Validity and Reliability of the Persian Translation of the Diagnostic Criteria for Temporomandibular Disorders Questionnaire

Abstract

Background: The Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) Questionnaire is a validated instrument extensively used to diagnose TMD. Objectives: This study aimed to determine the reliability and validity of the Persian translation of the DC/TMD. Methods: A team of specialists assessed the questionnaire's final version for content and form validity after translation. A questionnaire was given to 150 students at the Kermanshah Faculty of Dentistry. The convergent validity was assessed by determining the connection between item scores and computing Cronbach's alpha coefficient. The test-retest reliability was evaluated by comparing the results obtained in two phases using the correlation and intraclass correlation coefficients of 30 students from the Faculty of Dentistry. Results: The ICC coefficient of the Persian DC/TMD questionnaire was 0.98. The questionnaire's overall Kaiser-Meyer-Olkin (KMO) measure was 0.62, suggesting that the questions were acceptable. The Bartlett's test was significant (P < 0.0001). The internal consistency of each question was strong, with a Cronbach's alpha rating of 0.90 or above. The content validity index (CVI) indicated an appropriate degree of content validity, which was 0.95. Conclusions: The Persian version of the questionnaire can be utilized in clinical settings to diagnose and assess TMD among Persian speaking populations.