How should the needle be oriented when giving a PSA nerve block?

• A. Upward, Inward, and Backward
• B. Upward, Inward, and Forward
• C. Upward, Outward, and Backward
• D. Downward, Inward, and Backward

Answer: (A)

The needle should be directed upward, inward, and backward to reach the posterior superior alveolar nerve as it enters the maxilla from the infratemporal space. Directing the needle upward helps position the tip above the maxillary tuberosity and toward the posterior maxilla, avoiding the floor of the orbit and aligning with the nerve’s path. The inward angle brings the tip toward the midline so it meets the nerve trunks as they course medially. The backward direction targets the posterior aspect of the maxilla where the PSA nerves enter, allowing the anesthetic to surround the nerve before it branches to the molars.

Using this orientation helps place anesthetic near the nerve before it branches, increasing the chance of effective anesthesia for the molar region while reducing the risk of injecting into unintended structures.