Effects of different stimulus locations on inhibitory responses in human jaw-closing muscles

Abstract

The aim of this study was to examine the inhibitory responses in bilateral masseter and temporalis muscle activity when electrical stimulation with short or long duration was applied to six oro-facial locations. The exteroceptive suppression period (ES2) and inhibitory responses were recorded in the surface electromyogram (EMG) of bilateral masseter and temporalis muscles in 16 healthy subjects. Two stimulus durations (1 ms single pulse and 450 ms pulse train) adjusted to a perceived intensity of 7 (distinct painful) on a 0-10 Numerical Rating Scale (NRS) were applied to the following six oro-facial locations on the right side while the subject was biting at 50% of the maximal voluntary contraction: masseter muscle, temporalis muscle, temporomandibular joint, infraorbital nerve, supraorbital nerve, and mental nerve. The stimulus intensity required to reach an NRS score of 7 was significantly lower for 450 ms train stimuli than for 1 ms single stimuli (P<0·001). There were no significant differences in the magnitude of ES2 suppression among the six different locations (P>0·876) for the 1 ms single stimuli. There were significant decreases in Root-Mean-Square-EMG values in the 400-500 ms post-stimulus epoch compared with the pre-stimulus epoch (P<0·023) for 450 ms train stimuli, but there were no significant differences in the magnitude of inhibition among the six different locations (P<0·893). Short- and long-lasting electrical stimulation of various oro-facial locations induces similar bilateral inhibitory effects in the jaw-closing muscles but with different propensity which may reflect the somatotopic organisation of these responses.

Assessment of sleep parameters during contingent electrical stimulation in subjects with jaw muscle activity during sleep: a polysomnographic study

“…Application of electrical stimuli to the trigeminal area is known to elicit an inhibitory reflex response in contracting jaw-closing muscles (20)(21)(22)(23). This principle can be used for contingent stimulation when the jaw muscles become active during sleep.…”

Efficacy of biofeedback therapy on sleep bruxism: A systematic review and meta‐analysis

“…It seems that the tested approaches (ie, ECG‐based CES [one article], EMG‐based CES [one article] and vibratory feedback [one article]) may reduce SB without substantial damage to sleep as evaluated by questionnaires based on the bruxer's self‐report. Indeed, findings by Jadidi et al are in line with their previous PSG study showing that CES at non‐painful intensities does not cause major arousal responses in sleep parameters or interfere with self‐report sleep quality. However, to determine the degree to which the newly developed biofeedback methods used in the other two studies may have affected sleep structure will require PSG investigations.…”

Effects of neuromuscular electrical stimulation, laser therapy and LED therapy on the masticatory system and the impact on sleep variables in cerebral palsy patients: a randomized, five arms clinical trial

“…It is hypothesized that oxyhemoglobin desaturation, caused by pauses in breathing during sleep, can lead to harmful function in neuromuscular system in individuals with CP. We also hypothesize that electrical stimulation, led therapy and laser therapy will contribute to balance the muscular function, adjusting to physiologic patterns of muscular activity, in rest and isometric positions [17,18]. The sample will be divided according the randomization rules, in 5 groups with 10 patients (G1,G2,G3,G4,G5).…”

“…Some therapies may be suggested to treat muscular alteration in CP, such as electrical stimulation, LED therapy and laser therapy [17,18]. Neuromuscular electrical stimulation has been proposed as a potentially useful modality for muscle strengthening in children with CP.…”