An index of chin breadth/height (“shape”) is contrasted with a measure of jaw size (mandibular length, units in mm) for the Tigara sample. Sexing for the sample is based on Costa [79]. Regression is nonsignificant (), indicating that the general geometry of the human symphysis is insensitive to size. The female sample range encompasses the male range for shape. Thus, shape differences are not apparent between the sexes in midsagittal section. Comparison of sexes by analysis of covariance (ANCOVA) reveals no significant difference between male and female slopes () or intercepts ().
