Fig. 1.

Oblique view of the ADAMS wireframe dynamic model (left) and the conventions used to express symphyseal forces and torques (right). Muscle action lines are described elsewhere (Langenbach & Hannam, 1999; Langenbach et al. 2002). The rigid joint linking the two halves of the mandible is not indicated but is located at the centre of the symphysis approximately at the origin of the axes shown at the right. Forces exerted by the working-side corpus on the balancing-side corpus are positive when they are in the same direction as the axes. Arrows around each axis indicate the directions of positive torques exerted by the working-side corpus on the balancing-side.