A trans mucosal neuromuscular electrical stimulation device including a mouthpiece, electrodes associated with the mouthpiece. The device and/or mouthpiece incorporates electrical circuitry operatively connecting to the electrodes to a power source and is configured to provide, in use, electrical stimulation to one or more palate and/or tongue muscles via the electrodes through the oral mucosa. The treatment regime, including the location of stimulation and the parameters used, is designed to increase resting muscle tone and/or muscle tone during sleep.