Statistical analyses
Changes in VAS, SNOT-22, and nasalance scores before and after FESS were tested using the Wilcoxon signed rank test. The Mann-Whitney U test was used to compare differences between the limited and wide opening surgery groups. The chi-square test or Fisher’s exact test were used for all other between-group comparisons. Percentage changes in subjective abnormal nasality assessment before and after FESS were statistically analyzed using the McNemar-Bowker test. The relationships between the groups were assessed by the spearman correlation analysis. A p-value < 0.05 was considered to indicate statistical significance. All analyses were performed using SPSS version 22 software (IBM Corp., Armonk, NY, USA).