Figure 2. Oblique sagittal MR images (2,000/20) of the TMJ of a volunteer show partial anterior displacement of the disk with the mouth closed in A and B and show the normal position of the disk with the mouth open in C. A, The disk is anteriorly displaced in the lateral portion of the joint. B, The disk is in the normal position in the medial portion of the joint. With mouth opening, the disk position normalizes, which indicate disk displacement with reduction. Arrow indicates the posterior band of the disk.