MUSCLES AFFECTED AND ITS ACTION
Frontalis (scalp muscle) - draws scalp anteriorly, raise eyebrows and wrinkles forehead skin
Orbicularis oris (eyes) - closes and protrudes lips, lip compression against teeth, shapes lips during speech
Orbicularis oculi (eyes) - closes the eye, blinking
Buccinator (cheeks) - allows blowing, sucking, and whistling.
Platysma (neck) - depresses the mandible, depresses and wrinkles skin on the lower face and mouth.
In Bell’s palsy, the facial nerve or the cranial nerve VII is damaged which causes the facial muscles to be paralyzed on one lateral side of the face, hence, causing the entire side of the face to droop. Some other symptoms a patient could exhibit as a result of facial muscle weakness includes difficulty in speech, difficulty in making facial expressions, difficulty in closing an eye, and drooling.