# Soft-Tissue Facial Profile Is Associated With Tongue Pressure in Adults: A Cross-Sectional Study

## TL;DR

This study finds that facial shape, specifically the sagittal profile, is linked to tongue pressure in older adults, suggesting a non-invasive way to assess oral health.

## Contribution

The study identifies a novel association between soft-tissue facial morphology and tongue pressure in adults.

## Key findings

- Tongue pressure is significantly correlated with the N'-Sn-Pog' angle but not the N'-Tra-Me' angle.
- The N'-Sn-Pog' angle independently predicts tongue pressure after adjusting for age, sex, and height.
- Skeletal muscle mass is positively associated with the N'-Sn-Pog' angle when sex is excluded from the model.

## Abstract

Objective

Oral frailty, including reduced tongue pressure, has been increasingly recognized as a risk factor for systemic frailty in older adults. Although the relationship between skeletal and perioral muscle function and maxillofacial morphology has attracted growing attention in orthodontics, it is insufficiently understood. This study aimed to investigate the associations between sagittal and vertical soft-tissue facial profile and tongue pressure and skeletal muscle mass in adults.

Materials and methods

This cross-sectional study included 75 participants (median age: 69 years; 67% women) from the Kanagawa Dental University Hospital. Lateral facial photographs were used to measure the soft-tissue nasion-subnasale-soft-tissue pogonion (N'-Sn-Pog') angle (sagittal morphology) and soft-tissue nasion-tragion-soft-tissue menton (N'-Tra-Me') angle (vertical morphology). Tongue pressure was assessed using a balloon-type device, and skeletal muscle mass was measured via body composition analysis. Spearman’s correlation and multiple regression analyses, adjusted for age, sex, and height, were performed.

Results

Tongue pressure showed a significant positive correlation with the N'-Sn-Pog' angle and no correlation with the N'-Tra-Me' angle. Multiple regression indicated an independent association between tongue pressure and the N'-Sn-Pog' angle. A positive association between skeletal muscle mass and the N'-Sn-Pog' angle was found in a model excluding sex as a variable.

Conclusion

In middle-aged and older adults, sagittal soft-tissue facial morphology, as indicated by the N'-Sn-Pog' angle, was positively associated with tongue pressure. These findings suggest that a simple and non-invasive assessment based on facial photographs may serve as a potential indicator of reduced tongue pressure.