How does the mastication machine work ?

The main mastication parameters allowing the adaptation to the food texture are the force generated by the mastication muscles, the number of cycles (number of bites), the length of the mastication sequence (from the moment the food is put into the mouth to when it is swallowed) or still the mastication rate (rhythm). The technology we used most certainly makes the AM2 a simple and robust machine while allowing the simulation and adjustment of the main mastication parameters.
 
1 - AM2 operating principle :
It is based on the confrontation of two jaws, a fixed one and a mobile one, each bearing a "dental arch". These "dental arches" have a mastication surface similar to the dental surfaces at work in human mastication. They do not reproduce human anatomy, but they have been devised to impose the same types of shear and compression constraints as those exerted in vivo. The jaws are driven by engines that are themselves automated (see animations).
 
2 - Controlled parameters :
The parameters are controlled by computer, thus allowing the experimenter to master them. The main parameters the experimenter can select are :
  • the type of constraints exerted on the food : shear/compression associated to the type of movements reproducing circumduction, that is the vertical and lateral movements of the lower jaw.
  • the number of masticatory cycles, the cycle duration and the duration of the mastication sequence.
  • the force range to be applied according to the masticated food.
  • an artificial saliva whose composition can be adjusted is proposed. It is injected into the mastication chamber by means of a mechanized pump controlling its rhythm and flow.
  • The mastication chamber temperature is also controlled.
 
3 - Data acquisition :
The time course of the forces applied to the food during mastication and the mastication chamber temperature are recorded continuously. The different strategies used to adjust the mastication parameters can be stored and used again.
 
4 - Bolus analysis :
Various analyses can be performed on the mastication platform to characterize the bolus made by AM2 :
  • granulometry of the bolus (analysis of the size or shape distribution of the particles).
  • rheological performance of the bolus (plasticity, cohesion, ...).
  • various other analyses.