Temporo-Mandibular Joint (TMJ)
What is TMJ?
TMJ refers to the Temporo-Mandibular Joint. This is the area where the lower jaw or mandible attaches to the skull at the temporal bone, just in front of and below the ears. The TM Joint is an articulating joint similar to the knee. A thin disc of cartilage separates the bony surfaces and is stabilized and supported by various muscles. This normally allows smooth movement when chewing, talking and swallowing. Palpation of the joint is generally painless.
What is TMJ Dysfunction?
TMJ Dysfunction refers to abnormalities related to the joint cartilage or bone, or the muscles which function to open and close the jaw. This can occur as a result of minor or major trauma, malocclusion (teeth not fitting together properly resulting in an imbalanced bite), bruxism (nighttime grinding of teeth), or excessive clenching of the jaw muscles which is often stress related. Either one or both joints may be affected.
What are the Symptoms of TMJ Dysfunction?
Symptoms may vary significantly, but ear pain, pressure and fullness are most common. This may be a chronic aching sensation which can radiate to the temple or down the jaw into the upper neck or throat. Pain can also be sensed in the cheek bone (maxilla) or area above the eye (frontal headache). An occasional sharp shooting or stabbing pain may occur as a result of muscle spasm similar to a cramp.
The jaw may click, pop or lock. This discomfort can be stimulated by chewing, yawning, or lying on the involved side when sleeping during the night. Exposure to a cold wind against the ear may cause aching as a result of the reflex contraction or tightening of the jaw muscles. Headaches are a frequent complaint. TMJ Dysfunction can also contribute to echoing, a false sensation of reduced hearing, noise in the ear (tinnitus) and dizziness (vertigo).
How is the Condition Diagnosed?
TMJ Dysfunction can usually be diagnosed by a proper history and physical exam. Palpation of the joint and muscles often produces varying degrees of tenderness and crepitus (clicking), and asymmetrical joint movement may also be present. An underlying malocclusion may be apparent as well. Symptoms are frequently muscular in nature, and abnormalities will not necessarily be apparent on dental x-ray studies.
How is this Condition Treated?
Symptomatic treatment of TMJ related problems can involve:
- Patient education.
- Joint rest (soft diet, avoidance of chewing , especially gum).
- Alternating ice packs and heat ( 5 minutes each) two to four times daily.
- Relaxation techniques and stress reduction.
- Non-steroidal anti-inflammatory medications with or without muscle relaxants.
Long-term management of chronic difficulties generally involves the care of a dentist with a special interest and expertise in this condition. This may involve the use of an occlusal splint which places the jaw into a relaxed position and reduces the wear and tear on the joint and teeth caused by bruxism.
Neuromuscular dentistry, physiotherapy, relaxation therapy and exercises to improve core strength and posture may also be necessary for certain individuals. Surgical treatment is indicated in a small minority.