Table 2.

Comparison of facial regions at different periods ($\overline{\mathrm{X}}$±SD)

Region	Non-extraction	Extraction	P-value	Non-extraction	Extraction	P-value	Non-extraction	Extraction	P-value	Non-extraction	Extraction	P-value
	T1–T0	T1–T0		T2–T0	T2–T0		T3–T0	T3–T0		T4–T0	T4–T0
W	− 2.59 ± 0.35	− 2.56 ± 0.31	0.768	− 2.4 ± 0.39	− 2.76 ± 0.62	0.068	− 2.21 ± 0.42	− 2.54 ± 0.50	0.101	− 2.13 ± 0.41	− 2.54 ± 0.37	0.657
R1	− 1.27 ± 0.52	− 1.21 ± 0.40	0.717	− 1.11 ± 0.41	− 0.93 ± 0.37	0.099	− 0.93 ± 0.36	− 1.00 ± 0.44	0.577	− 0.98 ± 0.30	− 0.98 ± 0.32	0.938
R2	− 1.01 ± 0.54	− 1.18 ± 0.39	0.245	− 0.88 ± 0.39	− 1.01 ± 0.40	0.271	− 0.86 ± 0.39	− 0.89 ± 0.34	0.779	− 0.93 ± 0.54	− 0.85 ± 0.37	0.507
R3	− 1.07 ± 0.43	− 1.05 ± 0.79	0.857	− 1.05 ± 0.40	− 1.07 ± 0.35	0.88	− 0.74 ± 0.30	− 0.94 ± 0.39	0.068	− 0.93 ± 0.30	− 0.91 ± 0.34	0.814
R4	− 0.65 ± 0.3	− 0.73 ± 0.38	0.474	− 0.65 ± 0.38	− 0.72 ± 0.43	0.557	− 0.70 ± 0.35	− 0.91 ± 0.40	0.317	− 0.85 ± 0.33	− 0.89 ± 0.35	0.691
R5	− 0.89 ± 0.48	− 1.04 ± 0.84	0.455	− 0.71 ± 0.38	− 1.15 ± 0.36	0.317	− 0.60 ± 0.29	− 0.77 ± 0.37	0.061	− 0.84 ± 0.32	− 0.97 ± 0.43	0.257
R6	− 1.08 ± 0.50	− 1.18 ± 0.51	0.5	− 0.88 ± 0.48	− 1.22 ± 0.43	0.081	− 0.76 ± 0.23	− 1.13 ± 0.32	0.242	− 0.97 ± 0.35	− 1.06 ± 0.38	0.401
R7	− 0.84 ± 0.42	− 1.02 ± 0.43	0.171	− 0.80 ± 0.47	− 1.09 ± 0.54	0.052	− 0.83 ± 0.38	− 1.19 ± 0.33	0.064	− 1.07 ± 0.24	− 1.03 ± 0.45	0.71
R8	− 1.2 ± 0.66	− 1.49 ± 0.66	0.152	− 1.25 ± 0.55	− 1.87 ± 0.59	0.254	− 1.21 ± 0.48	− 1.62 ± 0.56	0.439	− 1.18 ± 0.38	− 1.55 ± 0.59	0.062
R9	− 1.16 ± 0.5	− 1.37 ± 0.81	0.293	− 1.05 ± 0.42	− 1.31 ± 0.32	0.252	− 0.92 ± 0.39	− 1.15 ± 0.31	0.144	− 1.05 ± 0.29	− 1.23 ± 0.39	0.067
R10	− 1.17 ± 0.5	− 1.46 ± 0.52	0.27	− 1.04 ± 0.47	− 1.26 ± 0.42	0.084	− 0.81 ± 0.28	− 1.31 ± 0.36	0.113	− 1.03 ± 0.28	− 1.11 ± 0.40	0.422
R11	− 1.36 ± 0.48	− 1.76 ± 0.50	0.008**	− 1.35 ± 0.56	− 1.59 ± 0.47	0.115	− 1.10 ± 0.40	− 1.44 ± 0.41	0.005**	− 1.05 ± 0.33	− 1.43 ± 0.49	0.002**

R1, infraorbital region; R2, cheekbone region; R3, zygomatic region; R4, paranasal region; R5, upper cheek region; R6, sub-zygomatic region; R7, upper cheilion region; R8, lower cheilion region; R9, buccal region; R10, mandibular angle region; R11, temporal region; T₀, before bracket bonding; T₁, 3 months after treatment initiation; T₂, 6 months after treatment initiation, T₃, 12 months after treatment initiation; T₄, at the end of treatment; W, Overall facial area. ** P < 0.01

Values are all expressed as mean ± SD. *Significant difference between the Non-extraction and Extraction groups with P < 0.05; **Significant difference between the Non-extraction and Extraction groups with P < 0.01