Shape variation of the human orbital cavity

Shape analysis of the human orbital cavity is challenging due to several reasons. First, it is a smooth surface where only few anatomical landmarks can be identified. Second, data acquisition via CT-scanning is limited due to poor representation of the orbital walls caused by the so-called partial volume effect. The structure of the orbital walls can also lead to gray values differing from the rest of the bony tissue. Hence, automatic segmentations based on gray value thresholds will not include them in the segmentation and produce pseudoforamina in the segmented orbital walls.

In this study, a symmetric template mesh representing the orbital region was created. Forty-six landmarks were placed manually onto skull surfaces which were automatically segmented from CT-scans of 656 individuals of European (♀:n=164, ♂:n=164) and Chinese (♀:n=164, ♂:n=164) origin. A statistical model was computed on basis of the template mesh and semi-automatically matched onto the skull surfaces. This way, the defects in the representation of the orbital wall were interpolated. Next, 600 bilateral semi-landmarks, evenly distributed on the surface of the orbital cavity, were placed automatically on each individual. Procrustes analysis and principal component analysis were performed on these configurations. Shape variation depending on the factors sex and population affinity was analysed using the principal component (PC) scores of the PCs accounting for 98% of the total variance. The results indicate significant influence of population affinity and sex on orbital cavity shape with weak interaction between the two.

Rüdell, A. 2016. Shape variation of the human orbital cavity. In: Program of the 85th annual meeting of the American Association of Physical Anthropologists. American Journal of Physical Anthropology 159:277.

Contact: Alexandra Rüdell

Additional Info

Field	Value
Author	Alexandra Rüdell
Contact	[email protected]