Mylohyoid Muscle

Description

Arising from the mylohyoid line on the medial surface of the mandible, the mylohyoid muscle forms a thin paired sling that spans the submandibular region and meets its fellow at the median raphe in the floor of the mouth. Posterior fibers insert on the body of the hyoid bone, while the anterior fibers angle inferomedially toward the symphysis, creating a diaphragm that sits inferior to the tongue and superior to the suprahyoid compartment. Laterally, the mandibular body and dental arcade frame the field, and the muscle of mastication masseter occupies the lateral ramus, with temporalis superiorly and the pterygoid muscles positioned deep and medial to the mandible. Cervical vertebrae appear posteriorly as a positional reference beneath the cranial base. Understanding the mylohyoid’s orientation matters whenever you map the floor of mouth. The mylohyoid divides the sublingual space (above) from the submandibular space (below), so odontogenic infection from mandibular molars can track differently depending on whether the tooth apex lies superior or inferior to the mylohyoid line, a distinction that can steer a clinician toward intraoral versus extraoral drainage. It also explains why the lingual nerve and submandibular duct course in the sublingual region while the submandibular gland wraps around the posterior border of the muscle. Clear boundaries. Fewer surprises. Use this plate in head and neck anatomy teaching, oral and maxillofacial surgery texts, dental curricula covering fascial spaces, and ENT references addressing floor-of-mouth infection pathways and submandibular gland approaches. Anatomical accuracy verified by SciePro's Medical Advisory Board.