MUSCLES AFFECTED
Five muscles that Bell's palsy affect are the Frontalis muscle, Orbicularis oculi, Orbicularis oris, Buccinator, and Platysma.
The action of the Frontalis is this muscle lift the eyebrows, while the Orbicularis oculi close the eyelids tightly and gently and compress the lacrimal sac. The Orbicularis oris closes the mouth, compresses, and protrudes lips. On the other hand, the Buccinator maintains the tightness of the cheeks and presses them against the teeth during chewing. It also assists the tongue in keeping the bolus of food central in the oral cavity. The Platysma's action is that it depresses the mandible and angle of the mouth and tenses the skin of the lower face and anterior neck.
MECHANISM OF BELL'S PALSY
Bell's palsy is an idiopathic condition of facial muscle weakness or paralysis. Discomfort usually occurs on one side of the face or head. This condition results from damage to the facial nerve (the 7th cranial nerve). Its onset is rapid and unilateral.
OTHER SYMPTOMS
Other symptoms include weakness of one side of the face, sensitivity to sound, and changes or loss of taste. Smiles appear to be one-sided, and difficulty in closing the eyes may also happen. Pain around the jaw or behind the ear on the affected side may also occur. Lastly, there are changes in the number of tears and saliva that an individual with Bell's palsy produces.
References:
Bell’s Palsy. (2021, August 8). Johns Hopkins Medicine. Retrieved September 22, 2022, from https://www.hopkinsmedicine.org/health/conditions-and-diseases/bells-palsy#:%7E:text=Bell’s%20palsy%20is%20an%20unexplained,of%20the%20face%20or%20head.
Mayo Clinic. (2022, May 4). Bell’s palsy - Symptoms and causes. Retrieved September 22, 2022, from https://www.mayoclinic.org/diseases-conditions/bells-palsy/symptoms-causes/syc-20370028