ObjectivesThis study aimed to evaluate the effects of factors related to periapical lesions (PALs) on sinus membrane thickening (SMT) in the Chinese population using cone-beam computed tomography (CBCT). MethodsIn this retrospective study, CBCT images (n = 512) of maxillary sinuses of 446 patients were evaluated by two examiners for SMT and PALs, PAL size, and the distance between the maxillary sinus floor (MSF), and the PAL’s edge/root apex. The data were analyzed using analysis of variance, the Kruskal-Wallis test, χ2-test, and logistic regression. ResultsA binary logistic regression model showed that the prevalence and severity of SMT > 2 mm were significantly associated with older age (>60 years) (odds ratio [OR]: 4.03, 95% confidence interval [CI]): 2.24–7.72, P < 0.001], male sex (OR: 2.08, 95% CI: 1.21–3.56, P < 0.006), and PALs (OR: 6.89, 95% CI: 3.93–12.08, P < 0.001). The type of contact and penetration between the MSF and PALs or root apex showed a more significant relation with SMT > 2 mm than did distance after adjusting for confounding factors, including age and sex (PALs: OR = 10.17 and 14.57, P < 0.001; root apex: OR = 3.49 and 5.86, P < 0.001). ConclusionsThe prevalence and severity of SMT were significantly associated with older age, male sex, PALs, PAL size, and the distance between the MSF and PALs/root apex. Therefore, communication between dental surgeons and an otolaryngology specialist is important for the timely diagnosis and treatment of SMT of dental origin.