Muscular Anatomy of the Face
There are quite a few anatomy resources on the web, but not a lot that combine clear illustrations with pictures of the muscles in action.
With the help of a patient model and a fine illustrator, I hope this resource helps clarify how the face can make so many expressions.
You will also find a link to my Craniometric Landmarks web app which is a part of my online forensic sculpture class.
The Buccinator is a deep muscle that origintes on the maxilla and on the mandible in the regions of the roots of the molars beneath the masseter. It inserts into the Orbicularis oris at its lateral margins. It enables us to draw the corners of our mouths back, which can casue some dimpling at the corners of the mouth, stretching the Orbicularis oris laterally. Trumpeters tense this muscle as they play, which spreads their Orbicularis oris more uniformly over their teeth.
The Corrugator, a.k.a. Corrugator supercilii, originates along the medial edge of the supraorbital ridge by the nose, into the tissue of the eyebrow. It enables us to furrow our brow in grief or anger. The young man in the images is using his corrugator and his procerus.
Depressor anguli oris
The Depressor anguli oris is used when we experience disgust. It pulls the corners of the mouth downward and outwards. The model is demonstrating a rather extreme contraction of this muscle.
Depressor labii inferioris
This muscle, like the Depressor anguli oris, brings the lower lips down and outwards. It stretches the lowerlip. It's used in sad expressions. When acting in some individuals, it makes distinct cord-like inflections in the surface form that extend from the lateral portion of the lower lip to the lower extent of the muscle.
The frontalis is a pair of sheet-like muscles on the forehead. They help raise the eyebrows and wrinkle the forehead. These muscles are one of the ones frequently injected with botox, creating a frozen expression in the brow.
Levator labii superioris
This muscle originates on the lower margin of the orbit to the upper margin of the Orbiularis oris. It is a wide flat muscle and its medial extent can pull the outer edge of the nostril up when contracting. We use this muscle when we sneer.
Levator labii superioris alaeque nasi
This muscle has the longest name of any muscle on the body. I read somewhere that it is nicknamed Otto's Muscle because there was an anatomist by that name who argued that the muscle's name was too long.
In any case, this muscle is closely strung to the Levaor labii superioris. It is parallel and closer to the nose. It also draws the lip and wing of the nose upwards.
The Masseter is a large rope-like muscle that attaches along the lower margin of the zygomatic arch and also the ramus and lower margin of the mandible. When we chew and clench our jaws we use this muscle as well as the Temporalis.