Start practicing

Oral Surgery · single question

Accessory innervation to mandibular molars that can cause failed IANB is MOST commonly from:

  1. The mental nerve
  2. The mylohyoid nerve
  3. The buccal nerve (long buccal)
  4. The auriculotemporal nerve
Show answer and explanation

Correct answer: B. The mylohyoid nerve

  • A. The mental nerve supplies the lower lip and chin — not the molar pulp.
  • B. Correct. The mylohyoid nerve, a branch of the inferior alveolar nerve that exits BEFORE entering the mandibular foramen, can provide accessory sensory innervation to the mandibular first molar (especially the mesiolingual root). It runs in a groove on the medial aspect of the mandible and is not blocked by a standard IANB — this is a classic cause of failed anesthesia that requires supplemental infiltration.
  • C. The long buccal nerve innervates the buccal soft tissue of mandibular molars — it does not provide pulpal innervation.
  • D. The auriculotemporal nerve is sensory to the TMJ, parotid, and external ear — not a source of accessory molar innervation.

Practice Oral Surgery questions Oral Surgery study notes

More Oral Surgery practice questions