Relationship between maximal isometric tongue pressure and limit of fracture force of gels in tongue squeezing

Abstract

Background: There is no clear objective indicator for selecting soft foods that are required for food bolus formation in older people with impaired oral function.

Objective: This study aimed to investigate the relationship between maximal isometric tongue pressure (MITP) and the mechanical properties of gels that can be crushed by the tongue.

Methods: This study included 65 healthy participants aged 22-96 (young group; 15 males, 15 females; older dentate group; 7 males, 8 females; older edentulous group; 10 males, 10 females). MITP was measured by the balloon-probe device. Agar gel with 10 different kinds of fracture force from 10N to 100N was used. The limit of fracture force of gels (LFFG) that were crushed by the tongue was measured by the up-and-down method. In the older edentulous group, two items were measured with and without dentures. Spearman's rank correlation coefficient was used to evaluate the relationship between MITP and LFFG in each group (p < .05).

Results: There were positive correlations between MITP and LFFG in all groups (overall groups: r_s = .66, young group: r_s = .46, older dentate group: r_s = .61, older edentulous group with dentures: r_s = .60, older edentulous group without dentures: r_s = .47).

Conclusion: MITP and LFFG were positively correlated in young, older dentate and older edentulous groups, suggesting that MITP has the potential to be an objective indicator of the range of mechanical properties of soft food that can be crushed by the tongue.

Keywords: ageing; food texture; gels; oral function; squeezing; tongue pressure.