Table 2.

Classification of Malocclusion in Each Group Before Treatment^a

	Non-ext (n = 36)	4-ext (n = 31)	2-ext (n = 18)	P Value
Crowdingb	29	21	15	.347
Open bitec	1	4	1	.567

^anon-ext indicates nonextraction group; 4-ext, extraction of two maxillary and two mandibular premolars; 2-ext, extraction of two maxillary premolars;

^bCrowding indicates that the subject had more than four dislocated teeth on each maxillary and mandibular arch;

^cOpen bite indicates that the subject had over –3 mm overbite at centric occlusion.