Abstract: Objective　 To establish a 3D finite element model of the craniomaxillo face including the temporomandibular joint in order that we can study the stress and strain of the active force and reaction force in the craniomaxillarcomplex, the mandible, the condyle process and articular fossa during the maxillary protraction. Methods　The heads of the volunteers were scanned by the spiral CT, and then the DICOM data were processed by Mimics and then the thecraniomaxilloface including the temporomandibulary joint were meshed. Results　A three dimensional (3-D)finite element model (FEM) of the skull was established successfully including temporomandibular joint. The final 3-D FEM was meshed with 110770 entity elements and 28740 nodes. The model of the cranial-maxillary was meshed with 76892 entity elements and 20387 nodes, and the model of the mandibular was meshed with 33878 entity elements and 8353 nodes. The FEM established was relatively complete in structure, with good-quality elements and reasonable partitioning meshes and similar to the human anatomical structure. Conclusions　An accurate 3-D FEM of the skull including the TMJ has been established successfully. The FEM model can be used to study the stress distribution and the displacement change on the mandible when a force is loaded on the chin. A solid foundation has been laid for further study.

Key words: TMJ, 3-D finite element model, craniofacial