The levator labii superioris muscle is used when a person makes facial expressions. It is shaped like a broad, flat sheet that starts next to the nose and extends to the zygomatic bone, which is more commonly referred to as the cheekbone.
This muscle arises from the top portion of the upper jaw’s frontal process and passes in a downward direction, dividing into two lateral slips. One of the slips goes into the skin and cartilage of the nose. The other slip blends into the orbicularis oris (a muscle that encircles the mouth) and infraorbital head (located below the eye socket) after extending into the top of the lip.
In addition to making general facial expressions, the levator labii superioris muscle is primarily responsible for elevating the upper lip.