The Morphological Interaction Between the Nasal Cavity and Maxillary Sinuses in Living Humans

Abstract

To understand how variation in nasal architecture accommodates the need for effective conditioning of respired air, it is necessary to assess the morphological interaction between the nasal cavity and other aspects of the nasofacial skeleton. Previous studies indicate that the maxillary sinuses may play a key role in accommodating climatically induced nasal variation such that a decrease in nasal cavity volume is associated with a concomitant increase in maxillary sinus volume. However, due to conflicting results in previous studies, the precise interaction of the nasal cavity and maxillary sinuses, in humans, is unclear. This is likely due to the prior emphasis on nasal cavity size, whereas arguably, nasal cavity shape is more important with regard to the interaction with the maxillary sinuses. Using computed tomography scans of living human subjects (N=40), the goal of this study is to assess the interaction between nasal cavity form and maxillary sinus volume in European- and African-derived individuals with differences in nasal cavity morphology. First, we assessed whether there is an inverse relationship between nasal cavity and maxillary sinus volumes. Next, we examined the relationship between maxillary sinus volume and nasal cavity shape using multivariate regression. Our results show that there is a positive relationship between nasal cavity and maxillary sinus volume, indicating that the maxillary sinuses do not accommodate variation in nasal cavity size. However, maxillary sinus volume is significantly correlated with variation in relative internal nasal breadth. Thus, the maxillary sinuses appear to be important for accommodating nasal cavity shape rather than size.