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).

Videoendoscopic measurement of food bolus formation for quantitative evaluation of masticatory function

PURPOSE

In the field of prosthodontics, many methods for evaluating the masticatory function involve ejection of the food bolus from the mouth. In addition, these methods could not evaluate mastication and swallowing function comprehensively. The present study aimed to quantitatively evaluate masticatory functions during a series of masticatory and swallowing movements by using videoendoscopy.

METHODS

Subjects are ten healthy dentulous adults without dysphagia. The test foods used were 2-colored (green and white) molded rice and uirou (rice cake). The test foods were consumed under the restriction on the number of mastication (10, 15, 20, and 30), and under the instruction to "chew normally" or "chew well". The masticatory function was evaluated by observing the food bolus in the oropharynx with a videoendoscope. The bolus formation index (BFI), in terms of the degree of mixing of the green and white parts, was quantitatively determined using an image measurement software.

RESULTS

The BFI of the rice and uirou increased significantly with increase in the number of mastication times (p<0.01). A significantly correlation coefficient was observed between the BFI and the number of mastication (0.84 for rice and 0.89 for uirou). The BFI obtained by "chewing well" was significantly higher than that obtained by "chewing normally" (p<0.01).

CONCLUSIONS

The results of this study confirm that the endoscopic measurement of food bolus formation by mastication in terms of the color tones of 2-colored test foods enables quantitative evaluation of the masticatory function during a series of masticatory and swallowing movements.