<prompt> Mullers manoeuver isForceful expiration against closed glottisForceful inspiration against closed glottisForceful expiration against open glottisReverse of Valsalvas maneuver  <response>: Mullers manoeuvre: Used to find the level and degree of obstruction in sleep-disordered breathing. It is performed while using flexible nasopharyngoscope. First, the examiner sees the upper airways at rest and then during the time when the patient makes a maximal inspiratory effo with nose and mouth closed. The base of tongue, lateral pharyngeal wall and palate are examined for collapsibility and then rated from 0 minimal collapse to 4 complete collapse. Ref: Textbook of ENT, Dhingra; 6th edition; Pg no: 449 