Microbiological and Clinical Predictors of Surgical Intervention in Odontogenic Sinusitis

<b>Background:</b> Odontogenic sinusitis (ODS) is a frequent but under-recognized cause of chronic maxillary sinusitis, often requiring multidisciplinary management. Understanding clinical and microbiological predictors for oral and maxillofacial surgery (OMS) treatment may aid in early risk stratification. <b>Methods:</b> We retrospectively reviewed 47 patients diagnosed with ODS at a tertiary referral center between January 2023 and April 2025. Clinical characteristics, dental pathologies, and microbiological findings were analyzed. Univariate and multivariate logistic regression analyses were performed to identify independent predictors of OMS intervention. <b>Results:</b> The cohort included 20 males and 27 females, with a mean age of 59.5 years. OMS intervention was performed for 21 patients (44.7%). These patients were younger, and more frequently presented with gingival pain or swelling, oroantral fistula, antibiotic-resistant organisms, and polymicrobial infections compared with the non-OMS group. <i>Staphylococcus epidermidis</i> was the most common isolate, followed by <i>Streptococcus constellatus</i>, <i>Klebsiella pneumoniae</i>, and <i>Pseudomonas aeruginosa</i>. Antibiotic resistance was observed in 29.8% of patients and was significantly more prevalent in the OMS group (52.4% vs. 7.7%, <i>p</i> < 0.001). Multivariate analysis identified dental diagnosis and antibiotic resistance as independent predictors for OMS intervention. All patients achieved full recovery following surgery, with no treatment failures. <b>Conclusions:</b> ODS demonstrates distinct clinical and microbiological characteristics, with antibiotic resistance and specific dental pathologies serving as independent risk factors for OMS intervention. Recognition of these features may guide early multidisciplinary planning and improve clinical outcomes.