2024 Volume 31 Issue 1 Pages 1-8
The various organs involved in mastication perform movements appropriate to the physical properties of the food. Using the teeth, peanuts are crushed into small pieces and meat is cut into smaller pieces and eaten. Soft foods such as jelly are not chewed but crushed with the tongue and hard palate. The tongue presses the food against the hard palate immediately after the food is taken into the mouth to determine whether it should be chewed or crushed.
In this study, we aimed to find a method to observe the tongue movement of chewing gum with teeth and tofu compressed by the tongue and palate using ultrasound images and to examine the difference in chewing patterns.
Study participants consisted of 10 healthy volunteers（mean age, 29.6 ± 3.8 years）. Tongue movement was observed using a portable ultrasound device and a linear probe. Mandibular kinesiographs were used to measure jaw movements. Gum and tofu were selected as test foods. Three consecutive strokes were selected for each food. The average values of the distance of mandibular opening and the distance of lateral movement were obtained. Cycle time of tongue movements were measured. The distance from the submental skin surface to the top and bottom points of the dorsal tongue movement trajectory was measured. In this study, the upper and lower points of the region of high ultrasonic intensity near the submental skin surface were measured.
In the ultrasound image, the trajectory of the tongue’s dorsum and the proximal region moved up and down almost simultaneously in gum chewing. Conversely, in the crush, the trajectory of the tongue’s dorsum moved up and down, but the proximal region hardly moved. It was suggested that this imaging method could be used to examine the difference between chewing and crushing.
