The depth of the anterior incurvatio of the human chin (units in mm) is contrasted with the thickness of the chin (mm) at the tuber symphyseos in the Tigara sample. Thickness is measured perpendicular to the vertical tangent at the most anterior point of the symphyseal tuber; this measurement will be approximately parallel to the occlusal plane. Sexing for the sample is based on Costa [79] who employed multiple criteria including features of the os coxae. A deep incisura generally gives the appearance of a more salient chin, while chin thickness provides a size measure with no necessary indication of distinctiveness. Interestingly, the different shapes said to differentiate males from females are not reflected by these measures, that is, there is substantial overlap of the sexes. Thus, there is no definitive sex difference in shape (as measured here) of the chin in midsagittal section. Nevertheless, regression is significant (), indicating that large chins are also more salient, in that they are associated with larger anterior incisures. Comparison of sexes by analysis of covariance (ANCOVA) reveals no significant difference between male and female slopes () or intercepts ().
