Temperomandibular Joint Disorders – TMJ

 The temporomandibular joint (TMJ) is the area directly in front of the ear on either side of the head where the upper jaw (maxilla) and lower jaw (mandible) meet. Muscles attached to and surrounding the jaw joint control the position and movement of the jaw. This joint is a unique sliding “ball and socket” that has a disc sandwiched between it, it is the only joint in the body which can move in all directions. The temporomandibular joint functions to move the jaw, especially in biting and chewing, talking, and yawning. It is one of the most used joints in the body.

The temporomandibular joints are very complex and are made up of muscles, tendons, a disc and bones.You have a temperomandibular joint on each side of your jaw (right and left side). Each part contributes to the smooth movement of the temperomandibular joint. When the muscles are relaxed and in balance and both jaw joints open and close comfortably, we are able to talk, chew, or yawn without discomfort or pain.

We can find the TMJ by placing a finger on the triangular area in front of the ear. The finger is moved just slightly forward and pressed firmly while opening the jaw. The motion felt is from the TMJ opening. We can also feel the joint motion if we put a little finger against the inside front part of the ear canal. If a patient is experiencing TMJ difficulty the simple act of opening and closing your mouth can cause considerable pain.

 Opening your mouth allows the rounded ends of the lower jaw (condyles) to glide along the joint socket of the temporal bone. The condyles are able to slide back to their original position when you close your mouth. The motion is kept smooth by a soft disc of cartilage that lies between the condyle and the temporal bone, creating a gliding cushion so that bone doesn’t rub across bone.  Chewing creates a very strong force. This disc is able to distribute the forces of chewing throughout the joint space. TMJ disorders (also called TMJ Syndromes) are a complex set of problems of the jaw joint.

The muscles and joints work as a team. A problem with either one can lead to stiffness, headaches, ear pain, bite problems ( also called a malocclusion), clicking sounds, or locked jaws. TMJ disorders can be caused by many different types of problems. These can include arthritis, trauma to the jaw, or muscle fatigue from clenching or grinding your teeth. TMJ disorders most commonly occur in women between the ages of 30 and 50, but can occur in teens after braces, and in both men and women at any age.

Behaviors that can Lead to TMJ Disorders

• –Teeth grinding (bruxism) speeds up the wear and tear on the cartilage lining of the TMJ. People who grind or clench their teeth may be not even be aware they are doing it. Many patients wake in the morning with jaw pain, ear pain or even a headache. Teeth grinding as a habit can result in muscle spasm and inflammatory reactions, thus causing the initial pain. Changes in the normal stimuli or height of the teeth, misalignment of the teeth, and changes in the chewing muscles may cause temporomandibular joint changes. Generally, someone who has a teeth grinding habit usually does so during his or her sleep.
• -Teeth Clenching. People who clench continually bite on things while awake. This might be as simple as chewing gum, a pen or pencil, or even fingernails. The constant pounding on the joint causes the pain. Stress is often the leading cause of teeth clenching.
• -Habitual gum chewing or fingernail biting -Dental problems and misalignment of the teeth (malocclusion). Patients may complain that it is difficult to find a  comfortable bite or that the way their teeth fit together has changed.  Chewing on only one side of the jaw can lead to or be a result of TMJ  problems.
• -Trauma to the jaws: Previous fractures in the jaw or facial bones can lead to TMJ disorders. Trauma is split into 2 types: micro trauma and macro trauma. Micro trauma is considered internal, such as grinding the teeth (bruxism) and clenching (jaw tightening). This continuous pounding on the temporomandibular joint can change the alignment of the teeth. The muscle involvement causes inflammation of the membranes surrounding the joint. Teeth grinding and clenching are habits that may be diagnosed in people who complain of pain in the temporomandibular joint or have facial pain that includes the muscles involved in chewing. Macro trauma is from an external trauma like a punch to the face or a car accident. This trauma can fracture the jawbone, cause dislocation of the TMJ, or cause damage to the cartilage disc of the joint. Pain in the TMJ can also occur following dental treatment whereby the joint is stretched open for extended periods of time. Massage and heat application following your dental appointment can help relive the discomfort.
• -Stress frequently leads to unreleased nervous energy. It is very common for people under stress to release this nervous energy by either consciously or unconsciously grinding  and clenching their teeth.
• -Routine tasks or habits such as holding the telephone between the head and shoulder may contribute to TMJ disorders.
• -Anatomy. You may have a malformed jawbone, joint, or disc, leading to poor function, wear and pain. TMJ pain can usually occur because of unbalanced activity, spasm, or overuse of the jaw muscles.

Symptoms tend to be chronic, and treatment is aimed at eliminating the cause. Many symptoms may not appear related to the TMJ itself.  

Common TMJ Disorder Symptoms

• -Headache. About 80% of patients with a TMJ disorder complain of headache and about 40% report facial pain, and ear pain. Pain is often worsened while opening and closing the jaw. Exposure to cold weather or air may increase muscle contraction and facial pain.
• -Ear pain. About one half of patients with a TMJ disorder notice ear pain and do not have any signs of ear infection. The ear pain is usually described as being in front of or below the ear. Because ear pain occurs so commonly in TMJ patients. Ear specialists are routinely called on to make the definitive diagnosis of a TMJ disorder.
• -Sounds. Grinding, crunching, clicking, or popping sounds (medical term = crepitus) are common for patients with a TMJ disorder. These sounds are not always associated with increased pain.
• -Dizziness. Approximately 40% report a slight sense of dizziness or imbalance. The cause of this type of dizziness is not known.
• -Fullness of the Ear. About one third of patients with a TMJ disorder describe muffled, clogged, or full ears. They may be aware of ear fullness and pain during airplane takeoffs and landings. These symptoms are usually caused by Eustachian-tube dysfunction (structure responsible for the regulation of pressure in the middle ear). It is believed that patients with TMJ syndromes have hyperactivity (muscle spasms) of the muscles responsible for regulating the opening and closing of the Eustachian tube.
• –Tinnitus (ringing or noise in ear). For reasons unknown, 33% of patients with a TMJ disorder experience tinnitus. 50% of those patients will have resolution of their tinnitus after successful treatment of their TMJ disorder.

Diagnosis

Many  conditions can cause similar symptoms to TMD. These include a toothache, sinus problems, arthritis, ear infection, or gum disease. Your dentist will conduct a careful patient history, dental examination, and take necessary x-rays to determine the cause of your symptoms.  A CT scan can provide the doctor or dentist very detailed images of the bones involved in the joint and MRI’s can show issues with the joint’s disk.

Treatment

Patients TMJ issues can sometimes go away on their own. If your symptoms persist, your doctor may recommend medications or a night guard to help keep you from grinding your teeth at night. Surgery may be required (in very rare cases) to repair or replace the joint. Conventional treatment consists of a diet of soft foods along with warm compresses to settle down the tension of the muscles.

Medications for Treatment of TMJ Disorders

• -Painkillers. Dentist or doctor will recommend over the counter medications (like Aleve or Motrin), or prescription medications such as Dolobid are a first option to relieve pain. If pain continues, they may prescribe something stronger to deal with pain.
• -Tricyclic antidepressants (Amitriptyline or Nortriptyline). Antidepressants prescribed to be taken at bedtime have been successful in relieving TMJ pain in some patients.
• -Muscle relaxants (Valium). These types of drugs are sometimes used for a few days or weeks to help relieve pain caused by TMJ disorders.
• -Corticosteroid drugs. These drugs can be injected into the joint space to provide relief. This is only used in patients with sever pain and discomfort.
• -Botulinum toxin. Botox Injections into the jaw muscles may give relief to pain associated with TMJ disorders.

Therapies Available

• –Night Guard. For patients who grind their teeth patients may gain from wearing a  firm custom made appliance. This night guard prevents your teeth from coming together in contact, and repositions teeth to decompress the jaw joint.
• -Psychological Therapy. For patients whose main symptom is from stress or anxiety they may benefit from a visit to a psychotherapist. This would allow the patient to become self aware of stress triggers as well learning relaxation techniques to relieve stress.

Surgical Treatment

• -Dental Adjustments. Your dentist may improve your bite by adjusting the biting surfaces of your teeth. This will allow for your bite to be in a more balanced state. Other options include replacing missing teeth, or replacing needed fillings or crowns. These actions sometimes worsen TMJ pain.
• -Joint Aspiration (Arthrocentesis). This procedure allows for joint irrigation. The joint will be irrigated to remove debris and inflammatory by products.
• -Surgery. This is considered to be a last resort. The surgery would be done to repair or replace the joint. This should be avoided when possible. Only about 1% of those with TMJ disorders requires surgery for joint replacement.

Most patients are quite successful with conventional conservative therapy (such as resting the jaw or night guard). The success of treatment depends on how severe the symptoms are and how well you comply with treatment. As always, it is best to maintain regular appointments to see your dentist and let them know if there any TMJ issues developing.