Odontogenic sinusitis is a common cause of unilateral sinus disease with maxillary sinus opacification

BACKGROUND: Unilateral sinus disease (USD) carries a broader differential diagnosis than bilateral sinus disease, including various inflammatory and neoplastic conditions. Odontogenic sinusitis (ODS) is a common cause of unilateral maxillary sinusitis, but few studies have examined its incidence among all USD etiologies. The main purposes of this prospective study were to determine the incidences of ODS and other etiologies causing USD with complete maxillary sinus opacification on computed tomography (CT), and to compare CT features of ODS and non-odontogenic USD patients. In addition, clinical features of the ODS cohort are described. METHODS: A prospective case series of 134 patients with USD with complete maxillary sinus opacification on CT was conducted from August 2015 to November 2018. Based on nasal endoscopy, sinus CT, and dental examination and imaging, patients were categorized as having unilateral ODS or non-odontogenic USD. Patients with non-odontogenic USD were categorized as inflammatory or neoplastic. Demographic and clinical data were reported for ODS patients. RESULTS: Of the 134 patients, 45% had ODS, 36% had non-odontogenic inflammatory conditions, 17% had inverted papilloma, and 2% had malignancies. Of the 60 ODS cases, 86.7% were associated with middle meatal purulence on nasal endoscopy. On CT, 88.3% had extramaxillary sinus disease extension, and 65.5% of CT reports made no mention of dental pathology. CONCLUSION: ODS caused nearly 50% of all USD cases with maxillary sinus opacification on CT, and was the most common individual etiology. ODS was frequently associated with anterior ethmoid and frontal sinus disease on CT, and middle meatal purulence on nasal endoscopy.