Motor pauses in EMG activity during chewing and biting.

Biting on hard particles during chewing sometimes produced motor pauses but more often abrupt atypical terminations of the EMG patterns occurred. A series of tests with different experimental biting and chewing situations were performed. The results indicate that the motor inhibition that occurs during biting and chewing mainly are of two different origins. The inhibition that occurs during tooth tapping and biting on hard particles is caused by tendon and muscle stretching occurring as a result of the mechanical stop of the jaw movement. The inhibition occurring when crushing a brittle bolus has a different origin and occurs before tooth contact and is a form of unloading reflex. The periodontal receptors or surface sensibility appears to be of minor importance for these types of motor inhibition.