TMI about TMJ

[AllegroRondo]

http://en.wikipedia.org/wiki/TMJ

TMJ stands for Temporomandibular joint. It is the proper name for the jaw joint. We all have two of them, one on each side. The name is derived from the two bones which form the joint: the Mandible which is the lower jaw bone, and the Temporal bone which is the upper. The most unique feature of the TMJ’s is the articular disk. It is a piece of cartilage (like the firm but flexible part of the ear) which is positioned between the two bones that form the joint. The TMJ’s are the only joints in the human body to have such a structure. In essence each TMJ is two joints. The compartment formed by the mandible and the articular disk is involved in rotational movement (opening and closing movements). The compartment formed by the articular disk and the temporal bone is involved in translational movements (sliding the lower jaw forward or side to side). The part of the mandible which mates to the bottom of the disk is the condyle and the part of the temporal bone which mates to the upper surface of the disk is the fossa.

Some erroneously refer to pain in the temporomandibular joint as TMJ, when in fact, TMJ is really the name of the joint. TMD stands for Temporomandubular dysfunction (or disorder). This term is used to reference a general group of problems involving the TMJ’s and the muscles, tendons, ligaments, blood vessles, and other tissues associated with them. Some practitioners might include the neck, the back and even the whole body in describing problems with the TMJ’s.