WHAT ARE TMJs?
Temporomandibular joints — TMJs — are located on both sides of the face in front of the ears, connecting the jawbone (mandible) to the skull (temporal bone). They’re the most complicated joints in the human body, providing rotation (pivoting) movement like all joints, as well as sliding movement, called translation. That’s what allows us to open our mouths wide and move our jaws from left to right. Between the top end of the jaw (condyle) and the socket in the skull is a disc of cartilage, which — like the discs in the neck and back — serve as shock absorbers, protecting the bones from hitting each other.
The joints work with the neuromuscular system
The movement of the jaw is orchestrated by a complex set of muscles, which are, in turn, controlled by the body’s local and central nervous system. Together, they’re called the neuromuscular system. The whole jaw-joint system is held together by ligaments, which limit the range of motion in all directions — as they do in all the joints of the body.
A unique system of many parts The TMJ joint system is unique in many ways. The left and right joints must coordinate, working at the same time for the jaw to move. While the opening, lateral and forward movements of the jaw are controlled by the shape of the bones and are a function of muscles and ligaments, the closing end-point of the jaw movement is controlled by the coming together of the teeth — the bite or occlusion. No other joint in the body has such a rigid end-point limit.
The proper, healthy function of the TMJ system requires normal structure and function of all the component parts, including muscles, nervous system, ligaments, joints (bones, discs and connecting tissues) and the dental occlusion.
WHAT ARE TMJ / TMD’s?
Temporomandibular disorders (TMJ / TMDs) are often called “TMJ” by doctors, patients and even insurance companies, although the term TMJ actually refers only to the jaw joints themselves.
TMD/TMJ describes a group of diseases that can involve the jaw joints, the muscles that control jaw movement and the dental occlusion. TMJ / TMDs are physical disorders arising from an imbalance in the delicate working relationship of the jaw and skull with the muscles that move the jaw, as well as the nervous system associated with these systems. This imbalance results in muscle fatigue, spasm and/or joint dysfunction, and even changes in the teeth, which in turn cause a variety of symptoms, unique for each person.
THE CAUSES OF TMJ / TMD
The symptoms of TMJ / TMD, which affect millions of adults and children, can gradually appear with no apparent, specific cause. They also can occur after a trauma, such as a traffic accident or a blow to the face. Even subtle repeated traumas, like clenching the teeth or excessive gum chewing, nail biting or cradling a phone between your shoulder and the side of your head can cause TMJ / TMD . These conditions can also be caused by a bad bite (dental malocclusion), which is not synchronized with healthy muscle and joint function. Systemic diseases and developmental abnormalities also can cause TMJ / TMD.
Stress may play a part
Stress and tension may awaken a quiet, asymptomatic TMJ / TMD or aggravate an existing temporomandibular condition. However, stress alone does not cause TMJ / TMD if a patient has healthy dental occlusion and muscle and jaw function.
A thorough exam is critical
A thorough analysis of each patient is essential to determine the source of pain. Early and appropriate treatment of a TMJ / TMD may avoid the progression to a chronic pain state.
DO YOU HAVE TMJ / TMD ?
If you think you may have a temporomandibular disorder, ask yourself these questions.