Comparison of upper lip bite test with thyromental distance for predicting difficulty in endotracheal intubation: A prospective study

Abstract

The present study has aimed to compare the upper lip bite test (ULBT) and thyromental distance (TMD) in predicting difficulty in intubation. 140 consecutive patients aged 18 – 60 years were included in the study. Each patient was evaluated regarding ULBT, TMD. Laryngoscopy was assessed by an attending anesthesiologist blinded to the study. In our study we found both the tests have a negative predictive value more than 90%, thus stressing the fact that, these tests can be good predictors of easy intubation, rather as positive predictors of difficult intubation which has a very low incidence. But out of the two tests, positive predictive value of ULBT is more and statistically significant, so better than TMD.