Effect of facet inclination and location on TMJ loading during bruxism: An in-silico study.

[Display omitted] • Sheds new light on the important potential connection between tooth grinding and temporomandibular joint loading • Demonstrates a larger effect of grinding inclination than grinding position on TMJ loading • Creates a novel computer simulation of TMJ disc stress during dynamic tooth grinding tasks • Uses state-of-the-art in silico methods for a highly multidisciplinary investigation, which is not feasible in vivo • Presents a tracking simulation approach to work around the highly complicated recording of masticatory muscle EMG acquisition Functional impairment of the masticatory region can have significant consequences that range from a loss of quality of life to severe health issues. Increased temporomandibular joint loading is often connected with temporomandibular disorders, but the effect of morphological factors on joint loading is a heavily discussed topic. Due to the small size and complex structure of the masticatory region in vivo investigations of these connections are difficult to perform. We propose a novel in silico approach for the investigation of the effect of wear facet inclination and position on TMJ stress. We use a forward-dynamics tracking approach to simulate lateral bruxing on the canine and first molar using 6 different inclinations, resulting in a total of 12 simulated cases. By using a computational model, we control a single variable without interfering with the system. Muscle activation pattern, maximum bruxing force as well as TMJ disc stress are reported for all simulations. Muscle activation patterns and bruxing forces agree well with previously reported EMG findings and in vivo force measurements. The simulation results show that an increase in inclination leads to a decrease in TMJ loading. Wear facet position seems to play a smaller role with regard to bruxing force but might be more relevant for TMJ loading. Together these results suggest a possible effect of tooth morphology on TMJ loading during bruxism. [ABSTRACT FROM AUTHOR]