Translation and Validation of the Gothenburg Trismus Questionnaire-2 into Italian Language

<b>Objectives:</b> This study aimed to translate and validate the Gothenburg Trismus Questionnaire-2 for Italian-speaking patients (I-GTQ2). <b>Methods:</b> A cross-sectional study was conducted with 200 participants. The translation process adhered to international standards. Patients completed the I-GTQ2 along with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ) and the Hospital Anxiety and Depression Scale (HADS) to evaluate construct validity. Reliability was assessed using internal consistency and test-retest reliability (ICC). Known-group validity was also analyzed. <b>Results:</b> The I-GTQ2 showed high reliability, with Cronbach's alpha ranging from 0.61 to 0.94 and ICC between 0.79 and 0.96. Known-group comparisons confirmed discriminative validity, with significant differences between patients with and without trismus in jaw-related problems (<i>p</i> = 0.005, <i>d</i> = 0.575) and large differences between patients and controls in most domains (<i>p</i> < 0.001, <i>d</i> > 0.65) except for muscular tension. Convergent validity was supported by strong correlations between GTQ-2 domains and EORTC QLQ-C30 (e.g., <i>r</i> = -0.54 for facial pain and global health status; <i>r</i> = 0.64 for jaw-related problems and pain) as well as moderate correlations with HADS anxiety (<i>r</i> = 0.39-0.52) and depression (<i>r</i> = 0.37-0.46). <b>Conclusions:</b> The I-GTQ2 is a reliable and valid tool for assessing the impact of trismus on the quality of life in Italian-speaking patients, and it is recommended for clinical and research use. Future studies should investigate its relationship with objective trismus measurements.