Effect of meal posture adjustment management on tongue movements during mastication

Abstract

Although posture adjustment in mealtime management is related to mastication, it is not clear how it affects tongue movement during eating. This study was undertaken to evaluate the effect of posture adjustment in mealtime management on tongue movement. We used ultrasonography to observe the tongue movement of 8 healthy individuals. The study was done with unilateral mastication on the right side and free swallowing. The eating postures were an 80° reclined sitting position, 30° reclining position, and 30° reclining with the neck 15° anteflexed on a reclining chair. Test foods were steamed rice and chew‐swallow‐managing food, which is a food used in mastication studies that has the physical properties of jelly and paste. Tongue movements were divided into three stages based on mastication time from the M‐mode waveform. B‐mode images were extracted in five continuous M‐mode waveforms at each time. The height difference between the left and the right sides of the tongue was calculated. Friedman and Wilcoxon signed‐rank tests were performed to evaluate posture adjustment assistance and mastication time. In each posture for both foods, the tongue height difference significantly decreased as mastication progressed. In addition, the tongue height difference was significantly larger in the 30° reclining position than in other postures. Although the 80° sitting position is suitable for mastication, the 30° reclining position is not. (J Osaka Dent Univ 2019; 53: 63‐70)