Morphometric sex estimation from 3D computed tomography os coxae model and its validation in skeletal remains

In the last decade, the advances in imaging technologies have intensified the use of multislice computed tomography (MSCT) for anthropological purposes. The published literature has proved it to be a suitable tool for establishing sexually dimorphic characteristics in different anatomical areas. In this context, the main purpose of the present study was to explore the accuracy of traditional morphometric method when applied to data acquired in three-dimensional (3D) reconstructed os coxae of living Spanish population, to develop a series of statistically robust patterns for sex assessment and to test their validity in innominate remains. For this purpose, 150 volume-rendered innominate CT scans were selected to examine nine interlandmark linear distances by means of descriptive statistics and discriminant function analyses (DFA) employing the jackknife procedure for cross-validations. Five measurements were sexually dimorphic. Acetabular diameter was the single most accurate predictor. This, combined with innominate height and innominate breadth, contributed very significantly to sex estimation. Overall, classification accuracies were 89.3-95.3 % (89.3-94.7 % after cross-validation), with a sex-bias lower than 5 %. The second validation approach performed on a sample of 96 individuals from another contemporary Spanish reference collection comprising dry bones showed the high percentage of accurate classification (83.3-95.8 %). In conclusion, the assessment of sex using cross-sectional MSCT images of the os coxae is possible and the discriminant functions obtained on Spanish living individuals can also be effective for estimating sex from skeletal remains.