Figure 1: Location of the leading edge of the barium was defined by five anatomical regions: (1) the oral cavity; (2) the upper oropharynx behind the fauces but above the inferior border of the mandible; (3) the valleculae below the inferior border of the mandible but above the hypopharynx; (4) the hypopharynx below the epiglottis but not reaching the floor of the piriform sinus; and (5) the floor of the piriform sinus.