Temporomandibular disorder (TMD) is a prevalent chronic pain disorder that remains poorly understood. Recent imaging studies reported functional and gray matter abnormalities in brain areas implicated in sensorimotor, modulatory, and cognitive function in TMD, but it is not known whether there are white matter (WM) abnormalities along the trigeminal nerve (CNV) or in the brain. Here, we used diffusion tensor imaging, and found that, compared to healthy controls, TMD patients had 1) lower fractional anisotropy (FA) in both CNVs; 2) a negative correlation between FA of the right CNV and pain duration; and 3) diffuse abnormalities in the microstructure of WM tracts related to sensory, motor, cognitive, and pain functions, with a highly significant focal abnormality in the corpus callosum. Using probabilistic tractography, we found that the corpus callosum in patients had a higher connection probability to the frontal …