OBJECTIVETo develope a three-dimensional finite element model based on the individual occlusal contact data to analyze the influence of occlusal contact on the stress distribution in the temporomandibular joint (TMJ).

METHODSCT, cone-beam CT (CBCT), MRI and 3D scanner were used to create a three-dimensional finite element model of the stomatognathic system, which reflected the accurate morphological characteristics of the occlusal surface. The contact area was marked on the occlusal surface of the teeth based on the individual occlusal contact data obtained during the maximal volunteer clenching (MVC). Two occlusal contact conditions including normal occlusion and unilateral posterior crossbite (UPC) were constructed. The models were fixed on the contact areas to simulate the MVC condition in order to analyze the stress distribution in the TMJ.

RESULTSThe stress distribution of the TMJ was approximately symmetrical in normal occlusion, but the stress values were somewhat different. No significant difference was found in stress distribution between UPC and normal occlusion, but the values were significantly higher on the crossbite side. The maximum values of von Mises stress were 10.35, 3.82, 3.59 MPa, on condylar process, articular disk, articular fossa of the crossbite side, respectively while on the corresponding side of the normal occlusion maximum values were 7.32, 3.18, 2.84 MPa, respectively.

CONCLUSIONSThe stress distribution of the TMJ in three-dimensional finite element model which indicated the personal occlusal contact was highly sensitive to the change of the occlusal contact. The abnormal occlusal contact caused by the UPC could lead to the stress concentration of the TMJ on the crossbite side.