Anatomical Structure and Location of the Digastric Muscles

Description

Running along the anterolateral neck beneath the mandible, the digastric muscle is shown with its posterior belly arising from the mastoid notch of the temporal bone and coursing anteroinferiorly toward an intermediate tendon at the level of the hyoid. From there, the anterior belly continues anterosuperiorly to the digastric fossa on the inner surface of the mandibular body near the symphysis menti, lying superficial to the mylohyoid in the submandibular region. A lateral skull and cervical spine context places the suprahyoid complex immediately inferior to the mandibular angle and anterior to the upper cervical vertebrae. Clean bony landmarks anchor orientation. For teaching surface and surgical anatomy, this relationship between mastoid process, hyoid level, and chin matters because the posterior belly of digastric helps define the boundaries of the submandibular and carotid triangles, while the anterior belly contributes to the submental triangle over the mylohyoid. During submandibular gland excision or level I neck dissection, surgeons often use the digastric as a landmark to identify and protect the hypoglossal nerve as it crosses the carotid arteries toward the tongue. Small muscle, big landmark. Common use cases include head and neck anatomy labs, operative atlases illustrating triangle-based approaches, and radiology teaching files where correlating the digastric and mylohyoid plane improves interpretation of CT and MRI of the suprahyoid neck, including ranula, submandibular sialadenitis, and floor-of-mouth abscess spread. Anatomical accuracy verified by SciePro's Medical Advisory Board.