In this study, dynamic imaging was used to track the movements of oral
cavity and laryngeal structures during swallowing in 10 normal adult
subjects. The movements of tiny lead pellet markers attached to the li
ps, tongue, mandible, and soft palate, as well as anatomic landmarks o
n the hyoid bone, were measured in relation to a reference pellet affi
xed to the upper central incisors. Sagittal views of the oral cavity w
ere obtained using standard videofluorography. Each subject produced 1
0 swallows of 12 ml of tap water followed by 5 swallows with a bite bl
ock placed between the molars. The recorded video images were input to
a microcomputer where the x- and y-coordinates of the pellets were me
asured. Results of the analyses revealed considerable temporal overlap
in the timing of oral cavity and laryngeal movements, widespread indi
vidual variability in coordination patterns and movement trajectories,
and selective effects of the bite block. These data suggest the exist
ence of individual adaptive strategies in the programming and control
of swallowing movements.