Methods, devices, and systems are disclosed for controlled delivery of a therapy, such as a stimulant, to a mouth of a subject via an oral device positioned in a secured configuration in the mouth. At least one of a tongue position stimulator (TST) and tongue position sensor (TSE) is provided, according to certain aspects. According to another aspect, a stimulus is delivered to the mouth and/or tongue via a mouthpiece secured to the subject's teeth. In another regard, a stimulus is delivered that generates a natural response to eliminate or reduce sleep disorders, such as for example at least one of snoring and obstructive sleep apnea.