Validity and reliability of the Turkish version of the orthognathic quality of life questionnaire in patients with dentofacial deformity

Due to the lack of a specific quality of life (QoL) survey on dentofacial deformities (DFD) for Turkish speakers, the present research aimed to perform a translation of the English version of the Orthognathic Quality of Life Questionnaire (OQLQ) into Turkish (the OQLQ-TR) and provide cultural adaptation to the Turkish population. The process of this cross-cultural adaptation followed the six stages given in the guidelines that were proposed by Beaton et al. (2000), which comprised the following: 1) performing the initial translation, 2) synthesizing the translation, 3) performing the back translation, 4) presenting it to the expert committee, and 5) testing the prefinal version. Throughout the process of validating the Turkish version, the results of the OQLQ were compared with the Oral Health Impact Scale-14 (OHIP-14) and Short Form-36 (SF-36) questionnaires and the Visual Analogue Scale (VAS), which were previously validated in Turkish. All of these Turkish questionnaires (OHIP-14, SF-36, OQLQ) were applied to 69 patients at the Çukurova University Faculty of Dentistry. Analysis of the internal consistency of the OQLQ-TR exhibited good correlations for the domains. Moreover, the test-retest reliability also exhibited intra-class correlation coefficients that were excellent. The correlation between the OQLQ-TR and SF-36 was weak and negative. The OQLQ-TR exhibited good correlations with the OHIP-14 and VAS. The OQLQ-TR was found to be valid, reliable, and reproducible. Thus, it has become a useful instrument for assessing the quality of life of Turkish-speaking patients with dentofacial deformity.