Validity and reliability of the orthodontic experience questionnaire in Malayalam, an Indian language.

Aim: To translate the orthodontic experience questionnaire into Malayalam, an Indian language, and assess its validity and reliability in the Kerala population.

Materials and methods: The original questionnaire, which was developed in English, was translated into Malayalam. Face validity was assessed, and minor changes were made, followed by a content validity assessment by an expert panel. The final version was given to 324 patients who marked their responses on a Likert scale. Internal consistency reliability was tested using Cronbach's alpha, and test-retest reliability was tested using the intraclass correlation coefficient. Principal component factor analysis was performed to regroup the valid items.

Results: The principal component factor analysis revealed three domains. Reliability assessed by Cronbach's alpha of the whole questionnaire was 0.799, and that of the three domains was 0.73, 0.71, and 0.71, respectively. The test-retest reliability was found to be good (0.798).

Conclusion: The Malayalam version of the orthodontic experience questionnaire was found to be content valid with good reliability. To obtain a successful treatment result, an orthodontist must be aware of these and this questionnaire, with adequate validity and reliability, has been designed to achieve this in the Malayalam-speaking population.