The omohyoid muscle is an impoant landmark in both the anterior and posterior triangles of the neck. In the anterior triangle, the superior belly of the omohyoid muscle serves as the superolateral border of the muscular triangle and the anterior border of the carotid triangle. In the posterior triangle, the inferior belly of the omohyoid muscle divides the omoclavicular triangle from the occipital triangle. So, in both the anterior and posterior triangles, the omohyoid is an impoant muscle that subdivides the triangles. All of the other listed muscles are associated with the anterior triangle only. Geniohyoid runs from the hyoid bone to the genu of the mandible.it is a deep muscle on the floor of the mouth. It is found deep to the submental triangle. Mylohyoid is another muscle associated with the floor of the mouth.It is in the submandibular triangle and the submental triangle. Sternohyoid is a strap muscle;it is in the muscular triangle.