Sexual Dimorphism in the Subadult Mandible: Quantification Using Geometric Morphometrics^*

Abstract

There have been numerous attempts, with varying degrees of success, to differentiate males from females on the basis of the immature skeleton. We investigate here whether the mandible can discriminate immature individuals by sex; the techniques we apply are from the field of geometric morphometrics. The application of these methods in forensic anthropology is still relatively new; thus, an important aspect of this research is that it demonstrates potential applications in this discipline. The sample comprises 96 known age and sex subadult individuals; the three-dimensional coordinates of 38 landmarks are analyzed using the shape analysis software morphologika. Multivariate regressions indicated no significant sexual dimorphism in the subadult sample; this result is supported by poor cross-validated classification accuracy (59%). Our results suggest that the subadult mandible is not dimorphic (to the extent that dimorphism is not evident within the sample we studied); thus, sex determination using previously described criteria is likely to yield poor results.

Sex Determination in Mandibles in the First Year of Life by a Quantitative Approach

“…These findings are consistent with those reported by Franklin et al (2007), who have used geometric morphometry method on 38 landmarks and have concluded that no sexual dimorphism can be determined in subadults mandibles.…”

Sex Determination of Human Mandible Using Metrical Parameters

“…Standard deviation was 0.53 in males and 0.53 in females. Franklin et al, [18] based on measurements of 225 mandibles suggested that the mean of bicondylar breadth in males was 11.36 cm and for females was 10.86 cm. Standard deviation was 0.60 in males and 0.58 in females.…”

Ortopantomographic Blind Test of Mandibular Ramus Flexure as a Morphological Indicator of Sex in Chilean Young Adults

“…According to Kemkes-Grottenthaler et al (2002), the mandibular tooth loss and functional changes can influence the determination of the age by the Loth & Henneberg method. The features described have been analyzed in the mandibles of subadults too (Loth & Henneberg, 2001;Franklin et al, 2007).…”