Prevalence of Exostosis in Maxillary Sinus by Cone-Beam Computed Tomography Technique in a Population of Northern Iran

Antral exostosis in the maxillary sinus generally causes changes in the sinus, and its expansion may complicate planned sinus lift procedures before implant placement in the edentulous posterior maxilla. Therefore, before planning implant surgery, it is necessary to evaluate the presence of antral exostoses and other abnormalities, especially in the maxillary sinuses. The aim of the present study was to investigate the prevalence of exostoses in the maxillary sinus through cone beam computed tomography (CBCT) images in a population of northern Iran.

In this descriptive analytical study, 1068 scans were examined. Several parameters such as the presence of exostosis, location, bilateral or unilateral, type of exostosis and type of bone were investigated. In the coronal, sagittal, and axial images, the presence of exostosis and its location in the maxillary sinus, and its appearance and symmetry were recorded. Then, the collected data were analyzed by SPSS version 20 software and the significance level was considered P<0.05.

In the present study, 1068 samples were evaluated, and exostoses were observed in 15 cases. Out of the 15 cases of exostosis observed, there were 4 cases of bilateral (26.7%) and 11 cases of unilateral (73.3%) exostoses. 9 cases were on the right, 2 cases on the left side and 4 cases were both on right and left sides. 9 cases were observed in the lower wall, 3 cases in the medial wall and 7 cases in the lateral wall. There was no significant relationship between gender and the presence of exostoses (P=0.427).

The most frequently encountered exostoses were of broad-base type. Therefore, dentists are suggested to evaluate the position and condition of the maxillary sinus before performing implant surgery.