Muller's manoeuver is used ?

Ans. is 'c' i.e., To find degree of obstruction in sleep disordered breathing Muller's 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 patient makes maximal inspiratory effo with nose and mouth closed. Base of tongue, lateral pharyngeal wall and palate are examined for collapsibility and then rated form 0 (minimal collapse) to 4+ (complete collapse).