It has been reported that the left molar approach of laryngoscopy can make difficult intubation easier. The aim of this study was to investigate whether left molar approach to laryngoscopy provided a better laryngeal view in cases of unexpected difficult intubation.

Following the approval of local Ethics Committee and written informed consent from the patients, out of 1386 patients who underwent general anaesthesia for surgery, 20 patients who could be ventilated by face mask but could not be intubated with conventional midline approach on the first attempt were included in the study. Those 20 patients, who had Grade III-IV laryngeal views on laryngoscopy by conventional midline approach, were subjected to left molar laryngoscopy, and their laryngeal views were evaluated. The external laryngeal compression was routinely used to improve the laryngeal view. When endotracheal intubation failed by left molar laryngoscopy, we performed the conventional midline approach again. All data were recorded.

Of the 20 patients studied, 18 had a Grade III laryngeal view and two had a Grade IV laryngeal view. Eighteen of them had a better laryngeal view with left molar laryngoscopy. Eleven of the 20 patients underwent successful intubation with the left molar laryngoscopy, which provided a significantly better laryngeal view and success rate of tracheal intubation than did the conventional midline approach (P < 0.01 and P < 0.01, respectively).

Left molar laryngoscopy can make unexpected difficult intubation easier and should be attempted in cases of difficult intubation.