Whoever said that kissing wasn't complicated?

Starting at the top of the mouth and going down, the muscles that control the lips are:

• Orbicularis oris: this goes circumferentially around the mouth and closes and protudes the lips. All of the following muscles blend into this one.
• Levator labii superioris alaeque nasi: from the upper lip to the nose. This elevates the upper lip (e.g. a half-pucker or sneer) and flares the nostrils.
• Levator labii superioris: another muscle of the upper lip used to raise the lip. This stretches from the upper lip to below the eye. The sneering muscle.
• Zygomaticus minor: and another on the upper lip that's used to elevate the lip. Moves the mouth up and out, as in sadness (the trembing lip phenomenon.)
• Zygomaticus major: roughly across the cheek and used to draw the angle of the mouth up and back (as in smiling or laughing.)
• Levator anguli oris: this also pulls the mouth up and back, but not as much. More of a grin than a smile.
• Risorius: this follows the line of the mouth and pulls the mouth straight back, as with a grim expression.
• Depressor anguli oris: from the lower lip off of the chin. This muscle is used for frowning.
• Depressor labii inferioris: the lower lip down the side of the chin. Another frowning muscle.
• Levator menti: from the lower lip to the chin. This protrudes the lower lip in sort of a pout.

Note: As I am but a layman, I'm using vulgar (as in common) English rather than the standard and precise medical vocabulary.

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