Frequency of a Dental Source for Acute Maxillary Sinusitis

Objective: To identify radiographic features of odontogenic acute maxillary sinusitis and to determine the frequency of a causative dental infection in patients with radiographic evidence of maxillary sinus fluid. Study Design: Retrospective review of 101 sinus computed tomography scans with unilateral or bilateral maxillary sinus fluid. Methods: Each maxillary sinus was graded for extent of fluid, degree of mucosal thickening, and presence of dental pathology. Univariate chi-square analysis was used to identify potential radiologic and demographic features predictive of sinus fluid. Multivariate logistic regression was then used to determine which features were independently predictive. Results: 124 of the 202 maxillary sinuses (61%) had sinus fluid. Univariate analysis excluded age, gender, and prior surgery as predictive features. The multivariate analysis included the radiographic features of oroantral fistula, periapical abscess, periodontal disease, projecting tooth root, and dental caries. Of these, only oroantral fistula and the combination of periodontal disease with either a projecting tooth root or periapical abscess were identified as significant sources of maxillary sinusitis. In sinuses that were <1/3 opacified by fluid, 17% had a dental source of infection. In sinuses with 1/3 to 2/3 fluid opacification, 53% had an identifiable dental source, and in sinuses that were >2/3 opacified by fluid, 79% had an identifiable dental source. Mucosal thickening demonstrated a similar relationship with dental sources, so that sinuses having both >2/3 fluid opacification and moderate mucosal thickening were 86% likely to have an identifiable dental source. Conclusions: Odontogenic infections are often the source of acute maxillary sinusitis, especially if the radiographic findings of sinusitis are severe.