Musculus levator labii superioris
The levator nasolabialis is a broad, flat muscle that elevates both the upper lip and the nostril. It originates from the frontal and nasal bones between the orbits and inserts on the upper lip and lateral wing of the nostril. Related fibers or the levator of the upper lip elevate the upper lip. Both are innervated by the dorsal buccal branch of the facial nerve (CN VII). They are used during the flehmen response and for lip movement while eating.
Origin: Lacrimal and zygomatic bones, inferior to the orbit
Insertion: Upper lip and nostril cartilage
Action: Elevates the upper lip
Innervation: Dorsal buccal branch of facial nerve (CN VII)
Dysfunction can occur with facial nerve injury. Rarely a primary problem otherwise.
## Overview Facial nerve paralysis is loss of function of the facial nerve (cranial nerve VII), which controls the muscles of facial expression. It produces lip droop, ear droop, inability to blink,
## Overview Lip lacerations are traumatic tears of the upper or lower lip from fence wire, kicks, or bit accidents. They impair the horse’s ability to grasp feed and can leave permanent asymmetry if
Inability to elevate the upper lip or perform flehmen after facial trauma should be checked.
## Overview Facial nerve paralysis is loss of function of the facial nerve (cranial nerve VII), which controls the muscles of facial expression. It produces lip droop, ear droop, inability to blink, and muzzle deviation toward the normal side. Trauma and post-anesthetic neuropathy are common causes. ## Causes Trauma to the nerve as it crosses the face, prolonged halter pressure, or central lesions. Inflammation or infection can also be involved. ## Diagnosis Clinical observation of asymmetric facial movement. Neurologic examination localizes the lesion. Further diagnostics if a central cause is suspected. ## Treatment Anti-inflammatories if acute, eye protection to prevent corneal ulcers, and time for nerve recovery. Physical therapy or acupuncture is sometimes used. ## Recovery and Prognosis Variable. Many traumatic cases improve over weeks to months. Complete recovery is not guaranteed. ## Prevention Careful halter fit and avoidance of facial trauma. Signs include: lip droop; ear droop; inability to blink; muzzle pulled to the normal side; food falling from the mouth; drooling
## Overview Lip lacerations are traumatic tears of the upper or lower lip from fence wire, kicks, or bit accidents. They impair the horse’s ability to grasp feed and can leave permanent asymmetry if not repaired carefully. The lip has a good blood supply and usually heals well. ## Causes Sharp trauma. ## Diagnosis Visual examination of the wound and assessment of function. ## Treatment Thorough cleaning and surgical repair with fine sutures when the laceration is full-thickness or involves the margin. Antibiotics and tetanus prophylaxis as indicated. Soft feed during healing. ## Recovery and Prognosis Good with proper repair. Minor scars are common but function usually returns. ## Prevention Safe fencing and careful bitting. Signs include: visible wound on the lip; difficulty grasping hay or grass; swelling and asymmetry of the muzzle
Dysfunction can occur with facial nerve injury. Rarely a primary problem otherwise.
Inability to elevate the upper lip or perform flehmen after facial trauma should be checked.
See the Levator of the Upper Lip on our interactive 3D horse model. Open 3D Model