Anthropology, University of Freiburg, Germany
Saturday All day, Clinch Concourse
The zygomatic bone is an important element of the viscerocranium. Several muscles attach here, and its shape has a marked effect on facial appearance. As a consequence, shape variation of the zygomatic bone is crucial in forensic facial reconstruction, reconstructive surgery and evolutionary studies.
We analysed the shape of the zygomatic bone in 200 individuals, divided into four subgroups, representing females and males of Chinese and European origin. Our data consists of surface meshes extracted from CT-scans. First, eight manually placed landmarks provided a rough alignment of these meshes. Then, both rigid and elastic surface matching algoritms were applied, using iterative closest point matching and smoothed displacement fields. After the registration process, all vertices of the matched surfaces were corresponding throughout the sample. Based on this information, statistical shape analysis was performed, using 1000 mesh vertices.
Our results show significant shape divergences related to sex and population affinity. Sex differences are hardly distinguishable with the naked eye. A comparison in terms of origin proofs the average Chinese shape to be more robust than the European. The variation depending on population affinity concentrates on the orbital border of the zygomatic bone, with less variation at the temporal border.