Orbicularis oris:

• Originates on the skin and other muscles around the mouth and inserts into the skin of the lips; it closes the lips.

Zygomaticus major:

• Originates on the lateral side of the zygomatic bone and inserts into the angle of the mouth; it draws the corner (aka, angle) of the lips laterally and superiorly.

Zygomaticus minor:

• Originates on the anterior aspect of the zygomatic bone and inserts into the skin of the upper lip, which it elevates.

Levator labii superioris:

• Originates on the maxilla (specifically, from the infraorbital margin), and inserts into the skin of the upper lip, which it elevates; it also dilates (flares) the nostrils.

Buccinator:

• Originates on the surfaces of the maxilla and mandible, and inserts into the lips; it compresses the cheeks.

Risorius:

• Originates on connective tissues on the lateral sides of the face and the skin of the cheeks and inserts into the angle of the mouth; it retracts the lips at the angle of the mouth.

Mentalis:

• Originates on the body of the mandible and inserts into the skin of the chin and lower lip, which it elevates and protrudes.

Depressor labii inferioris:

• Originates on the mandible (specifically, from the anterolateral body) and inserts into the skin of the lower lip, which it depresses.

Additional Information:

• These muscles blend into one another
• Cranial nerve VII innervates them.