CorpusHuman Anatomy
MuscularMuscle

Mylohyoid

Musculus mylohyoideus

Also known as: diaphragma oris, floor of mouth

A flat, triangular sheet that, with its partner, forms the muscular floor of the mouth. It raises the floor of the mouth and the tongue during swallowing.

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Overview

Each mylohyoid arises from the mylohyoid line on the inner surface of the mandible. The two muscles meet at a midline raphe from the symphysis to the hyoid, and their posterior fibres insert on the body of the hyoid. Together they form a sling-like diaphragm of the oral floor, separating the sublingual space above from the submandibular space below. The two spaces communicate around the free posterior border of the muscle. The submandibular gland wraps around this posterior border, and its duct runs forward above the muscle.

Mylohyoid raises the floor of the mouth and the tongue at the start of swallowing, pushing the bolus back toward the pharynx. It also elevates the hyoid or depresses the mandible.

Anatomy

Origin

Mylohyoid line of the mandible.

Insertion

Median raphe and the body of the hyoid bone.

Action

Raises the floor of the mouth, the tongue and the hyoid; depresses the mandible.

Innervation

Nerve to mylohyoid (branch of the inferior alveolar nerve, CN V3).

Nerve roots

CN V3; no spinal roots

Arterial supply

Submental artery (facial artery) and the mylohyoid branch of the inferior alveolar artery.

Relations

Above it: sublingual gland, submandibular duct, lingual and hypoglossal nerves. Below it: anterior belly of digastric, superficial part of the submandibular gland.

Function

  • Elevates the floor of the mouth and the tongue (swallowing)
  • Elevates the hyoid or depresses the mandible

Clinical significance

Ludwig angina

A rapidly spreading cellulitis of the submandibular and sublingual spaces, usually from infected lower molar roots, which lie below the mylohyoid line. It raises the floor of the mouth and the tongue and can obstruct the airway.

Compiled from standard anatomy and physiology references — see the Muscular System sources. For education only; not medical advice.