All data were entered into SPSS 16.0 for Windows (SPSS Inc., Chicago, IL). Categorical variables are presented as the percentage frequency of occurrence, and study groups were compared using chi-square tests or the Fisher’s exact test, as appropriate. Continuous variables are presented as means with standard deviations (SDs) or 95% confidence intervals (CIs), and comparisons were performed using t-tests after ascertaining the normality of the data. Categorical variables are presented as percentages, and comparisons were performed using chi-square tests or Kruskal-Wallis test. A sample of 60 patients (30 patients in each group) provided an 80% power to detect a difference of 15 mm on the VAS. A value of a = 0.05 was used to determine the level of significance with no adjusting for multiple comparisons.