The Anatomy of the Lingual Nerve

Providing sensation to the tongue and helping with taste

In This Article

The lingual nerve branches off from the mandibular (jaw) division of the trigeminal nerve. It supplies feeling to the floor of your mouth and the front two-thirds of the tongue. Additionally, it carries specialized fibers that allow taste signals to be sent between the tongue and the brain. Injury to the lingual nerve is most often caused by oral surgery or dental procedures, which can cause considerable pain and other problems.

Anatomy

The nerves that run throughout your body branch out like trees so they can carry sensations (sensory information) to and from your brain and the rest of your body, and promote motion (motor function).

Structure

The nerves of the head are called cranial nerves. They all exist as symmetrical pairs, with one on each side of your head or face. Even so, they're usually referred to as a single nerve.

Unlike the rest of your nerves, which branch off of the spinal cord, the twelve cranial nerves originate in the brain itself. Ten of them, including the trigeminal nerve, emerge from the brainstem, which sits low at the back of your brain and connects your brain to your spinal cord.

The trigeminal nerve is the fifth cranial nerve. As it travels around the head toward the face, it splits off into three branches called the ophthalmic nerve, the maxillary nerve, and the mandibular nerve.

The lingual nerve is a branch of the mandibular nerve.

Location

The lingual nerve splits off from the mandibular nerve right around the base of your ear. It then runs down the inside of your jaw just in front of the ear and comes into contact with your lower jaw right at the third molar (typically called the "wisdom tooth"). From there, the lingual nerve splits into two branches that run to the tongue and floor of the mouth.

Muscles the lingual nerve interacts with include:

  • Tensor veli palatini
  • Lateral pterygoid
  • Medial pterygoid
  • Superior constrictor
  • Mylohyoid
  • Hyoglossus
  • Genioglossus

Anatomical Variations

Not all lingual nerves follow the exact same course. Studies, including one on human cadavers, have shown a fair amount of variation in the anatomy related to this nerve .

For example, the precise spot where the nerve begins its curve up from the floor of the mouth toward the tongue could be at the first or second molar. In all but one of the cadavers studied, the lingual nerve looped around a structure called the submandibular duct (which drains saliva from the mouth), but the loop was sometimes at the second molar and sometimes at the third.

Along the surface of the tongue, the lingual nerve splits into between two and four branches.

Measurements varied at other locations, as well. Researchers said increased knowledge of these anatomical variations could help avoid nerve injury during surgery and dental work.

Function

The trigeminal nerve provides sensation to the face and allows for chewing and biting motions. Each of its branches provides sensation to a different area of the head and face.

  • The ophthalmic nerve carries sensory information from the eye, skin of the upper face, and scalp to the central nervous system (CNS).
  • The maxillary nerve transmits sensation to the CNS from the upper jaw, the roof of your mouth, nostrils, sinuses, and middle of your face.
  • The mandibular nerve provides sensation and motion to the lower jaw and mouth, and it also provides sensory input from some areas of the scalp.

Of these three, the mandibular nerve is the only one that serves both sensory and motor functions. However, the lingual nerve itself is only sensory.

The lingual nerve provides sensation to the floor of your mouth and the forward two-thirds of the tongue.

The nerves that extend into your taste buds, called the chorda tympani, come from a different cranial nerve, called the facial nerve. However, they meet up with the lingual nerve as it descends to your lower jaw.

The lingual nerve then carries the chorda tympani's specialized taste fibers to the forward two-thirds of the tongue. So, while the lingual nerve isn't responsible for taste, it's involved in sending taste signals back and forth to your brain.

Also through its connection with the chorda tympani, the lingual nerve is involved with salivary function.

Damage and Injury

The lingual nerve can be damaged during surgery or dental procedures, or due to injury. Some of the common causes of injury include:

It should be noted that the risk of lingual nerve injury during most surgical and dental procedures is low. Your doctor or dentist should go over the risks with you before the procedure.

Lingual nerve damage can lead to numerous problems, such as:

  • Reduced secretion of saliva on the affected side
  • Loss of taste to the front two-thirds of the tongue
  • Slurred speech
  • Frequent biting of the tongue
  • Loss of sensation or change in sensation (i.e., pain or burning) to the floor of the mouth or front two-thirds of the tongue, which can be permanent or temporary

Mouth numbness due to impairment of the lingual nerve (or other nerves of the mouth) can also occur in multiple sclerosis. This symptom is usually not permanent, though, and will go away on its own.

Rehabilitation

When a lingual nerve injury occurs, treatment depends on multiple factors, including the nature and severity of the injury, how long ago it occurred, and the symptoms it causes.

Treatment can include anti-inflammatories such as steroids or ibuprofen, and possibly surgical repair. However, even with advancements in micro-neurosurgery, the lingual nerve is considered an especially difficult one to repair.

Was this page helpful?

Article Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Al-Amery SM, Nambiar P, Naidu M, Ngeow Wc. Variation in lingual nerve course: a human cadaveric study. PLoS One. 2016 Sep 23;11(9):e0162773. doi:10.1371/journal.pone.0162773.

Additional Reading