Analysis of Physiological Parameters of Masseter Muscle Activity During Chewing of Agars in Healthy Young Males

Abstract

This study examined the influences of rheological properties on mastication in eight healthy male subjects by recording an electromyogram (EMG) of the masseter (MS) muscle during chewing. Four different agars were tested: 0.5 and 1.5% ordinary agars (0.5OA and 1.5OA), and 2.5 and 4.0% . The hardness, adhesiveness and cohesiveness differed among the four agars, which is most likely because of the differences in the concentrations and constituents of the agars. Mastication time and the average amplitude of the MS EMG during chewing were longest and largest, respectively, with the 1.5OA followed by the 4.0IA. The activity pattern of the MS EMG differed between the first and last cycles of chewing sequences in each of the agars used; there were no differences between the first cycle activity patterns or the last cycle activity patterns when comparisons were made between the four agars. These results suggest that the rheological properties of the agars modify mastication and that the activity patterns of the MS muscle change during chewing. PRACTICAL APPLICATIONSThe present findings obtained by the analyses of rheological properties and physiological parameters, especially by the "T P " technique, suggest the following possible uses: (1) the T P technique can analyze foods at different angles from analysis by rheological properties; (2) a combination of rheologi-1

Automatic Identification of Temporal Sequences in Chewing Sounds

“…Similar results were found in earlier studies, where burst duration and mean voltage of the EMG as well as vertical mandibular movement decreased during the sequence [8]. Chewing of materials with different rheology indicated, that changes in the activity pattern of M. masseter occur on the chewing cycle level during a sequence, however sequence parameters did not differ for materials of varying rheology [9].…”

Synchronization of masseter activity patterns between the right and left sides during chewing in healthy young males

“…The materials and methods used in the present study were identical to those of our previous report [18] and this experiment was approved by the Ethics Committee of the Niigata University of Health and Welfare. Briefly, eight healthy males (18-21 years of age) participated in this study and surface electromyograms (EMGs) from their masseter (Mass) muscles were recorded bilaterally.…”

“…Ina-agar is a mixture of agar, k-carrageenan, locust bean gum and glucose and is softer and smoother than ordinary agar. These unique textural properties are the major reason this agar type was used in the original study [18]. One of the four test foods was randomly delivered to each participant while seated and the participant was instructed to chew the test food using a natural rhythm and to swallow it when he wanted.…”

The Effect of Masseter Activity Patterns during Chewing on Suprahyoid Activity in Subsequent Chewing Cycles

“…Two surface electromyograms (EMGs) were recorded according to our previous report [16]: i.e., one pair of adhesive electrodes (Ambu Inc., Blue Sensor, Baltorpbakken, Denmark) was attached to the skin just above the SH muscles, and the other pair was attached above the Mass muscle on the participant's habitual working side. The EMG signals were amplified, filtered (15 -5000 Hz), fully rectified and integrated (τ = 0.06 s) using the Power Lab system (AD Instruments Pty Ltd., Power Lab/8 sp, Bella Vista, Australia).…”