Which nerve would need to be anaesthetised to numb the buccal gum of a lower 5?

• A. Long buccal nerve
• B. Inferior dental nerve
• C. Mental nerve
• D. Incisive nerve

Answer: (B)

The key idea is understanding which nerve supplies the buccal gingiva of the lower molar region. The buccal gingiva around a mandibular first molar is innervated mainly by the long buccal nerve, a branch of the mandibular division (V3) of the trigeminal nerve. Blocking this nerve directly numbness the sensation of the buccal gingiva and cheek over that tooth.

The inferior alveolar (inferior dental) nerve mainly carries sensation to the lower teeth themselves via its dental branches and, after giving off the mental nerve, supplies the lower lip and chin. It is not the primary nerve for the buccal gingiva of the molars. The mental nerve serves the lip/chin area, and the incisive nerve supplies the anterior teeth and their gingiva. So, to numb the buccal gum of the lower first molar, the long buccal nerve is the correct target.