Change in masticatory movement according to food size in young Japanese females

This is the authors' abstract. We don't add key points for this paper.

The present study aimed to investigate the effect of food size on chewing behavior (number of chewing cycles, cycle duration and displacement of chin movement) from food intake to the terminal swallow. Twenty healthy females were recruited. Food intake behavior was recorded using two digital video cameras and threedimensional kinematic data were collected using three-dimensional image processing software. Multilevel model analysis was applied to describe the fit of the chin marker displacement curves during the chewing cycles. Our results showed that there was a significant tendency for the number of chewing cycles to increase with increasing rice ball weight. However, in contrast, the number of chews per rice weight decreased gradually with increasing weight. The displacement of the chin marker increased from the first to last chewing cycle as the rice ball weight increased. For time-dependent changes in displacement, the differences of displacement in the first cycle were greater than in the last cycle. There were significant differences in the vertical, lateral and anteroposterior displacement curves depending on rice ball weight. Vertical and lateral displacement generally decreased with time, and the curves showed steep slopes from the start to middle points of an intake. This study suggested that change in masticatory movement according to food size may be associated with appropriate eating behavior.