MSA Nerve Block — NDEB AFK MCQ
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Correct answer: A — Middle superior alveolar (MSA) nerve block
The middle superior alveolar (MSA) nerve block anaesthetises the maxillary premolars, mesiobuccal root of the maxillary first molar, and their associated buccal periodontium and bone. The MSA nerve is present in only approximately 72% of the population; when absent, the PSA and ASA nerves provide overlapping coverage. The injection site is the mucobuccal fold above the maxillary second premolar.
Reference: Malamed – Handbook of Local Anesthesia, 7th ed., 2020