Mylohyoid Muscles

Description

Seen from a superior approach into the floor of the mouth, the paired mylohyoid muscles form a broad muscular sling spanning the inner surface of the mandible and meeting at the median raphe in the midline. Their fibers run inferomedially from the mylohyoid line of the mandibular body toward the hyoid bone, placing the right and left bellies medial to the mandibular rami and deep to the dentition. Laterally, the mandibular corpus and angle provide bony context, while the masseter lies on the lateral surface of the ramus, posterior and lateral to the mylohyoid plane. The open oral aperture and adjacent cervical skeleton anchor the suprahyoid region in correct cranio-cervical orientation. For teaching the floor of mouth, few landmarks matter more than the mylohyoid “diaphragm” because it separates the sublingual space (superior) from the submandibular space (inferior), a distinction that directly predicts the spread of odontogenic infection from mandibular molars. Periapical infection from teeth whose apices lie superior to the mylohyoid line tends to elevate the tongue into the sublingual space, while roots inferior to the line more often drain into the submandibular space and can progress to Ludwig angina. Midline fusion at the raphe also clarifies why bilateral swelling can track across the floor of mouth. A simple barrier. Not an absolute one. Use this asset in head and neck anatomy labs, dental education modules on fascial spaces, and operative illustrations for submandibular gland excision, transoral ranula management, or incision and drainage planning where the relationship of mylohyoid to mandible and hyoid must be unambiguous. It also supports radiology teaching when correlating CT or MRI of the suprahyoid neck with expected compartment boundaries. Anatomical accuracy verified by SciePro's Medical Advisory Board.