Intraoral pressure patterns during swallowing

Abstract

Swallowing disturbances are common after neurological disease and oropharyngeal tumor resection. In this case the oral stage is often affected. So far the clinical evaluation of the oral phase is limited. Recently the role of pressure changes during oropharyngeal swallowing has been pointed out, but until now there are not enough data. Thereby 52 healthy adults aged between 20 and 45 years were examined using an oral shield (Silencos®, Bredent, Senden, Germany) connected to a digital manometer (GDUSB 1000®, Greisinger electronics, Regenstauf, Germany) able to record pressures in a range of 2,000 to −1,000 mbar at a frequency of 1 kHz. Three swallowing conditions were measured: an active bolus intake (ABI) of water, a passive bolus application of a water-bolus (PWA) and a passive application of a gel-bolus (PGA). We found negative pressures with a median value of −278.9 mbar during ABI, of −24.2 mbar during PWA and of −29.4 mbar during PGA. Significant differences in pressure amplitudes and the pressure pattern were observed depending on the kind of bolus application and its consistency. The used test presents a simple and easy to handle method to assess the oral phase of swallowing.

Real‐time MRI of swallowing: intraoral pressure reduction supports larynx elevation

“…A possible limitation of this study was the unavoidable use of a supine position for swallowing during real‐time MRI. This may relieve laryngeal elevation caused by the altered impact of gravitation which, in turn, may contribute to the variability of negative intraoral pressures when compared with the rather constant pressure conditions in a sitting position . In addition, the bolus itself may have affected the swallowing process in some volunteers, so that more physiological deglutition maneuvers may be expected during (‘dry’) swallowing of saliva.…”

“…This may relieve laryngeal elevation caused by the altered impact of gravitation which, in turn, may contribute to the variability of negative intraoral pressures when compared with the rather constant pressure conditions in a sitting position. 2 In addition, the bolus itself may have affected the swallowing process in some volunteers, so that more physiological deglutition maneuvers may be expected during ('dry') swallowing of saliva. Finally, the observed inter-subject differences in performance restricted the MRI and pressure analysis to a single major swallow, which precluded a more standardized test-retest evaluation.…”

“…The physiology of the human swallowing process has not yet been fully clarified. For example, to date, intraoral manometry of the isometric tongue pressure or atmospheric pressure in the oral cavity has been discussed exclusively within the context of oral bolus transport. Pushing the bolus is seen as the tongue's main task and a gradient of negative atmospheric intraoral pressure has been suggested to support bolus transport .…”

Application of a barometer for assessment of oral functions: Donders space

“…and Santander et al . reported only negative pressure during swallowing. We agree that negative pressure could be generated in the space during swallowing (as seen in Figs and ).…”

“…Pressure in the oral cavity has been measured by many studies (3,7,(14)(15)(16); however, most of the methods employed were conventional in that the pressure in a space was measured with a tube connected to a sensor placed outside of the oral cavity. Inconveniently, the tube may resist air flow during measurement, and thus, the response resolution may be low.…”