Muscle · Head and neck
Levator anguli oris: origin, insertion, action and innervation
The levator anguli oris runs from the canine fossa of the maxilla to the mouth corner. It lifts the corner; facial nerve, zygomatic and buccal branches.
Quick answer
- Latin name
- Musculus levator anguli oris
- Origin
- Canine fossa of the maxilla, just below the infraorbital foramen (skull)
- Insertion
- Modiolus at the angle of the mouth
- Action
- Elevates the angle of the mouth and deepens the nasolabial fold
- Innervation
- Facial nerve (CN VII), zygomatic and buccal branches
- Blood supply
- Superior labial artery (from the facial artery) and the infraorbital artery
See it on the 3D body
The levator anguli oris lit on the 3D head, as in the head quiz. Turn the body, peel the layers, tap any structure for its name.
The levator anguli oris is a deep muscle of the upper lip region that lifts the corner of the mouth. It runs from the canine fossa of the maxilla down to the angle of the mouth and is supplied by the zygomatic and buccal branches of the facial nerve (CN VII).
Where it is
The muscle lies in the cheek, between the side of the nose and the corner of the mouth. It is the deepest of the muscles that lift the upper lip and the mouth corner. The levator labii superioris and the zygomaticus minor cover its upper part, so it is hidden until those are lifted away.
A useful landmark: the infraorbital nerve and vessels, which come out of the infraorbital foramen below the eye, run down between the levator labii superioris in front and the levator anguli oris behind. The levator anguli oris arises just below that foramen.
Its fibers run almost straight down to the corner of the mouth. Older texts called it the caninus, after the canine fossa where it begins, which sits above the root of the canine tooth.
Origin and insertion
- Origin: the canine fossa of the maxilla, a shallow hollow on the front of the upper jaw just below the infraorbital foramen. The maxilla is one of the facial bones covered on the skull page.
- Insertion: the modiolus, the dense knot of muscle fibers at the angle of the mouth, where it blends with the orbicularis oris, the zygomaticus major and the depressor anguli oris.
Because it starts on bone and ends in a mobile point of soft tissue, it can lift the corner of the mouth without moving the lip as a whole.
What it does
The levator anguli oris elevates the angle of the mouth. It pulls the corner of the mouth straight up, while the zygomaticus major pulls it up and outward. In a smile, the two work together, and the levator anguli oris also helps to deepen the nasolabial fold, the crease that runs from the side of the nose to the corner of the mouth.
Its direct antagonist is the depressor anguli oris, which pulls the same corner down and out. Both end on the modiolus and pull it in opposite directions, up toward the canine fossa or down toward the jaw.
You can feel it work: put a fingertip on your cheek just above and slightly outside the corner of your mouth, then lift that corner as if starting a half smile. The muscle tightens under the skin, deep to the cheek fat.
Innervation and blood supply
The muscle is supplied by the zygomatic and buccal branches of the facial nerve. Both cross the face from the front edge of the parotid gland; the zygomatic branches run higher, toward the eye, and the buccal branches run lower, toward the upper lip.
Its blood comes from the superior labial artery, a branch of the facial artery inside the upper lip, and from the infraorbital artery, which comes out of the infraorbital foramen right above the muscle's origin.
How to remember it
- Levator anguli oris = lifter of the corner of the mouth. It is the mirror of the depressor anguli oris.
- Deepest of the lifters: it lies under the levator labii superioris, with the infraorbital nerve between them.
- Canine fossa, canine muscle: its old name, caninus, points to its origin above the canine tooth.
- Straight up versus up and out: levator anguli oris lifts vertically; zygomaticus major pulls diagonally.
Find it among the five upper lip lifters on the muscles of the face page, then test yourself in the head quiz.
Frequently asked questions
What does the levator anguli oris do?
It lifts the corner of the mouth and helps deepen the nasolabial fold, for example during a smile.
Which nerve supplies the levator anguli oris?
The zygomatic and buccal branches of the facial nerve (CN VII).
Where does the levator anguli oris originate?
In the canine fossa of the maxilla, just below the infraorbital foramen.
What is the antagonist of the levator anguli oris?
The depressor anguli oris, which pulls the corner of the mouth down and out.
