Table 3.

Simple and multiple Poisson regression analysis of association between discomfort due to the use of orthodontic appliance, and bio-psychosocial variables.

	Unadjusted Rate ratio			Adjusted Rate ratio
	PR	(CI 95%)	p*	PR	(CI 95%)	p**
Age  (n = 263)
9 to 14 years	1.0	(1.8; 11.7)	0.002	1.0	(1.2; 8.5)	0.020
15 to 28 years	4.5			3.2
Difficulty in eating
No	1.0	(1.6; 6.7)	0.001
Yes	3.3
Speech impairment
No	1.0	(1.2-4.9)	0.012	1.0	(1.1; 4.6)	0.032
Yes	2.4			2.2
Poor oral hygiene
No	1.0	(1.6; 6.4)	0.001	1.0	(1.2; 4.8)	0.018
Yes	3.2			2.4
Difficulty in performing school tasks
No	1.0	(0.0; 1.2)	0.074
Yes	0.2
Pain
No	1.0	(0.2; 1.3)	0.143
Yes	0.5
Tooth mobility
No	1.0	(2.7; 11.3)	< 0.001	1.0	(1.8; 8.1)	< 0.001
Yes	5.5			3.9
Halitosis
No	1.0	(2.4; 10.2)	< 0.001
Yes	4.9
Impaired taste
No	1.0	(1.8; 8.7)	0.001
Yes	3.9
Gingival bleeding
No	1.0	(2.8; 10.8)	< 0.001
Yes	5.5
Deformity of mouth/face
No	1.0	(0.9; 16.8)	0.056
Yes	4.0
Self-esteem (n=271)
High	1.0	(0.7; 4.3)	0.195
Low	1.8

^*Simple Poisson regression

^**Multiple Poisson regression.