What causes a hematoma and where is it most common?

What causes a hematoma and where is it most common?

• A. Arterial or venous puncture after PSA or IANB; common in the pterygoid plexus following PSA injection
• B. Infection
• C. Allergic reaction
• D. Needle breakage

Answer: (A)

A hematoma after local anesthesia results from a blood vessel being punctured during the injection, allowing blood to leak into surrounding tissues. The most common scenario involves the pterygoid venous plexus in the infratemporal region, particularly during posterior superior alveolar (PSA) or inferior alveolar nerve block injections. The pterygoid plexus lies near the PSA injection path, so an inadvertent puncture can bleed into this space and produce a cheek/infra-temporal hematoma. Infections, allergic reactions, and needle breakage cause different problems: infection presents over time with warmth and redness; an allergic reaction causes systemic symptoms such as hives or airway involvement; needle breakage is a mechanical issue and does not by itself create a hematoma.

A hematoma after local anesthesia results from a blood vessel being punctured during the injection, allowing blood to leak into surrounding tissues. The most common scenario involves the pterygoid venous plexus in the infratemporal region, particularly during posterior superior alveolar (PSA) or inferior alveolar nerve block injections. The pterygoid plexus lies near the PSA injection path, so an inadvertent puncture can bleed into this space and produce a cheek/infra-temporal hematoma. Infections, allergic reactions, and needle breakage cause different problems: infection presents over time with warmth and redness; an allergic reaction causes systemic symptoms such as hives or airway involvement; needle breakage is a mechanical issue and does not by itself create a hematoma.