Abstract: Objective: To explore the relationship between anatomic variations of the nasal cavity and chronic rhinosinusitis with or without polyps. Methods： Four hundred and eleven coronal plane CT scans of the paranasal sinuses were divided into three groups: the control group(A), the chronic rhinosinusitis group(B), and the deviation of middle turbinate group(C). The prevalence of anatomic variations in groups A, B and C was determined and analyzed by SPSS V.12.0 for windows. Results： The prevalence of concha bullosa, paradoxical middle turbinate and straight middle tubinate in group A was 23.39%, 8.06% and 3.23%, respectively, in group B was 38.52%, 18.58% and 12.84%, respectively and in group C was 37.45%, 21.70% and 17.02%, respectively. The prevalence of anatomic variations in the MT between groups A and B or C was statistically significant（P＜0.01）. The prevalence of pneumatization of the UP, superior divarication of the UP and paradoxical curvature of the UP in group A was 4.03%, 4.83% and 0.00%, respectively, in group B was 7.10%, 2.73% and 2.18%, respectively and in group C was 8.51%, 3.83% and 7.23%, respectively. Differences of paradoxical curvature of the UP were statistically significant between groups A and C（P＜0.01）and also statistically significant between groups B and C（P＜0.01）. Conclusions： Anatomic variations of the MT may be one of the reasons for chronic rhinosinusitis with or without polyps. The paradoxical curvature of the UP,superior divarication of the UP,nasal septal deviation and infraorbital ethmoid cells.

Key words: Sinusitis, Nasal polyps, Anatomy