Affected Muscles and Their Actions:
-
Orbicularis oculi
Action: Closes the eyelids (blinking) -
Frontalis
Action: Elevates the eyebrows and wrinkles the forehead -
Zygomaticus major
Action: Draws the corner of the mouth upward and outward (smiling) -
Orbicularis oris
Action: Closes and protrudes lips (kissing), compress lips against teeth, shapes lips during speech -
Buccinator
Action: Laterally pulls corner of mouth, presses cheek against teeth
Mechanism of Muscle Weakness:
Bell's palsy is a neurological condition caused by inflammation of the facial nerve, specifically the seventh cranial nerve, which is primarily responsible for controlling facial muscles. This inflammation disrupts the nerve impulses that manage facial expressions and functions, leading to muscle weakness.
Other Symptoms of Bell's Palsy
-
Difficulty in speaking- Difficulty in producing sounds or pronouncing words could indicate muscle weakness in the mouth or cheek region.
-
Difficulty eating and drinking: The patient might experience difficulty chewing or swallowing because of weakened facial muscles.
-
Difficulty in smiling- The weakening of zygomaticus major muscle causes the difficulty in smiling.
-
Difficulty in closing one eye- Weakening of the orbicularis oculi
Facial pain- Facial pain or discomfort is sometimes the cause of inflammation of the facial nerve.