Impact of Maxillary Sinus Septa on Sinus Volume: A Retrospective Cross‐Sectional Radiographic Study

Objectives This study aimed to evaluate maxillary sinus volume and its relationship to maxillary sinus septa using cone‐beam computed tomography (CBCT). Materials and Methods This retrospective cross‐sectional study assessed 253 CBCT scans (506 sinuses) of adult patients from the archive of the University Dental Hospital of Sharjah (UDHS) using Planmeca Romexis software. Sinus volume was measured, and septa were assessed for presence, location, orientation, and completeness. Results A total of 253 CBCT scans were analyzed, including 116 males (45.8%) and 137 females (54.2%), with a mean patient age of 39.3 ± 13.6 years. These scans encompassed 506 maxillary sinuses assessed for the presence of septa, while 467 sinuses were suitable for volumetric analysis. Septa were present in 48.2% of cases, with nearly equal unilateral and bilateral distributions. Males had significantly larger sinus volumes than females (14.68 ± 5.38 cm 3 vs. 12.10 ± 3.61 cm 3 ; p < 0.001), and no significant differences in sinus volume were observed among age groups ( p = 0.508). Sinus volume was significantly higher in the presence of septa ( p < 0.001), while septa position, orientation, and completeness had no significant impact ( p > 0.05). Septa were most commonly located in the middle region ( p < 0.001) and were predominantly oriented coronally ( p < 0.001). No significant differences in sinus volume or septa prevalence were observed among fully dentate, partially edentulous, and completely edentulous groups ( p > 0.05). Conclusion Males exhibited larger sinus volumes, while dentition status showed no significant effect. Septa were present in approximately half the cases, most often in the middle region with predominant coronal orientation, and were linked to greater sinus volume. These findings highlight the value of individualized preoperative CBCT assessment for safe implant and sinus floor elevation planning and question the assumption that sinus pneumatization consistently follows tooth loss.