Tongue and upper airway function in subjects with and without obstructive sleep apnea

Obstructive sleep apnea (OSA) is characterized by repeated occlusion of the oropharyngeal airway during sleep and can have a significant impact on quality of life. In this article, I review the current knowledge of the physiological and pathological functions of the tongue and the genioglossus muscle, one of the upper airway dilatory muscles, in subjects with OSA when they are awake and asleep. Research findings clearly reveal that the genioglossus muscle has important functions in maintenance of upper airway patency and in the pathophysiology of obstructive sleep apnea. Despite extensive study of the functional properties of the genioglossus muscle and its motor units, the availability of OSA prevention and treatment measures remains limited. This review indicates there is a need for further study on more effective prevention and treatment strategies.