Altered neural activation pattern during teeth clenching in temporomandibular disorders

Objective The aim was to explore the neural activations during teeth clenching in TMD s patients pre‐ and post‐treatment. Subjects and Methods Thirty TMD s patients and 20 controls underwent clinical evaluations and functional magnetic resonance imaging with a teeth clenching task. Eleven patients received repeat evaluation and imaging after wearing a stabilization splint for 3 months. Results During teeth clench, the TMD s patients showed decreased positive activity in the left precentral gyrus, right and left inferior temporal gyrus, and left cerebellum and increased negative activations in the right medial prefrontal cortex ( P  < 0.05 after AlphaSim correction). The 11 TMD s patients after treatment showed a return to normal neural activity in these areas. No brain areas in TMD s patients showed differences in activation after treatment compared with the controls, except for an increase in activation in the right cerebellum in the 11 TMD s patients ( P  < 0.05 after AlphaSim correction). Conclusion Decreased activations in cerebral areas associated with motor and cognitive functions in TMD s patients during teeth clenching were observed. Normalized activations of these areas happened in patients after routine treatment. These findings may facilitate the understanding of TMD s pathogenesis and the therapeutic mechanisms of the stabilization splint.