The form that the facial features take when showing emotion is dictated by the facial muscles. This post shows and discusses those muscles and their function to change the surface features of the face. Below are two diagrams of the muscles in front view and in profile view.
The following list of facial muscles describe the function of each muscle as it transforms the surface features when emotion is being portrayed:
- Depressor Labii Inferioris – draws the lower lip down, as in sadness.
- Depressor Anguli Oris – pulls the lower lip down and out, creating a convex curve, as in disgust or grief.
- Mentalis – pulls lower lip down and out, as in a pout.
- Masseter – lifts the lower part of the jaw and is evident when the jaw is closed in anger or when chewing.
- Temperalis – lifts the jawbone when chewing and grinding. It is also evident when angered, as it clenches up.
- Zygomaticus Minor – draws the ends of the upper lip down when showing grief.
- Zygomaticus Major – draws the mouth into a smile. The cheeks swell and the lower eyelids are pushed up. The edges of the mouth point toward the ears.
- Orbicularis Oris – moves the mouth in all types of emotion and chewing.
- Buccinator – pulls lips backward, as when pronouncing an “E” sound.
- Risorius – moves lips in an upward and outward manner, when grinning as in a false smile, or shouting in anger. It works with the Platysma muscle of the neck to form expressions of rage.
- Frontalis – originates at Frontal Protuberance. It raises the eyebrows in surprise.
- Currugator – draws in and swells the eyebrows to express grief. Creates vertical wrinkles between eyebrows and dimples above the eyebrows.
- Orbicularis Oculi – squeezes eye shut. The inner part of the muscle, the Levator Palpebrae, opens and closes the lid of the eye.
- Procerus – draws eyebrows down, creating a horizontal line between the eyebrows. It works in conjunction with the Corrugator in anger and disdain.
- Nasalis – draws the wings of the nose up, creating horizontal wrinkles on the nasal bone.
- Canonis (Levator Anguli Oris) – short deep muscle connects from the upper maxillary bone to the upper lip. It raises the lips at the corners and pulls them to the outside, revealing canine teeth, as in disdain.
- Levator Labii Superioris/Nasi – two muscles that lift the lips and cheek into expressions of disdain.
The following photos show the muscles at work as a variety of emotions are displayed:
Lastly, the following sets of diagrams show the vast majority of facial changes during emotion. Try to fit the face with the muscles that are creating it. Note that correctly drawing an emotion, such as joy, involves more of the face than just the mouth. Drawing only a smiling mouth does not portray happiness unless the cheeks and swells beneath the eyes also are drawn. This is because the Zygomaticus Major works on both the mouth and the cheeks as it contracts. Likewise, an emotion such as disdain is created by the use of several muscles working together (Canonis, Nasalis, and Levator Labii Superioris/Nasi), which means that vertical wrinkles on the nasal bone, canine revealing lips, and drawn up wings of the nose must all be drawn into the facial expression. Study the muscles and their function, and you will better be able to draw convincing facial expressions.