TMJ is an abbreviation for the temporomandibular joint which connects the mandibular, or your lower jaw, to the temporal bones of the skull. The TMJ is one of the more unique joints within your body as it allows you to move your jaw forward, backward, and side to side so that you can chew, talk, sing, yawn, and more. This joint can be found just in front of your ears on both sides of your head.
Any problem with the muscles, ligaments, discs, bones, or the joint itself are known as temporomandibular disorders or TMD and refers to the actual disorder, where the jaw joint is misaligned and causing problems such as pain, inflammation, and inability to move or operate the jaw. However, these problems or conditions are often incorrectly called by the joint name of TMJ instead.