Abstract
The purpose of the present study was to obtain fundamental data about the tongue movements when swallowing in order to establish objective evaluation for the tongue movements by using the simultaneous recording system with the tongue pressure changes on the palate and the masticatory muscle activity.
Five subjects who were diagnosed to have normal deglutition, participated in the study. For measurements of the tongue movements, an artificial palatal plate was prepared, in which three strain gauges for measuring tongue pressure were set in three positions in the mid line of the palate, frontal, middle and rear parts of the palate antero-posterioly. The tongue pressure changes and the masticatory muscle activity were measured when swallowing 5,10 ml of water and saliva, respectively. The measurements were performed one hour later, and 1,2,3 days later after wearing the artificial palatal plate. The starting time of the deglutition was so defined that the larynx rose up to the anterior direction.
Though significant coefficient variation was found in the duration of the deglutition for 10 ml water among the days when the experiment was conducted after wearing the artificial palatal plate, no significant difference was found among the days in the first and second peak times of manifestation from the start of swallowing and in the maximum tongue pressure.
In addition, no significant difference among the days w as found either in the duration between the start of deglutition and each masticatory muscle activity.
In conclusion, the reproducibility of this syste m in measuring tongue pressure changes among the experimental days was confirmed, and tongue movements when swallowing were found to become smooth with time.
