Geniohyoid

The geniohyoids originate at the genial tubercles which are in the midline of the mandible at the near inferior edge. They run deep to the mylohyoid muscle. As they are anterior and superior to the hyoid bone, they will result in the hyoid bone moving superiorly and anteriorly if the mandible’s position is fixed. Of course, like other suprahyoids connected to the mandible if the infrahyoids fix the hyoid in place this muscle can also help open the mandible. It is innervated by fibers that originate in C1 (the first cervical nerve) but travel with Cranial nerve XII (the hypoglossal nerve).

Figure 28.
Illustration showing the geniohyoids muscle