The Temporomandibular joint is the joint of the jaw and is frequently referred to as TMJ. There are two TMJs, one on either side, working in unison. The name is derived from the two bones which form the joint: the upper temporal bone which is part of the cranium (skull), and the lower jaw bone called the mandible. The unique feature of the TMJs is the articular disk. The disk is composed of fibrocartilagenous tissue (like the firm but flexible cartilage of the ear) which is positioned between the two bones that form the joint. The disk divides each joint into two. The lower joint compartment formed by the mandible and the articular disk is involved in rotational movement (opening and closing movements). The upper joint compartment formed by the articular disk and the temporal bone is involved in translational movements (sliding the lower jaw forward or side to side). The part of the mandible which mates to the under-surface of the disk is the condyle and the part of the temporal bone which mates to the upper surface of the disk is the glenoid (or mandibular) fossa.
Pain or dysfunction of the temporomandibular joint is commonly referred to as "TMJ", when in fact, TMJ is really the name of the joint, and Temporomandibular joint disorder (or dysfunction) is abbreviated TMD. This term is used to refer to a group of problems involving the TMJs and the muscles, tendons, ligaments, blood vessles, and other tissues associated with them. Some practitioners might include the neck, the back and even the whole body in describing problems with the TMJs
What are the signs and symptoms of TMJ disorder-
There are many signs and symptoms of TMJ disorder but most common are
- Patient complaints of pain in or around the ear which according to the patient spreads to the face.
- Tenderness of the jaw muscles.
- Patient complains of clicking or popping noise on opening or closing of the mouth
- Patient has the difficulty in opening the mouth.
- The jaws they get stuck or locks called as locked jaw. In this the patient is not able to close the jaw after opening.
- Pain is there while opening the jaws widely, while yawning or while chewing.
- Patient complains of headaches or neck aches.
On seeing the signs and symptoms dentist makes the diagnosis which is based on detailed history and the series of diagnostic tests like x-rays or the impressions of the teeth.