Nocturnal bruxism (NB) is a temporomandibular disorder characterized by an excessive clenching and involuntary parafunctional grinding of the teeth during sleep. In this paper, we present a device that generates electrical stimulation to produce an inhibitory action of the muscles involved in the elevation of the jaw. The device measures the electromyographic (EMG) signal of the left temporalis anterior (LTa) muscle to determine the intensity of contraction. It then, stimulates the right mental nerve to produce a decrease in the contraction intensity of the jaw elevation muscles. The device was used by one bruxist subject for 12 nights. The results showed that, on average, the percentage decrease of the EMG activity was 43.55% when a bruxism event occurred. The events of nocturnal bruxism appeared mostly one and three hours after going to sleep. In conclusion, the electrical stimulation device generated an important inhibitory action of the LTa muscle when the subject was performing nocturnal bruxism. Thus, this result indicates that the device could be useful as a possible treatment for bruxism. Copyright © 2014 SCITEPRESS - Science and Technology Publications. All rights reserved.