Roles of the Palate in the Recognition of lngested Food Texture

Abstract

We used five subjects whose hard palates were covered with resin plates to examine their modes of masticatory movement while they were eating soft and solid test food (agar jelly and cookies). We conducted videofluorography in order to investigate the roles of the palate in recognizing the ingested food texture． While the subjects were chewing agar jelly with the resin plates attached to their hard palates， we confirmed that they were chewing more frequently for a longer period of time before swallowing． Some subjects changed their soft food crushing technique from compressing with the tongue and the hard palate to chewing with teeth． This change in food crushing technique corresponded to the time when the subjects recognized the change in the hardness of food． ln these cases the mechanism to recognize the texture of ingested food was impaired by the application of the resin plates and the threshold of recognizing hard food was lowered．While the subjects were chewing cookies with the resin plates attached to their hard palates， we also confirmed that they were chewing more frequently and for a longer period of time before swallowing． ln this experiment we recognized the effects of the motility of tongue and the salivary secretion on this phenomenon which were not observed in the former experiment using soft food． Further work is necessary before the findings obtained in the present study are confirmed．