What is the trigeminal nerve?
The trigeminal nerve is the part of the nervous system responsible for sending pain, touch and temperature sensations from your face to your brain. It's a large, three-part nerve in your head that provides sensation. One section called the mandibular nerve involves motor function to help you chew and swallow.
What is the purpose of the trigeminal nerve?
The trigeminal nerve primarily helps you feel (sensory), although the mandibular nerve branch has both sensory and motor functions. The trigeminal nerve helps with:
- Biting, chewing and swallowing.
- Facial and scalp sensations.
Where is the trigeminal nerve?
The trigeminal nerve, also called the cranial nerve V (that's the Roman numeral five), is the fifth of 12 cranial nerves.
You have two trigeminal nerves, one on each side of your body. They start in your brain and travel throughout your head.
What is the anatomy of the trigeminal nerve?
Like a tree extending from your brain throughout your face, the trigeminal nerves have roots and branches:
- The trigeminal nerves begin within four nuclei — or collections of nerve cell bodies — in your brain. Three of these nuclei control the functioning of your senses. The fourth controls motor function (or your movement).
- These three sensory nuclei merge to become one sensory root near the pons, which is the largest, central part of your brainstem.
- This sensory root becomes the trigeminal ganglion as it leaves the brainstem on each side. (A ganglion is a collection of nerves outside the nervous system.) Each trigeminal ganglion is located near your temple at the side of your head, in front of your ear.
- The trigeminal ganglion splits into three trigeminal nerve branches. These branches travel along each side of your head to different parts of your face.
What are the trigeminal nerve branches?
The trigeminal nerve has three branches that perform distinct functions:
- Ophthalmic: This branch sends nerve impulses from the upper part of your face and scalp to your brain. Ophthalmic refers to the eye. The ophthalmic nerve relates to your eyes, upper eyelids and forehead.
- Maxillary: This nerve branch is responsible for sensations in the middle part of your face. Maxillary refers to the upper jaw. The maxillary nerves extend to your cheeks, nose, lower eyelids and upper lip and gums.
- Mandibular: The mandibular (lower jaw) branch aids sensation to the lower part of your face, such as the jaws, lower lip and gum. These nerves also have a motor function. They help you bite, chew and swallow.
Conditions and Disorders
What conditions and disorders affect the trigeminal nerves?
Trauma and injuries can affect the trigeminal nerves. Accidents, tumors and damage from dental procedures or facial surgery can bruise or cut the nerves.
A trigeminal nerve injury may affect a small area, like part of your gum, or a large area, like one side of your face. The injury can cause problems with chewing and speaking. The extent depends on where the nerve damage occurs.
You may have ongoing numbness or facial pain in the area that the nerve serves. These symptoms are trigeminal neuropathy.
An injured trigeminal nerve often recovers its function in time. Rarely, surgery is needed to reconnect severed nerves. Some people need a nerve graft to replace the damaged nerve with a healthy one.
What is trigeminal neuralgia?
Trigeminal neuralgia is a type of trigeminal neuropathy brought on by nerve damage. The condition causes sudden, intense facial pain on one side of your face. The pain can feel like an electrical shock. Approximately 150,000 people develop trigeminal neuralgia every year. It's also called tic douloureux.
What causes trigeminal neuralgia?
Causes of trigeminal neuralgia include:
- Primary trigeminal neuralgia occurs when an artery or vein wraps around the trigeminal nerve and causes irritation.
- Secondary trigeminal neuralgia occurs when a tumor, cyst or facial injury puts pressure on the trigeminal nerve. Multiple sclerosis also causes a form of secondary trigeminal neuralgia.
What are the signs of trigeminal neuralgia?
Trigeminal neuralgia tends to affect only one side of your face. Some people develop facial twitches (tics) after the pain subsides.
Healthcare providers classify the pain symptoms into types:
- Type 1 (TN1) causes sharp, shock-like facial pain that comes and goes. Your face may throb. The pain may last for a few seconds or as long as a couple of minutes. These stabbing pains can occur repeatedly throughout the day and night. Over time, the pain may intensify and last longer. Often, the brief pains are triggered by actions such as chewing, talking or touching the face.
- Type 2 (TN2) causes a constant (chronic) burning or aching feeling. You may also have stabbing pain, but it’s less intense than type 1.
How are trigeminal nerve problems diagnosed?
Trigeminal nerve problems can be challenging to diagnose because there isn’t a specific test to assess the health of these nerves. In addition, other conditions like cluster headaches, temporomandibular disorders and sinus infections can cause facial pain and similar symptoms.
Your healthcare provider may rely on symptoms and a physical examination to make a diagnosis. You may also get an MRI, CT scan or X-rays. These tests can show if a cyst, tumor or artery is pressing against the trigeminal nerve.
How can I protect my trigeminal nerves?
These lifestyle changes can keep the nervous system healthy:
- Be physically active most days of the week.
- Eat a nutritious diet and drink plenty of water to prevent dehydration.
- Find healthy ways to manage stress, like meditation or gardening.
- Improve your sleep habits.
- Manage conditions like diabetes and high blood pressure that can affect nerve function.
- Get help for substance use disorders or to quit smoking.
When to Call the Doctor
You should call your healthcare provider if you experience:
- Facial twitches (tics).
- Intense facial pain.
- Loss of sensation in the face or scalp.
A note from Cleveland Clinic
The trigeminal nerves play essential roles in helping your face feel pain, touch, warmth or cold. The mandibular branches of the trigeminal nerves help you bite, chew and swallow. In some cases, people develop numbness or other signs of trigeminal neuropathy from an accident, dental procedure or facial surgery. Trigeminal neuralgia can cause stabbing, shock-like facial pain or a constant burning sensation. Talk to your provider about finding relief from these trigeminal nerve conditions.
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