Table 4. Post-hoc tests for Little's Irregularity Index and the intercanine width (at the cusp level) in the pairwise comparisons†.

† Bonferroni was used to detect any significant difference between every two groups, LII: Little's Irregularity Index, CWC: intercanine width at the cusps level, T1: after 1 month, T2: after 2 months, T3: after 3 months, T4: at the end of the leveling and alignment phase, Group 1: traditional brackets group, Group 2: self-ligating brackets group, Group 3: self-ligating brackets + flapless piezocision group; NS: there was no statistically significant difference at P > 0.05, *: statistically significant at P < 0.05, **: statistically significant at P < 0.01, ***: statistically significant at P < 0.001

Variable	Time	Group comparison	Mean difference	95% CI for difference		P-value	Significance
				Lower bound	Upper bound
LII	T1	Group 1 vs. Group 2	1.75	0.99	2.51	>0.001	***
		Group 1 vs. Group 3	3.15	2.39	3.91	>0.001	***
		Group 2 vs. Group 3	1.40	0.63	2.16	>0.001	***
	T2	Group 1 vs. Group 2	2.14	1.55	2.73	>0.001	***
		Group 1 vs. Group 3	4.31	3.72	4.90	>0.001	***
		Group 2 vs. Group 3	2.16	1.57	2.76	>0.001	***
	T3	Group 1 vs. Group 2	1.79	1.21	2.38	>0.001	***
		Group 1 vs. Group 3	4.02	3.44	4.61	>0.001	***
		Group 2 vs. Group 3	2.23	1.63	2.82	>0.001	***
CWC	T4	Group 1 vs. Group 2	1.15	0.10	2.21	0.027	*
		Group 1 vs. Group 3	1.33	0.28	2.39	0.008	**
		Group 2 vs. Group 3	0.17	-0.88	1.24	1.000	NS