Objective: To evaluate the acceptance of the mobile application (“app”) by adolescents in orthodontic treatment for a better applicability of this resource. Methods: Ninety orthodontic patients, aged between 13 and 17, of both sexes, used an application, chosen for presenting a Portuguese version and reaching the target audience. Then they registered their acceptance through the SUS (System Usability Scale) questionnaire, which measures user satisfaction through ease of use of the application, with its Satisfaction and Usability Indexes. The findings were subjected to descriptive and comparative statistical analysis using the Kruskal Wallis and Dunn test, adopting a significance level of 5%. Results: The application presented the above-average Satisfaction and Usability Index (79.1). The domain (quality component) with the highest index was "Learnability" (85,3), in relation to "Efficiency" (79,0), "Satisfaction" (76,0), "Memorability" (72,2) and "Errors" (71,4) (p≤0,05). Conclusion: Mobile app was accepted by adolescents in orthodontic treatment due to the ease and speed that it was used. However, its acceptance was negatively influenced by the reported frequency of use. Therefore, its application as an educational and motivational tool in clinical practice is suggested, as long as the different aspects that involve its best applicability are considered.
