Development and Validation of a Mastication Simulator

Objectives: The food bolus obtained after mastication and the corresponding food disruption process are being increasingly studied. However, the food bolus collected before swallowing does not represent the whole food bolus being swallowed. Therefore, a simulator of mastication was developed to allow collection of the full quantity of the bolus.

The first aim of this study was to build a simulator of mastication reproducing human masticatory behaviour and producing a food bolus with similar texture to an in vivo food bolus. The second aim was to validate the simulator by comparing the food boluses obtained in vitro and in vivo.

Methods: Food boluses were obtained from both the simulator and 30 young healthy and full dentate subjects (23,7 ± 2,2 years old) chewing peanuts and carrots. The food boluses were characterized by the particle size distribution. The boluses were cleaned in a 0.1 mm aperture sieve, dried and scanned. The images were analysed with a specific software (PowderShape®, IST-Ag, Vickers, Switzerland). The D50 of the particle size was chosen as the dependent variable. Simulator calibration was realised by adjusting the different parameters (number of masticatory cycles, rotation and translation amplitudes of the mandibular piston head, masticatory force, temperature of the chamber, addition of artificial saliva).

Results: Number of cycles and applied force were the predominant parameters in determining the in vitro particle size (D50). Setting the number of cycles at the mean value observed in vivo and choosing the force of the simulator allowed to obtained agreement between in vitro and in vivo values (Bland and Altman method, Lancet, 1986) for each food. Addition of artificial saliva and control of the temperature only marginally influenced the D50 values.

Conclusion: The food boluses obtained in vitro with the simulator display the same D50 values as the food boluses produced in vivo.