Table 4.

Severity of apical root resorption of individual tooth in the two groups

Measurements (mean ± SD, mm)	Root length			Apical root resorption	P value
	Before treatment	After treatment
Clear aligners
Maxillary central incisor	21.55 ± 1.86	21.29 ± 2.01		0.26 ± 0.42	< 0.001
Maxillary lateral incisor	20.60 ± 1.94	20.37 ± 2.02		0.23 ± 0.37	< 0.001
Maxillary canine	23.89 ± 2.63	23.75 ± 2.72		0.14 ± 0.53	0.075
Mandibular central incisor	18.56 ± 1.39	18.36 ± 1.29		0.20 ± 0.45	0.001
Mandibular lateral incisor	19.83 ± 1.40	19.79 ± 1.31		0.04 ± 0.48	0.463
Mandibular canine	22.61 ± 2.37	22.67 ± 2.35		−0.06 ± 0.47	0.289
Average	21.09 ± 2.61	20.96 ± 2.66		0.13 ± 0.47	0.500
Fixed appliances
Maxillary central incisor	21.25 ± 1.85	20.02 ± 1.94		1.23 ± 1.31	< 0.001
Maxillary lateral incisor	20.23 ± 1.53	18.92 ± 1.97		1.31 ± 1.33	< 0.001
Maxillary canine	23.39 ± 2.19	21.86 ± 2.54		1.53 ± 1.92	< 0.001
Mandibular central incisor	18.26 ± 1.06		17.61 ± 1.26	0.65 ± 0.89	< 0.001
Mandibular lateral incisor	19.52 ± 1.21		18.50 ± 1.27	1.02 ± 0.98	< 0.001
Mandibular canine	21.98 ± 1.71		20.96 ± 2.01	1.02 ± 1.33	< 0.001
Average	20.74 ± 2.31		19.62 ± 2.36	1.12 ± 1.34	< 0.001