Table 1.

Internal consistency analysis of the Serbian version of the Orthognathic Quality of Life Questionnaire (OQLQ).

Subscale/item	Item-total correlation	Alpha coefficient for each component	Intra-class correlation coefficient
Social aspects of deformity
15. Cover mouth when meeting people	0.78
16. Worry about meeting people	0.68
17. Worry people will make hurtful comments	0.77
18. Lack confidence socially	0.74	0.91	0.91 (p=0.001)
19. Do not like smiling	0.66
20. Get depressed about appearance	0.73
21. Sometimes think people are staring	0.60
22. Comments about appearance upset me	0.70
Facial aesthetics
1. Self-conscious about appearance of my teeth	0.42
7. Don’t like seeing side view of face (profile)	0.67
10. Dislike having photograph taken	0.59	0.85	0.90 (p=0.001)
11. Dislike being seen on video	0.72
14. Self-conscious about appearance	0.60
Oral function
2. Problems biting	0.52
3. Problems chewing	0.71
4. Avoid eating some foods	0.53	0.75	0.88 (p=0.001)
5. Don’t like eating in public	0.30
6. Pains in face/jaw	0.55
Awareness of facial deformity
8. Spend time studying face	0.67
9. Spend time studying teeth	0.69	0.85	0.89(p=0.001)
12. Stare at people’s teeth	0.73
13. Stare at people’s faces	0.65

Clinical validity was assessed through comparison with PAR pre-treatment score