Abstract: Objective　To find the reasons why patients always have temporomandibular disorders (TMD) after condylar frac- ture by analyzing the stress distribution change of the condylar surface whose subcondylar fracture ware fixed by miniplate during the whole healing process.Methods　Analyzing the stress distribution change of the condylar surface whose subcondylar fracture were fixed by miniplate during the whole healing process by three-dimension finite element method (3D FEM).Results　During the whole healing process of the fracture, the miniplate osteosynthesiswas helpful to the biomechanics environment rehabilitation of the condylar local, but it still had differencewith normal afterfixing 12 weeks long.Conclusion　The difference of stress distribu- tion of condylar surface that fractured and fixed by miniplate with normal may be part of the reason of TMD after the subcondylar fracture miniplate osteosynthesis.

Key words: three-dimensional finite element, fracture, internal fixation, condyle