Clinical Characteristics of Odontogenic Sinusitis With Oroantral Fistula: Indicating the Need for Multidisciplinary Surgical Collaboration

Background: Odontogenic sinusitis (ODS) is a form of maxillary sinusitis caused by dental infections. In patients with ODS, oroantral fistula (OAF) is a common complication often requiring multidisciplinary management. However, clinical indicators of when to perform oral and maxillofacial surgery (OMS) remain unclear, particularly the need for surgical closure and coordination with endoscopic sinus surgery (ESS). Objective: To identify large OAF predictors and determine when OMS co-management is warranted in patients undergoing ESS for ODS. Methods: Data of adults with ODS and OAF who underwent ESS at a tertiary center (2014-2021) were retrospectively reviewed, and stratified by concurrent OMS intervention at the time of index surgery (ESS alone vs ESS + OMS). The maximum bony defect diameter of the OAF size on preoperative paranasal sinus computed tomography, measured in millimeters on coronal/axial reformats using the picture archiving and communication system (PACS) caliper, was reported as β with 95% confidence intervals (CIs) and P-values. Results: Ninety-one patients were included (ESS alone, n = 47; ESS + OMS, n = 44). OMS cases had larger OAFs (mean 9.5 ± 5.2 vs 5.6 ± 5.2 mm); the between-group mean difference was 3.9 mm (95%CI 1.8-6.0). In multivariable analysis, odontogenic cysts (β=9.78 mm, 95%CI 5.30-14.25; p < .001) and OMS treatment (β=2.78 mm, 95%CI 0.30-5.26; p = .028) were independently associated with greater OAF size. Gingival pain/swelling and shorter symptom duration were more common among patients with OMS, suggesting more acute presentations. Conclusion: Adjusted analyses showed that odontogenic cysts were independently associated with larger OAFs. OMS involvement at the index operation reflected predefined clinical and radiological criteria, rather than cyst status alone. These findings highlight the importance of standardized dental-sinonasal co-planning and provide descriptive insights into surgical patterns and outcomes in ODS with OAF, while recognizing the limitations of a retrospective, single-center cohort.