TITLE:
The Effect of Masseter Activity Patterns during Chewing on Suprahyoid Activity in Subsequent Chewing Cycles
AUTHORS:
Yozo Miyaoka, Ichiro Ashida, Hajime Iwamori, Shin-ya Kawakami, Takako Yamazaki, Naoko Ito
KEYWORDS:
Masseter; Activity Pattern; Suprahyoid; Textural Property; Chewing; Adult
JOURNAL NAME:
Journal of Behavioral and Brain Science,
Vol.4 No.2,
February
11,
2014
ABSTRACT: Few studies have evaluated the effects of activity
patterns of the jaw
closing muscles assessed by specific parameters on jaw opening in subsequent
cycles during the chewing of food. The objective of this study was to quantitatively
analyze the effect of the masseter (jaw closer) activity patterns on suprahyoid
(jaw opener) activity during
subsequent cycles. The assessments were performed while participants naturally
chewed six test foods that differed in size dimensions and textural properties.
Surface electromyograms of the masseter (on the habitual working side) and
suprahyoid muscles were recorded in ten healthy young adults, each of whom
randomly received one of the six test foods. The activity patterns were
assessed using three parameters specifically developed for their
quantification. Changes in suprahyoid activity during each of the subsequent
chewing cycles were examined by three amplitudinal (minimum, maximum, and net
values of the integrated suprahyoid electromyogram) parameters and one
durational (active duration) parameter. The main finding was that two of the
three activity pattern parameters had a statistically significant effect only
on the three amplitudinal parameters in three of the six test foods. These
results suggest that masseter activity patterns partially affect suprahyoid
activity during subsequent chewing cycles and that the effect is food
dependent. A possible neural mechanism responsible for this effect is
presented.