Oral Surgery · single question
A biopsy is planned in the retromolar pad region. Which anesthetic technique is required?
Show answer and explanation
Correct answer: D. Inferior alveolar nerve block plus long buccal nerve block
- A. The MENTAL nerve supplies the lower lip, chin and labial mucosa ANTERIOR to the mental foramen. It has no supply to the retromolar region.
- B. Simple infiltration is unreliable in the mandible because of the dense cortical plate in the posterior region.
- C. The long buccal block alone would anesthetise the buccal soft tissue but leave underlying bone and periosteum unanesthetised if the biopsy extends deeper.
- D. CORRECT. The retromolar pad and the surrounding buccal soft tissue are innervated by the LONG BUCCAL nerve, a branch of the anterior division of V3. The INFERIOR ALVEOLAR block covers the teeth, bone and the lingual soft tissue via the lingual nerve, but it does NOT reliably anesthetise the buccal soft tissue in the molar region. Both injections are therefore required for soft tissue surgery in this area — and failure of the long buccal block is the classic reason a patient feels a retromolar biopsy despite a profoundly numb lip.
Note: Innervation map for mandibular soft tissue: BUCCAL molar region → long buccal nerve; BUCCAL anterior region → mental nerve; LINGUAL throughout → lingual nerve. Any mandibular soft tissue procedure needs the buccal or mental supply addressed separately from the inferior alveolar block.