Bruxism is excessive teeth grinding and/or jaw clenching, and is a common behavior that may affect as much as 8–31% of the general population. It tends to decrease with age, with the highest prevalence during childhood and the lowest in people over 65. Many people clench or grind their teeth on occasion, but only a small percentage of people do so with such regularity that they develop dental problems. Tooth wear can happen with grinding, but is not prevalent with jaw clenching, which may cause problems with facial muscles and joints – exerting 250 pounds (or more) worth of force.
There are two main types of bruxism: one that occurs during sleep (sleep bruxism) and one that occurs during wakefulness (awake bruxism). They are thought to have different causes, but dental damage seems to be similar in both types. Some characteristics are:
- Prevalence in general population 9.7 to 15.9%
- Symptoms tend to be worse on waking and improve during the day
- More common in females
- A grinding or tapping noise during sleep
- Involuntary rhythmic masticatory muscle activity (RMMA) *
- Nervous system neurotransmitter abnormalities involving a sleep arousal trigger
- Associated with obstructive sleep apnea, loud snoring
- May be accompanied by gastroesophageal reflux
- Sleep position – lying face up may be a trigger
- May be genetic
- Smoking: twice as common in smokers, related to dopamine release by the central nervous system
- Heavy alcohol or caffeine use, some antidepressant drugs, recreational ecstasy & cocaine are factors
- Treatment is usually a night guard or splint, and possibly medication
* The rhythmic muscle activity that occurs in sleep bruxism peaks in the minutes before rapid eye movement (REM) sleep. This suggests that there might be some mechanism related to transitions in sleep stages that influence the motor neurons of bruxism. This pattern may be repeated many times (maybe thousands) during the night.
- Prevalence in general population 22.1 to 31%
- Symptoms may not be present at all on waking, but worsen during the day
- Males and females are affected in equal proportions
- Rarely any noises
- May be stress related, especially emotional
- In children, may be related to earache or teething
- May occur during periods of concentration
- Treatment is usually behavior and habit modification
If bruxism is severe, it can cause significant tooth wear, and sometimes dental restorations (crowns, fillings etc.) are damaged or lost, sometimes repeatedly. For that reason, most dentists prefer to keep dental treatment in people with severe bruxism very simple and only provide restorations when essential, since any dental work has the potential to fail in the long run. Treatments like dental implants and complex bridgework, for example, may be problematical. Porcelain veneers on the incisors are particularly vulnerable to damage. In the case of crowns, the strength of the material used becomes more important than aesthetics, because sometimes a crown can be perforated by wear from the opposing teeth. A full coverage gold crown has many advantages, not the least of which is durability and a degree of flexibility, causing the least amount of wear on opposing teeth. It also involves less removal of the tooth structure, and therefore less weakening, making it still the most successful restoration.
Several symptoms commonly associated with bruxism are:
- Hypersensitive teeth to heat and cold
- Pain and/or stiffness in jaw muscles
- Earaches & headaches (particularly in the temples and upon waking)
- Fatigue upon awakening
- Tooth wear, particularly flattening of the biting surfaces
- Tooth fractures
- Damage to dental restorations (e.g. crowns and fillings)
- Cheek and/or lip biting
- A burning sensation on the tongue
- Enlarged muscles that move the jaw
- TMJ pain and/or clicking in the joint
Symptoms may be minimal, without the patient being aware of the condition. The causes are not completely understood, but probably involve multiple factors. There are several treatments in use, although effectiveness is questionable. One treatment is:
Occlusal splints: They are divided into partial or full-coverage splints according to whether they fit over some or all of the teeth, and may be of some benefit in reducing the tooth wear that can accompany bruxism, but only by mechanically protecting the teeth, rather than curing the bruxing. In a minority of cases, sleep bruxism may be made worse by an occlusal splint. A splint may become worn with holes worn through them, either because the bruxism is aggravated, or because the splint has not been effective. When tooth-to-tooth contact is possible through the holes in a splint, it provides no protection against tooth wear and needs to be replaced. A splint is worn all the time, while a night guard is only worn during sleep.
Other treatments may include stress management, medication, Botox, Biofeedback, bite adjustment, but most commonly, a night guard. However, a night guard fails to treat the root cause of why teeth grinding occurs: For one, if you stop breathing at night, as in Obstructive Sleep Apnea (OSA), your brain stimulates the grinding response. This motion pushes the jaw forward, reopening your airway, allowing you to breathe again. Teeth grinding is a red flag for this serious underlying condition, and if you are experiencing sleep bruxism, you should be screened for OSA.
While a night guard will protect your teeth from wear, it won’t protect your grinding muscles and jaw joints from damage, and you should be concerned with two things:
- Protecting your teeth from the strong vertical forces of grinding, which can cause them to break, crack, become sensitive, cause you pain, and prematurely yellow and cause your gums to recede.
- That you are likely to have sleep apnea and should be tested for this potentially life-threatening condition.
If you have sleep apnea, a night guard should only be a temporary solution because it can make bruxism worse by preventing your ability to push out your lower jaw, in turn preventing the airway from opening. This results in effectively choking you and causing you to grind harder and more frequently in order to breathe, not to mention compromising your sleep.
Healthy teeth are vital to your comfort and well-being, if you have bruxism, however, your teeth are at risk of erosion and pain. A night guard cushions your teeth from the force of clenching and prevents the molars from grinding together. This not only safeguards your teeth, but allows you and your loved ones to sleep soundly.
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