Dysphagia

, Volume 22, Issue 2, pp 100–107

Chewing and Food Consistency: Effects on Bolus Transport and Swallow Initiation

  • Eiichi Saitoh
  • Seiko Shibata
  • Koichiro Matsuo
  • Mikoto Baba
  • Wataru Fujii
  • Jeffrey B. Palmer
Article

DOI: 10.1007/s00455-006-9060-5

Cite this article as:
Saitoh, E., Shibata, S., Matsuo, K. et al. Dysphagia (2007) 22: 100. doi:10.1007/s00455-006-9060-5
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Abstract

Preswallow bolus formation usually occurs in the mouth for liquids and in the oropharynx for solid foods. We examined the effect of chewing on the relationship between bolus transport and swallow initiation. Fifteen healthy subjects were imaged with lateral projection videofluorography while eating liquids, solid foods, and a mixture of liquid and solid foods in upright and facedown postures. Videotapes were reviewed to measure the location of the leading edge of the barium at swallow initiation. Chewing and initial consistency each altered the relationship between food transport and swallow initiation. In particular, when chewing liquid (or consuming foods with both liquid and solid phases), a portion of the food commonly reached the hypopharynx well before swallow onset. This transport to the hypopharynx was highly dependent on gravity, but transport to the valleculae for chewed solid food was active, depending primarily on tongue-palate contact. Chewing appeared to reduce the effectiveness of the posterior tongue-palate seal, allowing oral contents to spill into the pharynx. Consuming two-phase foods with both solid and liquid phases may increase the risk of aspiration in dysphagic individuals with impaired airway protective reflexes.

Keywords

DeglutitionChewingMouthPharynxFluoroscopyViscosityDeglutition disorders

Copyright information

© Springer Science+Business Media, Inc. 2007

Authors and Affiliations

  • Eiichi Saitoh
    • 1
    • 5
  • Seiko Shibata
    • 1
  • Koichiro Matsuo
    • 2
    • 3
  • Mikoto Baba
    • 1
  • Wataru Fujii
    • 1
  • Jeffrey B. Palmer
    • 3
    • 4
  1. 1.Department of Rehabilitation Medicine, School of MedicineFujita Health UniversityToyoakeJapan
  2. 2.Department of Gerodontology, Graduate SchoolTokyo Medical and Dental UniversityTokyoJapan
  3. 3.Department of Physical Medicine and Rehabilitation Johns Hopkins UniversityBaltimoreUSA
  4. 4.Department of Otolaryngology-Head and Neck Surgery and Center for Functional Anatomy and EvolutionJohns Hopkins UniversityBaltimoreUSA
  5. 5.Department of Rehabilitation Medicine, School of MedicineFujita Health UniversityToyoakeJapan