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

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.