Evaluation of masticatory performance by motion capture analysis of jaw movement.

BACKGROUND: The assessment of masticatory performance (MP) is conducted in hospitals, but is difficult to perform in nursing facilities that lack specialists in dysphagia. To select the appropriate food textures in nursing practice, a simple method of evaluating the MP should be developed. OBJECTIVE: The purpose of this study was to investigate motion parameters that influence MP by motion capture analysis of maxillofacial movement on chewing gummy jelly in healthy adults. METHODS: The subjects were 50 healthy adults. The state of chewing gummy jelly was photographed using a high-speed camera. Simultaneously, we evaluated the amount of glucose extracted (AGE) obtained with gummy jelly as a reference value for MP. The subjects were divided into two groups: normal and low masticatory groups (NG and LG, respectively) based on the AGE. The cycle of mastication was classified into three phases: closing phase (CP), transition phase (TP) and opening phase (OP) through motion capture analysis of the video photographed. Parameters of jaw movement and their associations with the AGE were examined. RESULTS: The transition phase rate (TR) and opening phase rate (OR) were correlated with the AGE. Furthermore, the TR in the NG was significantly higher than in the LG, whereas the OR was significantly lower than in the LG. The age, TR and opening velocity were significant independent variables. CONCLUSION: Motion capture technology facilitated the analysis of jaw movement. The results suggested that MP can be evaluated by analysing the TP and OP rates.

Relationships between the Nutrition Status and Oral Measurements for Sarcopenia in Older Japanese Adults.

INTRODUCTION: The purpose of the present study was to clarify the relationships between the risk of malnutrition as a preliminary stage of malnutrition and overall and oral measurements for sarcopenia in older Japanese adults. METHODS: Forty-five participants (79.7 ± 6.1 years) were included in the analysis. The nutrition status of the participants was assessed using the Mini Nutritional Assessment-Short Form (MNA-SF) and classified into two groups: normal and at risk of malnutrition. Overall measurements for sarcopenia in the present study were the skeletal muscle mass index, grip strength, and walking speed, while oral measurements were the cross-sectional area of the geniohyoid muscle, tongue pressure (TP), and oral diadochokinesis. RESULTS: MNA-SF correlated with TP (r = 0.347, p = 0.019). We observed decreases of 5.7 kPa in TP and 3.9 kg/cm2 in BMI in the at risk of malnutrition group. A multiple regression analysis of parameters contributing to the risk of malnutrition identified TP as an independent variable (ß = 0.913, p = 0.042). CONCLUSIONS: The present results demonstrate that the risk of malnutrition is associated with TP as an oral measurement for sarcopenia, but not overall measurements for sarcopenia. Therefore, low TP may be related with the risk of malnutrition.