<prompt> McEwens triangle is a landmark forAntral drainMastoid surgerySubmucous resectionUncinectomies  <response>: Mac Ewens Suprameatal Triangle: Boundaries of the triangle are: a. Anteriorly: posterosuperior border of the bony external auditory canal along with the spine of Henle. b. Posteriorly: a veical line drawn tangential to the posterior margin of the external, canal. c. Superiorly: the supramastoid crest. It is land mark for exposure of lateral surface of mastoid. 