Definition and causes
The following gives an overview of the subject of bruxism, incl. definition, causes, symptoms, diagnostic problems, associated factors, conventional treatment options etc. Adapted by Healing Teeth Naturally from Wikipedia, the free encyclopedia. For healing suggestions which are likely to address bruxism at the causal level, see Healing bruxism.
Definition of bruxism
Bruxism (from the Greek βρυγμÏŒς [brugmós], gnashing of teeth) is the grinding of the teeth, and is typically accompanied by the clenching of the jaw. It is an oral parafunctional activity that occurs in most humans at some time in their lives. In most people, bruxism is mild enough not to be a health problem; however, 25% of people suffer from significant bruxism that will become symptomatic.
While bruxism may be a diurnal [daytime] or nocturnal [nighttime] activity, it is nocturnal bruxism which causes the majority of health issues, and can even occur during short naps. Bruxism is one of the most common sleep disorders.
Causes of bruxism
In general, Bruxism is caused by the activation of reflex chewing activity; it is not a learned habit. Chewing is a complex neuromuscular activity that is controlled by reflex nerve pathways, with higher control by the brain. During sleep, the reflex part is active while the higher control is inactive, resulting in bruxism. In addition, when using MDMA (ecstasy), the user will sometimes experience bruxism.
The etiology of problematic bruxism is unknown, although several related conditions are known to be linked to bruxism. It is also theorized that certain medical conditions can trigger episodes of bruxism, including digestive ailments and anxiety.
Signs, symptoms and sequelae
Most bruxers are not aware of their bruxism and only 5% go on to develop symptoms such as jaw pain and headache which will require treatment. In many cases, a spouse or parent will notice the bruxism before the person experiencing the problem.
Bruxism can result in abnormal wear patterns of the occlusal surface, abfractions and fractures in the teeth. This type of damage is categorised as a sign of occlusal trauma.
Over time, dental damage will usually occur. Bruxism is the leading cause of occlusal trauma and a significant cause of tooth loss and gum recession.
In a typical case, the canines and incisors of the opposing arches are moved against each other laterally, i.e. with a side-to-side action by the lateral pterygoid muscles that lie medial to the temporomandibular joints bilaterally. This movement abrades tooth structure, and can lead to the wearing down of the incisal edges of the teeth. People with bruxism may also grind their posterior teeth, which will wear down the cusps of the occlusal surface.
Bruxing can be loud enough to wake a sleeping partner. Some individuals will clench the jaw without significant lateral movements. Teeth hollowed by previous decay (caries), or dental drilling, may collapse, as the cyclic pressure exerted by bruxism is extremely taxing on the tooth structure.
Patients may present with a variety of symptoms, including:
- Stress or Tension
- Eating Disorders
- Jaw Pain
Eventually, bruxing shortens and blunts the teeth being ground, and may lead to myofacial muscle pain, temporomandibular joint dysfunction and headaches. In severe, chronic cases, it can lead to arthritis of the temporomandibular joints. The jaw clenching that often accompanies bruxism can be an unconscious neuromuscular daytime activity, which should be treated as well, usually through physical therapy (recognition and stress response reduction).
Bruxism can sometimes be difficult to diagnose as it is not the only cause of tooth wear. Over-vigorous brushing, abrasives in toothpaste, acidic soft drinks and abrasive foods can also be contributing factors, although each has characteristic wear patterns that a trained professional can identify. Additionally, the presenting symptoms may be difficult for a physician to attribute to bruxism.
The effects of bruxing may be quite advanced before sufferers are aware they brux. Abraded teeth are usually brought to the patient's attention during a routine dental examination. If enough enamel has been abraded, the softer dentine will be exposed and abrasion will accelerate. This opens the possibility of dental decay and tooth fracture, and in some people, gum recession. Early intervention by a dentist is advisable.
A recently introduced device called the BiteStrip enables at-home overnight testing for sleep bruxism. It is proposed that this might help diagnose bruxism before damage appears on the teeth. The device is a miniature electromyograph machine that senses jaw muscle activity while the patient sleeps.
A dentist can establish the frequency of bruxing, which helps in formulating a treatment plan. Anyone having major occlusal rehabilitation should be aware that bruxism can easily ruin prosthetic dental work.
The following factors are associated with bruxism.
- Disturbed sleep patterns and other sleep disorders, (obstructive sleep apnea, hypopnea, snoring, moderate daytime sleepiness)
- Malocclusion, in which the upper and lower teeth occlude in a disharmonic way, e.g., through premature contact of back tooth
- Relatively high levels of consumption of caffeinated drinks and foods, such as coffee, colas, and chocolate
- High levels of blood alcohol
- High levels of anxiety, stress, work-related stress, irregular work shifts, stressful profession and ineffective coping strategies
- Medication, such as SSRIs and stimulants
- Hypersensitivity of the dopamine receptors in the brain
- Stimulant drugs, particularly those of the amphetamine-based family (MDMA)
- GHB and similar GABA-inducing analogues such as Phenibut, when taken with high frequency
- Disorders such as Huntington's and Parkinson's diseases
There is no single accepted cure for bruxism. However, treatments are available.
Bruxism may be reduced or even eliminated when the associated factors, e.g. sleep disorders, are treated successfully.
Mouthguards and repositioning splints
Ongoing management of bruxism is based on minimizing the abrasion of tooth surfaces by the wearing of an acrylic dental guard or splint, designed to the shape of an individual's upper or lower teeth from a bite mould. Mouthguards are obtained through visits to a dentist for measuring, fitting, and ongoing supervision.
There are four possible goals of this treatment: constraint of the bruxing pattern such that serious damage to the temporomandibular joints is prevented, stabilization of the occlusion by minimizing the gradual changes to the positions of the teeth that typically occur with bruxism, prevention of tooth damage, and the enabling of a bruxism practitioner to judge — in broad terms — the extent and patterns of bruxism, through examination of the physical indentations on the surface of the splint.
A dental guard is typically worn on a long-term basis during every night's sleep.
Professional treatment is medically recommended to ensure proper fit, make ongoing adjustments as needed, and check that the occlusion (bite) has remained stable. Monitoring of the mouthguard is suggested at each dental visit. 
Another type of device sometimes given to a bruxer is a repositioning splint. A repositioning splint may look similar to a traditional night guard, but is designed to change the occlusion, or "bite," of the patient. Randomly controlled trials with these type devices generally show no benefit  over more conservative therapies and they should be avoided under most if not all circumstances.
The NTI-tss device is another option that can be considered. The NTI covers only the front teeth and prevents the rear molars from coming into contact, thus limiting the contraction of the temporalis muscle. The NTI must be fitted by your dentist.
The efficacy of such devices is debated. Some writers propose that irreversible complications can result from the long-term use of mouthguards and repositioning splints.
Botulinum toxin (Botox) has recently been seen to be very successful in treating the grinding and clenching of bruxism. Botox is an injectable medication that weakens muscles and is used commonly in cosmetic procedures to relax the muscles of the face and decrease the appearance of wrinkles.
Botox was not originally developed for cosmetic use, however. It was, and continues to be, used to treat diseases of muscle spasticity such as blepharospasm (eyelid spasm), strabismus (crossed eyes) and torticollis (wry neck).
Bruxism can also be regarded as a disorder of repetitive, unconscious contraction of the masseter muscle (the large muscle that moves the jaw). Botox works very well to weaken the muscle enough to stop the grinding and clenching, but not so much as to interfere with chewing or facial expressions.
The strength of Botox is that the medication goes into the muscle, weakens it and does not get absorbed into the body. The procedure involves about five or six simple, relatively painless injections into the masseter muscle. It takes a few minutes per side and the patient starts feeling the effects the next day. Occasionally, some bruising can occur, but this is quite rare. The symptoms that are helped by this procedure include:
- Grinding and clenching
- Morning jaw soreness
- TMJ pain
- Muscle tension throughout the day
- Migraines triggered by clenching
- Neck pain and stiffness triggered by clenching
The optimal dose of Botox must be determined for each person as some people have stronger muscles that need more Botox. This is done over a few touch up visits with the physician injector. This treatment is expensive, but sometimes Botox treatment of Bruxism can be billed to medical insurance (plans vary - its good to call your plan beforehand to find out what is covered and what documentation is necessary).
The effects last for 3 months or so. The muscles do atrophy, however, so after a few rounds of treatment it is usually possible to either decrease the dose or increase the interval between treatments. 
Other authorities caution that Botox should only be used for temporary relief for severe cases and should be followed by diagnosis and treatment to prevent future bruxism or jaw clenching, suggesting that prolonged use of Botox can lead to permanent damage to the jaw muscle.
There is limited evidence that suggests taking certain combinations of dietary supplements may alleviate bruxism; pantothenic acid, magnesium, lavender, and calcium have been examined.
Various biofeedback devices are currently available, but their effectiveness is as yet unproven. While anecdotal evidence suggests that they may be useful, some bruxism authorities remain unconvinced.
One biofeedback mechanism that has significant promise was developed by Moti Nissani, PhD and is called "The Taste-Based Approach to the Prevention of Teeth Clenching and Grinding." The therapy involves suspending sealed packets containing a bad-tasting substance (e.g. hot sauce, vinegar, denatonium benzoate, etc.) between the rear molars using an orthodontic-style appliance. Any attempt to bring the teeth together will rupture the packets and alert the user to the habit.
While no cure exists for bruxism, this approach, if implemented properly and rigorously, has promise to be an effective treatment for bruxism. Importantly, the Taste-Based Approach does not suffer from the risk of desensitization that other available sound-based biofeedback approaches may have. (There is effectively no limit to the aversive taste of certain substances. We can therefore be sure that some harmless substance exists that will alert anyone to the habit.)
One of these devices, the Oralsensor, comprises a pneumatic pouch embedded in a soft polymer plate that fits over upper or lower teeth. When the teeth come together—to a threshold pressure set each night by the user—an alarm is sounded in an earpiece worn by the user.
Another biofeedback device, GrindAlert, is a battery-powered device that sounds a tone when it senses EMG (electromyographic) muscle activity in the temporalis muscles of the forehead. This device delivers nightly data on the number of bruxism events that last for at least two seconds, and the total duration of those events. The volume of the alarm and the sensitivity of the piezo device to EMG signals from the muscles are adjustable.
In 2005, a new type of occlusive device was patented that produces a movement incompatible with teeth clenching. When nighttime bruxism occurs, people breathe through the nose. The device forces people to breathe through the mouth; by forcing the opening of the mouth, the device is claimed to stop clenching. The occlusive device has an electromyogram system that monitors the electric activity of the jaw muscle via wireless electrodes. These electrodes transfer jaw-muscle activity by radio frequency to an external monitoring system. Once the signal has been interpreted by the monitoring system, if a person clenches, the monitoring unit sends a radio frequency signal to a transceiver integrated in a mechanical actuator. The mechanical actuator has two occlusive flaps that block the nostrils, forcing breathing to occur through the mouth. Once the patient stops clenching, the flaps open, allowing breathing through the nose again. The occlusive device does not wake up people since it blocks nostrils slowly, and it never closes them completely to avoid sleep disruption.
Repairing damage to teeth from bruxism
Damaged teeth can be repaired by replacing the worn natural crown of the tooth with prosthetic crowns. Materials used to make crowns vary; some are less prone to breaking than others, and can last longer. Porcelain fused to metal crowns may be used in the anterior (front) of the mouth; in the posterior, full gold crowns are preferred. All porcelain crowns are now becoming more and more common and work well for both anterior and posterior restorations. To protect the new crowns and dental implants, an occlusal guard should be fabricated to wear during sleep.
Note: Healing Teeth Naturally does not endorse the use of crowns or implants, see Dr. Hulda Clark on dental detox (incl. metal crowns) and for greater detail, the "Bridges and Crowns" section as well as Potential risks of dental implant surgery: from implant failure to irreparable nerve damage.
- Answers.com Article on Bruxism
- The use of a bruxChecker in the evaluation of different grinding patterns during sleep bruxism. (Clinical report)
- Training for Bruxism/TMJ
- Maurice M. Ohayon, MD, DSc, PhD; Kasey K. Li, DDS, MD and Christian Guilleminault, MD: "Risk Factors for Sleep Bruxism in the General Population";Stanford University School of Medicine, Sleep Disorders Center, Stanford, CA;
- Y. Kobayashi, M. Yokoyama, H. Shiga, and N. Namba: 1198 Sleep Condition and Bruxism in Bruxist, Nippon Dental University, Tokyo, Japan
- Oksenberg A, Arons E.: "Sleep bruxism related to obstructive sleep apnea: the effect of continuous positive airway pressure.";Sleep Disorders Unit, Loewenstein Hospital-Rehabilitation Center, P.O. Box 3, Raanana, Israel
- Ng DK, Kwok KL, Poon G, Chau KW "Habitual snoring and sleep bruxism in a paediatric outpatient population in Hong Kong." Department of Paediatrics, Kwong Wah Hospital, Waterloo Road, Hong Kong, SAR China.
- Lurie, Orit; Zadik, Yehuda; Tarrasch, Ricardo; Raviv, Gil; Goldstein, Liav (February 2007). "Bruxism in Military Pilots and Non-Pilots: Tooth Wear and Psychological Stress". Aviat Space Environ Med 78 (2): 137-9. PMID 17310886. Retrieved on 2008-07-16.
- A proposed mechanism for diurnal/nocturnal bruxism: hypersensitivity of presynaptic dopamine receptors in the frontal lobe.
- Winocur E, Gavish A, Voikovitch M, Emodi-Perlman A, Eli I: "Drugs and bruxism: a critical review.";Department of Occlusion and Behavioral Sciences, Maurice and Gabriela Goldschleger, School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
- Bruxism/Teeth grinding - MayoClinic.com
- Nissani, Moti: "When the Splint Fails: Non-Traditional Approaches to the Treatment of Bruxism",Author's website, Wayne State University.
- Capp, N.J. (1999-03-13.) "Tooth surface loss; Part 3: Occlusion and splint therapy". British Dental Journal, Vol. 186, No. 5, via nature.com. Retrieved on 2007-10-14.
- Clark, GT, Minakuchi, H: Oral Appliances, TMDs An Evidence-Based Approach to Diagnosis and Treatment, Chicago, 2006, Quintessence, pp. 377-390
- Dao, TTT, Lavigne, GJ.: Oral Splints: The Crutches For Temporomandibular Disorders and Bruxism? Crit Rev Oral Biol Med 9:345-361, 1998 Abstract Full Text
- Widmalm, Sven E. "Use and Abuse of Bite Splints", (Website, lectures from author's homepage), University of Michigan, 2004-10-27. Retrieved on 2007-10-14.
- Schwartz M, Freund B. Treatment of temporomandibular disorders with botulinum toxin. Clin J Pain. 2002 Nov-Dec;18(6 Suppl):S198-203
- Guarda-Nardini L, Manfredini D, Salamone M, Salmaso L, Tonello S, Ferronato G. Efficacy of botulinum toxin in treating myofascial pain in bruxers: a controlled placebo pilot study.Cranio. 2008 Apr;26(2):126-35.
- Dr Davidson, University of California (San Diego) "Consultation for Temporal Mandibular Joint Disease (TMJ)" Author's website. Retrieved on 2008-8-25.
- Ploceniak, C. (1990.) " Bruxism and magnesium, my clinical experiences since 1980" Rev Stomatol Chir Maxillofac, 1990;91 Suppl 1:127. Translation from French by James Michels, Wayne State University. Retrieved on 2007-10-15.
- Nissani, Moti. "Unrecommended bruxism treatments." Author's website, Wayne State University. Retrieved on 2007-10-15.
- "Abfrageergebnisse". Retrieved 2007-10-15.