[Analysis of the condyle in the state on the mandibular protraction by means of the three-dimensional finite element method]

Abstract

Objective: Studies on the stress distribution and the displacement of the condylar cartilage will be conducive to expound the mechanisms of mandibular orthodontic therapy.

Methods: The model was constructed from young man. Transverse sections of mandible, included TMJ, were scanned by means of CT. An articular disk and condylar cartilage were constructed according to their normal shape and elastic modulus as the same age as to current results of studies. Stimulate the stomotologic muscles' and ligaments' function by means of cable element. The model is consisting of 1364 x 2 bricks and 1954 x 2 nodes.

Results: Stimulate the mandibular protraction (advancement) was revealed: (1) Compressive stress widely distributed in the anterior area of condylar cartilage (-2425 g/cm(2) - -7399 g/cm(2)). (2) Tensile stress distributed in the posterior-upper area (10,000 g/cm(2)).

Conclusion: The results indicate that the mandibular protraction can increase the growth of mandible to treat the skeletal Class II malocclusion.