Odontogenic maxillary sinusitis (OMS) is a disease in which inflammation from the teeth extend into the maxillary sinus, causing symptoms of unilateral sinusitis. OMS can recur, with some being resistant to antibiotics. In intractable cases, exodontia and endoscopic sinus surgery (ESS) are necessary treatments. Here we report our analysis on the indications for surgical intervention in cases diagnosed with and treated as OMS. We retrospectively examined 186 patients who were diagnosed with sinusitis on a computed tomography (CT) scan. For cases diagnosed with OMS, the site of the causative tooth and the presence or absence of oroantral fistula to the maxillary sinus was examined. In addition, we analyzed the therapeutic efficacy of the initial treatment of antibiotics, and what the indications were for ESS. Among the patients examined, OMS was diagnosed in 44 cases (23.6%). In 14 out of 20 cases that underwent a post-medical treatment CT scan, OMS found to be treatment-resistant. Of these 14 cases, 12 (88%) had oroantral fistulae to the maxillary sinus. In all cases where exodontia, fistula closure surgery, and endoscopic sinus surgery (ESS) were performed, the fistula disappeared and the shadow of inflammation in the paranasal sinus improved. In OMS with oroantral fistula, ESS, exodontia, and fistula closure should be recommended over medication such as macrolide therapy.
