Chewing Index: A Pilot Trial to Measure Masticatory Effort

Background/Objectives: Population aging presents new challenges for achieving healthy aging. Edentulism is a condition that diminishes quality of life. Several studies have attempted to analyze the impact of edentulism on masticatory function either by evaluating the final stage of the food bolus or the masticatory process itself. The present study aims to develop a chewing index (Ci) based on chewing time, the number of cycles, and the muscular activity of the masseter and temporal muscles. Methods: Two groups (n = 10 each, 60-80 years old), one with functional dentition (21 or more teeth) (Group F) and one with complete denture wearers (Group D), were used. Participants were asked to chew a total of 36 food samples. The number of chewing cycles (N), chewing time (T), and bilateral activity of the masseter and anterior temporal muscles were recorded and quantified using the root mean square. This activity was normalized with respect to a 5 s maximum voluntary clenching (T_MAV). A chewing index (Ci) was calculated using the equation Ci = N × V%¯ × T/T_MAV, where V%¯ represents the average normalized activity of the four muscles. Results:Ci values ranged from 0 to 62 for Group F and 0 to 262 for Group D. For 15 out of the 36 food samples, Ci was higher in Group D than in Group F. Conclusions: The results of this study are consistent with previous research showing that complete denture wearers must chew for a longer time and perform a greater number of chewing cycles compared with subjects with functional dentition.