The superior mental spine, also known as the mental spicule or spine of the mental protuberance, is a small bony protrusion located on the mandible (lower jaw) just below the lower lip. It is a small, elongated structure that projects outward from the surface of the mandible and serves as an attachment point for muscles and ligaments of the mouth.
Structure
The superior mental spine is a small, slender bony projection that is located on the mandible, specifically on the mental protuberance, which is the rounded, protruding part of the mandible located just below the lower lip. The superior mental spine is one of two mental spines present on the mandible, the other being the inferior mental spine. These two spines are located on either side of the mandible and are separated by a shallow, triangular depression known as the mental foramen.
It is formed by the fusion of two bones called the maxilla and the mandible. The maxilla is the bone that forms the upper jaw and the mandible is the bone that forms the lower jaw. The superior mental spine is located at the midline of the mandible and is composed of compact bone tissue, which is denser and stronger than other types of bone tissue.
Location
The superior mental spine is located on the mandible, specifically on the mental protuberance. It is situated just below the lower lip and is located at the midline of the mandible. The superior mental spine is easily visible and can be palpated (felt) with the fingers.
Function
The primary function of the superior mental spine is to provide an attachment point for muscles and ligaments of the mouth. These muscles and ligaments are responsible for various functions of the mouth, including smiling, frowning, and controlling the movement of the lower lip.
The superior mental spine also serves as a point of attachment for the mentalis muscle, which is a thin, flat muscle that originates from the superior mental spine and inserts into the skin of the lower lip. The mentalis muscle is responsible for lifting and wrinkling the skin of the lower lip, which is important for facial expressions such as smiling and frowning.
