The purpose of this study was to investigate the mean integral EMG level of the masseter muscle, which was obtained from the EMG biofeedback of the frontal muscle of those patients whom once had a case of mandibular dysfunction, and to use this as an effective means of treatment. Furthermore, the correlation between the psychological characteristics of mandibular dysfunction patients and EMG bi...

Concussions are acceleration-deceleration injuries that occur when biomechanical forces are transmitted to the cerebral tissues. By limiting acceleration of the head, enhanced cervical muscle activity derived from clenching with a mouthguard (MG) may reduce the incidence or severity of concussions following impact. The purpose of this study was to investigate the effect of voluntary clenching w...

The present study was designed to examine the effect of sympathetic tonic activity on parasympathetic vasodilation evoked by the trigeminal-mediated reflex in the masseter muscle in urethane-anesthetized rats. Sectioning of the superior cervical sympathetic trunk (CST) ipsilaterally increased the basal level of blood flow in the masseter muscle (MBF). Electrical stimulation of the peripheral cu...

The synthesis rates of different myosin isoenzymes in a single muscle, and of the same isoenzymes in different muscles (soleus, masseter and plantaris), were measured. The rate of total protein synthesis was significantly higher in the soleus [greater than 95% slow myosin (SM)] than in the plantaris [greater than 95% fast myosin (FM)]. Two fast isoenzymes, FM2 and FM3, were synthesized at diffe...

Peripheral N-methyl-d-aspartate (NMDA) receptors are found in deep tissues and may play a role in deep tissue pain. Injection of the endogenous NMDA receptor agonist glutamate into the masseter muscle excites deep craniofacial afferent fibers in rats and evokes pain in human subjects. It is not clear whether peripheral NMDA receptors play a role in these effects of glutamate. Accordingly, the e...

BACKGROUND Rapid eye movement sleep (REMS) is characterized by activation of the cortical and hippocampal electroencephalogram (EEG) and atonia of non-respiratory muscles with superimposed phasic activity or twitching, particularly of cranial muscles such as those of the eye, tongue, face and jaw. While phasic activity is a characteristic feature of REMS, the neural substrates driving this acti...

The present study aimed to investigate whether facial electromyography (EMG) recordings reflect the perception of effort and primary active lower limb muscle activity during incremental workload cycling. The effects of exercise intensity on EMG activity of the corrugator supercilii (CS), masseter and vastus lateralis (VL) muscles, heart rate (HR) and the rating of perceived exertion (RPE) were ...

The purpose of this study is to obtain normative values of the masseter muscle of myasthenia gravis (MG) patients and healthy volunteers by single-fiber electromyography (SFEMG). Stimulation of SFEMG in the masseter muscle was studied in 15 healthy volunteers (men 8, women 7; mean age 40.2, range 21-77) and 30 patients affected by MG (men 16, women 14; mean age 42.8, range 12-75). The mean cons...