Motor pause frequency in the masseter muscle in relation to food texture

EMG activity was recorded from the masseter muscles of 10 naturally dentate subjects during the chewing of hazelnuts, peanuts, Optosil and chewing gum. The frequency of motor pauses (10-50 ms long) in the EMG patterns was found to be related to the textural properties of the test food. It was also found that the frequency varied for different parts of the chewing sequence, being significantly higher initially than in the last part of the chewing sequence. Motor pauses of this length, however, were absent from many of the EMG patterns. It is concluded that these motor pauses are signs of certain events during chewing but are probably not part of any basic reflex necessary for the neurophysiological regulation of chewing.