Objectives: to assess the correlation between maxillary sinus inferior mucosal thickening and sinus outflow obstruction.
Material and methods: the study included 280 computerized tomography (CT) scans (560 maxillary sinuses). CT aimed to assess sinusitis; trauma to the face and intubated patients were excluded. Mucosal thickening was graded as < 5 mm (1), < 10 mm (2), < 15 mm (3), < 20 mm (4) and > 20 mm (5), and classified by appearance as normal, rounded, circumferential, irregular, or complete. Maxillary sinus outflow was classified as patent or obstructed.
Results: mucosal thickening was found in 36.1% of the maxillary sinuses, graded as 31.2% (1), 34.2% (2), 12.9% (3), 5.4% (4) and 16.3% (5), and classified as rounded (11.8%), irregular (10.4%), circumferential (8.8%) and complete (5.2%). Sinus outflow was obstructed in 15% of the scans. Mucosal thickening of < 5 mm (11.1%), < 10 mm (36.2%) and > 10 mm (74.3%) was associated with sinus obstruction (P<0.0001). Rounded (6.1%), circumferential (55.2%), irregular (38.8%) and complete (100%) mucosal appearances were associated with sinus obstruction (P<0.001). When statistically combined, a substantial risk for sinus obstruction was observed with irregular mucosal appearance of > 5 mm (56.5% for grade 2 up to 82.6% for grades 3-5) and circumferential appearance (21.4% for grade 1 up to 100% for grades 3-5). A low risk for obstruction was found with the rounded appearance (mean 6.1%).
Conclusions: irregular (> 5 mm), circumferential and complete mucosal appearance are associated with an increased risk for sinus outflow obstruction and an ENT consultation is recommended. A rounded mucosal appearance of any grade is associated with a low risk for sinus obstruction. Routine CT scans, including the maxillary sinus ostium, are recommended.