Abstract: Objective To retrospectively investigate the parameters of maxillary sinus exostoses (MSEs) in a dental implant potients using cone-beam computed tomography (CBCT) and evaluate its association with age and sex. Methods This study reviewed CBCT scans of the maxillary sinuses from 533 patients who underwent preoperative imaging for implant treatment at our hospital between July 2023 and April 2025. Data on MSE location, size, morphology, symmetry, presence of concurrent mucoperiosteal abnormalities, sinus septa, and demographic variables were collected. Statistical analyses included chi-square test, Fisher’s exact test, and one-way ANOVA. Results Among 1,066 maxillary sinuses in 533 patients, MSE was identified in 74 sinuses of 59 patients, with bilateral occurrence in 15 patients (25.4%). Morphologically, 54.1% (40/74) were pearl-shaped, 35.1% (26/74) flat-shaped, and 10.8% (8/74) irregular-shaped. MSEs were predominantly located on the lateral wall (51.4%, 38/74) and sinus floor (43.2%, 32/74), with 5.4% (4/74) on the medial wall. Concurrent mucoperiosteal abnormalities were observed in 54.1% (49/74) of sinuses, sinus septa in 8 sinuses (10.8%), and multiple independent MSEs in 16.2% (12/74) of affected sinuses. The mean MSE size was (7.67±4.86) mm. No significant differences were found in MSE prevalence or location across sex or age groups (P>0.05). Conclusion Most MSEs were solitary, unilateral, and located on the lateral wall or floor of the maxillary sinus without sinus septa. Approximately half were small, pearl-shaped lesions, and mucoperiosteal abnormalities coexisted in nearly half of the affected sinuses. No demographic correlations were observed, but significant variations existed in MSE morphology and size.

Key words: Maxillary sinus, Exostosis, Cone beam computed tomography, Oral implant, Sinus floor elevation