Effect of Jaw Opening on Masticatory Muscle EMG-Force Characteristics

Abstract

This study was designed to evaluate the way in which changes in vertical jaw opening affected the relative contributions of various masticatory muscles to bite force production. EMG activity was recorded simultaneously from the masseter, and anterior, middle, and posterior temporalis muscles, during controlled isometric biting at different force levels and vertical jaw openings. EMG-force characteristics were compared between muscles and bite openings. All but the posterior temporalis muscle displayed significant increases in muscle activity with increased bite force production; the masseter muscle demonstrated the largest activity increments. Statistically significant changes in muscle function due to jaw opening were demonstrated only for the masseter muscle, though similar trends were observed for the anterior and middle temporalis muscles. Minimum increases in muscle activity associated with increases in bite force occurred between 9 and 11 mm of opening, measured at the first molar, for all three muscle groups. The results of this study suggest that changes in masticatory muscle length resulting from vertical jaw opening cause alterations in muscle contractile properties, but the relative contributions of various masticatory muscles toward bite force production may also be affected by biomechanical factors and neural control adaptations.

Modeling masticatory muscle force in finite element analysis: Sensitivity analysis using principal coordinates analysis

“…EMG amplitudes in the superficial masseter muscle and strain magnitudes in the zygomatic arch of macaques. Moreover, masticatory muscle EMG amplitudes are correlated with bite force during isometric biting (Pruim et al, 1978(Pruim et al, , 1980Lindauer et al, 1993;Mao and Osborn, 1994) and rhythmic open-close movements against simulated food resistance (Ottenhoff et al, 1996) and are modulated to food texture (Blanksma and Vaneijden, 1995), even within the first power stroke of a chewing sequence (Ottenhof et al, 1993;Peyron et al, 2002). Thus, use of r.m.s.…”

Effects of Cross-sectional Area on Human Bite Studied with Raw Carrot andSurimiGel

“…Several dental researches have been carried out to study the relations between activity in surface EMGs and bite force measured by single-point sensors for clenching or biting without food. [23][24][25][26][27][28][29] This relation has been used to estimate bite force on food from EMG activity, because previous sensors such as the bite fork were hard and large and difficult to use to measure with food, unlike the EMG technique. We also compared the bite force and EMG results with those of the previous methods.…”

Oral feeding behavior during a whole meal

“…Table 1 shows the mean values and correlations of each parameter related to food intake. The total intake time was 367.1 ± 132.1 s (149-704 s), and the number of mouthfuls was 23.5 ± 5.0 (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36). The mouthful weight was 12.1 ± 2.4 g (7.5-16.2 g), and the intake interval was 15.1 ± 5.1 s (7.8-25.7 s).…”

“…Multiple stomatognathic organs are involved in this complex process. In previous studies, various approaches have been used to evaluate feeding behavior in terms of stomatognathic functions: surface electromyography [27,28]; videofluoroscopy [29][30][31]; videoendoscopy [32,33]; ultrasonography [34,35]; and two-and threedimensional motion analysis systems [36]. However, only some steps in this activity have been analyzed, and investigations did not include all the steps in eating.…”