The block that anesthetizes the maxillary molars and buccal gingiva is which injection?

• A. Posterior superior alveolar injection
• B. Inferior alveolar nerve block
• C. Infraorbital nerve block
• D. Mental nerve block

Answer: (A)

The main idea is which maxillary nerve block matches the region you want numbed. For numbing the maxillary molars and the corresponding buccal gingiva, the posterior superior alveolar nerve block is used. The posterior superior alveolar nerve supplies the maxillary molars (usually all roots) and the buccal gingiva around those teeth. The injection is given high in the mucobuccal fold above the second molar, near the posterior superior alveolar foramina on the infratemporal surface of the maxilla, so the anesthetic is deposited close to the PSA nerve before it enters the bone. This block specifically targets the molar region; the anterior maxillary teeth and premolars are typically spared, which helps distinguish it from blocks like the infraorbital, which covers more of the anterior maxillary teeth and their buccal tissues. The inferior alveolar and mental nerve blocks, on the other hand, address the mandible, not the upper molars. A practical note: sometimes the mesiobuccal root of the first maxillary molar isn’t fully covered by the PSA block, and a supplemental infiltration may be needed.