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A number of previous studies have demonstrated that osteometric analysis of the sternum provides a highly accurate method for discriminating adult sex in diverse population groups. In this study, sternal measurements were recorded from posteroanterior digital radiographs of the chest plate of 116 Spanish individuals (65 males and 51 females). Results demonstrated that all linear dimensions of the manubrium and mesosternum, sternal area, and sternal index were significantly sexually dimorphic in this population group. Discriminant function analyses incorporating several of these variables, individually or in combination, provided sex classification accuracy rates greater than 80.0%, with associated sex biases below 5.0%. A stepwise procedure, which can be used when a complete sternum is present, yielded the highest correct sex classification rate at 89.7%. Only slightly lower allocation accuracy rates were obtained for multivariate equations which incorporated either dimensions of the manubrium or mesosternum (87.1% for both formulae). Thus, the derived discriminant function equations should prove useful in forensic investigations, particularly those in which the pelvis or bones of the extremities are not available for analysis.

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Digital photogrammetric methods were employed to assess the level of sexual dimorphism present in permanent maxillary molar cusp areas of black South Africans (130 males, 105 females). Odontometric standards were then developed for diagnosing sex, based on the cusp area data derived for these teeth. Results demonstrated that all cusp area measurements of both the first and second maxillary molars were significantly dimorphic (P < 0.0001) in this group. Univariate and multivariate discriminant function analyses yielded overall sex prediction accuracy rates between 59.6 and 74.5%. Comparable allocation results were also obtained for binary logistic regression analyses, but with larger classification sex biases. The highest classification accuracies were observed for different combinations of just two cusp areas for the first molar. Allocation rates of formulae derived for second molar dimensions were on average 4.3% lower than those obtained for the first molar. Analyses incorporating cusp areas of both maxillary molars did not improve classification accuracies achieved when only using first molar measurements. The classification rates are below the suggested minimum accuracy of 75-80% for reliable forensic application of a method; however, the derived formulae may provide a useful statistical indication as to the sex of fragmentary remains in which complete or even partial tooth crowns are the only materials available for examination. Furthermore, the formulae can be applied not only to adults but also to subadults (above the age of 3 years) in which the more accurate sex discriminating features of the pelvis and skull are yet to develop.

The determination of sex from human skeletal remains is of fundamental importance in both medicolegal and bioarchaeological investigations. In the present study, the basal region of the occipital bone in a documented French collection was analyzed for sex differences using standard osteometric techniques. The results demonstrated that a low level of sexual dimorphism is present in the cranial base of this sample, with few of the measured variables exhibiting statistically significant differences between the sexes. The cross-validated classification accuracies obtained in this study for the derived discriminant functions are appreciably lower than those previously reported for other disparate populations. A stepwise procedure, which selected maximum length of the left occipital condyle and minimum distance between occipital condyles (MnD), produced the best overall result with a classification accuracy rate of only 67.7%. The most effective single dimension, bicondylar breadth (BCB), also correctly classified 67.6% of the individuals examined, but with a much higher sex bias. Osteometric analysis of cranial base dimensions, therefore, cannot be regarded as a sufficiently reliable method for determining sex in this population group.Keywords Sex dimorphism · Foramen magnum · Occipital condyles · Discriminant function analysis Résumé La détermination du sexe à partir de vestiges du squelette revêt une importance fondamentale pour les recherches médicolégales et bioarchéologiques. Dans cette étude, les différences sexuelles dans la morphologie de la région basale de l'os occipital ont été mesurées dans une collection d'échantillons français à l'aide de méthodes classiques d'ostéométrie. Nos résultats démontrent qu'un niveau faible de dimorphisme sexuel est observé dans les os de la base du crâne dans la mesure où un faible nombre des variables mesurées présentent des différences significatives entre mâles et femelles. La précision d'une fonction de discrimination du sexe a été mesurée par une méthode de validation croisée sur la population d'origine et est notoirement plus faible que celle documentée dans d'autres populations. La précision maximale obtenue avec une méthode de sélec-tion progressive est de 67,7 % pour une fonction de discrimination basée sur la longueur maximale du condyle occipital gauche et la distance minimale entre les condyles occipitaux. La meilleure fonction de discrimination univariée, basée sur la largeur de l'articulation bicondylaire, atteint une précision légèrement plus faible de 67,6 % mais avec un biais sexuel plus fort. En conclusion, les analyses biométriques des dimensions des os de la base du crâne ne permettent pas de déterminer le sexe avec précision dans cette population.