An in vitro model to evaluate the effect of saliva lubrication during swallowing
Résumé
By aging, the prevalence of age-related diseases and medical events increases. The prevalence of swallowing difficulties in patients with Parkinson’s disease is between 54% and 82%, and in patients with Alzheimer’s disease is 84%. The leading causes of these impairments are the perturbation of muscle coordination, the weakness and rapid fatigue of muscles, and the lack of saliva, also known as xerostomia, considered more a risk factor than a direct cause. Due to the high medicine intake recommended to these patients, side effects such as dry mouth can affect bolus formation and flow.
This study develops an in vitro soft robotic tongue that simulates the interaction between the tongue and the palate when the bolus is transported along the oral cavity. Artificial saliva was used to evaluate bolus behavior in the presence and absence of oral lubrication. Bolus pressure against the palate, timings of bolus exiting the cavity, residues remaining after swallowing, and image analysis were assessed.
There is a significant reduction of bolus pressure (6.56 kPa to 4.89 kPa) and oral residues (6.22 g to 4.92 g) when lubrication is mimicked. The evaluation of bolus behavior with and without lubrication shows that lubrication creates a cohesive bolus, while without lubrication, the bolus breaks, making an unsafety swallow.
The lack of tools to evaluate and simulate swallowing disorders allows this study to provide a new and innovative perspective on how oral physiology during swallowing needs to be considered to assess food products.