The way in which orthodontic patients swallow poses a major problem during treatment, especially for long-term stability of the end result. If clinical diagnosis of atypical swallowing performed in an empirical manner by the practitioner, aided or not by rehabilitation devices, has been the subject of numerous studies, surface electromyography seems to bring new insight in diagnosing the way patients swallow and in re-training atypical deglutition. After a short refresher about the anatomy and physiology of the mechanisms of swallowing as well as the basic principles of electromyography, a descriptive and comparative study was carried out with 60 patients in order to understand and to prove the reliability and pertinence of this diagnostic tool. The results of the study are based on a collection of graphic and visual data compared to maxillo-facial kinesiographic studies where patients underwent a parallel double blind diagnosis. The objective was to determine if surface electromyography provides reliable, exact and reproducible data based on daily screening. Finally, it may be possible to create a flowchart for clinical decision making by using the results of our study as well as the findings in the literature.