Table 4.

Periodontal indexes of the two groups before and after treatment

	PLI			SBI
	Before orthodontic treatment	3 months after orthodontic treatment	6 month after orthodontic treatment	Before orthodontic treatment	3 month after orthodontic treatment	6 month after orthodontic treatment
Control group (n=42)	0.94±0.11	0.78±0.15*	0.65±0.08*	1.87±0.38	1.34±0.23*	1.03±0.17*
Observation group (n=55)	0.93±0.13	0.62±0.10*	0.46±0.12*	1.83±0.56	1.06±0.20*	0.80±0.11*
t	0.4007	6.2929	8.8617	0.3979	6.4010	8.0687
P	0.6895	<0.0001	<0.0001	0.6915	<0.0001	<0.0001
	GR (%)			PPD (mm)
	Before orthodontic treatment	3 month after orthodontic treatment	6 month after orthodontic treatment	Before orthodontic treatment	3 month after orthodontic treatment	6 month after orthodontic treatment
Control group (n=42)	0.38±0.08	0.44±0.11*	0.56±0.17*,#	4.15±0.46	3.47±0.33*	2.79±0.29*,#
Observation group (n=55)	0.37±0.10	0.62±0.15*	0.78±0.21*,#	4.08±0.52	3.01±0.45*	2.17±0.13*,#
χ2/t	0.5309	6.5451	5.5411	0.6901	5.5755	14.1220
P	0.5967	<0.0001	<0.0001	0.4918	<0.0001	<0.0001
	CAL (mm)
	Before orthodontic treatment		3 month after orthodontic treatment		6 month after orthodontic treatment
Control group (n=42)	4.17±1.06		3.87±0.84*		3.06±0.94*,#
Observation group (n=55)	4.12±1.13		3.25±0.71*		2.18±0.67*,#
χ2/t	0.2217		3.9355		5.3827
P	0.8249		0.0001		<0.0001

Note: PIL: plaque index; SBI: sulcus bleeding index; GR: gingival recession; PPD: periodontal probing depth; CAL: clinical attachment loss.

Compared with the same group before orthodontic treatment;

^*P<0.05.

Compared with the same group 3 month after orthodontic treatment;

^#P<0.05.