Suprahyoid Musculature : names , origin and insertions
- geniohyoid, and
- stylohyoid muscles.
Digastric muscle : The digastric muscle has two bellies. The posterior belly has its origin medial to the mastoid process and extends anteriorly, inferiorly, and medially to the hyoid bone; here it attaches to the bone and connects with the anterior belly by means of an intermediate tendon. The anterior belly inserts in the digastric fossa on the inner side of the mandible.
Mylohyoid muscle : The mylohyoid muscle extends from the step-like myohyoid line on the inner aspect of the body of the mandible to the body of the hyoid bone.
Geniohyoid muscle : The geniohyoid muscle arises at the inner side of the mandibular symphysis, and from there its parallel fibers run directly to the body of the hyoid bone. The pair of geniohyoid muscles can function together as jaw openers, but they can also lift the floor of the mouth and pull the hyoid bone forward.
Stylohyoid muscle : The stylohyoid muscle runs from the styloid process of the temporal bone to the greater horn of the hyoid and serves to stabilize the hyoid.
Posterior view of an anatomical preparation of the left half of the jaw showing the posterior belly of the digastric (1), stylohyoid (2), styloglossus (3), and stylopharyngeus (4) muscles as well as the stylomandibular ligament (5). Except for the digastric muscle, all these structures have their origin on the stylohyoid process (6). Muscle fibers of type I, type 11 A, and type MB each make up one-third of the digastric muscle (Eriksson etal. 1982).