Differences in mandibular movements and muscle activities between natural and guided chewing cycles.

Mandibular movements and muscle activities during chewing were analyzed in normal subjects under two experimental situations: (1) chewing food with different physical properties (marshmallow, crisp bread, carrot, cheese, and dried cuttlefish) and (2) chewing gum at rates paced by audio signals. Whatever the type of food, both masseteric and digastric bursts were shortened as the chewing rate increased, though the former was more closely related to the chewing rate than the latter. However, when the chewing rate was altered voluntarily, the duration of the digastric burst varied more than the masseteric burst.