Abstract
BACKGROUND: There is growing international interest in the prevention of decreased oral function for managing oral health in older people. OBJECTIVE: The aims of the present study were to identify factors related to decreases in masticatory performance and masticatory function until swallowing in subjects aged 20-79 years old. METHODS: A total of 152 subjects, ranging in age from 20 to 79 years, were divided into six groups according to their chronological age: 20-29, 30-39, 40-49, 50-59, 60-69 and 70-79 years. Grip strength, maximum occlusal force, maximum tongue pressure, masticatory performance and swallowing threshold were measured in all subjects. Masticatory performance and swallowing threshold were determined according to the concentration of dissolved glucose obtained from gummy jellies; decreased masticatory performance and decreased swallowing threshold were defined as glucose concentrations in the lowest 20th percentile. A multivariate binary logistic regression analysis was used to identify factors associated with decreased masticatory performance and decreased swallowing threshold. A self-administered lifestyle questionnaire was also completed. RESULTS: Logistic regression analyses revealed that factors related to decreased masticatory performance included use of more than one kind of medicine for treating chronic diseases and removable denture use, while factors related to decreased swallowing threshold included eating between meals once or more per day, poorer mental health and decreased saliva flow. CONCLUSIONS: Different factors are related to decreased masticatory performance and decreased swallowing threshold, although both of these phenomena are closely associated with general health status.