattern of ossification was very different between the PIOS and AIOS. The ossification of the PIOS was very consistent between subjects.…”

“…4 The two lateral occipital bones fuse with the basi-occipital bone in the anterior portion and the squamous occipital bone in the posterior portion at a young age. 9,10 Anatomically, the AIOS can be divided into two segments: the horizontal segment, separating the condylar and jugular portions of the hypoglossal portion; and the vertical segment, which includes the lateral occipital and basi-occipital.…”

“…As in previous reports, asymmetric synchondrosis of the occipital area occurred very rarely (AIOS: two cases, 0.9%; PIOS: five cases, 2.2%). 4 Thus, assessing just one side may be sufficient to estimate real age.…”