Effects of Wearing Palatal plate on Swallowing and Its Habituation

PURPOSE: The aim of this study was to evaluate the effects of wearing a palatal plate on swallowing and its habituation. METHODS: Nine healthy dentate subjects participated in this study. They wore palatal plates of 1.5 mm thickness. While they were eating agar jelly, jaw movements and surface EMGs were recorded and the changes of duration of mastication, number of times of mastication, duration from the end of mastication to the beginning of pharyngeal stage, and duration of pharyngeal stage immediately after insertion of the palatal plate from the control were evaluated. We also investigated habituation from the daily changes of duration from the end of mastication to the beginning of the pharyngeal stage. RESULTS: Although no difference was found in duration of mastication, number of times of mastication or duration of pharyngeal stage, a significant prolongation in duration from the end of mastication to the beginning of the pharyngeal stage was found. This prolongation decreased by one day after wearing the plate to the same level as the control. Although a significant decrease was found in the duration one day after wearing from immediately after wearing the plate, no difference was found two days after, and a significant decrease was found again from three days after. No difference was found in the change within subjects. CONCLUSION: These results suggested that the duration from the end of mastication to the beginning of the pharyngeal stage was affected by wearing the palatal plate, but habituation was obtained about 3 days after wearing and its effect disappeared.