Muscles Affected by Bell’s Palsy
- Frontalis - raise eyebrows, wrinkle forehead
- Orbicularis oculi - closes the eyelids and assists in pumping the tears from the eye into the nasolacrimal duct system
- Orbicularis oris - closes, protrudes and compresses the lips
- Buccinator - compresses the cheeks against the teeth and is used in acts such as blowing
- Platysma muscles - depresses the mandible and lower lip and tenses the skin of the anterior neck
Mechanism of Muscle Weakness
Bell palsy is a disorder of the nerve that controls movement of the muscles in the face. This nerve is called the facial or seventh cranial nerve. Damage to this nerve causes weakness or paralysis of these muscles. Paralysis means that you cannot use the muscles at all. It directs the muscles on one side of the face, including those that control eye blinking and closing and facial expressions such as smiling.
Other Symptoms
Other symptoms may include drooping of the mouth, drooling, inability to close eye (causing dryness of the eye), and excessive tearing in one eye. Individuals may also have facial pain or abnormal sensation, altered/loss of taste, and intolerance to loud noise.