There are 12 cranial nerves in the body, all originating in the brain. They come in pairs and connect different body areas and organs to the brain.
Cranial nerves can transmit two types of information:
- Sensory information includes details about smells, sights, tastes, touch, and sounds.
- Motor information refers to signals that affect the movement or activity of muscles and glands.
Nerves that send sensory information have sensory functions. Those that send motor information have motor functions. While some nerves have only sensory or motor functions, others can have both.
The trigeminal nerve is one of the cranial nerves that has both sensory and motor function. Cranial nerves are classified using Roman numerals based on their locations. The trigeminal nerve is also called cranial nerve V.
The trigeminal nerve is the largest of the 12 cranial nerves. Its main function is transmitting sensory information to the skin, sinuses, and mucous membranes in the face. The nerve communicates touch, pain, and temperature to the brain.
It also stimulates movement in the jaw muscles. The trigeminal nerve includes the nerves in our muscles involved in chewing.
The trigeminal nerve has three branches. It joins at the trigeminal ganglia and branches out to different parts of the face. Each branch division has a slightly different function.
The ophthalmic division conveys sensory information from the:
- upper parts of the sinuses
- upper eyelid and associated mucous membranes
- cornea of the eye
- bridge of the nose
Like the ophthalmic division, the maxillary division of your trigeminal nerve has a sensory component. It transmits sensory information from the:
- lower eyelid and associated mucous membranes
- middle part of the sinuses
- nasal cavity and middle part of the nose
- upper lip
- some of the teeth of the upper jaw and associated mucous membranes
- roof of the mouth
The mandibular division is the only part of the trigeminal nerve that has both sensory and motor functions.
It communicates sensory information from the:
- outer part of the ear
- lower part of the mouth and the associated mucous membranes
- front and middle parts of the tongue
- teeth of the lower jaw and the associated mucous membranes
- lower lip
It also stimulates movement of the muscles in the jaw and some of the muscles within the inner ear.
The image below shows the location of the 12 cranial nerves, including the trigeminal nerve.
Explore the interactive 3-D diagram below to learn more about the trigeminal nerve.
The trigeminal nerve plays a role in many sensations that are felt in different parts of the face. As a result, there are several ways to test the function of the trigeminal nerve.
Common methods include:
- Pin or cotton swab test. One or both sides of the face are touched with either a pin or cotton swab. The person will then be asked whether they felt anything, and if so, where they felt it. A doctor may also lightly touch the cornea of the eye with a cotton swab to test the ophthalmic division. If the person doesn’t blink, the ophthalmic division of their trigeminal nerve may be damaged.
- Clenching test. A doctor will ask someone to clench their teeth or try to open their jaw when resistance is applied. They’ll check muscle tone and movement for any signs of trigeminal nerve damage.
The trigeminal nerve can also be a source of intense pain for some people. This is part of a chronic condition called trigeminal neuralgia (TN). It happens when the trigeminal nerve is under pressure or irritated. TN is more common in women than men and in people over
Although sometimes the cause of TN is never found, several things can cause irritation of the trigeminal nerve, including:
- facial injuries or injuries of the mouth
- brain tumor
- compression from swollen blood vessels
- neurological conditions, such as multiple sclerosis
The pain associated with trigeminal neuralgia can be very painful. People often describe it as a shooting or jabbing pain that lasts anywhere from a few seconds to several hours.
Pain can also be achy or burning. It tends to occur more often over time. Many things can trigger the pain, including touching the face, shaving, eating, yawning, or talking. It can affect one or both sides of the face. TN can cause long-term difficulties with chewing and speaking.
TN is usually managed with medications commonly used for neuropathic pain conditions, including anticonvulsants, antidepressants, and muscle relaxers. But some people may eventually stop responding to medication, and the condition can improve and resolve over time.
Cluster headaches can also signal a problem with the trigeminal nerve. Cluster headaches are severe headaches on the side of the face. The cause is unknown.
Sometimes surgery is needed to remove what’s irritating the trigeminal nerve. In other cases, injecting a numbing agent into the nerve can help.
You can protect your nervous system by engaging in healthy lifestyle practices like exercising regularly, drinking water, and eating a balanced diet.
Maintaining a regular sleep schedule is also essential to preserve the full function of the nervous system.
Additionally, mindfulness and relaxation techniques, such as meditation or yoga, can help to relax muscles and ease stress on the nervous system.
Make an appointment with a doctor if you are feeling sharp, sudden facial pains or long-lasting burning. If you’re not experiencing any feeling in your face at all, you should also schedule a visit with a doctor.
Your doctor may refer you to a pain management specialist or a neurologist to conduct tests for the conditions associated with the trigeminal nerve.
The trigeminal nerve is one of the 12 cranial nerves. It can transmit both sensory and motor information to the brain. The trigeminal nerve branches out to different parts of the face to communicate sensory information like temperature, touch, and pain. It also stimulates movement in the jaw muscles.
If you are experiencing pain in your face, it might be due to pressure on the trigeminal nerve. This could be a symptom of trigeminal neuralgia or another condition associated with the trigeminal nerve. Make an appointment with your doctor if you are feeling jabbing or burning pains in your face.