Change of Mandibular Position during Two-Phase Orthodontic Treatment of Skeletal Class II in the Chinese Population

Table 1

Age at the beginning of phase 1 (T0), end of phase 1/beginning of phase 2 (T1) and end of treatment (T2), and duration of the treatment phases of the study sample () and the three subgroups ( in each subgroup).

	Average age (years )			Average time of treatment phases (years)
	T0	T1	T2	T0-T1	T1-T2	T0–T2
Whole study sample	13.4 ± 1.20	14.5 ± 1.20	16.4 ± 1.50	1.1 ± 0.20	1.9 ± 0.80	3.0 ± 0.90
Positive group	12.8 ± 1.07^ns	13.9 ± 1.12^ns	16.2 ± 1.92^ns	1.1 ± 0.27^ns	2.2 ± 0.74^ns	3.3 ± 0.82^ns
Stable group	13.9 ± 1.21^ns	15.0 ± 1.17^ns	16.6 ± 1.37^ns	1.1 ± 0.26^ns	1.6 ± 0.75^ns	2.7 ± 0.87^ns
Negative group	13.4 ± 1.07^ns	14.5 ± 1.08^ns	16.4 ± 1.32^ns	1.1 ± 0.25^ns	1.8 ± 0.77^ns	3.0 ± 0.85^ns

SD: Standard deviation.
^nsNon-significant, , , .