Abstract
OBJECTIVES: The Oral Health Impact Profile for Temporomandibular Disorders (OHIP-TMDs) is a validated condition-specific outcome measure to help guide decision-making in the management of the condition. There is no Thai version of OHIP-TMDs, and therefore the original English version needs cross-cultural adaptation translation, and validation with a Thai population to reduce the anomalies due to language and cultural differences. This study aimed to develop the Thai-language version of OHIP-TMDs, perform a cross-cultural adaptation to Thailand, and assess its content validity, internal consistency, reliability, and construct validity. METHODS: The original English version of OHIP-TMDs was forward and backward translated into Thai language using the International Network for Orofacial Pain and Related Disorders methodology (INfORM) protocol for cross-cultural adaptation. The Content Validity Index (CVI) was performed by 5 orofacial pain (OFP) specialists to establish content validity. The OHIP-TMDs-T was then tested in 2 groups of Thai dental patients including 110 TMD patients and 110 control participants. The internal reliability and test-retest reliability (n = 30) were investigated in the TMD group using Cronbach alpha coefficient and intraclass correlation coefficient (2-way mixed effect model), respectively. The difference in OHIP-TMDs-T score between the TMD group and control group was investigated for known group validity. RESULTS: Cronbach alpha and intraclass correlation coefficients were 0.942 and 0.797, respectively. The CVI collected from the OFP specialists was 0.92. There was a statistical difference in the OHIP-TMDs-T overall score between the TMD group (95% CI, 40-46) and control group (95% CI, 2.0-3.4) (Z = 9.060, r = 1, P < .001). CONCLUSIONS: The OHIP-TMDs-T is a valid and reliable tool for evaluating the quality of life and the impact on oral health in Thai patients with TMD.