This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diagnostic and operative ENT, Subject name: ENT
Mucoperichondrial flap in septoplasty is made on 
Select and explain. 
A. Alar cailage, B. Septal cailage, C. Maxillary spine, D. Sphenoid spine
B: Septal cailage
Answer: B: Septal cailage 
Explanation: In cases of deted septum, make a slightly curvilinear incision, 2-3 mm above the caudal end of septal cailage on the concave side (Killian's incision). In case of caudal dislocation, a transfixion or hemitransfixion (Freer's) incision is made. The latter is septocolumellar incision between caudal end of septal cailage and columella. Raise mucoperichondrial or mucoperiosteal flap on one side only. Separate septal cailage from the vomer and ethmoid plate and raise mucoperiosteal flap on the opposite side of septum. Ref: Dhingra 7e pg 473.