The use of craniometrics in the estimation of juvenile sex by means of discriminant function analysis: a revised method

Abstract

This study provides evidence that there is sex dimorphism within the craniofacial growth of juveniles. This study was modeled after the study produced by Gonzalez (2012) and updates the methodology used in that study. Computed tomography (CT) images of 351 juvenile individuals, ages three to sixteen, both male and female, from the Department of Radiology at Boston University School of Medicine were measured. Of the twenty six measurements taken, nineteen were used for analysis. Measurements were made using OsiriX, an open-source software that allows the manipulation and measurement of CT images. The data was analyzed using discriminant function analysis in order to make classification models based on age groups. Gonzalez’s study showed that the male head is both taller and longer than a female’s and that based on his data set, sex estimation using this method is 78 to 89% accurate. The current study exhibited rates from 66-85% correct classification depending on the age group when analyzed with a stepwise analysis and rates of 74-92% when analyzed without; both analyses exhibited a trend towards improved classification rates in the older individuals. The neurocranium and the areas affected by the growth of the nasopharynx were found to be the most dimorphic. In general, males tend to have a longer and wider neurocrania as well as increased growth in the anterior direction of the facial region. In addition females had higher correct classification rates compared to males, despite having fewer females within the sample collection; this trend was also reflected in the original results produced by Gonzalez.