Association between Nasal Septal Deviation Angle and Maxillary Sinus Pathology: A Cross-Sectional CBCT-Based Study

Background: Nasal septal deviation (NSD) is a common anatomical variation that may affect sinonasal airflow and drainage, potentially contributing to maxillary sinus pathology. However, the relationship between deviation severity and sinus disease remains unclear. This study evaluated the association between NSD angle and maxillary sinus pathology using cone-beam computed tomography (CBCT)-based analysis. Materials and Methods: A total of 460 randomly selected CBCT scans were retrospectively analyzed. NSD was assessed for presence, laterality, and severity based on angular measurement and categorized as mild (<10°), moderate (10–15°), or severe (>15°). Maxillary sinus pathologies, including mucosal thickening, retention cysts, and polypoidal lesions, were recorded. Statistical analysis included inferential testing, multivariable logistic regression, and feature importance assessment. Results: NSD was identified in 89.6% of subjects, with right-sided deviation being more common. Maxillary sinus pathology was present in 83.5% of cases, predominantly mucosal thickening. A significant association was observed between NSD and sinus pathology (90.3% vs. 25.0%, P < 0.001), with higher ipsilateral involvement ( P < 0.001). The prevalence of sinus pathology increased with deviation severity, indicating a dose–response pattern. Logistic regression identified NSD angle (OR = 2.95), age (OR = 1.41), and right-sided deviation (OR = 1.98) as significant predictors, while gender was not significant. The predictive model demonstrated high performance (accuracy 87.6%, AUC 0.89). Conclusion: NSD angle is significantly associated with maxillary sinus pathology, with greater deviation severity linked to higher pathological prevalence. CBCT-based assessment of NSD may aid in identifying individuals at increased risk of sinus disease.