The human face has a total of forty-four muscles.
These muscles, along with the blood vessels and nerves woven around the cartilage and bones of the face, and the smooth, taut skin stretched over them—all these tissues are interconnected and work in concert.
They can push, pull, and twist in various ways, creating a staggering variety of over five thousand facial expressions.
Research shows that humans have at least eighteen unique types of smiles, and each smile subtly uses a different combination of facial muscles.
For example, let's consider our most common smiles.
They are created by the zygomaticus and risorius muscles, which lift the corners of the mouth.
The depressor labii inferioris muscle contracts, causing the lower lip to curl.
The orbicularis oris muscle relaxes.
The orbital and palpebral parts of the orbicularis oculi muscle contract.
The contraction of the levator labii superioris alaeque nasi muscle causes the nostrils to flare.
