An oral appliance for the treatment of sleep disorders, such as obstructive sleep apnea, in a user is presented. The oral appliance may include a mouthpiece configured to receive a user's dentition. The mouthpiece may include an oxygen sensor, a pressure sensor, an airflow sensor, an actigraphy sensor, a noise detector, and at least one stimulator for providing stimulation to a user's tongue in the event of decreased oxygen saturation levels, increased pressure applied to occlusal surfaces of the user's dentition, decreased actual airflow levels and/or increased noise levels. The mouthpiece or a separate portion of the mouthpiece may be provided with an EEG sensor to determine sleep state based on EEG rhythms. The mouthpiece may be provided with pharmaceutical compound reservoirs that deliver pharmaceutical compounds to the oral mucosa of the user, which compounds treat symptoms of sleep apnea. The mouthpiece may further include a microprocessor that receives data from the oxygen sensor, pressure sensor, airflow sensor, actigraphy sensor and noise detector, and activates the at least one stimulator and/or pharmaceutical compound reservoirs.