The outline of the pubic symphyseal surface is sexually dimorphic and changes with age in humans

The bony symphyseal surface is an important trait for age-at-death estimation from human skeletal remains. In this paper, we demonstrate for the first time that the outline of the human symphyseal surface is sexually dimorphic and that it changes with age. We present a geometric morphometric analysis based on a sample of 323 symphyseal pubic bones from males and females in the age range of 14 to 82 years. These bones were surface-scanned and the resulting surface models were measured along the ventral and dorsal borders of the symphyseal surface using two fixed and 36 curve semilandmarks. Our findings imply that age-related changes in the outline of the symphyseal surface differ between the sexes. According to our results, age explains 5% of total shape variation in females, but less than 1% in males. These findings for the outline, could potentially complement existing sex and age-at-death estimation methods based on other features of the bony pubic surface.