1Department of Anatomy, Des Moines University, 2Department of Pathology and Anatomical Sciences, University of Missouri
March 27, 2015 , Archview Ballroom
Maxillary sinus volume has previously been shown to track ecogeographic differences in nasal cavity form. However, little is known about how maxillary sinus shape relates to overall facial morphology. Employing a total of 31 coordinate landmarks collected from digitally rendered crania, this study investigates how maxillary sinus and midfacial shape covary in a sample of modern humans from two climatic extremes: “hot/wet” (Sub-Saharan Africans; n = 34) and “cold/dry” (Siberian and Arctic; n= 37). Principal Components Analysis reveals clear discrimination between the two samples along PC1, which contrasts “cold” individuals exhibiting relatively wider, taller sinuses and narrower, taller noses from “hot” individuals exhibiting relatively narrower, shorter sinuses and wider, shorter noses. A Two-Block Partial Least Squares (2B-PLS) test demonstrates moderate but significant covariation (RV = 0.32, P < 0.001) between the facial skeleton (block1) and maxillary sinus (block2). This 2B-PLS test again indicates that most of the covariation (49%) relates to the height/breadth of both the nasal cavity and maxillary sinus. While these results support previous arguments that maxillary sinus morphology relates to ecogeographic patterns of the nasal cavity, our study also reveals more nuanced relationships between the maxillary sinus and other aspects of facial morphology, such as maxillary body height and relative positioning of the zygomatic bone. Therefore, our results further suggest that the maxillary sinus serves as a zone of accommodation at the convergence of multiple facial components, potentially minimizing the morphological impacts of evolutionary alteration in one component (e.g., the nose) upon other aspects of the face.
Funding for this project was obtained through Richard Gilder Graduate School Collection Study Grant; Texas A&M Vision 2020 Dissertation Improvement Grant; and Texas Academy of Science.