Dynamic 3D FE modelling of the human temporomandibular joint during whiplash.

Rear-end impacts account for more than one-third of vehicle accidents, and nearly 40% of these accidents produce whiplash injuries. Whiplash injury to the neck has often been considered a significant risk factor for the development of temporomandibular disorders (TMD). The objective of this study was to simulate the dynamic response of the temporomandibular joint during two types of impacts: a rear end and a frontal impact. To understand the dynamic forces acting on the joint, we extended a previous human temporomandibular joint model and analyzed the stress distributions in the soft elements of the joint. In the rear-end impact, it could be appreciated that the inertia of the mandible caused it to move posteriorly slower than the head, and this resulted in downward and forward displacements of the disc-condyle complex relative to the cranial base. Consequently, a rapid and big mouth opening occurs. In contrast, during the frontal impact, the mouth hardly opened, because the superior maxilla pushed the mandible to move together. There was not differential movement between bony components of the joint and therefore the soft tissues of the joint were not subjected to high loads. From these results, and despite the limitations of the simulations performed, we could conclude that neither a rear-end impact at low-velocity nor a frontal impact would produce damage to the soft tissues of the joint.