Stability of class II subdivision malocclusion treatment with 3 and 4 premolar extractions

Progress in Orthodontics

Table 2 Intergroup comparison of the studied variables (t test)

Variable	Group 1 (3 premolar extractions) n = 24		Group 2 (4 premolar extractions) n = 28
Variable	Mean	SD	Mean	SD	p
AGE1	13.54	2.36	13.33	1.34	0.68
AGE2	17.03	2.65	16.31	1.61	0.23
AGE3	23.45	3.58	23.70	4.17	0.82
Treatment time	3.48	1.15	2.98	1.24	0.14
Long-term posttreatment time	6.43	2.81	7.40	4.37	0.36
PAR1	20.46	8.64	18.11	7.88	0.31
PAR2	2.54	1.56	3.18	1.63	0.16
PAR3	4.04	2.12	3.86	2.10	0.75
PAR treatment changes	17.92	8.27	14.93	7.59	0.18
PAR long-term posttreatment changes	1.50	2.77	0.68	2.18	0.24
Percentage of PAR treatment changes (%)	86.04	8.46	80.94	10.66	0.07
Percentage of PAR long-term posttreatment changes (%)	9.37	16.90	4.98	16.08	0.34

AGE 1, PAR1: age and PAR index value at T1 - pretreatment; AGE 2, PAR2: age and PAR index value at T2 - posttreatment; AGE 3, PAR3: age and PAR index value at T3 - long-term posttreatment.