Three-dimensional CBCT evaluation of maxillary sinus dimensions and volume in relation to sagittal and vertical skeletal patterns: a multivariable analysis

Maxillary sinus morphology is closely related to craniofacial skeletal structures and may influence orthodontic diagnosis and treatment planning, particularly when planning posterior tooth movement and evaluating anatomical limitations of the posterior maxilla. However, the relationship between maxillary sinus dimensions and different sagittal and vertical skeletal patterns remains unclear. This study aimed to evaluate the association of maxillary sinus dimensions and volume with sagittal and vertical skeletal patterns using cone-beam computed tomography (CBCT). In this retrospective analytical cross-sectional study, 147 archived CBCT scans of patients aged 15–24 years were analyzed. Maxillary sinus length, width, height, and volume were measured bilaterally. Sagittal skeletal class was classified as Class I, II, or III malocclusion, and vertical skeletal pattern was classified as low-, normal-, or high-angle. Linear mixed-effects models (LMMs) were applied with sinus side as a repeated factor, adjusting for age, sex, and vertical skeletal pattern. Exploratory ordinal logistic regression and receiver operating characteristic (ROC) curve analyses were performed. Sinus width and volume differed significantly among sagittal skeletal classes. Compared with Class III, sinus width was greater in Class I ( p = 0.010) and Class II ( p < 0.001), whereas sinus volume was smaller in Class I ( p < 0.001) and Class II ( p = 0.038). Vertical skeletal pattern was also associated with sinus width and volume, with low-angle patterns demonstrating reduced sinus width and greater sinus volume relative to high-angle patterns ( p < 0.05), whereas age and sinus side were not. Sex was associated with sinus height ( p = 0.015) but not with sinus volume ( p = 0.751). In exploratory ordinal logistic regression analyses, sinus height, length, and width were associated with sagittal skeletal class ( p < 0.05). ROC analysis demonstrated good discrimination for sinus volume (AUC = 0.828, 95% CI: 0.780–0.869). Maxillary sinus width and volume were significantly associated with sagittal skeletal class, and sinus volume was also related to vertical skeletal pattern. Although several sinus dimensions were associated with sagittal skeletal class in exploratory analyses, only sinus volume demonstrated acceptable discriminatory performance in ROC analysis.