 Whereas older adults demonstrate a delay in the onset of specific pharyngeal events, such as opening of the upper esophageal sphincter (UES) to permit bolus passage from the pharynx into the esophagus, an equally critical finding is that the range of UES opening is diminished.A scintigraphic study revealed increased pharyngeal residue with age, possibly related to the limited UES opening.Again, these findings indicate exposure of an open airway to material retained in the pharynx, increasing the risk for aspiration in older individuals.