Dental Terms
Temporomandibular joint syndrome (TMJ) Ottawa
Temporomandibular joint is the jaw joint and is frequently referred to as TMJ. Temporomandibular joint syndrome is a disorder of the jaw muscles and nerves caused by injury to the temporomandibular joint. The temporomandibular joint is the connection between the jawbone and the skull. The injured temporomandibular joint leads to pain with chewing, clicking, crackling, and popping of the jaw; swelling on the sides of the face; nerve inflammation; headaches, including migraines; tooth grinding (bruxism); Eustachian tube dysfunction; and sometimes dislocation of the temporomandibular joint. Temporomandibular joint syndrome is also known as temporomandibular joint disorder.
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 TMJs are one of the only synovial joints in the human body with an articular disk, another being the sternoclavicular 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 vessels, 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 TMJ syndrome symptoms and signs?
The main symptom of TMJ syndrome is pain in the jaw joint. This joint is located just in front of the ear, and pain associated with TMJ syndrome may involve the face, eye, forehead, ear, or neck. Signs and symptoms of TMJ syndrome include the following:
- Pain or tenderness in the jaw, especially at the area of the joint
- Popping/clicking of the jaw
- Pain that feels like a toothache
- Ear pain or sounds of cracking in the ears
- Ringing or popping sounds in the ears (tinnitus) or a sense of fullness in the ears
- Headaches, including migraines
- Blurred vision
- Tight, stiff, or sore jaw or neck muscles
- Muscle spasms in the jaw
- Facial pain, mouth pain, jaw pain, cheek pain, or chin numbness or tingling
- Pain at the base of the tongue
- Pain, swelling, or a lump in the temple area
- Difficulty chewing
- Shoulder pain
- Locking or dislocation of the jaw (usually after widely yawning), referred to as lockjaw
- Dizziness or vertigo
