The inferior alveolar nerve is a branch of the mandibular nerve, which is itself the third branch (V3) of the fifth cranial nerve, the trigeminal nerve (cranial nerve V). The inferior alveolar nerve enters the mandible (lower jaw) via the mandibular foramen, located on the medial surface of the mandible. The inferior alveolar nerve is located in the mandibular canal within the mandible, where it supplies the mandibular (lower) teeth with sensory branches. Anteriorly, the nerve exits the mandible via the mental foramen, where it terminates as the mental nerve (supplying sensory branches to the chin and lower lip).

The inferior alveolar nerve is a common target for anesthesia during dental procedures involving the mandibular teeth. Administration of anesthesia near the mandibular foramen causes blockage of the inferior alveolar nerve and the nearby lingual nerve (supplying the tongue). This is why the freezing of the lower jaw during dental procedures causes the patient to lose sensation in their teeth (inferior alveolar nerve block), their lower lip and chin (mental nerve block), and their tongue (lingual nerve block).