Mallampati test with phonation, tongue protrusion and supine position is most correlated with Cormack–Lehane test

Many modified Mallampati tests have been developed to date. Samsoon’s modified Mallampati test (standard Mallampati test) is currently widely used. We newly designed seven types of assessment protocol of Mallampati test, in addition to standard Mallampati test. In this study, we studied the correlation between eight types of protocol (standard and seven alternative protocols) of Mallampati test and Cormack–Lehane test. We newly designed assessment protocols as new Mallampati test. These are different protocols depending on the presence or absence of phonation, those of protrusion of tongue, and sitting position or supine position. The oropharyngeal structures visualized by these eight types of Mallampati test for total of 145 patients undergoing dental oral surgery were evaluated. The scores derived via eight types of Mallampati test were recorded. The influence of phonation, tongue protrusion and body position on Mallampati test score was analyzed, respectively. The relationships between eight types of Mallampati test and Cormack–Lehane test were analyzed. Tongue protrusion, phonation and sitting position tended to lower the score of Mallampati test (p < 0.001, respectively). The standard Mallampati test was not correlated with Cormack–Lehane test. In the new Mallampati tests, assessment protocol with tongue protrusion, phonation and sitting position, that with tongue protrusion and supine position, or that with tongue protrusion, phonation and supine position were significantly correlated with Cormack–Lehane test, respectively. (p = 0.020, p = 0.007 and p = 0.004, respectively). The standard Mallampati test did not correlate with Cormack–Lehane test. Mallampati test with phonation, tongue protrusion and supine position were most correlated with Cormack–Lehane test.