OBJECTIVETo find the reasons why patients always have temporomandibular disorders (TMD) after condylar fracture by analyzing the stress distribution change of the condylar surface whose subcondylar fracture ware fixed by miniplate during the whole healing process.

METHODSAnalyzing 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).

RESULTSDuring the whole healing process of the fracture, the miniplate osteosynthesis was helpful to the biomechanics environment rehabilitation of the condylar local, but it still had difference with normal after fixing 12 weeks long.

CONCLUSIONThe difference of stress distribution 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.