What is the landmark for the injection for the inferior alveolar nerve block?

• A. Coronoid notch
• B. Mental foramen
• C. Pterygomandibular raphe
• D. Buccal vestibule

Answer: (A)

The main idea is that a reliable external reference marks the path to the mandibular foramen where the inferior alveolar nerve enters. The coronoid notch—the deepest hollow on the anterior border of the mandible’s ramus—provides that anchor. Feeling this notch tells you where the ramus begins to curve away from the body, so you can estimate the site where the mandibular foramen lies medially. From there, the needle is directed posteriorly and medially into the pterygomandibular space, about 6–10 mm above the occlusal plane of the molars, toward the foramen.

Other options don’t serve as the primary landmark for this block. The mental foramen is farther forward on the mandible and would risk targeting the wrong nerve. The buccal vestibule is relevant for buccal infiltration or for guiding soft-tissue landmarks, not for locating the mandibular foramen. The pterygomandibular raphe helps with orientation but is a soft-tissue reference rather than the primary bony cue. So the coronoid notch is the key landmark for the injection.