Bell’s Palsy is a condition that results in sudden, unilateral facial muscle weakness or paralysis. It is typically due to inflammation of the facial nerve (cranial nerve VII), which controls the muscles of facial expression.
5 MUSCLES AFFECTED:
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Orbicularis Oculi: Closes the eyelids and assists in blinking and winking.
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Orbicularis Oris: Closes and protrudes the lips
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Buccinator: Compresses the cheeks against the teeth, aiding in chewing and blowing, and helps keep food between the teeth.
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Zygomaticus Major: Pulls the corners of the mouth upward and outward, contributing to smiling.
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Frontalis (part of the Occipitofrontalis muscle): Raises the eyebrows and wrinkles the forehead.
MECHANISM OF MUSCLE WEAKNESS:
The facial nerve (cranial nerve VII) innervates all the facial expression muscles. Bell's palsy is thought to be caused by inflammation of this nerve, often due to viral infections. The inflammation impairs the nerve’s ability to transmit signals to the muscles, leading to weakness or paralysis of the muscles on one side of the face.
OTHER SYMPTOMS OF FACIAL MUSCLE WEAKNESS:
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Excessive Tearing or Drooling
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Inability to Close the Eye Properly
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Hyperacusis
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Changes in Taste