Under the surface: Correlates with maxillary sinus shape.

Despite the central role that the maxillary sinus plays in facial architecture, its shape has never been robustly analyzed in part due to its amorphous morphology and the lack of repeatable landmarks. While previous research has examined correlations between sinus volume and two-dimensional measurements with factors like sex, age, and environmental influences, less is known about finer structural variations, such as trabeculation and surface complexity, in relation to these variables. This study aimed to explore how maxillary sinus size and shape correlate with factors such as age, sex, tobacco, and drug use. The left and right maxillary sinuses of 109 adult individuals were segmented from CT scans. A novel application of spherical harmonic analysis was conducted to quantify maxillary sinus shape. Statistical analyses, including principal component analysis, t-tests, and Mann-Whitney U tests, were employed to assess differences in sinus shape due to sex, age, tobacco use, and drug use. Results showed significant differences in sinus shape due to sex, tobacco, and drug use. The areas of highest variation between groups were at the lateral-most apex and the anterior wall at the superior and inferior corners. Males have larger sinuses, but no other significant differences in sinus size or asymmetry were identified among the groups tested. Previously identified patterns in maxillary volume across age groups were not supported. This study illustrates the areas of highest variability in relation to each variable and has important implications for future studies seeking to understand sinus structure and drainage across groups.