The lingual nerve carries sensory innervation from the anterior two-thirds of the tongue. It contains fibres from both the

mandibular division In neuroanatomy, the mandibular nerve (V) is the largest of the three divisions of the trigeminal nerve, the fifth cranial nerve (CN V). Unlike the other divisions of the trigeminal nerve (ophthalmic nerve, maxillary nerve) which contain only aff ...

of the

trigeminal nerve In neuroanatomy, the trigeminal nerve ( lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for sensation in the face and motor functions such as biting and chewin ...

(CN V₃) and from the

facial nerve The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of tas ...

(CN VII). The fibres from the trigeminal nerve are for touch, pain and temperature (general sensation), and the ones from the facial nerve are for taste (special sensation).

Structure

The lingual nerve lies at first beneath the

lateral pterygoid muscle The lateral pterygoid muscle (or external pterygoid muscle) is a muscle of mastication. It has two heads. It lies superior to the medial pterygoid muscle. It is supplied by pterygoid branches of the maxillary artery, and the lateral pterygoid ner ...

, medial to and in front of the

inferior alveolar nerve The inferior alveolar nerve (IAN) (also the inferior dental nerve) is a branch of the mandibular nerve, which is itself the third branch of the trigeminal nerve. The inferior alveolar nerves supply sensation to the lower teeth. Structure The in ...

, and is occasionally joined to this nerve by a branch which may cross the

internal maxillary artery The maxillary artery supplies deep structures of the face. It branches from the external carotid artery just deep to the neck of the mandible. Structure The maxillary artery, the larger of the two terminal branches of the external carotid artery, ...

. The

chorda tympani The chorda tympani is a branch of the facial nerve that originates from the taste buds in the front of the tongue, runs through the middle ear, and carries taste messages to the brain. It joins the facial nerve (cranial nerve VII) inside the facia ...

(a branch of the facial nerve, CN VII) joins it at an acute angle here, carrying taste fibers from the anterior two-thirds of the tongue and parasympathetic fibers to the

submandibular ganglion The submandibular ganglion (or submaxillary ganglion in older texts) is part of the human autonomic nervous system. It is one of four parasympathetic ganglia of the head and neck. (The others are the otic ganglion, pterygopalatine ganglion, and cil ...

. The nerve then passes between the

medial pterygoid muscle The medial pterygoid muscle (or internal pterygoid muscle), is a thick, quadrilateral muscle of the face. It is supplied by the mandibular branch of the trigeminal nerve (V). It is important in mastication (chewing). Structure The medial ptery ...

and the ramus of the

mandible In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...

, and crosses obliquely to the side of the tongue beneath the

constrictor pharyngis superior The superior pharyngeal constrictor muscle is a muscle in the pharynx. It is the highest located muscle of the three pharyngeal constrictors. The muscle is a quadrilateral muscle, thinner and paler than the inferior pharyngeal constrictor muscle a ...

and

styloglossus The styloglossus, the shortest and smallest of the three styloid muscles, arises from the anterior and lateral surfaces of the styloid process near its apex, and from the stylomandibular ligament. Passing inferiorly and anteriorly between the int ...

, and then between the

hyoglossus The hyoglossus, thin and quadrilateral, arises from the side of the body and from the whole length of the greater cornu of the hyoid bone, and passes almost vertically upward to enter the side of the tongue, between the styloglossus and the infe ...

and deep part of the

submandibular gland The paired submandibular glands (historically known as submaxillary glands) are major salivary glands located beneath the floor of the mouth. They each weigh about 15 grams and contribute some 60–67% of unstimulated saliva secretion; on stimula ...

; it finally runs from laterally to medially inferiorly crossing the duct of the submandibular gland, and along the tongue to its tip becoming the sublingual nerve, lying immediately beneath the

mucous membrane A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...

. A well known rhyme has been used by anatomy students for many years to remember some features of the lingual nerve anatomy mentioned above: "The Lingual Nerve, Describes a Curve, Across the Hyoglossus...

Function

The lingual nerve supplies

general somatic afferent The general somatic afferent fibers (GSA, or somatic sensory fibers) afferent fibers arise from neurons in sensory ganglia and are found in all the spinal nerves, except occasionally the first cervical, and conduct impulses of pain, touch and temp ...

innervation from the

of the anterior two-thirds (body) of the tongue, while the posterior one-third (root) is innervated by the glossopharyngeal. It also carries nerve fibers that are not part of the trigeminal nerve, including the

chorda tympani nerve The chorda tympani is a branch of the facial nerve that originates from the taste buds in the front of the tongue, runs through the middle ear, and carries taste messages to the brain. It joins the facial nerve (cranial nerve VII) inside the facia ...

of the

, which provides special sensation (taste) to the anterior 2/3 part of the tongue as well as

parasympathetic The parasympathetic nervous system (PSNS) is one of the three divisions of the autonomic nervous system, the others being the sympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part of t ...

and sympathetic fibers. The

is suspended by two nerve filaments from the lingual nerve.

Clinical significance

Lingual nerve injuries

The most common cause of lingual nerve injuries is third molar (

wisdom tooth A third molar, commonly called wisdom tooth, is one of the three molars per quadrant of the human dentition. It is the most posterior of the three. The age at which wisdom teeth come through ( erupt) is variable, but this generally occurs betwe ...

) surgery, less commonly the lingual nerve can be injured by local anaesthetic dental injections (particularly inferior dental block injections) and sublingual or submandibular surgery. Any injury to sensory nerves can result in pain, altered sensation and/or numbness, but usually a combination of all three symptoms arises. This can have a significant negative effect on the patient's quality of life affecting their daily function and psychological health. Patients should be routinely warned about lingual nerve injuries prior to wisdom tooth and floor of mouth surgery. The risk associated with wisdom tooth surgery is commonly accepted to be 2% temporary and 0.2% permanent. Warning patients of nerve injury prior to administration of deep dental injections has a risk of injury in approximately 1:14,000 with 25% of these remaining persistent. Preoperative warning about these injuries is routinely undertaken in the US and Germany. This reflects good practice recommended by the Royal College of Anaesthetists (prior warning of potential nerve injury in relation to spinal and epidural blocks 1 on 24–57,000 risk). Infiltration dentistry is a technique that may reduce the possibility of lingual nerve injuries by avoiding deep injections. Avoiding lingual access when undertaking wisdom tooth surgery will also avoid unnecessary lingual nerve injuryEur J Dent Educ. 1999 May;3(2):52-5.The effect of surgical technique on lingual nerve damage during lower 3rd molar removal by dental students.Robinson PP, Loescher AR, Smith KG.

Additional images

File:Gray178.png, Mandible of human embryo 24 mm. long. Outer aspect. File:Gray781.png, Mandibular division of the trifacial nerve. File:Gray782 updated.png, Mandibular division of trifacial nerve, seen from the middle line. File:Gray788.png, Plan of the facial and intermediate nerves and their communication with other nerves. File:Gray794.png, Hypoglossal nerve, cervical plexus, and their branches. File:Gray842.png, Sympathetic connections of the submaxillary and superior cervical ganglia. File:Slide1vv.JPG, Lingual nerve File:Slide11dddd.JPG, Lingual nerve File:Slide2cec.JPG, Mandibular nerve and bone. Deep dissection. Anterior view. File:Slide7cece.JPG, Infratemporal fossa. Lingual and inferior alveolar nerve. Deep dissection. Anterolateral view

References

External links

* * * () * () * {{Authority control Mandibular nerve Gustatory system Innervation of the tongue