If you answered yes to any of the above, there may be a chance you have a TMD, or are chronically clenching and/or grinding. TMD (Temporomandibular Disorder) can be caused by a number of reasons including issues with your jaw joint, stress, or a misaligned bite. The TMD joint is the joint that connects your skull to the lower jaw and allows you to do things such as speaking, yawning, and chewing. However, when there are imbalances within the TMD joint, doing these things can be difficult or even painful.