Cerebral Representation of Splint Therapy in Bruxism Patients; An fMRI Experiment

Abstract

Objective: The aim of this study was to investigate the effects of the novel Nociceptive Trigeminal Inhibition Tension Suppression System (NTI-tss) splint therapy in bruxism patients based on the view that the etiology is derived from central nerveous system. It was also aimed to evaluate the differences in cortical activity between bruxism patients and healthy subjects during the clenching function. Material and Methods: A total of 30 volunteers (15 bruxist and 15 healthy) attending the KırıkkaleUniversity Faculty of Dentistry for various dental reasons were included in the study. For the diagnosis of bruxism, the criteria determined by an international consensus in 2013 were used. Brain activity was examined by functional magnetic resonance imaging during tooth clenching and rest tasks for each participant with the BrainVoyager QX 2.8 statistical data analysis program. This protocol was approved by the ethics committee of the medical faculty of Kırıkkale University, Turkey (02/04). Results: When the average rate of brain activity in healthy subjects and bruxism patients was compared, hypoactivation was observed during the clenching task in the inferior parietal lobe (Brodmann 39 ve 40) and dorsal posterior cingulate area (Brodmann 31). The group analysis between pre-and post-treatment groups revealed one activation cluster in the post-treatment group that may indicate increased activation in the mentioned cortical areas after 11 nights of NTI-tss splint therapy. When control group compared with post-treatment group no differences observed. Conclusion: With the aid of a neuroimaging technique, the decrease in activation in certain areas of the cerebral cortex in patients with bruxism. Our findings indicate that wearing the NTI-tss splint for 11 nights increased BOLD in the mentioned cortical area. These results might improve the understanding and physiological handling of sleep bruxism.