1. Platysma
Origin: Fascia over deltoid and superior portions of pectoralis major muscle
Insertion: Mandible, skin of buccal region, and skin of lower face
Action: Draws outer part of lower lip inferiorly and posteriorly as in pouting; depresses mandible
2. Mentalis
Origin: Incisive fossa of mandible
Insertion: Skin of chin
Action: Protrusion of lower lip
3. Orbicularis oris
Origin: Muscles surrounding the mouth
Insertion: Skin and mucous membrane of lips
Action: Closes and compresses the lips
4. Corrugator supercilii
Origin: Medial end of superciliary arch
Insertion: Skin of eyebrow
Action: Draws eyebrow together inferiorly, producing wrinkles
5. Orbicularis oculi
Origin: Front surface of orbital margin
Insertion: Circular around orbit
Action: Closes the eyelids
6. Occipitofrontalis (frontal belly)
Origin: skin of eyebrow, muscles of forehead
Insertion: Superior to supraorbital
Action: Elevates eyebrows, wrinkles of forehead
References:
Tortora, G., & Derrickson, B. (2017). Principles of Anatomy & Physiology (15th ed.). John Wiley & Sons, Inc.
Sendic, G. (2023). Facial muscles. https://www.kenhub.com/en/library/anatomy/the-facial-muscles