Abstract

Calcium hydroxide is commonly used as a root canal disinfectant due to its high alkalinity and biocompatibility. However, excessive injection pressure may cause extrusion beyond the root apex, leading to complications such as nerve or vascular injury. This report showed a case of a 58-year-old woman who developed cutaneous necro-sis and sensory disturbance in the left midface and nasal alar region following endodontic treatment on the left maxillary second molar. Computed tomographic imaging revealed calcified occlusion of the posterior superior alveolar artery. The patient was treated with debridement, stromal vascular fraction injection, and split-thickness skin graft. This case demonstrates a rare but serious complication, known as Nicolau syndrome, resulting from intra-arterial injection of calcium hydroxide. Clinicians should be aware of this potential risk and exercise cau-tion during delivery of intracanal medicaments, especially in vascular-rich anatomical regions. (J Korean Dent Assoc 2025; 63(10): 329-334)