Tongue resting pressure of the tongue anchorage pad in different body positions: a pilot study.

We designed a modified transpalatal arch (tongue anchorage pad, TAP) to help control the vertical dimension. This study aimed to evaluate its efficiency by measuring the tongue resting pressure at different anteroposterior positions of the TAP in the upright and supine positions and to investigate the effect of changes in body position. Our study recruited 17 volunteers with individual normal occlusion (4 males, 13 females, age 22-33 years). An individualised TAP was designed for each subject. With a miniature sensor (FSS1500NS) installed in the device, we measured the pressure at the level of the distal second premolar (PM2), the first molar (M1) and the second molar (M2) in both the upright and supine positions. Nonparametric analysis was applied with the level of significance set at 0.05. In the upright position, tongue pressures obtained at PM2, M1 and M2 were 183.94, 130.81 and 113.07 Pa, respectively, with the maximum value detected at PM2 (P = 0.001). While in the supine position, pressures of 187.03, 156.87 and 201.69 Pa were detected at the same sites, with significantly higher values for M1 (P = 0.002) and M2 (P = 0.004). Tongue resting pressure decreases from the anterior aspect to the posterior aspect in the upright position. In the supine position, the pressure is consistent across the midline with pressure enhancement at M1 and M2. As many questions remain about this appliance and appropriate intruding force, further clinical and basic studies are required prior to its clinical implementation.