Background: Various anatomical measurements & noninvasive clinical tests, singly or in various combinations can be performed to predict difficult laryngoscopy & intubation in apparently normal patients. Recently introduced “Upper Lip Bite Test (ULBT)” & “Ratio of Height to Thyromental Distance (RHTMD)” are claimed to have high predictability in comparison to commonly used Mallampatti Grading (MPG). Materials and Methods: We conducted a prospective single blinded observational study of 150 adult patients of ASA Grade I & II, assessed them for MPG, ULBT & RHTMD according to standard methods & correlated with the Cormack & Lehane grade. The Data analysis was done using Graphpad Software. Result: ULBT & RHTMD had more sensitivity, specificity, positive predictive value & negative predictive value, i.e., 83%, 85%, 69%, 89%, 56%, 78%, 89%, 92% respectively as compared to MPG 28%, 85%, 48%, 73%. P - value for both the tests were < 0.01
in comparison with MPG. Conclusion: Amongst the three methods used, RHTMD is best predictive test for difficult laryngoscopy in apparently normal patients, but ULBT can also be used as an acceptable alternative which is less cumbersome than RHTMD.