Temporomandibular Disorders (TMD)

Temporomandibular disorders (TMD) occur as a result of problems with the jaw, jaw joint and surrounding facial muscles that control chewing and moving the jaw. These disorders are often incorrectly called TMJ, which stands for temporomandibular joint.

What Is the Temporomandibular Joint (TMJ)?

The temporomandibular joint (TMJ) is the hinge joint that connects the lower jaw (mandible) to the temporal bone of the skull, which is immediately in front of the ear on each side of your head. The joints are flexible, allowing the jaw to move smoothly up and down and side to side and enabling you to talk, chew, and yawn. Muscles attached to and surrounding the jaw joint control the position and movement of the jaw.

What Causes TMD?

The cause of TMD is not clear, but dentists believe that symptoms arise from problems with the muscles of the jaw or with the parts of the joint itself. Injury to the jaw, temporomandibular joint, or muscles of the head and neck – such as from a heavy blow or whiplash – can cause TMD. Other possible causes include:

  • Grinding or clenching the teeth, which puts a lot of pressure on the TMJ
  • Dislocation of the soft cushion or disc between the ball and socket
  • Presence of osteoarthritis or rheumatoid arthritis in the TMJ
  • Stress, which can cause a person to tighten facial and jaw muscles or clench the teeth
  • People with TMD can experience severe pain and discomfort that can be temporary or last for many years. More women than men experience TMD, and TMD is seen most commonly in people between the ages of 20 and 40.

    Common symptoms of TMD include:

  • Pain or tenderness in the face, jaw joint area, neck and shoulders, and in or around the ear when you chew, speak, or open your mouth wide
  • Pain or tenderness in the face, jaw joint area, neck and shoulders, and in or around the ear when you chew, speak, or open your mouth wide
  • Jaws that get "stuck" or "lock" in the open- or closed-mouth position
  • Clicking, popping, or grating sounds in the jaw joint when opening or closing the mouth (which may or may not be accompanied by pain) or chewing
  • A tired feeling in the face
  • Difficulty chewing or a sudden uncomfortable bite – as if the upper and lower teeth are not fitting together properly
  • Swelling on the side of the face
  • May occur on one or both sides of the face
  • Other common symptoms of TMD include toothaches, headaches, neck aches, dizziness, earaches, hearing problems, upper shoulder pain, and ringing in the ears (tinnitis).

    How Is TMD Diagnosed?

    Because many other conditions can cause similar symptoms to TMD – including atoothache, sinus problems, arthritis, or gum disease – your dentist will conduct a careful patient history and physical examination to determine the cause of your symptoms.

    How Is TMD Diagnosed?

    Your dentist will examine your temporomandibular joints for pain or tenderness; listen for clicking, popping, or grating sounds during jaw movement; look for limited motion or locking of the jaw while opening or closing the mouth; and examine bite and facial muscle function. Sometimes panoramic X-rays will be taken. These full face X-rays allow your dentist to view the entire jaws, temporomandibular joint, and teeth to make sure other problems aren't causing the TMD symptoms. Sometimes, other imaging tests, such as magnetic resonance imaging (MRI) or a computer tomography (CT), are needed. The MRI views the soft tissue such as the TMJ disc to see if it is in the proper position as the jaw moves. A CT scan helps view the bony detail of the joint.

    Your dentist may decide to send you to an oral surgeon (also called an oral and maxillofacial surgeon) for further care and treatment. This oral health care professional specializes in surgical procedures in and about the entire face, mouth, and jaw area.

    What Treatments Are Available for TMD?

    Treatments for TMD range from simple self-care practices and conservative treatments to injections and surgery. Most experts agree that treatment should begin

    with conservative, nonsurgical therapies first, with surgery left as the last resort. Many of the treatments listed below often work best when used in combination.

    Basic Treatments for TMD

    Some basic, conservative treatments for TMD include:

  • Apply moist heat or cold packs. Apply an ice pack to the side of your face and temple area for about 10 minutes. Do a few simple stretching exercises for your jaw (as instructed by your dentist or physical therapist). After exercising, apply a warm towel or washcloth to the side of your face for about 5 minutes. Perform this routine a few times each day.
  • Eat soft foods. Eat soft foods such as yogurt, mashed potatoes, cottage cheese, soup, scrambled eggs, fish, cooked fruits and vegetables, beans, and grains. In addition, cut foods into small pieces to decrease the amount of chewing required. Avoid hard and crunchy foods (like hard rolls, pretzels, raw carrots), chewy foods (like caramels and taffy) and thick and large foods that require your mouth to open wide to fit.
  • Take medications. To relieve muscle pain and swelling, try nonsteroidal anti-inflammatory drugs (NSAIDs), such as naproxen or ibuprofen (Advil, Motrin, Aleve). Your dentist can prescribe higher doses of these or other drugs for pain relief. Muscle relaxants, especially for people who grind or clench their teeth, can help relax tight jaw muscles. Anti-anxiety medications can help relieve stress that is sometimes thought to aggravate TMD. Antidepressants, when used in low doses, can also help reduce or control pain. Muscle relaxants, anti-anxiety drugs, and antidepressants are available by prescription only.
  • Low-level laser therapy. This is used to reduce the pain and inflammation, as well as increase range of motion to the neck and in opening the mouth.
  • Wear a splint or night guard. Splints and night guards are plastic mouthpieces that fit over the upper and lower teeth. They prevent the upper and lower teeth from coming together, lessening the effects of clenching or grinding the teeth. They also correct the bite by positioning the teeth in their most correct and least traumatic position. The main difference between splints and night guards is that night guards are only worn at night and splints are worn all the time. Your dentist will discuss with you what type of mouth guard appliance you may need.
  • Undergo corrective dental treatments. Corrective treatments including replacing missing teeth and using crowns, bridges, or braces to balance the biting surfaces of your teeth or to correct a bite problem.
  • Avoid extreme jaw movements. Keep yawning and chewing (especially gum or ice) to a minimum and avoid extreme jaw movements such as yelling or singing.
  • Don't rest your chin on your hand or hold the telephone between your shoulder and ear. Practice good posture to reduce neck and facial pain.
  • Keep your teeth slightly apart as often as you can to relieve pressure on the jaw. To control clenching or grinding during the day, place your tongue between your teeth.
  • Learning relaxation techniques to help control muscle tension in the jaw. Ask your dentist about the need for physical therapy or massage. Consider stress reduction therapy, including biofeedback.
  • More Controversial Treatments for TMD

    When the basic treatments listed above prove unsuccessful, your dentist may suggest one or more of the following treatments for TMD:

  • Transcutaneous electrical nerve stimulation (TENS). This therapy uses low-level electrical currents to provide pain relief by relaxing the jaw joint and facial muscles. This treatment can be done at the dentist's office or at home.
  • Ultrasound. Ultrasound treatment is deep heat that is applied to the TMJ to relieve soreness or improve mobility.
  • Trigger-point injections. Pain medication or anesthesia is injected into tender facial muscles called "trigger points" to relieve pain.
  • Radio wave therapy. Radio waves create a low level electrical stimulation to the joint, which increases blood flow. The patient experiences relief of pain in the joint.
  • Surgery for TMD

    Surgery for TMD should only be considered after all other treatment options have been unsuccessful. Because surgery is irreversible, it is wise to get a second or even third opinion from other dentists.

    There are three types of surgery for TMD: arthrocentesis, arthroscopy, and open-joint surgery. The type of surgery needed depends on the TMD problem.

  • Arthrocentesis. This is a minor procedure performed in the office under general anesthesia. It is performed for sudden-onset, closed lock cases (restricted jaw opening) in patients with no significant prior history of TMJ problems. The surgery involves inserting needles inside the affected joint and washing out the joint with sterile fluids. Occasionally, the procedure may involve inserting a blunt instrument inside of the joint. The instrument is used in a sweeping motion to remove tissue adhesion bands and to dislodge a disc that is stuck in front of the condyle (the part of your TMJ consisting of the "ball" portion of the "ball and socket")
  • Arthroscopy. Patients undergoing arthroscopic surgery for TMD first are given general anesthesia. The surgeon then makes a small incision in front of the ear and inserts a small, thin instrument that contains a lens and light. This instrument is hooked up to a video screen, allowing the surgeon to examine the TMJ and surrounding area. Depending on the cause of the TMD, the surgeon may remove inflamed tissue or realign the disc or condyle.
  • Compared with open surgery, this surgery is less invasive, leaves less scarring, and is associated with minimal complications and a shorter recovery time. Depending on the cause of the TMD, arthroscopy may not be possible, and open-joint surgery may be necessary.

    Open-joint surgery. Patients undergoing open-joint surgery also are first given general anesthesia. Unlike arthroscopy, the entire area around the TMJ is opened so that the surgeon can get a full view and better access. There are many types of open-joint surgeries. This treatment may be necessary if:

  • The bony structures that comprise the jaw joint are deteriorating
  • There are tumors in or around your TMJ
  • There is severe scarring or chips of bone in the joint.
  • Surgery for TMD continued...

    Compared with arthroscopy, open-joint surgery for TMD results in a longer healing time and there is a greater chance of scarring and nerve injury.


    B) Dental Sleep Apnoea

    Oral Appliances

    Oral appliances (OA) are a front-line treatment for patients with mild to moderate Obstructive Sleep Apnea (OSA) who prefer OAs to continuous positive airway pressure (CPAP), or who do not respond to CPAP, are not appropriate candidates for CPAP, or who fail treatment attempts with CPAP or treatment with behavioral measures such as weight loss or sleep position change. This small plastic device fits in the mouth during sleep like a sports mouth guard or orthodontic retainer. Oral appliances help prevent the collapse of the tongue and soft tissues in the back of the throat, keeping the airway open during sleep and promoting adequate air intake. Oral appliances may be used alone or in combination with other treatments for sleep-related breathing disorders, such as weight management, surgery or CPAP.

    Standards of Care

    Patients with primary snoring or mild OSA who do not respond to, or are not appropriate candidates for treatment with behavioral measures such as weight loss or sleep-position change.

    Patients with moderate to severe OSA should have an initial trial of nasal CPAP, due to greater effectiveness with the use of oral appliances.

    Patients with moderate to severe OSA who are intolerant of or refuse treatment with nasal CPAP. Oral appliances are also indicated for patients who refuse treatment, or are not candidates for tonsillectomy and adenoidectomy, cranofacial operations, or tracheostomy.

    Oral Appliance Therapy

    Oral appliance therapy involves the selection, fitting and use of a specially designed oral appliance that maintains an open, unobstructed airway in the throat when worn during sleep. Custom-made oral appliances are proven to be more effective than over-the-counter devices, which are not recommended as a screening tool nor as a therapeutic option.

    Dentists with training in oral appliance therapy are familiar with the various designs of appliances and can help determine which is best suited for your specific needs. A board certified sleep medicine physician must first provide a diagnosis and recommend the most effective treatment approach. A dental sleep medicine specialist may then provide treatment and follow-up.

    The initial evaluation phase of oral appliance therapy can take several weeks or months to complete. This includes examination, evaluation to determine the most appropriate oral appliance, fitting, maximizing adaptation of the appliance, and the function.

    Ongoing care, including short- and long-term follow-up is an essential step in the treatment of snoring and Obstructive Sleep Apnea with Oral Appliance Therapy. Follow-up care serves to assess the treatment of your sleep disorder, the condition of your appliance, your physical response to your appliance, and to ensure that it is comfortable and effective.

    Advantages of Oral Appliance Therapy

  • Oral appliances are comfortable and easy to wear. Most people find that it only takes a couple of weeks to become acclimated to wearing the appliance.
  • Oral appliances are small and convenient making them easy to carry when traveling.
  • Treatment with oral appliances is reversible and non-invasive.
  • How Oral Appliances Work

  • Repositioning the lower jaw, tongue, soft palate and uvula
  • Stabilizing the lower jaw and tongue
  • Increasing the muscle tone of the tongue
  • Types of Oral Appliances

    With so many different oral appliances available, selection of a specific appliance may appear somewhat overwhelming. Nearly all appliances fall into one of two categories. The diverse variety is simply a variation of a few major themes. Oral appliances can be classified by mode of action or design variation.

    Tongue Retaining Appliances

    Tongue retaining appliances hold the tongue in a forward position using a suction bulb. When the tongue is in a forward position, it serves to keep the back of the tongue from collapsing during sleep and obstructing the airway in the throat.

    Mandibular Repositioning Appliances

    Mandibular repositioning appliances reposition and maintain the lower jaw in a protruded position during sleep. The device serves to open the airway by indirectly pulling the tongue forward, stimulating activity of the muscles in the tongue and making it more rigid. The device also holds the lower jaw and other structures in a stable position to prevent the mouth from opening.

    For people with mild to moderate sleep apnea, particularly those who sleep on their backs or stomachs, dental devices may improve sleep and reduce the frequency and loudness of snoring. Also, people are more likely to use their dental appliances regularly than CPAP.

    Dental devices have also been shown to control sleep apnea long term compared to uvulopalatopharyngoplasty (UPPP), the standard surgical procedure for apnea, in which the surgeon removes soft tissue from the back of the throat. However, dental devices do have some potential drawbacks, including altered bite, movement ofteeth, pain, dry lips, and excessive salivation.

    If you are fitted with a dental device you should have a checkup early on to see if it is working and periodic checkups for possible adjustment or replacement. If you experience pain or changes in your bite, your dentist or orthodontist who fitted your device may be able to make modifications to correct the problem.

    The best treatment for obstructive sleep apnea depends on a number of factors, including the severity of your problem, the physical structure of your upper airway, other medical problems you may have, as well as your personal preference. You should work with your doctor or sleep specialist to select the best treatment option for you.


    c) Sport Dentistry

    Do athletic mouthguards have a role in reducing the incidence and severity of cerebral concussion in sports?

    This is a controversial question now being asked by the sporting world, especially for high-impact sports such as hockey and football. The apparent increase in concussion rates has led to claims by dentists and over-the-counter mouthguard suppliers regarding the use and effectiveness of athletic mouthguards in reducing concussions. Numerous minor hockey leagues have introduced mouthguard rules as a possible result of concussion, rather than dental concerns.

    Though anecdotal, there are three possible theories on the potential benefits of properly-fitting athletic mouthguards and the reduction of the incidence or severity of concussions. It should be noted that these are theories, which in most cases are NOT PROVEN in the medical/dental literature.

    1. Direct dissipation and/or absorption of force of an upward blow to the jaw.
    2. Increased separation of the head of the condyle and glenoid fossa
    3. Increased head stabilization by activating and strengthening neck muscles.

    Dissipation of forces

    Mouthguard materials by nature must have shock absorption qualities. They must be resilient and yet soft enough to absorb impact energy and reduce transmitted forces. The thickness of mouthguard material is directly related to energy absorption and inversely related to transmitted forces when impacted. However, wearer comfort is also an important factor in their use. Thicker mouthguards are often not user-friendly. Transmitted forces through different thicknesses of the most commonly-used mouthguard material (ethylene vinyl acetate – EVA - Shore Hardness of 80) were compared when impacted with identical forces capable of damaging the oro-facial complex. The results showed that the optimal thickness for EVA mouthguard material with a Shore Hardness of 80 is around 4 mm. on the occlusal surface. All teeth must be properly covered and the bite balanced accordingly. Increased thickness, while improving performance marginally, may result in less wearer comfort and acceptance.

    Stenger, in 1964, reported that forces from mandibular impact would be attenuated with a mouthguard, resulting in fewer injuries. Hickey discussed that mouth protectors reduced pressure changes and bone deformation within the skull in a cadaver model. He demonstrated a decrease of 50% in the amplitude of the intracranial pressure after a blow to the chin when wearing a mouthguard.

    Increased Condylar Separation

    When a properly-fitted and balanced custom-made mouthguard is in place there is a forward/ downward movement of the jaw, thus opening the space between the glenoid fossa and the condylar head. This may reduce the opportunity for the condylar head to directly impact the glenoid fossa after an upward blow to the jaw, thus reducing the impact and acceleration forces to the entire temporal region. Again, while it might be advantageous to significantly open this space for protection, an excessive thickness of material on the biting surface might compromise both comfort and performance.

    Increased head stabilization by activating and strengthening neck muscles

    Dr. Karen Johnston, a prominent Canadian concussion researcher, noted that: "The force required to concuss a fixed head is almost twice that required to concuss a mobile head". Further, there is some correlation between the degree of rotation that the head goes through on impact and the severity of the concussion that might result. By activating additional head and neck muscles at the time of impact this arc of rotation might be decreased, leading to less harmful movement of the brain inside the skull. Some researchers have begun to show that by being able to clench down harder on a mouthguard the activation of the head and neck muscles might serve to stabilize the head. Some have suggested further that this effect might be in place whether or not the athlete sees the impact coming.

    The Bottom Line

    As Dr. Paul McCrory once stated about the connection between mouthguards and concussions "Absence of proof is not proof of absence". We should always remember that the primary role of mouthguards is the protection of the teeth and orofacial structures, and mouthguards should be primarily designed to accomplish this goal – with adequate protection in the areas most likely to be traumatized (maxillary incisor teeth).

    However, there are some basic design elements that can and should be included in any mouthguard that might enhance the potential concussion-prevention aspects of mouthguards. All mouthguards should have an adequate thickness and should cover as much of the occlusal surface as the athlete can tolerate. Mouthguards must have proper retention built into them to ensure that they stay in place at the moment of impact. Mouthguards should not be over trimmed in the posterior, which might actually force the condyles into the glenoid fossae. All mouthguards should be balanced occlusally to ensure an even distribution of force across the entire surface.

    NOTE: The authors would like to stress and emphasize that the above information is theory ONLY and has not yet been proven in the medical/dental literature. We DO NOT support the claims made by mouthguard manufacturers and other dentists that there is a definite relationship between mouthguards and cerebral concussion. Until it is proven in the medical literature, this stand will continue. Athletic mouthguards, until proven different, are primarily for the reduction of orofacial injury.

    References

    Westerman B, Stringfellow PM, Eccleston JA., EVA mouthguards: How thick should they be? Department of Mathematics, The University of Queensland, Brisbane, Australia. Dental Traumatology, Vol. 18 Issue 1 Page 24 February 2002

    Duhaime CF, Whitmyer CC, Butler RS, Kuban B., Comparison of Forces Transmitted Through Different EVA Materials, Department of Dentistry, The Cleveland Clinic Foundation, Cleveland, OH 44195, USA. Dent Traumatol. 2006 Aug;22(4):186-92.

    Stenger JM,Lawton EA, Wright JM, Ricketts J, Mouthguards: Protection Against Shock to Heqad, Neck and Teeth, Basal Facts. 1987;9(4):133-9. PMID: 2975489 Stenger JM,Lawton EA, Wright JM, Ricketts J, Mouthguards: Protection Against Shock to Head, Neck and Teeth, J Am Dent Assoc. 1964 Sep;69:273-81.PMID: 14178758 McCrory, Paul. Do mouthguards prevent concussions? Br. J. Sport Med. vol. 35, pp. 81 - 82, 2001
    K.M. Johnston et all, 2001

    Think mouthguards are just for varsity athletes? Consider this: According to a recent study in theJournal of Strength and Conditioning,mouthguards can improve upper and lower body-loaded power exercises during a workout.

    The study of 26 men and 24 women found participants generated more power when performing explosive exercises like the bench throw—a bench press where you throw the barbell away from your chest and catch it—and vertical jumps when they were wearing a mouthguard than when they weren't. What gives? Researchers believe clenching your teeth—like you do when you're wearing a mouthguard—is similar to chewing. It can increase blood flow to areas of the brain associated with memory, and awareness as well as motor control, timing, and fear.

    More from MensHealth.com: Protective Sports Gear That Works

    But it's not without risks. Storing your mouthguard in a sock, helmet, or protective padding, for example, can harbor bacteria, yeast, and fungal elements that irritate the tissues in the mouth and upper GI tract, allowing microorganisms access to the bloodstream. According to a recent study, mouth guards can also contain alarming amounts of bacteria.

    And if exercise-induced asthma ever kills your game, your filthy mouthguard could be to blame. "Sucking in these spores can create allergy-like symptoms," says Richard Glass, Ph.D., a professor at Oklahoma State University. Worse, if you're a Gatorade drinker (sugar feeds bacteria), store your mouthguard in a cool, damp environment—like a locker room or a gym bag—and only wash that baby with a squirt of water, you're basically breeding bacteria.

    Here's how you can keep your guard pristine: Replace it every two weeks, and between uses, treat it like Granny treats her dentures, says Glass. Consider an antibacterial rinse like Defense Sport Mouthguard Rinse from Sani Brands Inc., the first product of its kind. Many NFL teams—including the Philadelphia

    Eagles, Pittsburgh Steelers, and New York Giants—use it.

    Prefer a DIY solution? Soak the mouthpiece overnight in a small cap of Clorox with a cup of water or a teaspoon of baking soda with 6 ounces of water.

    Dear Dr. Gadekar, first of all I would like to thank you for transforming my approach to life, so drastically. I feel that I have grown a lot in confidence now