Objective: To further explore the best Forsus load power by analyzing the change of mandible's stress and displacement after Forsus protruded mandible instantaneously under different vertical component for providing theoretical basis.
Methods: The pre-built Forsus protruding mandible model were build through Abaqus 6.5 software. The change of mandible's stress, displacement, and pathway trend under three different working conditions(horizontal component 4 N and vertical component 2, 4, 1 N).
Results: Torsion occurred in all condyles under three working conditions, and the stress was large. Under vertical component 2 and 1 N, the mandible demonstrated counterclockwise rotation, the maximum displacement occurred in the chin, respectively 1.150 mm and 2.141 mm; under vertical component 4 N, mandible rotation was not obvious, the maximum displacement of chin was only 0.188 mm.
Conclusion: With the vertical component gradually decreased, the protrusion trend of chin increased; Forsus could promote the mandible counterclockwise rotation and modification when protruding mandible.