What is the Inferior Alveolar Nerve and what does it innervate?

The inferior alveolar nerve (IAN) is part of the cranial nerve number V – the trigeminal nerve (Cranial Nerve V, CNV). The trigeminal nerve is divided into three branches, the V1, V2, and V3. The IAN is one of the final branches in the posterior division of the V3 (mandibular) nerve.

The IAN innervates sensory information to various portions of the mandible.

(n.d.) Dr. Brzezinski. Cranial Nerves V, VII, IX, and X. Missouri School of Dentistry and Oral Health.

(n.d). Dr. Caputo. Local Anesthesia Review. Missouri School of Dentistry and Oral Health.

What does the IAN block anesthetize?

• Mandibular teeth to the midline
• Buccal soft tissues anterior to the mandibular first molar
• The body of the mandible, inferior portion
• Anterior 2/3rds of the tongue
• Lingual soft tissues/ periostium (must anesthetize lingual nerve)

What is the correct technique for anesthetizing the IAN?

The injection should be along the pterygomandibular raphe. The syringe cartridge should be aligned with the contra-lateral premolars. If the syringe is hitting bone before full insertion, the needle is placed too far anteriorly.