Best way to evaluate discrepancy in articular disc of TMJ is:
Soft tissues of the joint (articular disk) can be imagined with MRI or Arthrography. MRI produces superb images of the soft tissues in internal derangement of the disk. Arthrography is invasive and has the risk of infection and allergic reaction due to the contrast agent.
Transpharyngeal projection
MRI
Arthrography
Arthroplasty