Objective physiological measures of lingual and jaw function in healthy individuals and individuals with dysphagia due to neurodegenerative diseases

Swallowing is a neuromuscular process that involves a complex sequence of sensorimotor events, which are executed to efficiently and safely transport food and liquid from the mouth to the stomach. Safe oropharyngeal swallowing involves the activation, modulation, and coordination of oral, pharyngeal, laryngeal, and esophageal structures and musculature. Impaired or atypical patterns of swallowing are considered characteristic of a swallowing disorder, otherwise referred to as dysphagia, and affect the performance of all stages, i.e., oral preparatory, oral transit, pharyngeal, and esophageal. Lingual and jaw musculature play critical roles in mediating swallowing function, particularly during the oral preparatory and oral transit stages. This current study presents an adapted simple, economical, and clinically relevant protocol that may be used to quantify lingual and jaw movement in healthy and disordered swallowing, and thus track physiological changes in lingual and jaw musculature over time in individuals with dysphagia due to neurodegenerative diseases. • Jaw ROM tasks, adapted from [1,2], were adapted and utilized to measure the jaw during three postures: opening, lateralization, and protrusion. • Adapting a scale developed by Lazarus and colleagues [3], objective lingual ROM values were obtained using the TheraBite(Ⓡ) tool [4] and categorized according to functional status. • Upon methodological adaption and collation of lingual ROM and jaw ROM tasks, a comprehensive set of images clearly depicting each procedural task and a clinically friendly form were developed to guide data collection for research and clinical use.