ORIGINAL ARTICLE Morphometric analysis of pelvic sexual dimorphism in a contemporary Western Australian population Daniel Franklin & Andrea Cardini & Ambika Flavel & Murray K. Marks Received: 3 February 2014 /Accepted: 16 April 2014 # Springer-Verlag Berlin Heidelberg 2014 Abstract Requisite to routine casework involving unidenti- fied skeletal remains is the formulation of an accurate biolog- ical profile, including sex estimation. Choice of method(s) is invariably related to preservation and by association, available bones. It is vital that the method applied affords statistical quantification of accuracy rates and predictive confidence so that evidentiary requirements for legal submission are satis- fied. Achieving the latter necessitates the application of con- temporary population-specific standards. This study examines skeletal pelvic dimorphism in contemporary Western Australian individuals to quantify the accuracy of using pelvic measurements to estimate sex and to formulate a series of morphometric standards. The sample comprises pelvic multi- slice computer tomography (MSCT) scans from 200 male and 200 female adults. Following 3D rendering, the 3D coordi- nates of 24 landmarks are acquired using OsiriX® (v.4.1.1) with 12 inter-landmark linear measurements and two angles acquired using MorphDb. Measurements are analysed using basic descriptive statistics and discriminant functions analyses employing jackknife validation of classification results. All except two linear measurements are dimorphic with sex dif- ferences explaining up to 65 % of sample variance. Transverse pelvic outlet and subpubic angle contribute most significantly to sex discrimination with accuracy rates between 100 % (complete pelvis—10 variables) and 81.2 % (ischial length). This study represents the initial forensic research into pelvic sexual dimorphism in a Western Australian population. Given these methods, we conclude that this highly dimorphic bone can be used to classify sex with a high degree of expected accuracy. Keywords Sex discrimination . Forensic anthropology . Pelvic measurements . Computed tomography . Population standards . Sexual dimorphism Introduction In routine and nontraditional investigations, a forensic anthro- pologist draws upon an intimate and specialized knowledge of human anatomy and osteology complemented by established morphoscopic (visual—observational) and morphometric (linear—measurement) standards. Those standards are used to identify biological attributes in the skeleton, such as (but not limited to) basic differences between sex and age-related landmarks. In satisfying requirements for legal admissibility, morphometric approaches have a robust statistical foundation readily accepted when appropriate contemporary population- specific standards are applied. Geographically and genetically isolated human groups, however, display population-specific skeletal characteristics, many of which are evident in the relative expression and magnitude of sexually dimorphic fea- tures [1, 2]. For the forensic practitioner, the latter is an important consideration in selecting appropriate anthropological stan- dards, especially as it is well established that the application of non-population-specific standards (e.g. for estimating sex) results in a reduction in classification accuracy [3–5]. Another D. Franklin (*) : A. Cardini : A. Flavel : M. K. Marks Centre for Forensic Science, The University of Western Australia, M420, 35 Stirling Hwy, Crawley 6009, Western Australia, Australia e-mail: daniel.franklin@uwa.edu.au A. Cardini Dipartimento di Scienze Chimiche e Geologiche, Università di Modena e Reggio Emilia, l.go S. Eufemia 19, 41121 Modena, Italy A. Cardini Hull York Medical School, University of Hull, Cottingham Road, Hull HU6 7RX, UK M. K. Marks Department of General Dentistry, Graduate School of Medicine, University of Tennessee Medical Center, Knoxville, TN, USA Int J Legal Med DOI 10.1007/s00414-014-0999-8