Ratio of height to thyromental distance as a predictor of difficult laryngoscopy: A prospective observational study.

Background And Aim: Various airway indices are used either singly or in combination to predict difficult laryngoscopy. Recently introduced ratio of height to thyromental distance (RHTMD) is reported to have better predictability. We aimed to assess the prediction of difficult laryngoscopy by RHTMD and compared it with other indices.