RESUMO
In health-related research, an increasing number of clinical assessment tools are translated and cross-culturally adapted for cross-national and cross-cultural studies and comparisons. However, when translating and cross-culturally adapting clinical assessment tools for use across new countries, cultures, or languages, we must follow a thorough method to reach semantic, idiomatic, experiential, and conceptual equivalences between translated and original versions. Therefore, in this study, we translated and cross-culturally adapted the Protocolo MBGR (Marchesan, Berretin-Felix, Genaro, and Rehder) from Brazilian Portuguese into English, following international guidelines, and named it "MBGR Protocol." To verify its content validity, we used the Content Validity Index. Results indicated excellent content validity: a Scale-Content Validity Index of 0.96 and 97% of all translation units with an Item-Content Validity Index of 1.00. Also, to prove its face validity and confirm whether it worked in the target population's linguistic-cultural setting, we used it with 35 subjects. Again, results demonstrated excellent face validity: in the pretest, 91% of all translation units were considered comprehensible and clear; in the pilot test, 98% of all translation units were considered comprehensible and clear. Thus, we concluded that the MBGR Protocol is promising to enhance the uptake of studies in Orofacial Myology worldwide and support researchers and health professionals in assessing and diagnosing orofacial myofunctional disorders in children, adolescents, adults, and the elderly. Also, it may support evidence-based practice and assist in standardizing assessment and diagnostic criteria. The MBGR Protocol should have its psychometric properties tested before being used in clinical practice or scientific research. Therefore, future studies are needed, and collaborations among researchers from South and North American countries are encouraged to create an international network and advance with knowledge and skills in the Orofacial Myology discipline.