Evaluating chewing function: Expanding the dysphagia field using food oral processing and the IDDSI framework

The dysphagia field is still in relative infancy with a sophisticated knowledge base amassed since the early 1980's. The desire to identify aspiration and prevent life threatening pneumonia has resulted in a focus on the complexities of swallowing liquids. However, humans also ingest saliva, food, and oral medications, with the potential for these substances to incompletely clear the pharynx, be aspirated or block the airway. Safe swallowing of solid food in particular requires adequate chewing function, good oral control, and sufficient higher cortical function. Although screening and assessment for liquid swallowing safety is well established, the same cannot be said for the evaluation of safety to chew and swallow different food textures. While research into liquid swallowing physiology and its clinical application has largely come from the medical and allied health fields, our knowledge of chewing function for food textures comes from food texture research and food sensory science arenas. There is an exciting opportunity to bring the medical and food texture science fields together to expand our knowledge base on human chewing function, with clinical application to people with dysphagia. The development of the IDDSI Framework as an international standardized way of describing and labelling food texture and drink thickness allows the field to move toward management of texture modified food and thick liquids in a coordinated fashion, speaking the same language. This commentary will describe what we know of chewing function and how it is assessed clinically, proposing methods of assessment that utilize the IDDSI Framework.