Effects of Palatal Plate on the Tongue-Palate Contact during Swallowing in Normal Adults with an Experimentally Enlarged Oral Cavity

Abstract

Purpose: The tongue plays an important role in bolus formation and transportation to the oropharynx and in retaining pharyngeal pressure during mastication and swallowing. Recently, the palatal augmentation prosthesis (PAP) has been used for compensating deteriorated tongue-palate contact during swallowing and articulation in dysphagic patients. However, the detailed mechanisms by which PAP improves tonguepalate contact during swallowing are not well understood. The purpose of this study was to examine the effects of a palatal plate on the tongue-palate contact during swallowing in normal adults with an experimentally enlarged oral cavity.

Methods: An experimental occlusal splint (＋5 mm bite height) for increasing oral cavity volume and a palatal plate (5 mm thick) to compensate for the enlarged oral cavity were made for 10 healthy young volunteers with perfect dentition. Tongue pressure against the hard palate during swallowing of 10 ml of water and 10 g of pudding was recorded by the sensor sheet with five measuring points in each subject under three conditions: control (no splint or palatal plate), with splint, and with both splint and palatal plate. The order of onset, duration, maximum magnitude and integrated value of tongue pressure were compared among the three experimental conditions.

Results: Compared to the controls, the order of tongue pressure onset was significantly disorganized with splint, but tended to be increased with splint and palatal plate. The duration, maximum magnitude, and integrated value of tongue pressure decreased with splint, but tended to be increased to the control levels with splint and palatal plate during swallowing of water and pudding. This tendency was remarkable at the anterior-median and posterior-median parts of the palate.

Conclusion: The results of this study that the experimental palatal plate restored tongue-palate contact during swallowing by compensating for enlargement of the oral cavity by the occlusal splint suggested a part of the mechanism of the effect of PAP on dysphagic patients.