The trigeminal nerve helps a person’s face not only perceive pain and sensations of touch, heat, and cold, but also enables chewing.
Due to its large size and diverse functions, damage to the trigeminal nerve can cause a wide range of symptoms.
The trigeminal nerve is responsible for movement and sensation in the head and face. It is a large cranial nerve composed of three branches and transmits signals from the brain to parts of the face and back again.
Every person has two trigeminal nerves — one on each side of the face. Together, they form one pair among the twelve pairs of cranial nerves.
What Is the Function of the Trigeminal Nerve?
The motor fibers of the trigeminal nerve tell the muscles when and how to move. Its sensory fibers transmit sensations of pain, touch, and temperature from the skin to the brain.
The trigeminal nerve consists of three divisions: the ophthalmic, maxillary, and mandibular branches.
Each of these divisions performs different functions.
The ophthalmic branch provides sensory information from the facial and cranial region located between the eyelids of each eye. It also supplies sensation to parts of the nasal cavity.
The nerve fibers of this division play an important role in pupil dilation and provide sensation to the eyes.
The maxillary nerve provides sensory information from parts of the nasal cavity and sinuses, as well as the upper teeth.
It also supplies sensation to the middle portion of the face and skull — the area below the eyes and above the mouth.
The mandibular division is the largest of the three and contains both sensory and motor fibers.
It provides sensation to the inner cheeks, mouth, lower teeth, and tongue.
It also controls the muscles involved in chewing and plays an important role in swallowing.
Overall, the structure of the trigeminal nerve resembles the branches of a tree extending from the brain throughout the face.
Conditions and Disorders
Several conditions and situations can affect the function of the trigeminal nerve:
- head trauma or brain disorders;
- pressure from nearby blood vessels, tumors, or swelling;
- inflammation caused by certain infections, such as herpes zoster (the virus responsible for shingles);
- circulatory disorders, including microvascular disease;
- autoimmune diseases such as scleroderma and Sjögren’s syndrome;
- accidental injury to the brain or facial structures;
- dental surgery and procedures.
Specific disorders associated with trigeminal nerve dysfunction include:
- Trigeminal Neuralgia: This chronic disorder causes episodes of severe facial pain. It usually occurs when a blood vessel compresses the trigeminal nerve near the brainstem.
- Trigeminal Neuropathy: This is a general term describing damage to the trigeminal nerve. Symptoms commonly include numbness, pain, and abnormal sensations (paresthesia).
- Cluster Headache: This condition causes severe pain on one side of the head lasting from 15 minutes to three hours. Attacks may occur daily for weeks or months, often at the same time each day and up to eight times per day. Irritation or inflammation of part of the trigeminal nerve may contribute to cluster headaches.
- Lateral Medullary Syndrome (Wallenberg Syndrome): This condition develops following an event that affects blood supply to the brainstem, such as a stroke or blood clot. It may impair trigeminal nerve function and cause symptoms including difficulty swallowing, dizziness, and involuntary eye movements.
Treatment
Treatment of trigeminal nerve injuries depends on the underlying cause of the inflammation. The trigeminal nerve can often recover from minor damage over time. Pain-relieving medication is usually prescribed.
In rare cases, surgery may be required to reconnect severed nerves.
Some individuals may even require a nerve graft to replace a damaged nerve with a healthy one.
What Are the Symptoms of Trigeminal Nerve Damage?
The symptoms of trigeminal nerve injury vary significantly due to the nerve’s large size and diverse functions.
Damage to the trigeminal nerve may affect a small area (such as part of the gums) or a larger area (such as one side of the face). The symptoms depend on the location of the nerve injury.
Some symptoms of trigeminal nerve damage include:
- numbness or tingling in the face;
- facial pain;
- vision problems;
- spasms or weakness of the jaw muscles;
- difficulty chewing, speaking, or swallowing.
Consult a healthcare professional if you experience any of these symptoms.
Trigeminal Nerve Injury During Dental Procedures
Damage to the trigeminal nerve may occur as a result of dental treatment, including root canal therapy, dental implant placement, tooth extraction, local anesthetic injections, and other procedures.
It should be noted that trigeminal nerve injury during dental procedures is uncommon. Most procedure-related nerve injuries are temporary and resolve within three months.
After nerve injury during a dental procedure, many patients initially experience numbness in the affected area. However, some individuals may experience pain or discomfort that can occur spontaneously or be triggered by movement, eating, or touch.
If you have undergone dental treatment or surgery and notice any of the symptoms listed above after the effects of local anesthesia should have worn off, it is very important to seek advice from your dentist.
During dental procedures, both the maxillary and mandibular divisions of the trigeminal nerve may be affected.
For this reason, it is essential to choose your dental clinic and dentist carefully. Other risk factors associated with nerve injury include age and the complexity of the dental procedure.
How to Prevent Trigeminal Nerve Damage
The trigeminal nerve is part of the human nervous system. The following steps may help keep your nervous system, including the trigeminal nerve, healthy:
- eat nutritious foods, especially those rich in vitamin D and vitamin B12, as these vitamins support nerve health;
- manage chronic conditions that may damage nerves, such as diabetes and hypertension;
- quit smoking, as tobacco use reduces blood flow to the nerves;
- achieve and maintain a healthy body weight;
- reduce stress through meditation, walking, or other healthy coping strategies.
If you experience problems with your eyes or jaw, or if you notice unusual sensations in your face such as pain or numbness, this may be a sign of trigeminal nerve damage. Consult a healthcare professional to determine the cause of these symptoms.
This article does not replace a medical consultation. For complete and personalized information, please consult your dentist.