Influences of occlusal and skeletal discrepancies on biomechanical environment in the TMJ during maximum clenching: an analytic approach with the finite element method

The purpose of this study was to investigate the influences of occlusal and skeletal discrepancies on temporomandibular joint (TMJ) stresses during ma ximum clenching. A three-dimensional (3-D) finite element model of the mand ible including the TMJ was developed as a standard model. Furthermore, nine modified models were established; one dentoalveolar open bite model and ei ght skeletal open bite models with varying gonial angles or mandibular plan e angles (FMAs). For the dentoalveolar open bite model, the TMJ stresses we re larger than those for the standard model, although the distribution patt ern was not essentially varied. In the skeletal open bite model with greate r gonial angle or FMA, the TMJ stresses were significantly larger than thos e in the dentoalveolar open bite model. in conclusion, the TMJ stress was a ffected by occlusal and/or skeletal discrepancies, if coexisted in particul ar, indicating the association with degenerative changes of the TMJ compone nts.