Oral Surgery · single question
What is the most common complication associated with a Posterior Superior Alveolar (PSA) nerve block?
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Correct answer: A. Hematoma
Hematoma (A) is the most common complication of the PSA (posterior superior alveolar) block. The PSA nerve block is performed in the pterygopalatine fossa area, near the pterygoid plexus of veins. Accidental puncture of this venous plexus causes a rapidly expanding hematoma in the infratemporal fossa → visible swelling and bruising developing in the pterygoid/temporal region within minutes to hours.
• Prevention: aspirate before injecting, avoid excessive needle penetration, use a 27-gauge short needle.
• Management: apply pressure extraorally (cheek), ice packs, reassure patient. Usually self-limiting.
• The PSA block carries the highest hematoma risk of any intraoral injection because of proximity to the pterygoid plexus.
• Trismus (D): more associated with inferior alveolar nerve block (intramuscular injection into medial pterygoid).
• Prevention: aspirate before injecting, avoid excessive needle penetration, use a 27-gauge short needle.
• Management: apply pressure extraorally (cheek), ice packs, reassure patient. Usually self-limiting.
• The PSA block carries the highest hematoma risk of any intraoral injection because of proximity to the pterygoid plexus.
• Trismus (D): more associated with inferior alveolar nerve block (intramuscular injection into medial pterygoid).