Over-insertion of which injection could potentially penetrate the pterygoid plexus?

The pterygoid plexus is a network of veins located in the infratemporal fossa, and its proximity to dental structures is a crucial consideration during local anesthesia injections, particularly in the upper jaw. The posterior superior alveolar nerve block (PSA) is the injection that carries the risk of penetrating the pterygoid plexus if over-inserted.

When performing a PSA block, the needle is typically placed at the posterior superior aspect of the maxilla in order to anesthetize the maxillary molars. If the needle is inserted too deeply or at an incorrect angle, it may enter the pterygoid plexus, leading to the potential for complications such as hematoma formation. This risk is heightened due to the plexus's location near the maxilla and its tendency to be fairly close from this injection site.

In contrast, while other blocks such as the infiltration block, inferior alveolar (IA) block, and maxillary block have their own anatomical considerations and potential complications, they are not typically associated with the pterygoid plexus in the same way that the PSA block is. Understanding these anatomical relationships and potential risks is essential for the safe administration of local anesthesia in dentistry.