Predictable value of cranial traits used in the visual assessment of sex in the chilean population: a Geometrics Morphometrics analysis.

The variation of five cranial traits used in the visual assessment of sex were recorded in a set of landmarks coordinates and analized by geometrics morphometrics methods to put into practice a metrical method to evaluate the reliability of this traits for sex determination in chilean population. The cranial traits analized were glabella, mastoid process, zygomatic process of the temporal, zigomatic bone and the orbital form. The 3D coordinates for morphometrical analysis were taken from 120 craniums (60 male, 60 female) with know sex from the Cemeterio General collection of the Anthropology Department of the University of Chile. The coordinates set for each trait were compare between females and males through a permutation test for means difference, and by Generalised Procustes analysis (GPA) and thin-plate splines for size and shape variables to carry out statistical analysis and to visualize the morphological variation for this cranial trais. Significant differences owed to sex were found for glabella, mastoid process, zygomatic bone and zygomatic process of the temporal and the size and shape variables discriminant functions gave significant clasification for sex over the 89% of the sample cases. The 3D thin-plate splines visualization and the size and form varition of this traits allowed us to describe the morphological variation from hyperfeminine to hypermasculine cases of this population, descriptions that could be applyed to methods for cranium visual sex assesment. Finally, we conclude that this cranial traits can be measured to validate this methods in a particular population