Odontogenic Sinusitis is a Common Cause of Operative Extra-Sinus Infectious Complications.

Background: Orbital, intracranial, and osseous extra-sinus complications can arise from bacterial or fungal sinusitis. Odontogenic sinusitis (ODS) can cause extra-sinus complications, but its prevalence remains poorly characterized.

Objective: To determine the frequency of ODS as a cause of operative extra-sinus infectious complications and describe clinical features of all complicated sinusitis cases.

Methods: A multi-institutional retrospective review was performed on all operative sinusitis-related extra-sinus complications from 2011 to 2020. ODS was diagnosed by sinus computed tomography (CT) and dental evaluations when available. Demographics, complication types, sinusitis etiologies, and various clinical features were analyzed.

Results: Forty-five patients were included (mean age 55.5 years, 56% male). Of the extra-sinus complications, 40% were orbital only, 22% intracranial only, 13% osseous only, and 25% involved combined complications. The 2 most common causes of extra-sinus complications were ODS (40%) and mucopyocele (27%). When invasive fungal etiologies were excluded, and only unilateral maxillary opacification on CT was considered, nearly 60% of extra-sinus complications were due to ODS. Unilateral maxillary sinus opacification on CT was present in 100% of complicated ODS compared to 44% of nonodontogenic cases, and oral anaerobes were only identified in ODS cases. No complicated ODS patients underwent dental interventions during hospitalization.

Conclusion: ODS was the most common cause of operative extra-sinus infectious complications. Clinicians should consider ODS high on the differential diagnosis of all patients presenting with complicated sinusitis, especially when sinusitis is unilateral and invasive fungal infection is not suspected.