TMJ Health and Occlusal Disease
“TMJ” is a popular term used to describe a disorder of the jaw joints, chewing muscles and bite. Symptoms masquerade as a multitude of other problems such as sinus headaches, migraines, neck and shoulder stiffness, earaches and tooth problems. These symptoms are caused by an instability in your jaw joint and can be successfully treated by a dentist who has specialized training in managing these disorders, such as Dr. James Segulyev.
TMD (TMJ dysfunction) is the dental term describing a collection of symptoms, which result when the chewing muscles, bite and jaw joints do not work together correctly.
TMJ stands for the temporomandibular joints. These are the two joints that connect your jaw to your skull. When these joints are not functioning as designed, they can cause many problems, such as:
- Clicking or popping noises
- Pain to opening or closing the jaw
- Locking or limited opening of your mouth
Muscle spasm goes hand-in-hand with displaced jaw joints. Because the nerves and muscles are so complex in this area, when these muscles are in spasm, the problems can be far-reaching. People suffer from symptoms they would never think to associate with their bite such as:
- Pain behind the eyes
- Earaches or ringing of the ears
- Clenching or grinding of the teeth
- Worn, broken loose and chipped teeth
- Neck, shoulder, or back pain
- Numbness, or tingling of the fingers
The primary problem can be in the joints themselves; the muscles of the face and jaw; the bite (how the teeth fit and work for chewing) or a combination of these. Because the symptoms masquerade as so many other conditions, many people travel from doctor to doctor in search of relief. It is estimated that as many as 10-15% of Americans suffer from one or more of these symptoms. Many never think to seek a dentist trained in TMD for help.
Open-Close: Comparison. This animation shows the functioning of the main muscles controlling the jaw for both the stable (on the left) and destructive (on the right) bites. In the destructive bite the upper and lower positioning muscles will quite often pull together as they fight the pull of the closing muscles and stop working in alternate phases as they do in the normal bite.
The structures that make it possible to open and close your mouth include the jawbones, jaw joints, and chewing muscles. These are very specialized and must work together whenever you chew, speak, or swallow. Your teeth are also inserted in your jaw bone. At the other end of your jaw bone are the temporomandibular joints. These joints attach your jaw to your skull. Muscles attach both the bones and joints and allow them to move. Any problem which prevents the complex system of teeth, muscles, bones, and joints from working together in harmony may result in TMD.
A “Bad Bite”
There are various ways this system can be disrupted, such as accidents involving a blow to the face or a whiplash. Yet the most common cause of TMD relates to your teeth and your bite. If your bite isn’t right, it can affect both the muscles and the joints. What do we mean by a “bad bite”? We mean that your upper and lower teeth do not come together in a way that provides the proper bracing support for your jaw against your skull. This might result from a missing tooth, misaligned teeth, or bite that has drifted due to tooth wear or teeth grinding.
Your upper and lower teeth must come together firmly each time you swallow. This happens over 1000 times each day and night! When your bite is unstable your muscles must work extra hard. This extra work makes them shortened and stiff. Eventually this strain makes them feel painful. A vicious cycle begins of increased tissue damage, muscle tenderness, and pain. The pain makes you feel tense and uptight. This worsens the muscle spasm, which in turn increases the pain.
The position of your teeth can also affect the position of your jaw joints. Each jaw joint is a ball and socket joint. When functioning properly, the ball and socket do not actually touch because a thin disc of cartilage rides between them. The disc acts as a cushion and allows the joint to move smoothly. Each disc is held in place and guided by muscle. If your bite is not right, the disc is pulled forward by hyperactivity of the muscle. Since the disc no longer serves as a cushion, the joint itself now rubs against the boney socket and presses on pain fibers. Mild displacements cause a clicking or popping sound in the jaw joint; more severe displacements can be very painful and eventually can cause permanent damage to the joint. An unstable bite can cause both jaw joint displacement and muscle strain and pain. When this condition is prolonged, the body begins to compensate and adapt by involving muscles in the neck, back, and shoulders.
Diagnosis and Treatment
Diagnosis of TMD involves a thorough history; an examination of the jaw joint and chewing muscles; evaluating joint noises; and checking the teeth and bite for wear and proper alignment. Additional records may include study models for detailed bite analysis and imaging such as Cone Beam Computed Tomography (CBCT).
Since the teeth, jaw joints, and muscles can all be involved, treatment for this condition can vary and will usually involve several phases. The first phase is to relieve the muscle spasm and pain and stabilize the jaw joint in the jaw socket. Often a temporary device known as a “bite splint” is worn over the teeth until the muscles relax and the pain is relieved. Once your jaw joint is stabilized, the second phase is to evaluate your bite for corrective options so you are not dependent on the “bite splint” for comfort and stability. Permanent correction involves refitting your bite and teeth with minimally invasive bonding materials – in some cases, building crowns on the teeth and/or orthodontics are needed. Rarely, if the jaw joint itself is damaged, it may need surgical care. Ultimately, Dr. Segulyev can stabilize your bite so that the teeth, muscles, and joints all work together naturally for optimal long-term health and comfort.
Proprioception. “Proprioception” describes the body’s ability to perceive an interference between teeth before it happens. The body quickly learns when teeth don’t fit together well when the jaw is fully seated in the jaw joint. The teeth will typically contact at a single point (called an interference) which will produce pain as all the force of closing is focused on that single point. You will naturally find a way of bringing the teeth together so that as many of them contact as possible, thus spreading the closing force across many teeth. Instead of closing on the interference and experiencing pain, you maneuver the jaw in a way that avoids the interference and closes in the more comfortable position of having many teeth together. This navigation is performed unconsciously, with the unconscious awareness of the interference being called “proprioception.”
What is a Stable and Unstable Chewing System?
The three reasons people lose their teeth are dental decay, gum disease and an unstable chewing system. Your chewing system consists of how your teeth fit together when your chewing muscles move your lower jaw up and down. An unstable chewing system, if not discovered and addressed, can cause excessive tooth wear; cracked or loose teeth; sensitive teeth; jaw joint disorders and early tooth loss.
Unstable: jaw joint not in socket where teeth fit
Stable: jaw joint in socket where teeth fit
Signs of an Unstable Chewing System:
You may have an unstable chewing system if you have one or more of the following signs and symptoms:
- Worn down, chipped, cracked or broken teeth
- Teeth that are sensitive to hot, cold and/or biting
- Multiple “root canals”
- Mobile or loosening teeth
- Clenching/grinding of your teeth
- Abfractions or wedge-shaped notches in the teeth at the gum line;
- Gum recession
- Severe localized bone loss around teeth
- Pain in the teeth and/or TMJ when you chew
- Headaches and facial muscle pain
- Teeth or dental work that fracture or break
On your back teeth, you will notice that there are points (cusps) and valleys (fossae). In a healthy bite, the cusps of your back teeth fit tightly into the fossae of your opposing teeth while the two jaw joints (TMJ’s) seat completely in their sockets. This is the least stressful and least destructive bite relationship for your teeth, bone, gums, TMJ’s, jaw muscles, and your existing dental work. The human bite is capable of generating forces measuring up to 900 pounds per square inch – so when your bite does not line up correctly, damage can and will occur.
In addition, a healthy bite has the proper amount of overlap of the upper front teeth over the lower front teeth to guide our side to side chewing motion (think of guardrails on a roadway). The front teeth protect the back teeth by limiting excess stress during chewing. When the front teeth are not aligned properly or are worn down, they are unable to provide this protective function, damaging the front and back teeth, bone, gums, TMJ’s and jaw muscles.
A simple way to demonstrate this “protective” function is by placing your hand on the side of your jaw and clenching fully on your back teeth. Can you feel how forcefully your muscles contract? Now, assuming that the upper and lower back teeth can separate from each other when your front teeth are edge-to-edge or canine-to-canine, try clenching with just your front teeth or canines. Can you feel how much less force is created by the muscles?
How is Occlusal Disease treated?
If your long-term goal is good dental health, you may choose to learn more about your unstable chewing system. We will recommend a detailed evaluation of your bite, which includes mounted study models, digital images and detailed records of your current condition. In many cases, bite splint therapy will be required to relax overworked chewing muscles and allow your jaw joint to properly seat in the jaw socket; years of an unstable bite can create chewing muscle imbalance and/or a TMJ disorder. Once your jaw joint is seated in the socket, a diagnosis of how your upper and lower teeth fit together is made to consider the most conservative option to stabilize your bite.