Facial Nerve Anatomy

The facial nerve (seventh cranial nerve) starts in the brain stem and travels through the base of the skull. The nerve exits the skull at an opening in the bone near the ear's base called the stylomastoid foramen. The facial nerve has five main branches, the anatomy of which can vary somewhat between individuals.

The role of the facial nerve is to transmit information to and from the facial structures. And the various branches of the facial nerve allow the facial nerve to provide sensation to different oral and facial structures. The seventh cranial nerve has four main components with unique functions, as the University of Iowa explains:

• Branchial Motor: These fibers make up the largest component of the nerve. It supports the muscles responsible for your facial expression.
• Visceral Motor: This component is responsible for the salivary glands and mucous membranes
• Special Sensory: This portion of the nerve provides taste sensation to the front two-thirds of the tongue.
• General Sensory: This part provides general senses from the external auditory canal and auricle.

Damage to the seventh cranial nerve can result in several conditions, depending on which nerve branch has been affected. Impairment of the nerve may temporarily paralyze certain muscles in the face, which can affect your speech or cause difficulty eating and drinking.

The most common condition affecting the function of the facial nerve is Bell's Palsy. According to The National Institute of Neurological Disorders and Stroke, there's good news: 85 percent of cases experience spontaneous recovery, and most individuals eventually recover normal facial function. Other medical conditions that may impair the facial nerve include Lyme disease, salivary gland tumors, stroke, and trauma, such as a skull fracture. Very rarely, nerve paralysis may result from dental treatment involving local anesthesia, according to a report in the Journal of Oral and Maxillofacial Radiology. If you're having a procedure with anesthesia and you have concerns, talk to your dentist about their process of protecting people from facial nerve damage.

So what is Bell's Palsy? Bell's Palsy is a condition where there's a sudden weakness in the facial muscles. When someone experiences Bell's Palsy, half of the face may appear to droop, and they may have trouble making facial expressions. This muscle weakness is associated with swelling or inflammation of the facial nerve, though the exact cause is unknown. In most cases, the paralysis is temporary and doesn't come back later in life.

What to do if you experience Bell's Palsy or other types of facial paralysis? Medical and dental professionals can work together to help you resolve concerns with the function of the seventh cranial nerve. A doctor will take tests to determine whether your muscle weakness is related to Bell's Palsy or another condition and recommend the appropriate treatment. They may suggest physical therapy or medications to help you recover and ensure no further damage is done to the nerve.

Can you go to your dentist for Bell's Palsy? Although your dentist can help you keep your oral health care on point if you're experiencing Bell's Palsy, it's best to check in with a doctor too.

Facial paralysis may make it difficult to brush and floss properly, especially on the face's affected side. Therefore, it's essential to pay special attention to your oral hygiene if you're experiencing facial nerve damage. Some issues with the seventh cranial nerve may also affect saliva production and lead to dry mouth. Talk to your dentist about a rinse or other treatment that might help you if you're experiencing dry mouth.

It's also important to let your dentist know if you're experiencing facial paralysis or if you have in the past. With professional attention and a regular oral care routine of brushing twice a day and flossing daily, you can help ensure your mouth stays healthy while receiving treatment to address the nerve problem.

Now you know the 411 on your facial nerve anatomy. As we discussed, the facial nerve does a lot to help us with our facial expressions and taste. It's important, and if it becomes damaged, facial paralysis can occur, like Bell's Palsy. If you're experiencing any facial paralysis, contact your doctor right away. Also, stay connected with your dentist to ensure you're caring for your teeth in the best way possible as you treat your paralysis. It'll keep your smile healthy as you heal.

Oral Care Center articles are reviewed by an oral health medical professional. This information is for educational purposes only. This content is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your dentist, physician or other qualified healthcare provider.