Bruxism (from the Greek βρυγμός (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 or nocturnal 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; 30 to 40 million Americans grind their teeth during sleep.
The etiology of problematic bruxism is unknown, though several conditions are known to be linked to bruxism. It is theorized that certain medical conditions can trigger bruxism, including digestive ailments and anxiety.
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 sleeping partner or parent will notice the bruxism before the person experiencing the problem.
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.
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.
Bruxism may be reduced or even eliminated when the associated factors, e.g. sleep disorders, are treated successfully.
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.
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. Video*
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.
One biofeedback mechanism that has significant promise was developed by Moti Nissani, PhD and is called style="font-style : italic;">"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.