The mylohyoid ridge, also known as the mylohyoid line, is a significant anatomical feature within the oral cavity. This distinct bony projection serves as a landmark on the internal surface of the lower jaw. Understanding this ridge provides insight into the complex architecture supporting various functions of the mouth and throat, highlighting the intricate relationships between bone and soft tissues.
What and Where It Is
The mylohyoid ridge is a prominent bony elevation found on the inner, or lingual, surface of the mandible. This ridge begins near the rear of the mouth, beneath the third molar tooth, and extends diagonally downwards and forwards across the internal surface of the jawbone. Its course forms a distinct line that divides the lingual surface of the mandible into two main areas.
This anatomical feature is a precisely located structure that organizes the lower jaw’s internal landscape. It acts as a clear demarcation point for several soft tissue attachments. Its consistent position and linear form make it a reliable reference point for dental and oral anatomy, allowing for broad attachment of structures.
Muscles and Functions
The mylohyoid ridge serves as an attachment site for several muscles, most notably the mylohyoid muscle. This muscle forms the primary component of the muscular floor of the mouth, creating a hammock-like structure that supports the tongue and other oral contents. When the mylohyoid muscle contracts, it elevates the floor of the mouth and the tongue, a coordinated action during the initial stages of swallowing.
The mylohyoid muscle also assists in depressing the mandible when the hyoid bone is fixed, contributing to jaw movement. Parts of the superior pharyngeal constrictor muscle and the pterygomandibular raphe also attach along the mylohyoid ridge. The superior pharyngeal constrictor muscle aids in constricting the pharynx, facilitating food propulsion towards the esophagus during swallowing. The pterygomandibular raphe is a fibrous band that provides an attachment point for muscles involved in chewing and swallowing, connecting the buccinator and superior pharyngeal constrictor muscles.
Neighboring Structures
Immediately above the mylohyoid ridge on the inner surface of the mandible is a shallow depression known as the sublingual fossa. This concavity houses the sublingual gland, one of the major salivary glands. The sublingual gland contributes to saliva production, secreting a mix of mucous and serous fluids that help lubricate food and initiate digestion.
Below the mylohyoid ridge, the submandibular fossa is found. This fossa houses the submandibular gland, another significant salivary gland. The submandibular gland produces the majority of saliva in the oral cavity, primarily secreting serous fluid rich in enzymes and mucous fluid for lubrication. These adjacent fossae and their glands are related to the mylohyoid ridge, highlighting its position within the oral cavity’s anatomy.