Fig. 3.

Von Mises stress distribution in symmetrical distal bite in normal (action of masticatory muscles only) and pull-back load cases (i.e. action masticatory muscles plus additional loading that simulates a pull along the Z-axis by postcranial musculature): Muscle tensional force plus 50 N force (Z-axis) applied at the midpoint node of the interdental beam (arrow), for heterogeneous and homogeneous models. Peak stresses have been scaled out. In contrast to biting at an anterior point in the tooth row, when biting at a distal point, stress is lower when loading is restricted to masticatory muscles only (normal) and the addition of pull loading along the Z axis (pull-back) increases stress.