Is the Modulation of Masticatory Behaviors in Response to Different Foods Associated with Oral Function?: A Preliminary Observational Study

Objective: Although it has been noted that a decline in oral function reduces dietary diversity, it remains unclear exactly how oral function influences changes in masticatory behaviors across different foods. Therefore, this study examined whether masticatory behavior modulation for different foods was associated with oral function indicators, namely maximum bite force and maximum tongue pressure. Methods: Fifteen young Japanese subjects with healthy dentition and occlusion participated in this study. While consuming 10 g each of three types of food—biscuits, kamaboko, and cucumber—their chewing behavior was recorded using an ear-hanging chewing counter, and masseter muscle activity was recorded using surface electromyography and muscle activity indices were defined as the average root mean square (RMS). Maximum occlusal force and maximum tongue pressure were also measured. The association between masticatory behavior modulation across different foods and oral function was examined from both temporal and biomechanical perspectives. Results: The number of chews and chewing time were higher for biscuits than for the other two foods, but there was no difference in chewing frequency among the foods. The number of chews for biscuits and cucumbers, as well as the chewing frequency for cucumbers, showed a negative correlation with maximum occlusal force. The relative ratio of average RMS between biscuits and other foods showed a negative correlation with maximum tongue pressure. Conclusions: This preliminary experiment suggested the possibility that masticatory behaviors are associated with maximum occlusal force, and that maximum tongue pressure is associated with the modulation of muscle activity across different foods.