1. Muscle Involved: Platysma
Origin: platysma that blends with the fascia covering the deltoid and pectoralis major muscles
Insertion: lower border of the mandible
Action: depresses the mandible and pulls the lower lip down
2. Muscle Involved: Mentalis
Origin: Incisive fossa of mandible
Insertion: skin of chin (Mentolabial sulcus)
Action: elevates, everts, and protrudes the lower lip while wrinkling the skin of chin
3. Muscle Involved: Orbicularis oris
Origin: midline of the mandible and the maxilla
Insertion: tissues of the upper and lower lips
Action: pursing or puckering of the lips
4. Muscle Involved: Corrugator supercilii
Origin: medial end of superciliary arches, fibers of orbicularis oculi
Insertion: skin above middle of supraorbital margin
Action: raises left eyebrow, and wrinkles the forehead
5. Muscle Involved: Orbicularis oculi
Origin: medial orbital margin, the medial palpebral ligament, and the lacrimal bone
Insertion: skin around the margin of the orbit and tarsal plates of the eyelid
Action: gently closes the eyelids
6. Muscle Involved: Occipitofrontalis
Origin: supreme nuchal line of the occipital bone
Insertion: epicranial aponeurosis
Action: wrinkles the forehead, draws the scalp backwards