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: ENT
[{'content': 'All of the following are true of submucous resection  operation for DNS except - \nSelect and explain. \nA. Indicated in septal deviation, B. Mucoperichondrium is removed, C. Preferably done after 16 years of age, D. Done in some cases of epistaxis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Submucous resection (SMR) of the nasal septum \n\nSubmucous resection (SMR) is a surgical procedure to correct the deformity of the nasal septum.\nThe principle of this procedure is to remove deviated cartilage and bone from beneath the mucosal lining of the nasal septum, leaving a corrected septum largely composed of scar tissue.\nSubmucous resection is not advocated in children up to 17 years of age as it may interfere with the development of the\xa0facial bones.\n\nIndications\n\nDeviated nasal septum (DNS) causing symptoms of nasal obstruction and recurrent headaches.\nDNS causing obstruction to ventilation of paranasal sinuses and middle ear, resulting in recurrent sinusitis and otitis media.\nRecurrent epistaxis from the septal spur.\nAs a part of septorhinoplasty for cosmetic correction of external nasal deformities.\nAs a preliminary step in hypophysectomy (transseptal transsphenoidal approach) or vidian neurectomy (transseptal approach).\n\nSteps of surgery\n\nGenerally done in adults under local anaesthesia\nConsists of elevating the mucoperichondrial and mucoperiosteal flaps on either side of the septal framework by a single incision made on one side of the septum, removing the deflected parts of the bony and cartilaginous septum, and then repositioning the flaps.', 'role': 'assistant'}]