Your temporomandibular joints, or TMJ for short, controls the motion of your jaw with a ball-and-socket connection, cushioned by a disk that rests between them. If anything disrupts this specific motion, even to a very small degree, it can cause a lot of pain and issues long term. Some common factors include arthritis, sleep disorders, dislocation/injury, misalignment of the teeth and jaw structure, and, of course, stress. All of these issues can cause strain to the muscles and joints, leading to clenching and grinding. Over time, this prolonged stress on the teeth and TMJ can cause generalized tooth sensitivity, cracked teeth, wear through the entire outer protective layer of the tooth (enamel) and sometimes even wear into the inner layer (nerve space), which can lead to a root canal, severe headaches, facial, neck, and shoulder pain, and eventually permanent damage to the TMJ by wear to the bone and disk. For most people, they notice clenching and grinding happening occasionally during the day in times of intense focus, physical exertion, or stress, but it also usually manifests at night when most are unaware. It is good to note, that people who drink alcohol and smokers are approximately twice as likely to grind their teeth at night.