Fig. 3. Results of Cormack-Lehane classification (A ) and rating score (B ). Closed circle = single case; square bracket = statistical difference (P < 0.05, Friedman test followed by Student-Newman-Keuls test). Some of the brackets are omitted for clarity. C = simple direct laryngoscopy; M = C with mandibular advancement; B = C with BURP maneuver; BM = C with both M and B.