Tongue pressure production while swallowing water and pudding and during dry swallow using a sensor sheet system

The tongue assumes an important role in bolus formation and transportation to the oropharynx and in retaining pharyngeal pressure during mastication and swallowing. Although the state of tongue-palate contact during swallowing is thought to change with bolus type, the details of these changes have yet to be clarified under normal physiological conditions. The purpose of this study was to examine the effect of bolus type on tongue pressure production against the hard palate during swallowing. Tongue pressures during swallowing 10 mL of water and 10 g of pudding and during dry swallow were measured with a sensor sheet system with five measurement points to evaluate normal physiological swallowing in 10 healthy dentate individuals. There was a common pattern in the sequential order of tongue pressure generation among the three swallowing conditions: tongue pressure was generated significantly earlier at the anterior-median part, followed by the posterior parts. During swallowing pudding and dry swallow, the duration of tongue pressure tended to increase at all channels except for the posterior-median part. The maximal magnitude of tongue pressure was significantly higher when swallowing pudding than when swallowing water at all channels except for the posterior-median part. The integrated value of tongue pressure was significantly higher when swallowing pudding than when swallowing water at all channels except for the posterior-median part. From these results, it was considered the tongue changed the sequential order, the duration and the magnitude of tongue pressure production according to the swallowing conditions (liquid swallowing, semisolid swallowing, dry swallow).