Inferior alveolar nerve
Encyclopedia
The inferior alveolar nerve (sometimes called the inferior dental nerve) is a branch of the mandibular nerve
, which is itself the third branch (V3) of the trigeminal nerve
(cranial nerve V).
, it first gives off the nerve to the mylohyoid
, a motor nerve supplying the mylohyoid
and the anterior belly of the digastric. It then enters the mandible via the mandibular foramen.
While in the mandibular canal
within the mandible, it supplies the mandibular (lower) teeth with sensory branches
that form into the inferior dental plexus and give off small gingival and dental nerves to the teeth.
Anteriorly, the nerve gives off the mental nerve
at about the level of the mandibular 2nd premolars, which exits the mandible via the mental foramen
(supplying sensory branches to the chin
and lower lip
).
The inferior alveolar nerve continues anteriorly as the mandibular incisive nerve
to innervate the mandibular canines
and incisors.
). This is why the numbing of the lower jaw during dental procedures causes patients to lose sensation in:
Mandibular nerve
The mandibular nerve is the largest of the three branches of the trigeminal nerve.-Roots:It is made up of two roots:* a large sensory root proceeding from the inferior angle of the trigeminal ganglion....
, which is itself the third branch (V3) of the trigeminal nerve
Trigeminal nerve
The trigeminal nerve contains both sensory and motor fibres. It is responsible for sensation in the face and certain motor functions such as biting, chewing, and swallowing. Sensory information from the face and body is processed by parallel pathways in the central nervous system...
(cranial nerve V).
Path
Before traversing the mandibular foramenMandibular foramen
The Mandibular foramen is an opening on the internal surface of the ramus for divisions of the mandibular vessels and nerve to pass.-Contents:...
, it first gives off the nerve to the mylohyoid
Mylohyoid nerve
The mylohyoid nerve is a nerve that innervates the mylohyoid muscle and the anterior belly of the digastric muscle.-Structure:...
, a motor nerve supplying the mylohyoid
Mylohyoid
Mylohyoid can refer to:* Mylohyoid muscle* Mylohyoid line* Mylohyoid nerve* Mylohyoid branch of inferior alveolar artery* Mylohyoid groove...
and the anterior belly of the digastric. It then enters the mandible via the mandibular foramen.
While in the mandibular canal
Mandibular canal
The mandibular canal is a canal within the mandible that contains the inferior alveolar nerve, inferior alveolar artery, and inferior alveolar vein...
within the mandible, it supplies the mandibular (lower) teeth with sensory branches
Sensory system
A sensory system is a part of the nervous system responsible for processing sensory information. A sensory system consists of sensory receptors, neural pathways, and parts of the brain involved in sensory perception. Commonly recognized sensory systems are those for vision, hearing, somatic...
that form into the inferior dental plexus and give off small gingival and dental nerves to the teeth.
Anteriorly, the nerve gives off the mental nerve
Mental nerve
Mental nerve is a general somatic afferent nerve which provides sensation to the anterior aspects of the chin and lower lip as well as the buccal gingivae of the mandibular anterior teeth and the premolars...
at about the level of the mandibular 2nd premolars, which exits the mandible via the mental foramen
Mental foramen
The mental foramen is one of two holes located on the anterior surface of the mandible. It permits passage of the mental nerve and vessels. The mental foramen descends slightly in edentulous individuals.- Variations :...
(supplying sensory branches to the chin
Chin
In the human anatomy, the chin is the lowermost part of the face.It is formed by the lower front of the mandible.People show a wide variety of chin structures. See Cleft chin....
and lower lip
Lip
Lips are a visible body part at the mouth of humans and many animals. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech...
).
The inferior alveolar nerve continues anteriorly as the mandibular incisive nerve
Mandibular incisive canal
The mandibular incisive canal is a bony canal within the anterior mandible that runs bilaterally from the mental foramina usually to the region of the ipsilateral lateral incisor teeth...
to innervate the mandibular canines
Canine tooth
In mammalian oral anatomy, the canine teeth, also called cuspids, dogteeth, fangs, or eye teeth, are relatively long, pointed teeth...
and incisors.
Anesthesia
Administration of anesthesia near the mandibular foramen causes blockage of the inferior alveolar nerve and the nearby lingual nerve (supplying the tongueTongue
The tongue is a muscular hydrostat on the floors of the mouths of most vertebrates which manipulates food for mastication. It is the primary organ of taste , as much of the upper surface of the tongue is covered in papillae and taste buds. It is sensitive and kept moist by saliva, and is richly...
). This is why the numbing of the lower jaw during dental procedures causes patients to lose sensation in:
- their teeth (inferior alveolar nerve block)
- their lower lipLower lipThe lower lip covers the anterior body of the mandible.It is lowered by the Depressor labii inferioris muscle....
and chin (mental nerveMental nerveMental nerve is a general somatic afferent nerve which provides sensation to the anterior aspects of the chin and lower lip as well as the buccal gingivae of the mandibular anterior teeth and the premolars...
block) - and The Anterior Two-Thirds Of the Tongue Of the same Side (lingual nerveLingual nerveThe lingual nerve is a branch of the mandibular nerve , itself a branch of the trigeminal nerve, which supplies sensory innervation to the tongue...
block).