The mylohyoid groove is a small but important feature in the anatomy of the human head and neck. Located in the floor of the mouth, it serves as a site for attachment for several muscles and ligaments that play a vital role in swallowing, speaking, and maintaining the structural integrity of the head and neck.
Structure
- The mylohyoid groove is a shallow, U-shaped depression that is located in the floor of the mouth, just below the tongue.
- It is formed by the mylohyoid muscle, which is a flat, triangular muscle that lies deep to the tongue and runs horizontally across the floor of the mouth.
- The mylohyoid muscle is divided into two parts: the anterior part, which forms the floor of the mouth, and the posterior part, which forms the roof of the mouth. The mylohyoid groove is located between these two parts of the muscle.
The mylohyoid groove is bordered by several important structures in the head and neck. Laterally, it is bordered by the mandible, or lower jaw bone, which is the only movable bone in the skull. Medially, it is bordered by the hyoid bone, a small, U-shaped bone that is located in the neck and serves as the attachment site for several muscles that control the movement of the tongue, larynx, and pharynx. Anteriorly, the mylohyoid groove is bordered by the genioglossus muscle, a thin, triangular muscle that is responsible for protracting and elevating the tongue. Posteriorly, it is bordered by the palatoglossus muscle, which is a small, triangular muscle that is responsible for elevating the posterior part of the tongue.
Location
The mylohyoid groove is located in the floor of the mouth, just below the tongue. It is situated in the midline of the oral cavity, between the two halves of the mandible. It is located just anterior to the hyoid bone and extends from the mental foramen (a small opening in the mandible) to the midline of the mandible.
Function
The mylohyoid groove serves as a site for attachment for several muscles and ligaments that play a vital role in swallowing, speaking, and maintaining the structural integrity of the head and neck. These muscles include:
- The mylohyoid muscle: As mentioned above, the mylohyoid muscle forms the floor of the mylohyoid groove and is responsible for elevating the hyoid bone and larynx during swallowing.
- The genioglossus muscle: The genioglossus muscle is a thin, triangular muscle that is responsible for protracting and elevating the tongue. It is attached to the mylohyoid groove by the genioglossal ligament, which helps to stabilize the tongue and prevent it from falling backwards during swallowing.
- The hyoglossus muscle: The hyoglossus muscle is a flat, quadrilateral muscle that is located in the floor of the mouth and is responsible for depressing the tongue. It is attached to the mylohyoid groove by the hyoglossal ligament, which helps to stabilize the tongue and prevent it from falling forwards during swallowing.
- The stylohyoid muscle: The stylohyoid muscle is a long, slender muscle that is located in the neck and is responsible for elevating the hyoid bone and larynx during swallowing. It is attached to the mylohyoid groove by the stylohyoid ligament, which helps to stabilize the hyoid bone and prevent it from falling backwards during swallowing.
In addition to these muscles, the mylohyoid groove also serves as a site for attachment for the lingual artery, which is a small blood vessel that supplies blood to the tongue and surrounding structures.
Clinical Significance
The mylohyoid groove and the muscles and ligaments that are attached to it play a vital role in swallowing, speaking, and maintaining the structural integrity of the head and neck. Dysfunction of these muscles and ligaments can lead to a variety of clinical problems, including difficulty swallowing (dysphagia), difficulty speaking (dysarthria), and a misalignment of the head and neck (cervical spine instability).
One common disorder that can affect the mylohyoid groove is mylohyoid groove syndrome, which is characterized by pain and tenderness in the floor of the mouth, difficulty swallowing, and a feeling of a foreign body in the throat. This condition is often caused by irritation or inflammation of the mylohyoid muscle or the ligaments that are attached to it. Treatment may include rest, ice, and over-the-counter pain medication, as well as physical therapy to stretch and strengthen the muscles and ligaments of the mylohyoid groove.
In rare cases, the mylohyoid groove may also be affected by cancer. Squamous cell carcinoma, which is a type of cancer that affects the lining of the oral cavity, can sometimes involve the mylohyoid groove. Treatment may include surgery to remove the cancerous tissue, radiation therapy, and chemotherapy.
