The mandible contributes only slightly to forensic assessment of ancestry. But it is very important in assessment of sex. Male mandibles are generally heavier and larger than female mandibles, and have larger teeth on average. In addition to size, there are several nonmetric features that reflect sex:
- Gonial angle: The point at which the mandibular corpus and ascending ramus meet is called gonion. In males, the angle formed by the corpus and ascending ramus is closer to 90 degrees. In females, this angle is greater, up to 110--120 degrees.
- Gonial eversion: At gonion, male crania tend to have rugose muscle attachments that curve outward, or evert from the surface of the mandible. Females more often lack this eversion or may even invert toward the midline.
- Chin: The chin tends to be larger in males, with a more widely-set trigon.
What to do: Use these features, along with size, to seriate the mandibles at this station. Which would you consider to be males, and which females?