An assembly of devices designed to apply electrical stimuli to the mastication and facial muscles. It typically consists of an electrical pulse generator, appropriate active electrodes that are usually placed on the coronoid notches of the mandible, and a common return electrode located at the nape of the neck below the hairline. The device is typically used in dentistry to relax the facial and mastication muscles to treat temperomandibular joint (TMJ) dysfunction and associated pain, to relieve symptoms associated with muscle spasm, to take occlusal registrations and denture impressions, and for other therapeutic measures.