Human maxillary sinus size, shape, and surface area: Implications for structural and functional hypotheses

Abstract

Objectives: Although research into human maxillary sinus (MS) morphology has overwhelmingly focused on sinus volume, other aspects of morphology (e.g., overall shape, mucosal surface area) factor prominently in hypotheses regarding MS form and function. Here, we investigate MS volume in conjunction with measures of MS shape and surface area in a large, diverse sample of modern humans. We test whether variation in MS volume is associated with predictable changes in MS shape (i.e., allometry) and investigate the influence of MS size-shape scaling on mucosal surface area dynamics.Materials and Methods: Measures of MS volume and surface area were obtained from computed tomographic (CT) scans of 162 modern human crania from three ancestral backgrounds-Equatorial Africa, Europe, and East Asia. 3D coordinate landmarks and linear measurements were also collected. Multivariate analyses were employed to test for associations between MS volume and other morphological variables.Results: Significant associations between MS volume and 3D shape were identified both across and within the subsamples. Variation in MS volume was found to predominantly relate to differences in MS height and width dimensions relative to MS length. This pattern of allometric scaling was found to differentially influence total mucosal surface area and the SAV ratio. Conclusion:This study suggests that variation in MS volume is disproportionately mediated by MS width and height dimensions. This finding has implications for hypotheses which structurally link MS morphology to craniofacial ontogeny and those which suggest that MS morphology may perform adaptive physiological functions.

Investigating the relationship between infraorbital canal morphology and maxillary sinus size

“…This suggests that these individuals are more likely to possess relatively shorter IOG‐IOF dimensions, at least for a given MS length. In terms of previous literature, several studies note individuals of Asian ancestry tend to exhibit superior–inferior taller, medial‐laterally wider, and antero‐posteriorly shorter sinuses compared to sub‐Saharan African and, to a lesser extent, European groups (Butaric, 2015; Maddux & Butaric, 2016); however, it is important to note that compared to MS height and breadth, MS length is less variable across geographically diverse populations (Kim et al, 2022b). While limited, previous studies have also noted ancestral based differences in the relative location of the IOF.…”

“…Two distance measures of the ION pathway were also collected from the CT scans, using the 3D models as a guide (see Figure 2c): the direct distance between the foramen rotundum to infraorbital foramen (FR‐IOF) and the direct distance from the posterior aspect of the infraorbital groove (at the edge of the inferior orbital fissure) to the infraorbital foramen (IOG‐IOF). While multiple clinical and anthropological studies focus on maxillary sinus size (i.e., volume), several studies indicate that it is the distribution of that volume (i.e., shape) that is most important when interpreting structural and/or functional relationships (e.g., Kim et al, 2022b; Maddux & Butaric, 2016). As such, the current study focuses on the linear dimensions of the sinus (see Figure 2a,b), not an overall measure of size.…”

Anatomical features of the maxillary sinus in people with a leptoprosopic form of the facial skull

“…The literature contains extensive information on the volume of MS, surface area, and wall thickness according to computed tomography (CT) [8][9][10][11][12][13], as well as on ground turtles [14][15][16]. Some author studies reveal features of multiple sclerosis in various forms of cerebral [17,18] and facial skull, demonstrating the degree of pneumatics [19].…”