Muscle · Head

Zygomaticus major

Musculus zygomaticus major

The slender strap that runs from the cheekbone down to the corner of the mouth and pulls it up and outward — the muscle of smiling. It is the clearest muscle to watch when testing the facial nerve, because a smile is a movement everyone can produce on request and any asymmetry is immediately visible. Its loss is one of the most distressing consequences of facial nerve palsy.