Influence of Habitual Tongue Posture on Tongue Pressure During Swallowing

Tongue pressure is essential for bolus transport and oral stability during swallowing and serves as a clinical marker of tongue function. Habitual tongue posture, defined as the resting position of the tongue, is associated with swallowing efficiency and craniofacial development.

This study investigated the association between habitual tongue posture and regional tongue pressure amplitudes.

We enrolled 52 healthy adult participants (26.0 [24.0-27.0] years). Habitual tongue posture was evaluated using standardised lateral cephalometric radiographs, measuring tongue-palate (T-P) and mandible-hyoid distances. Based on the mean T-P value, participants were divided into long-distance (LD) and short-distance (SD) groups. Tongue pressure during 5 mL water swallowing was measured using a tactile sensor system with five sensor points (Ch1-5).

Intra-group analysis revealed significantly lower pressure at Ch3 (2.1 [0.7-4.5] kPa) than at Ch4 (5.6 [2.0-9.9] kPa, p = 0.0286) and Ch5 (8.1 [3.8-15.7] kPa, p < 0.0001) in the LD group. Inter-group comparisons showed that the LD group had significantly lower tongue pressure than the SD group at Ch2 (3.2 [1.5-6.5] kPa vs. 6.8 [4.6-14.7] kPa, p = 0.0018), Ch3 (2.1 [0.7-4.5] kPa vs. 10.6 [6.0-21.2] kPa, p < 0.0001), and Ch4 (5.6 [2.0-9.9] kPa vs. 9.8 [5.5-11.8] kPa, p = 0.0203).

Our findings suggest that habitual low tongue posture impairs swallowing efficiency by reducing tongue pressure in certain areas, posing a risk for age-related dysphagia and swallowing difficulties.