Evaluating the Accuracy and Precision of Cranial Morphological Traits for Sex Determination

Abstract

Sex determination is a key analysis that forensic anthropologists perform in order to construct a biological profile of human remains. The techniques used in forensic investigations must meet the Mohan or Daubert criteria, for admissibility in a court of law. In this study, the precision and accuracy of 21 morphological characteristics of the skull were tested on a modern sample of 50 adult crania of European White ancestry. The following craniofacial features are identified as high-quality traits, defined by intraobserver error <or=10% and accuracy >or=80%: mastoid size, supraorbital ridge size, general size and architecture, rugosity of the zygomatic extension, size and shape of the nasal aperture, and gonial angle. Ninety-six percent accuracy and 92% precision were achieved using 20 traits in combination. Fisher's exact probability tests revealed no significant differences (p=0.05) in the levels of precision or accuracy between age categories. Sex-related bias in accuracy was found for the following cranial features: ramus symphysis (p=0.009), zygomatic extension (p=0.0016), and occipital markings (p=0.0013). These traits demonstrated a greater tendency to be scored male than female.

Metric sex determination from the pelvis in modern Greeks

“…Forensic anthropologists are continually attempting to improve methods of skeletal identification through development of new methods of determining sex or fine-tuning of existing methods on various parts of the skeleton so that it can be admissible in court [e.g., 29,30]. The aim of this paper was to follow in this tradition, by developing population specific formulae that could be used on people living in Greece and the Mediterranean.…”

Accuracy of mandibular measurements of sexual dimorphism using stabilizer equipment

“…In this context, various studies 2,3,4,5 have demonstrated that several anatomic landmarks of the skull and mandible can be used and that some of these landmarks typically present increased precision in identifying an individual compared with other. 3 Furthermore, the mandible is one of the most preserved bones in hominid and hominoid fossil records, 6 making it relevant to anthropological studies.…”

“…3 Furthermore, the mandible is one of the most preserved bones in hominid and hominoid fossil records, 6 making it relevant to anthropological studies.…”

“…2,3,4,5,7,8 On the other hand, the metric method is gaining increasing importance as technical reports or case discussion on tribunals make it necessary to statistically present data to prove a specific point of view. Additionally, a less subjective argumentation highlights the reliability of the data.…”

Identification of Sex using Lateral Cephalogram: Role of Cephalofacial Parameters

“…7,14 The cephalometric variables used in the present study were considered based on the evidences of previous studies that have reported high accuracy in determination of sex using a discrete number of morphological features of the cranium. 7,10,14,16 It has been reported that the skeletal characteristics are age-related phenomena which appear or become pronounced at puberty and many are affected by senility. 3,5 Hence, in the present study the lower limit of the age was set at 25 years, as the craniofacial growth is complete by this age, and the upper limit of the age was laid down at 55 years.…”