The smiling muscle
Zygomaticus major · musculus zygomaticus major
The muscle that pulls the corners of your mouth up and out into a smile.
What it does
The zygomaticus major runs from the cheekbone down to the corner of the mouth. It draws the corner of the mouth upwards and outwards, the main movement of a smile. In some people a split in it creates a cheek dimple.
Surprising fact
A genuine smile uses both this muscle and the muscle around the eyes; a polite smile often uses only this one, and people can usually tell the difference.
Why it matters
The difference between a real and a forced smile is a reminder of how finely the face communicates feelings, which is why facial paralysis affects people so deeply.
Nearby
Read more
Sources
Drafted with AI help; awaiting a human fact-check against these sources.
Open in the 3D atlas · Suggest a correction · Not medical advice.
3D models: Z-Anatomy & BodyParts3D (CC BY-SA 4.0 / 2.1 JP). Card text CC BY 4.0.