Outline analysis of sex and population variation in greater sciatic notch and obturator foramen morphology with implications for sex estimation

Abstract

The pelvis is known to be the most sexually dimorphic part of the adult human skeleton. Many pelvic sex traits, however, are difficult to analyze quantitatively, with practitioners relying on subjective qualitative descriptions. This study uses elliptical Fourier analysis to explore sexual dimorphism and population variation in two pelvic traits, greater sciatic notch (GSN) and obturator foramen (OF), in a diverse set of 329 ossa coxae. The resultant shape variables support the qualitative descriptions of sex differences. Discriminant function analyses on GSN variables reveal correct classifications over 80% for all sample subsets and 86.8% on the pooled sample; although significant population differences were noted with possible secular changes. Females display more notch variation than males, and age was not a significant factor. OF results were more variable and classification rates were not consistently high enough for use in forensic practice. Furthermore, GSN and OF shape are not significantly correlated.

Keywords: Elliptical fourier analysis; Forensic anthropology; Os coxae; Pelvis; Pubis; Sexual dimorphism.