<prompt> Alpha Lynch Howah surgery is forNasal septal perforationChronic frontal sinusitisAcoustic neuromaOtosclerosis  <response>: External frontoethmoidectomy Howahs or Lynch operation - The frontal sinus is entered through its floor by a curvilinear incision round the inner margin of the orbit. Diseased mucosa is removed, ethmoid cells exenterated and a new frontonasal duct created. Ref- Dhingra, 6th edition , page 196. 