How much anesthetic should be administered for a posterior superior alveolar nerve block?

In administering a posterior superior alveolar (PSA) nerve block, the recommended volume of anesthetic typically falls within the range of 0.9 to 1.8 ml. This volume is sufficient to ensure adequate anesthesia of the maxillary molars, as well as the surrounding buccal mucosa and the maxillary sinus area.

The rationale for this volume is that the PSA nerve block targets a specific area where the nerves branch off to innervate the teeth. Utilizing 0.9 to 1.8 ml allows for effective diffusion of the anesthetic and proper coverage of the anesthetic field, which includes the three maxillary molars and the adjacent soft tissues.

Too little anesthetic may result in incomplete anesthesia, while exceeding the recommended volume risk complications, such as vascular puncture or increased potential for systemic toxicity. Therefore, the correct volume ensures efficacy while minimizing risks, making the chosen range the best practice for achieving successful local anesthesia in this region.