3.1 General information
135 patients (90 males and 45 females) were included in the retrospective study (shown in Figure 1). The average follow-up period was 119.3 weeks, and the average age was 38.7 years old. 10.3% of patients suffered from allergic rhinitis, and 11.9% of patients were diagnosed as asthma. About 9.6% of patients were current smokers, and 46 out of 135 patients underwent endoscopic sinus surgery more than once.