Journal of Dental Research, Vol 63, 1310-1314, Copyright © 1984 by International & American Associations for Dental Research Online Journals
Frequency-dependent modulation of rhythmic human jaw movements
T. Morimoto, T. Inoue, T. Nakamura and Y. Kawamura
Modulation of jaw movement patterns by alteration of the chewing rhythm was
analyzed in nine subjects. Jaw movements were monitored by an electronic
transducer system. The subjects were asked to chew gum either at
voluntarily determined rates or at rates guided by a light flash that
varied from 2 to 7 Hz at 1-Hz intervals. The results can be summarized as
follows: Chewing was generally conducted at rates below 3 Hz when the
rhythm was voluntarily determined. When the rhythm was guided, however, the
maximum chewing rate could occasionally be raised up to 6 Hz; the duration
of the chewing cycle was more closely related to changes in the duration of
the opening and occlusion phases than to that of the closing phase; at
chewing rates below 3 Hz, the maximum gape did not appreciably change with
the chewing rhythm, while it decreased linearly at rates above 3 Hz; and at
chewing rates below 3 Hz, the jaw opening velocity increased with speed of
chewing, whereas it decreased or sometimes fluctuated over a wide range at
rates above 3 Hz. It is concluded that, during normal mastication at rates
below 3 Hz, chewing rhythm is altered by changing both the velocity of jaw
opening and the duration of the occlusion phase.
