Department of Pathology and Anatomical Sciences, University of Missouri
Saturday All day, Clinch Concourse
The zygomaxillary suture is widely employed in cranial assessments of ancestry, with most individuals of Asian/Native American ancestry suggested to exhibit “angled” sutures (where the lateral-most and inferior-most points along the suture are coincidental), and most individuals of European ancestry believed to possess “curved” sutures (distinct lateral-most and inferior-most points). The proportions of zygomaxillary suture configurations in other populations, such as those of African ancestry, are less well known, but are generally assumed to be less diagnostic. In this study, zygomaxillary suture curvature was assessed through the evaluation of a continuous series of 3D landmarks traced along the suture. The lateral-most point along the suture was identified by assessing the mediolateral deviation of each landmark from the midsagittal plane. When the inferior-most landmark was also the lateral-most, a specimen was scored as “angled.” Conversely, specimens with more superiorly positioned lateral-most landmarks were coded as “curved.” Landmarks were collected on a total of 341 human crania from five geographic regions: Sub-Saharan Africa (n=58), North American Arctic (n=71), Northeast Asia (n=60), aboriginal Australia (n=75), and Europe (n=77). Our results support a high percentage of angled sutures among Native Americans, with 86% of our Arctic sample exhibiting this configuration. Interestingly, only 50% of our Asian sample exhibited angled sutures, refuting the common assumption of sutural similarity between these two groups. Our European sample, however, did not exhibit a high proportion (55%) of curved sutures, rather, it was our African (81%) and aboriginal Australian (77%) subsamples which exhibited the highest incidences of this configuration.
This research was supported by grants from the Wenner-Gren Foundation, Leakey Foundation, and the University of Iowa.