Inferior Alveolar Nerve Block (IANB)


➡️ The inferior alveolar nerve along with its 2 terminal branches – the mental and incisive nerves innervates the mandibular teeth as well as the buccal soft tissue anterior to 1st molars. This also provides anesthesia to the lip and chin on the side of injection.

➡️ Buccal Nerve – Buccal mucosa and cheek from 3rd molars to 1st molar.

➡️ Structures/Landmarks:

  1. Coronoid Notch
  2. Internal Oblique Line
  3. Lingula
  4. Pterygomandibular raphe
  5. Retromolar triangle
  6. Retromolar fossa
  7. Mandibular fossa
  8. Posterior border of ramus
  9. Occlusal plane

➡️ A plane passing through the deepest portion of coronoid notch parallel to occlusal plane will pass just over the lingualar notch. This determines the height of injection.

➡️ The internal oblique line serves as the attachment for deep tendon of temporalis muscle is important as it determines the AP point of injection.

➡️ Also the distance from internal oblique line to lingula is 9-11 mm in most adults provides the clinician a reference of depth of needle penetration.

➡️ The finger is placed to the depth of coronoid notch to determine vertical height of injection.

➡️ The barrel of the syringe is positioned from opposite the premolar region parallel to occlusal plane with the needle at the predetermined height.

➡️ Posterior to Internal Oblique line and anterior to lingula – contact of the needle.


▪️Clinical Tip👇🏻

References: Internet; Handbook of LA, 6e by Stanley F Malamed; MONHEIMS LOCAL ANESTHESIA AND PAIN CONTROL IN DENTAL PRACTICE 7ED