1. Platysma
Origin: Fascia over the deltoid and pectoralis major muscles.
Insertion: Mandible (blends with muscles around the angle of the mouth and skin of the lower face)
Action: Draws the outer part of the lower lip inferiorly and posteriorly (like pouting) and depresses the mandible.
2. Mentalis
Origin: Mandible.
Insertion: Skin of the chin.
Action: Elevates and protrudes the lower lip and pulls the skin of the chin up (like pouting).
3. Orbicularis Oris
Origin: Muscle fibers surrounding the opening of the mouth.
Insertion: Skin at the corner of the mouth.
Action: Closes and protrudes the lips, functions for kissing, compresses lips against teeth, and shapes lips during speech.
4.) Corrugator supercilii
Origin: Medial end of the superciliary arch of the frontal bone.
Insertion: Insertion: Skin of the eyebrow.
Action: Draws eyebrows inferiorly and wrinkles skin of forehead vertically (like frowning).
5. Orbicularis oculi
Origin: Medial wall of the orbit.
Insertion: Circular path around the orbit.
Action: Closes the eyes.
15. Occipitofrontalis (Frontal Belly)
Origin: Epicranial aponeurosis.
Insertion: Skin superior to supraorbital margin.
Action: Draws scalp anteriorly, raises eyebrows, and wrinkles skin of forehead horizontally (like a look of surprise).