Table 3. Descriptive statistics of the intercanine widths and the canine rotation angle at two assessment times in the three groups and the results of significance test†.

† Employing one-way ANOVA test or Kruskal-Wallis test, SD: Standard Deviation, Min: minimum, Max: maximum, CI: confidence interval, T0: before the beginning of orthodontic treatment, 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, **: there was a statistically significant difference at P < 0.01

ANOVA: analysis of variance

Time	Group	Mean	SD	Min	Max	95% CI for difference		P-value	Significance
						Lower bound	Upper bound
Intercanine width at the cusps level
T0	Group 1	34.23	0.91	33.00	36.40	33.80	34.66	0.477	NS
	Group 2	34.56	1.24	33.00	37.20	33.96	35.16
	Group 3	34.81	1.34	33.00	36.90	34.16	35.46
T4	Group 1	35.40	0.90	34.10	37.40	34.97	35.82	0.005	**
	Group 2	36.55	1.29	34.20	39.00	35.93	37.18
	Group 3	36.73	1.69	34.20	39.00	35.92	37.55
Intercanine width at the cervical level from the lingual side
T0	Group 1	26.44	1.28	24.20	29.10	25.84	27.04	0.461	NS
	Group 2	26.95	1.38	24.80	29.80	26.28	27.62
	Group 3	27.05	1.75	24.50	29.40	26.20	27.89
T4	Group 1	27.27	1.31	25.10	29.70	26.65	27.88	0.329	NS
	Group 2	27.76	1.32	25.70	30.40	27.12	28.40
	Group 3	27.93	1.63	25.20	30.20	27.14	28.71
Canine rotation angle
T0	Group 1	46.19	7.87	34.40	62.90	42.50	49.87	0.894	NS
	Group 2	37.02	11.40	13.70	52.90	31.52	42.52
	Group 3	47.01	14.24	9.10	74.30	40.15	53.88
T4	Group 1	41.61	3.31	34.70	47.50	40.06	43.16	0.592	NS
	Group 2	40.81	3.70	36.10	47.40	39.03	42.59
	Group 3	41.61	3.61	36.30	49.30	39.87	43.35