Odontogenic Sinusitis: Clinical, Radiologic, and Quality-of-Life Characterization in a Prospective Study

Background: Rhinosinusitis is an increasingly prevalent condition that compromises patients’ quality of life and imposes a substantial burden on healthcare systems. Odontogenic sinusitis, a predominantly unilateral form of rhinosinusitis, accounts for up to 40% of unilateral maxillary sinusitis cases. This study aimed to characterize the clinical presentation, radiological extension, and quality-of-life impairment associated with odontogenic sinusitis. Methods: Thirty-eight patients with unilateral sinusitis caused by dental pathology/treatment were recruited. OS diagnosis criteria were established according to EPOS-2020 guidelines. The 22-item SNOT-22 questionnaire was used to assess symptom severity and social/emotional impact. In addition, all patients underwent CT imaging and were staged with the Lund–Mackay scale for involvement of the maxillary, anterior and posterior ethmoid, sphenoid and frontal sinuses. Results: Smoking was associated with significantly worse patient-reported quality of life, with higher SNOT-22 scores in current smokers than in non-smokers (59.4 vs. 38.2; p = 0.026). Purulent discharge was associated with greater radiological severity, longer symptom duration, and a markedly higher prevalence of extra-maxillary extension (92.3%; p < 0.001). Extra-maxillary involvement was identified in 71.1% of patients, predominantly affecting the anterior ethmoid sinus. Although Lund–Mackay scores objectively reflected radiological disease extension, their correlation with symptom burden was limited. Conclusions: Odontogenic sinusitis frequently presents with substantial extra-maxillary extension and significant impairment of quality of life. Smoking and purulent discharge were associated with markers of greater disease severity in this exploratory cohort. These associations should be interpreted cautiously and confirmed in larger studies using multivariable analyses.