Temporomandibular Dysfunction (TMD) is a term that collectively encompasses symptoms that result when the jaw joints, supporting muscles and teeth don’t work together properly. The chewing system is supported by 2 temporomandibular joints (TMJ’s) that connect your jaw to the rest of your skull. Clicking/popping sounds, pain with opening/closing, limited opening abilities and joint locking are all signs that these joints may not be functioning properly. When these joints are displaced, the supporting muscles may shorten, stiffen and spasm. The complex association between nerves and muscles in this condensed space can create problems far from the site of origin. People with TMD suffer symptoms they may never think to associate with their mouth, such as:
- Headaches, especially in the temporal areas or behind the eyes
- Earaches, ringing in the ears, clogging of the ears and compromised hearing
- Neck, shoulder or back pain
- Numbness or tingling in the fingers
The origin of the problem could be in the joints themselves, the supportive muscles, the occlusion (the “bite”) or a combination. Because of the challenges in determining the origin of TMD-related symptoms, many desperate patients unsuccessfully jump from doctor to doctor, hoping for a cure from a variety of specialists. Many patients never consider seeking a TMD-trained dentist for help and many doctors (ENT’s, Chiropractors, and other specialists) aren’t aware that the symptoms they’re observing in their patients are TMD-related.
What causes Temporomandibular Joint Dysfunction?
The complex structural relationship that makes it possible to open and close your mouth, to chew, to speak and swallow include the jawbones, jaw joints, supporting muscles and the teeth themselves. There are various ways this complex system can be disrupted. Some patients with TMD have experienced an accident where they received a blow to the head or whiplash, but the vast majority of TMD sufferers have as their culprit something far more allusive, a “bad bite.” We’ll define a “bad bite” as one where the teeth don’t align properly to allow for healthy bracing of your jaw against your skull. This could occur from only the loss of one tooth, the misalignment of several teeth or from accelerated breakdown of the system due to wear damage (i.e. grinding).
Every time you swallow, your upper and lower teeth make contact and this amounts to approximately 1,000 times per day and night. And of course, your teeth also make contact when you chew or if you have a parafunctional habit (i.e., grinding). When your bite is unstable, your muscles are forced into overdrive which shortens, stiffens and inflames those muscles and can lead to pain.
The position of your teeth can also influence the position of your jaw joints. Jaw joints are ball and socket joints. A thin cartilaginous disk sits between those ball and socket bones and allows for smooth, fluid movement while preventing bone-on-bone contact. These discs are held in place and guided by muscles. In the “bad bite” scenario already described, the disc can be pulled forward, out of its proper position by muscle hyperactivity. This deviation of the disc can lead to jaw popping/clicking, to severe pain and even permanent damage to the joint itself. The instability of jaw joint displacement and muscle pain can lead to muscle pain in the neck, back and shoulders as the body begins to compensate for the problem.
TMD- Diagnosis and Treatment
Diagnosing TMD requires a comprehensive examination of the jaw joints, the supporting muscles and the interrelationship of the teeth. During this exam the joints are evaluated for any signs of dysfunction (i.e., popping/clicking sounds, limited opening, locking, deviation with opening/closing). The muscles are palpated and evaluated for signs of tension or inflammation. The teeth are evaluated for signs of excessive wear and misalignment. Additional records often include mounted teeth models on a jaw simulator and Cone Beam Computed Tomography (CBCT).
Treatment objectives for TMD involve joint stabilization and relief of muscle tension. In most cases, patients with TMD can undergo a predictable, reversible process utilizing splint therapy that allows the jaw joints to ideally seat in their sockets and relax overworked chewing muscles. A “splint” is an appliance that looks much like a nightguard, but unlike a conventional nightguard that’s simply designed to protect your teeth from frictional wear damage, the splint is designed to create a temporary idealized bite and allows the joints to return to their healthy position without interference from the teeth. While protecting your teeth from the harmful effects of clenching and grinding much like a nightguard, it also allows your jaw joints to realign to a comfortable, stable position, and your muscles to relax and release tension. Additionally, splint therapy serves as a predictable, diagnostic tool for determining what’s causing the instability in the chewing system so that more definitive treatment can be offered.
In essence, the restorative goals are to eliminate the discrepancies between a patient’s current unstable system and the ideal system created with the splint. Those restorative options are different for each patient and cannot be predicted in advance of splint therapy. Some patients can have their unstable chewing systems corrected quite conservatively with minimally invasive bonding techniques. Others might require more extensive restorative processes to reestablish healthy cusp/fossa relationships on the back teeth and guidance patterns on the front teeth. Some patients might benefit from orthodontics or even jaw surgery.