The genioglossus is the largest tongue muscle and the most important muscle for maintaining upper airway patency during sleep. Its relaxation during sleep allows the tongue base to fall posteriorly into the pharynx — the primary mechanism of obstructive sleep apnoea. Hypoglossal nerve stimulation (Inspire therapy) activates the genioglossus to maintain airway patency as an alternative to CPAP.
| Origin | Superior mental spine (genial tubercle) on the inner mandibular symphysis — immediately above the geniohyoid origin |
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| Insertion | Dorsal tongue (entire length) via fan-shaped fibres; inferior fibres insert on the hyoid body |
| Nerve Supply | Hypoglossal nerve (XII) |
| Blood Supply | Lingual artery (dorsal lingual branches) |
| Actions | Protrudes the tongue (the primary tongue protruder); Depresses the central tongue surface (creating a midline groove during protrusion); Most importantly: maintains pharyngeal airway patency by pulling the tongue base forward |
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Hypoglossal nerve stimulation implant (upper airway stimulator) delivers electrical impulses to the hypoglossal nerve during inspiration to activate the genioglossus and open the pharyngeal airway. It is indicated for moderate-severe OSA who fail or cannot tolerate CPAP. Response rates of 80% and AHI reduction of 70% are achieved at 12 months.
The genioglossus is palpable as the bulk of the tongue body — tongue protrusion tests genioglossus strength.
Genioglossus tone loss during sleep allowing tongue base collapse treated with CPAP, mandibular advancement device, or hypoglossal nerve stimulator.
