Effect of foodstuff on muscle forces during biting off.

Abstract

The subject of this research is the human stomatognathic system and the process of biting off various foodstuffs. The research was divided into two stages - an experimental stage and a computational stage. In the first stage, tests were carried out to determine the force-displacement characteristics for the biting off food. For this purpose five different foodstuffs were tested in a testing machine and their strength characteristics were determined. The aim of the second stage was to build a computational model of the human cranium-mandible system and to run simulations of the process of biting off food in order to determine the muscular forces as a function of the food. A kinematic scheme was developed on the basis of a survey of the literature on the subject and used to create a computational model of the human stomatognathic system by means of dynamic analysis software (LMS DADS). Only the masseter muscle, the temporal muscle and the medial pterygoid muscle were taken into account - the lateral pterygoid muscle was left out. The simulations yielded the basic kinematic and dynamic parameters characterizing the muscles. Summing up, weaker occlusion forces are needed to bite off today's foodstuffs than the forces which the mastication muscles are capable of generating. Determined in the article the general equations will enable identification of the muscular forces acting on the mandible during biting off, performing basic strength calculations, and will also give an answer to which of the products the patient after a surgical procedure will be able to consume.