title: Flexible endoscopic evaluation of swallowing in healthy young and older adults.
abstract: OBJECTIVE
  Scant data exist on normal swallowing as assessed endoscopically. A lack of understanding for the range of normal swallowing may lead to inaccurate diagnoses and overly aggressive management of patients with dysphagia. Accordingly, the purpose of this study was to determine the effects of age (i.e., young versus older), gender, bolus volume (i.e., 5 versus 10 mL), and bolus condition (i.e., water versus milk) on Penetration-Aspiration Scale scores, bolus dwell time, pharyngeal closure duration, and residue in healthy adults.
  
  
  METHODS
  Twenty-three young adults (mean, 30.0 years of age) and 21 older adults (mean, 75.0 years of age) participated. Measurements were acquired during manoendoscopic swallowing assessments. The participants contributed 8 swallows, affording a study total of 352 swallows for analysis.
  
  
  RESULTS
  The older adults demonstrated penetration on 19 swallows and aspiration on 11 swallows out of 168 swallows. There was a significant difference in the proportion of Penetration-Aspiration Scale scores across age and gender groups. Longer bolus dwell times were seen in older adults and with milk boluses, whereas residue severity was less in young adults and with water boluses.
  
  
  CONCLUSIONS
  Endoscopic data on normal swallowing physiology were generated. These data may serve as an accurate benchmark for clinicians and researchers in the interpretation of dysphagia.
authors.affiliation: Department of Otolaryngology, Center for Voice and Swallowing Disorders, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
authors.forename: Susan G
authors.initials: SG
authors.lastname: Butler
authors.forename: Andrew
authors.initials: A
authors.lastname: Stuart
authors.forename: Shannon
authors.initials: S
authors.lastname: Kemp