You may spend most of your life unaware of the important little triangular-shaped joints located in front of each of your ears. Lined with cartilage, these joints move with a smooth, gliding motion. Under normal conditions, they join your lower jaw and temporal bone, allowing your mouth to open and close. However, stress-related reactions can wear down that cartilage, exposing nerve endings and creating jaw pain. In fact, the temporomandibular joint is highly sensitive to overall physical, emotional and psychological stress. Further, it's affected by the mechanics of your bite and the condition of your jaw muscles. So, a little extra stress, a little extra fatigue, a little change in your bite, and you may temporarily knock the whole system out of balance. The resulting TMJ disorder or TMD can cause a wide variety of mild to severe symptoms, from jaw clicking and minor discomfort to sharp pain in your temple, ear, jaw and teeth; it can also “lock” your jaw open or shut, or dislocate the jaw altogether.