Anatomy, Head and Neck: Eye Levator Labii Superioris Muscle

Excerpt

The levator labii superioris (LLS) muscle, also known as the quadratus labii, contributes to facial expression and mouth and upper lip movement. This muscle courses lateral to the nose and primarily elevates the upper lip (see Image. Eye Levator Labii Superioris Muscle). The LLS also creates facial expressions of disgust, sadness, and disdain. This muscle is also involved in nasal flaring, retching (vomiting), and oral movements. The LLS originates from the lateral nasal aspect, extending laterally toward the zygomatic bone. The facial artery's angular branch and the maxillary artery's infraorbital branch supply the muscle. The zygomatic branch of the facial nerve (cranial nerve VII) innervates the LLS. (See Image. Levator Labii Superioris).