Translation and Adaptation of the Diagnostic Criteria for Temporomandibular Disorders into the Malay Language: Psychometric Evaluation of Contents

Aims: To develop the Malay DC/TMD through a formal cross-cultural adaptation (CCA) process for use in non-English speaking populations and to determine the reliability and validity of the Malay Graded Chronic Pain Scale (M-GCPS) and Malay Jaw Functional Limitation Scale (M-JFLS). Methods: The English DC/TMD was translated into the Malay language using the forward-backward translation procedures specified in the INfORM guideline. The initial Malay instrument was pre-tested, and any discrepancies were identified and reconciled before producing the final Malay DC/TMD. Psychometric properties of the M-GCPS and M-JFLS were evaluated using a convenience sample of 252 subjects and were assessed using internal consistency and test-retest reliability, as well as face, content, concurrent, and construct validity testing. Internal consistency was assessed using Cronbach's alpha, while test-retest reliability was examined using intraclass correlation coefficient (ICC). Concurrent and construct validity of both domains were performed using Spearman rho correlation test. In addition, construct and discriminant validity were appraised using Kruskal-Wallis and Mann-Whitney U tests, respectively. Results: Cronbach's alpha values for the M-GCPS and M-JFLS were 0.95 and 0.97, respectively. The ICC was 0.98 for the M-GCPS and 0.99 for M-JFLS. The majority of the tested associations for both domains were found to be statistically significant, with good positive correlations. Conclusion: The M-GCPS and M-JFLS were found to be reproducible and valid. The Malay DC/TMD shows potential for use among Malay-speaking adults.