Figure 4

Stresses occurring in the PDL in occluso-apical direction (s _z normal stresses) during power stroke. A load of 1250N was applied at an angle of 45° to a plane through the alveolar crest. Diagram shows FE results for the three different age-groups (A-C) on both the shifting side (1) and side where shifting side is averted (2). Tensile stresses are demonstrated by positive scale values (yellow to red), compressive stresses by negative scale values (green to blue). Dimension of stresses increases with increasing tooth age (please note the different age-related scales).