Obstructive Sleep Apnea: Emerging Treatments Targeting the Genioglossus Muscle.

Obstructive sleep apnea (OSA) is characterized by repetitive episodes of upper airway obstruction caused by a loss of upper airway dilator muscle tone during sleep and an inadequate compensatory response by these muscles in the context of an anatomically compromised airway. The genioglossus (GG) is the main upper airway dilator muscle. Currently, continuous positive airway pressure is the first-line treatment for OSA. Nevertheless, problems related to poor adherence have been described in some groups of patients. In recent years, new OSA treatment strategies have been developed to improve GG function. (A) Hypoglossal nerve electrical stimulation leads to significant improvements in objective (apnea-hypopnea index, or AHI) and subjective measurements of OSA severity, but its invasive nature limits its application. (B) A recently introduced combination of drugs administered orally before bedtime reduces AHI and improves the responsiveness of the GG. (C) Finally, myofunctional therapy also decreases AHI, and it might be considered in combination with other treatments. Our objective is to review these therapies in order to advance current understanding of the prospects for alternative OSA treatments.