Levator labii superioris is a skeletal muscle located in the human head and neck region. It is one of the muscles of facial expression, which are responsible for controlling the movement of the skin and underlying tissues of the face. The name “levator labii superioris” literally means “lifter of the upper lip,” as this muscle plays a key role in raising the upper lip and forming facial expressions such as smiling and frowning.
Location
The levator labii superioris muscle is located in the upper part of the face, extending from the nose to the upper lip. It originates from the maxillary bone, which is a bone in the upper jaw, and inserts into the skin of the upper lip. The levator labii superioris is one of several muscles that make up the muscular system of the face, along with the orbicularis oris, zygomaticus major, and other facial muscles.
Structure (Anatomy)
The levator labii superioris muscle is a thin, elongated muscle that is composed of skeletal muscle fibers. It is located just beneath the skin of the upper lip and is surrounded by connective tissue, blood vessels, and nerves.
The muscle has two main heads, known as the transverse and oblique heads. The transverse head originates from the maxillary bone, while the oblique head originates from the zygomatic bone. The two heads converge and insert into the skin of the upper lip, forming a thin, flat tendon.
In addition to the transverse and oblique heads, the levator labii superioris muscle also has several smaller muscle fibers that attach to the upper lip and surrounding tissues. These fibers help to provide additional support and stability to the muscle, as well as allowing it to move more smoothly and effectively.
Function
As a muscle of facial expression, the primary function of the levator labii superioris is to control the movement of the upper lip and surrounding tissues. When the muscle contracts, it raises the upper lip and forms facial expressions such as smiling and frowning. This movement is essential for communication and expression, as it allows us to convey a wide range of emotions and feelings through our facial expressions.
In addition to its role in facial expression, the levator labii superioris muscle also plays a key role in speech and swallowing. When the muscle contracts, it helps to form the shape of the mouth and lips, which is necessary for producing certain sounds and speaking clearly. The muscle also helps to close the mouth and keep food from escaping during swallowing.
Clinical Significance
There are several conditions and disorders that can affect the levator labii superioris muscle and its function. These include:
Facial paralysis
Facial paralysis is a condition in which the muscles of the face are partially or completely paralyzed, resulting in difficulty moving the face and forming facial expressions. Facial paralysis can be caused by a variety of factors, including injury, stroke, and certain medical conditions. Treatment may involve medications, physical therapy, or surgery.
Bell’s palsy
Bell’s palsy is a type of facial paralysis that affects one side of the face. It is caused by damage to the facial nerve, which supplies the muscles of the face with nerve impulses. Symptoms include difficulty moving the face and forming facial expressions, as well as drooping of the face and difficulty speaking and swallowing. Treatment may involve medications, physical therapy, or surgery.
Facial spasm
Facial spasm is a condition in which the muscles of the face involuntarily contract and spasm, resulting in abnormal facial movements. This can be caused by a variety of factors, including nerve damage, muscle damage, or abnormal function of the facial nerve. Treatment may involve medications, physical therapy, or surgery.
Facial deformities
Certain conditions or injuries can result in deformities of the face, including the upper lip. For example, cleft lip and palate is a birth defect in which the upper lip and palate are not properly formed, resulting in an abnormal appearance of the mouth and upper lip. Treatment may involve surgery to correct the deformity.
In addition to these conditions, the levator labii superioris muscle may also be surgically altered or treated for cosmetic purposes. For example, some people may undergo surgery to lift or shape the upper lip, or to reduce the appearance of wrinkles or lines around the mouth.
