ABSTRACT
Among current treatment options for obstructive sleep apnea (OSA) including surgeries and oral appliances, positive airway pressure (PAP) is accepted as a standard modality, particularly for moderate to severe OSA patients. Because long-term compliance for PAP is less than 50%, however, strong demands for a novel therapy have existed. Based on the findings that electromyographic activities of pharyngeal dilator muscles are significantly decreased in OSA patients during sleep, researches on hypoglossal nerve stimulation (HGNS) have been conducted. Therapeutic effects of HGNS on OSA have been proven through a series of clinical trials, and the American Food and Drug Administration recently approved its application on moderate to severe OSA patients who failed or are intolerant to PAP treatment. Given recent advances in HGNS therapy, it would be timely to review the history of HGNS and discuss its clinical implications.