Table 1.

Pre-treatment variables

	Vestibular	Lingual	Aligner	V-L	V-A	L-A
				P signif.
n	41	37	39
Mean age (+−SD)	26.4 (+−7.3)	30 (+−6.9)	27.8 (+−6.9)	P < 0.05	NS	NS
Gender (male:female)	19:22	17:20	18:21	NS	NS	NS
Marital status (married:single)	14:27	11:26	13:26	NS	NS	NS
Education level (secondary:tertiary)	2:39	0:37	0:39	NS	NS	NS