This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and paranasal sinuses, Subject name: ENT
Incase of uncontrolled epistaxis,ligation of internal maxillary aery is to be done in the 
Select and explain. 
A. maxillary antrum, B. Pterygopalayine fossa, C. At the neck, D. Medual wall of orbit
B: Pterygopalayine fossa
Answer: B: Pterygopalayine fossa 
Explanation: Maxillary aery: Ligation of this aery is done in uncontrollable posterior epistaxis. Approach is Caldwell-Luc operation through pterygopalatine fossa Posterior wall of maxillary sinus is removed and the maxillary aery or its branches are blocked by applying clips. The procedure is now superceded by transnasal endoscopic sphenopalatine aery ligation. Ref: Dhingra 7e pg 201,469.