Nerve innervation can be described as the distribution of nerves in the body and nerve impulses supply across the body. The nerve system is divided into various distinct divisions, which is according to the Trigeminal Nerve, the foramina they pass through, the terminal branches and the fields of cutaneous innervation. The lower teeth are in the mandibular division which is described to be the largest branch (Williams & Wilkins, 2005). The nervous spinosum supplies the meninges through foramen spinosum and it is the first branch of the mandibular division (Scheinfeld, 2016). The medial pterygoid muscle is supplied by the first motor nerve. The posterior and anterior trunk of the mandibular nerve consists of both sensory and motor. The posterior trunk consists of the lingual and the inferior alveolar nerves with the lingual nerve supplying the anterior two thirds of the tongue and the mandibular gingiva surface (Scheinfeld, 2016).
The clear distinction between the sensory and the motor nerves in the anterior trunk gives reason for why a loss in sensory is not matched by a loss in motor nerves.
In extraction of the tooth, administrating local anaesthetic is a normal procedure for most of the practitioners mainly due to the levels of pain involved. However, sometimes complications may arise, some less adverse than others. An inferior alveolar nerve block is aimed at the mandibular teeth to the midline, the floor of the mouth and anterior two thirds of the tongue (Scheinfield, 2016). After the administration of anaesthetic, some side effects may include numb tongue, mouth or tooth, drowsiness, dizziness, blurred vision, or twitching muscles. These however are temporary effects and should wear off with time.
Lippincott Williams & Wilkins. DeJoung’s The Neurologic Examination. Part 327, 2005.
Noah S Scheinfeld, JD, MD, FAAD. Inferior Alveolar Nerve Block. MedScape, 2016