Are frontal sinuses useful indicators of sex?

Accurate sex prediction of skeletonised human remains excludes one-half of the population, enabling a more focussed search of missing persons' files. The skull is useful in sex assessment of skeletonised remains; however, its fragmentation precludes the use of all conventional craniofacial markers. The frontal bone may be recovered intact in fragmented remains and the sinuses therein may be useful in sex differentiation. A total of 100 paranasal sinus view radiographs of 50 males and females each were evaluated for potential differences in frontal sinus configuration following the methods of Yoshino et al. (Forensic Sci Int 1987; 34:289-99.) and Tang et al. (Forensic Sci Int 2009; 183:104.e1-3.). Data were assessed through univariate and multivariate statistics. The univariate Mann-Whitney U-test revealed statistically insignificant sexual dimorphism (p > 0.05) for the frontal sinuses. Moreover, multivariate logistic regression equations allowed correct sex identification in 60% of cases only. Possible reasons for the low sexual dimorphism may be frontal sinus' high inter-individual variability; also, existing techniques that employ frontal sinus classification systems may lead to a loss of information when features that require visual observation are grouped and assigned class numbers. The results herein suggest that frontal sinuses may have limited application as the sole predictor of sex.