Genioglossus Muscle Origin and Insertion
The genioglossus muscle originates from the superior mental spine (genial tubercle) on the inner surface of the mandible and inserts into the entire length of the tongue, from the hyoid bone to the tip of the tongue. 1
Anatomical Origin Details
- The genioglossus muscle originates specifically from the superior mental spine (genial tubercle) of the mandible. 1
- The superior mental spine has mean dimensions of approximately 5.82 mm in height, 6.98 mm in width, and 2.92 mm in process length. 1
- The genial tubercle is positioned approximately 10 mm from the incisor apex and 10 mm from the lower mandibular border. 2
- In males, the distance from the apices of the incisors to the superior edge of the superior mental spine averages 15.57 mm, while in females it is 9.36 mm, representing a statistically significant difference. 1
Anatomical Insertion Details
- The genioglossus muscle inserts into the entire dorsum of the tongue, extending from the region near the hyoid bone posteriorly to the tip of the tongue anteriorly. 3
- The muscle fibers fan out in a radiating pattern throughout the tongue substance, providing motor control to the tongue base and body. 3
Clinical Relevance
- Genioglossus contraction enlarges both the velo- and oropharynx and lowers the critical pressure in the upper airway. 3
- The genioglossus is one of many muscles acting in concert to prevent flow limitation in the pharynx during sleep. 3
- The genioglossus provides somatic motor innervation as part of the intrinsic and extrinsic muscles of the tongue (except the palatoglossus muscle). 3
Anatomical Relationship to Adjacent Structures
- The geniohyoid muscle originates from the inferior mental spine, which is positioned below the genioglossus origin. 1
- The geniohyoid begins on average 4.88 mm from the inferior border of the mandible and ends 10.03 mm from the inferior border. 4
- The genioglossus begins 11.91 mm from the inferior border and extends to 18.01 mm from the inferior border. 4
- In 28% of cadavers, the genioglossus and geniohyoid muscles overlap at their mandibular attachments, with an average intermuscular distance of 2.67 mm when present. 4