Effects of orthodontic reconstruction on brain activity in a patient with masticatory dysfunction

Brain functional magnetic resonance imaging (fMRI) was used to evaluate the effect of malocclusion therapy on the brain activity of a patient with malocclusion. A 29-year-old female patient had difficulty opening the mouth with occasional pain in the left temporomandibular joint (TMJ) and a maximum opening of only 29 mm. The treatment objectives included repositioning the displaced mandible and establishing occlusal support. Orthodontic treatment took 14 months. Treatment results were satisfactory in terms of the occlusion and function of the TMJ as well as aesthetics. Analyses of brain activity using fMRI before and after orthodontic treatment indicated clenching at the habitual intercuspal position (ICP) before treatment resulted in increased blood oxygen level dependent (BOLD) signals in the motor area of the oral region abnormally; however, this activity converged after treatment. These results suggested orthodontic treatment of malocclusion may relieve unpleasant symptoms.