This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
The most common serious complication which can occur following surgery in maxillary incisor region is 
Select and explain. 
A. Iritis, B. Cellulitis, C. Periapical abscess, D. Cavernous sinus thrombisis
D: Cavernous sinus thrombisis
Answer: D: Cavernous sinus thrombisis 
Explanation: None