Fig 1.

Staging system of Mallampati to predict difficult tracheal intubation, as modified by Friedman (to predict the outcome of uvulopalatopharyngoplasty). The size of the tongue is assessed in relation to that of the soft palate, while the tongue rests in the floor of the mouth. Stage 1 (top left): complete visualisation of the uvula, tonsils, and arches. Stage 2 (top right): complete visualisation of the uvula; the tonsils and arches are partly invisible. Stage 3 (bottom left): only the soft and hard palate are visible; the uvula is hidden. Stage 4 (bottom right): only the hard palate is visible