The analysis of tongue and soft palate movements during mastication and the relationship of these movements and dysphagia

点击翻译按钮获取中文摘要

(ア) This research was performed to clarify the contributions of soft palate muscles during food intake process by using an electromyographical technique.In sucking behavior, soft palate showed some different movements. In sucking using inspiration, soft palate was elevated by activation of the levator veil palatini muscles(LVP). In sucking using the oral negative pressure, soft palate was pulled down and contact with retro-tongue by activation of the palatoglossus muscle (PG), but in forced sucking using mouth-opening, LVP also showed its activities accompanied with activities of PG, to prevent the collapse of closed oral cavity. In chewing sequence, both PG and LVP showed phasic activities accompanied with jaw movements and these activities may contribute to position the food on molars. PG showed continuous activity in the chewing with water in the mouth. and this continuous activity may cause the inefficiency chewing, because these activities do not permit to large opening mouth.Our investigation concerning with the chewing position and the efficiency of the chewing showed the supine position decreases the efficiency of chewing and this trend was more clearly observed the chewing with water in oral cavity. This result may indicate that the PG activities observed in such condition may prevent the large opening mouth and the positioning of the foods in oral cavity. In conclusion, to know these activities of soft palate are very important to understand the mechanism of dysphagia.