<prompt> Killian dehiscence is seen in-Superior constrictorInferior constrictorMiddle constrictorNone  <response>: Ans. is b i.e., Inferior constrictor o Inferior constrictor muscle has two parts i Thyropharyngeous with oblique fibres, and ii Cricopharyngeous with transverse fibres.o Between these two parts of inferior constrictor exists a potential gap called Killans dehiscence. It is also called the gateway to tear as perforation can occur at this site during esophagoscopy. It is also the site for herniation of pharyngeal mucosa in case of pharyngeal pouch. 