RecruitingDevice studyTranscranial Electrostimulation and Obstructive Sleep Apnea SurgeryPostoperative pain after major surgery for obstructive sleep apnea (OSA), such as palatopharyngoplasty (PPP) and maxillomandibular advancement (MMA) is moderate-to-severe, and may persist for weeks. Control of this pain may be difficult, because OSA patients are very sensitive to traditional opioid pain medications, and their side effects. Poorly controlled pain slows down patients' recovery after surgery, including a return to normal daily activities and work, and may also delay wound healing. This study will investigate whether pain relief and recovery after surgery may be improved with the application of a weak electrical current to the skin of the patient's head (transcranial electrostimulation, TES). The TES works by blocking pain in the central nervous system through multiple mechanisms, which result in non-pharmacological pain relief, without drug-associated side effects.