Variation in maxillary sinus anatomy: Implications of ostium positioning on health disparities in sinusitis

Purpose - Over 30 million people were diagnosed with sinusitis in 2017, yet potential anatomical etiologies behind sinus infections remain poorly understood. Previous research has suggested regional differences in maxillary sinus (MS) size and shape as possible contributors to sinusitis susceptibility. Paranasal sinuses drainage is mediated by mucociliary transport and gravity, but the human orthograde posture and the superior positioning of the MS ostia result in a heavy reliance on the mucociliary system. The purpose of this study was to examine the anatomical relationships between MS and the MS ostium among different ancestral groups to assess potential impacts on drainage and infection risks. Methods - By utilizing CT scans (n=49) of crania from Europe, East Asia, and Sub-Saharan Africa, we collected 93 3D coordinate landmarks from which 34 linear measurements of MS and surrounding facial features were calculated. ANOVA and Tukey-Kramer tests were employed to test for statistically significant differences between groups. Results - ANOVA and Tukey-Kramer test results indicate that Asians have significantly taller MS compared to Europeans and Africans (F=9.4, p=0.0003) and a greater distance from the floor of MS to the ostium (F=8.4, p=0.0007). Further, the ratio of these two variables indicates that the ostium is more superiorly positioned among Asians (at 66% of MS height) than Europeans (61%) or Africans (60%). Conclusions From this data, we tested and support the hypothesis that MS size, shape, and ostium position differ between regional groups. Although limited by small sample size, these results suggest that MS and ostium structure may differentially influence mucus and pathogen clearance from the sinus among individuals of Asian ancestry relative to those of European or African ancestry. Additional research into the prevalence of MS sinusitis in these populations is warranted to evaluate potential contributions to health disparities.