Sexual Dimorphism Determination by Piriform Aperture Morphometric Analysis in Brazilian Human Skulls

Abstract

SUMMARY:The sex determination of human skeletons is important in forensic and anthropological research. It can be carried out through qualitative or quantitative analysis of morphological parameters of dimorphism. The shape of the piriform aperture is one of the classic indicators of sexual dimorphism since it describes differences between males and females according to strong populationspecific behavior. The purpose of this study was to analyze the presence of sexual dimorphism in the size of the piriform aperture and its relationship with individual skin color. We used 90 human skulls from the Collection of the Federal Universidad de Sao Paulo (UNIFESP), with registered data on sex, age and skin color (classified as white, black and brown). The dimensions studied were: height, upper width and lower width of piriform aperture. All dimensions were greater in males than females, however, only the piriform aperture height was found to be significant with p <0.01. By analyzing differences and grouping them according skin color, the piriform aperture height was found to be significantly higher (p <0.05) in white, black and brown males. In the group of black individuals skulls, we found significant differences in the upper width (p <0.05). The main differences, related to the piriform aperture height and the low influence of skin color in the presence of sexual dimorphism in the piriform aperture size, are in contrast with what has been reported in the literature and justify the revision of the classic indicators used for diagnosis of sex in specific populations.

Evaluation of apertura piriformis and related cranial anatomical structures through computed tomography: golden ratio

“…Knowing the differences between genders is very important in fields such as forensic medicine, anthropology, and archaeology with regard to determining human identity [2,11]. In our study, the difference between genders was found to be valid in both the 21-25 and 26-30 age groups.…”

“…The number of studies on PA is limited. Data on morphology vary according to ethnic differences, sexual dimorphism and age-related changes of the PA, which have already been published [4,6,11]. Studies have focused on the relationship between the nasal bone and PA, the shape of the PA and the size of the PA [7,12,19].…”

Sex prediction by metric and non-metric analysis of the hard palate and the pyriform aperture

“…Moreover, Abdelaleem et al [1] and Saini et al [26] reported that the inferior width of the PA offers 67.7-78.6% accuracy in predicting sex, similar results to those found in the present study where we report 74.2% accuracy and 0.764 AUC. In the present investigation we found no statistical differences between sexes for the inferior width of the PA, corroborating the findings of Cantín López et al [7]; however, it should be noted that this measurement presented moderate accuracy, good sensitivity and good PPV for sex diagnosis. Nevertheless, because of its low AUC, specificity and NPV, we do not consider it a good sex predictor.…”

“…We agree with Hunnargi et al [15] who state that the conflicting results found for the inferior width of the PA may be due to the fact that precision in sex determination may vary according to the statistical method used. For the superior width of the PA, Cantín López et al [7] found lower mean values than ours, of 13.29 mm for males and 12.75 mm for females; however like us, they found no significant difference between sexes in this dimension. Although the superior width pre-sents good PPV, the present investigation found low accuracy and sensitivity in the sex prediction capacity of this measurement.…”

“…Distortion of the soft tissues and bone fragmentation due to heat may make it difficult to determine sex [12]. The characteristics of the pyriform aperture (PA) offer a classic sex indicator [7]. The PA communicates the nasal cavity with the exterior; its superior limit is determined by the nasal bones and its lateral and inferior limits by the maxilla [2].…”