Measuring pressures under maxillary complete dentures during swallowing at various occlusal vertical dimensions. Part II: Swallowing pressures.

The swallowing pressures of seven edentulous patients were measured at seven different occlusal vertical dimensions. In addition, the projection surfaces of the maxillary dentures were measured and the forces on the maxillary denture-bearing surfaces were calculated. The swallowing pressures were measured from the maxillary denture base-mucosal surface interface by means of a "closed" hydraulic system described in Part I. The mean values of swallowing pressures increased from 7.95 +/- 2.25 to 10.18 +/- 3.42 kPa as the occlusal vertical dimension increased, and then decreased to 8.38 +/- 3.55 kPa at the highest occlusal vertical dimension. The results of a two-way analysis of variance showed significant differences of swallowing pressures between patients (p less than 0.001) and between different occlusal vertical dimensions (p less than 0.001). The projection surfaces of maxillary denture bases were measured and ranged from 21.65 to 27.78 cm2. The forces exerted on these surfaces during swallowing were also calculated and ranged from 12.5 to 47.7 N.