Chewing and the dimension of the pharyngoesophageal segment.

Masticatory efficiency was evaluated in 21 adults for four chewing parameters: mixing of a color-patterned chewing gum mass, shaping of a chewing gum mass, particle reduction of a silicone tablet, and number of chewing strokes before the first swallow of an almond. The results of these tests were correlated with the dimension of the pharyngoesophageal (PE) segment during swallow of liquid barium and solid meat. The transverse width of the PE segment during swallow of liquid barium correlated significantly with the chewing parameters. The sagittal width of the PE segment during swallow of liquid barium correlated only weakly with the chewing parameters. The PE segment dimension during swallow of a solid meat bolus did not correlate with the chewing parameters. The results suggest that there is feedback during chewing and swallowing between the PE segment and the oral cavity.