Inductive, Scaffold-Based, Regenerative Medicine Approach to Reconstruction of the Temporomandibular Joint Disk The TMJ disc is composed of soft cartilaginous material that acts as a shock absorber between the temporal bone of the skull and the lower jaw bone (the mandible) when the joint moves. Attempts to replace a diseased or degenerated disc by synthetic materials or tissues from other parts of a patient’s body have been unsuccessful or of only limited duration. However, Dr.