Table 4.

Comparison Between the Mild and Moderate Groups in the Mandible^a

Measurement	Mild (n = 23)	Moderate (n = 13)	Significance
Duration, mo	23.15 ± 2.94	24.49 ± 4.60	NS
Age, y	26.85 ± 11.04	24.96 ± 8.33	NS
Δ IMPA, °	−6.45 ± 7.13	−7.28 ± 5.21	NS
Horizontal movement of L1, mm	−3.19 ± 3.14	−4.05 ± 3.11	NS
Vertical movement of L1, mm	−1.03 ± 1.94	−2.76 ± 0.95	*
Crown ratio (tooth shape)	1.32 ± 0.09	1.34 ± 0.08	NS
Root angulation at T2, °	−2.69 ± 5.55	−2.76 ± 4.68	NS
Right CEJ–left CEJ distance at T2, mm	1.49 ± 0.34	1.75 ± 0.53	NS
Distance from ICP to ABC at T1, mm	4.89 ± 0.69	4.93 ± 1.14	NS
Distance from ICP to ABC at T2, mm	5.60 ± 0.91	6.30 ± 1.16	NS
Δ Distance from ICP to ABC, mm	−0.72 ± 0.98	−1.37 ± 1.04	NS
Crowding
A-P overlapped distance. mm	0.31 ± 0.50	0.29 ± 0.51	NS
Transverse overlapped distance, mm	0.49 ± 0.74	0.87 ± 1.00	NS
Rotation, °	10.36 ± 7.49	10.00 ± 7.73	NS

^aIndependent t-tests were used to compare between the mild and moderate groups, and Bonferroni correction was performed. Regarding root angulation, a negative value indicates that the two roots diverge apically. NS indicates not significant; IMPA, incisor mandibular plane angle; L1, mandibular incisor; T1, before treatment; T2, after treatment; Δ, T2-T1; CEJ, cementoenamel junction; ICP, interproximal contact point; ABC, alveolar bone crest; A-P, antero-posterior.

^*P < .05.