Force-time breakage characteristics of food during simulated initial phase of mastication

With the long range goal of gaining an insight into force control and muscle recruitment, it seems necessary to understand the task given to the masticatory apparatus. The purpose of this study was to characterize food breakage properties, and to study the influence of different compression speeds and occlusal morphologies on the categorized food properties. Experiments were carried out by means of a standard Instron instrument, modified with a switching relay. A stylus with 45 degree angulation and an opposing copperplated lower arch of either human or Macaca fascicularis were used for approximation of the natural situation. Crosshead speeds of 2 and 5 cm/min were selected. For future application, monkey chow was chosen as the testfood. Six parameters were defined to categorize food properties, which were initial breakage force (IBF), initial force buildup (IFB), maximum breakage force (MBF), breakage point (BP), temporal location of MBF (TL), and total compression time (TCT). The results showed that the force-time breakage characteristics of monkey chow were affected by different compression speeds in some aspects. However, this was not the case for the alteration of occlusal morphology.