What is a jaw joint (TMJ) problem and why does it occur?

The temporomandibular joint (TMJ) is a very special joint that connects the lower jaw to the skull and enables movements such as opening and closing the mouth. Problems with this joint are called “TMJ disorders.” Causes include clenching/grinding teeth (bruxism), stress, improper bite, trauma, bad habits (nail biting, one-sided chewing), and some rheumatic diseases. TMJ problems are not limited to jaw pain; they can also cause headaches, ringing in the ears, jaw locking, and facial pain.