Comparison of mouth rinsing performance between adults and children using a contactless vital sensing camera.

BACKGROUND: Evaluating mouth rinsing skills is useful for assessing oral function, however current evaluation methods are subjective. OBJECTIVES: This study compared mouth rinsing between adults and children using a contactless camera to capture lip motion. METHODS: The subjects comprised 16 adults and 13 children with no oral dysfunction. A compact vital sensing camera adapted from a Microsoft Xbox One Kinect Sensor® (Kinect) was placed 100 cm from the floor and 120 cm from the subject; 5, 10 and 15 ml of water were used as samples. Participants were instructed to hold the sample in the oral cavity, close the lips and move the sample alternatively left and right for 15 s. Maximum/minimum displacement from the reference plane and rinsing cycle for each sample were analysed by one-way analysis of variance. RESULTS: In adults, there was no significant difference in the maximum/minimum displacement between the left and right sides of the angulus oris due to differences in sample amount. In children, the right maximum significantly differed between the 5- and 15-ml and 10- and 15-ml samples, while the left maximum significantly differed between the 5- and 10-ml and 5- and 15-ml samples. The right minimum significantly differed between the 5- and 10-ml samples, as did the duration of mouth rinsing between the 5- and 15-ml samples. CONCLUSIONS: In children, lip movement and mouth rinsing duration tended to decrease with increasing sample volume. Evaluating lip movement using a contactless vital sensing camera is useful for assessing children's development of oral function.

Analysis of head motions during food intake in Japanese adults using a new motion capture system.

OBJECTIVE: A new motion capture system was developed to verify the hypothesis that "during food intake, head motion changes according to the properties of the food." DESIGN: Twenty healthy males and 20 healthy females with right-handed and normal occlusion participated in this study. The motion capture system used consisted of a Microsoft Xbox One Kinect Sensor® and a newly-developed program. Meatballs (solid), yogurt (paste), and water (fluid) were used as food samples. Head motion distance, head turning angle, and head forward angle were measured during food intake. Unpaired t-tests were used to analyze each head motion and compare the sexes. A one-way repeated measures analysis of variance was used to analyze each head motion for different food samples. RESULTS: Head motion distance was significantly smaller in females for the meatball and yogurt, but not for water. There were no significant differences between the sexes for head turning angle or head forward angle. Head motion distance and head forward angle were significantly larger for water than for meatballs and yogurt. The head turning angle was significantly smaller for the meatball than for yogurt and water. CONCLUSIONS: The results indicated that females tend to consume food without moving their heads when eating solid and paste foods. As the fluidity of the food increased, the head moved in a turning motion to avoid spilling the food, and the heads tilted forward. The motion capture system used in this study was also effective in analyzing head motion during eating.