▫️ Evaluation of tongue motor biomechanics during swallowing–—From oral feeding models to quantitative sensing methods

Overview of Tongue Motor Biomechanics during Swallowing

  • The article evaluates tongue motor biomechanics, focusing on swallowing dynamics.

  • Importance for dentists, especially in treating dysphagia due to the aging population.

  • Provides insights into monitoring and analyzing tongue function, addressing gaps in understanding.

Introduction

  • Increasing cases of dysphagia due to aging and related diseases.

  • The significant role of the tongue in mastication and swallowing.

  • Advances in human oral feeding models since the 1990s have contributed to understanding tongue function.

  • Modern quantitative evaluation methods include manofluorography, sensing probes, pressure sensors, and ultrasound imaging.

Tongue Function in Oral Feeding Models

1. Five Stages of Ingestion

  • Proposed by Leopold and Kagel (1983).

  • Stages include:

    • Anticipatory stage

    • Preparatory stage

    • Lingual stage

    • Pharyngeal stage

    • Esophageal stage

  • Dysphagia seen as an abnormality primarily affecting the pharyngeal stage.

2. Five Phases of Oral Stage

  • Feinberg's model dividing oral feeding into:

    • Ingestion

    • Processing/preparation

    • Transfer (pre-swallow activity)

    • Lingual activity

    • Transitional phase

  • Emphasizes the biomechanics of tongue movement in these phases.

3. Process Model

  • Palmer et al. (1997) explored relationships between mastication and swallowing, unveiling correlations in movement cycles and bolus transfer.

Biomechanical Analysis of Tongue Movement During Swallowing

1. Manometry in the Oral Cavity and Pharynx

Pressure-flow Dynamics in Oropharyngeal Swallow

  • Monitored via VF and strain gauge probes.

  • Intraoral pressure dynamics drive food bolus from mouth to pharynx.

Modification by Bolus Volume and Viscosity

  • Tongue duties change based on bolus characteristics, influencing swallowing dynamics.

2. Measurement of Tongue Pressure via Sensing Probes

Iowa Oral Performance Instrument

  • Measures pressures generated by the tongue.

  • Shows modulation of pressure by bolus viscosity but not volume.

Handy Probe

  • Disposable device for assessing tongue pressure.

  • Age negatively correlates with tongue strength and swallowing pressure.

Multiple Measuring Points Sensing Probe

  • Provides detailed insights into tongue function during different phases of swallowing.

3. Pressure Sensors in Palatal Plates

Experimental Palatal Plates with Sensors

  • Used in studies of tongue pressure patterns and their correlation with swallowing tasks.

  • Important for understanding pressure generation during various activities.

Ultrasound Imaging of Tongue Movement

  • Offers non-invasive methods to evaluate tongue movements during swallowing without radiation exposure.

  • Coordinated tongue and hyoid movements assessed in various studies.

Conclusion

  • The review emphasizes advancements in evaluating tongue biomechanics in swallowing.

  • Further research in measurement technologies and multidisciplinary studies necessary for enhancing rehabilitation approaches for dysphagia.