A numerical model to predict the force output of the jaw musculature

Numerical optimization has been incorporated into a step by step scientific investigation of the mechanical control of a biological system. The system is the human chewing apparatus and the aim is to produce a theoretical model which can use three-dimensional Newtonian mechanics to predict muscle forces based on an individual’s occlusion, craniofacial geometry and muscle angulations. However, mechanical principles alone are not sufficient to yield a unique prediction because the force system is innately indeterminate. This indeterminacy may be related to the number of different muscles which can pull on the mandible, and to the bilateral nature of the articulations which can slide as well as rotate. Therefore it is necessary to model the selection of muscles by the central nervous system using optimizing principles and a numerical algorithm. The predictions from the model can be tested using electromyographic recordings from the masticatory muscles and a scientific learning process is thereby established.