Teeth clenching and grinding (bruxism)

What is bruxism?

Bruxism is characterized by teeth grinding or clenching without any movement from the mastication muscles.

Because this habit does not fill any purpose, bruxism is defined as a parafunctional activity.

Bruxism – individual

People who grind their teeth are called bruxers.

Teeth grinding

The characteristic sound of teeth grinding is produced by lateral (side to side), protrusive or retrusive movements that cause friction between teeth. In this case, we talk about dynamic bruxism, because of the lower jaw movements. Most people who have heard someone grinding their teeth consider it to produce the most horrible and unforgettable sound!

People who clench their teeth without grinding them emit little or no sound because the movement involved is a vertical pressure on the teeth, without any lateral movement of the mandible; this is called static bruxism. A person can suffer from bruxism without making noise.

In theory, upper and lower teeth should never be in contact, except when chewing and swallowing (approximately 20 cumulative minutes per day). However, the situation is quite different for people suffering from bruxism.

Incidence

A large part of the population will experience bruxism at least once in their life; for some of them, bruxism will become a chronic disorder. Almost as many children (14%) as adults and elderly (11%) are affected on a regular basis, i.e. several times a week. Bruxism also touches equally both sexes.

According to studies conducted on this subject, bruxism tends to decrease with age, as most reported cases are among individuals aged between 20 and 50.

Bruxism: a disease

Bruxism is considered by many researchers as a full-fledged sleeping sickness. It can potentially cause other disorders, ranging from snoring to sleep apnea (respiratory arrest during sleep). Some even link bruxism to concentration problems, in both adults and children, and learning problems among school-age children.

Chronic bruxism is a disease that tends to worsen with time. Indeed, the more you grind or clench your teeth, the more your masticatory muscles will tend to tense up. An increase in the contraction of these muscles can result in tightness and more intense grinding, creating a vicious circle from which it is difficult to escape.

Night bruxism versus day bruxism

80% of the bruxers are active at night (night bruxism), while the other 20% bruxe during the day (day bruxism). The main difference between the two types of bruxism is the awareness of the gesture.

Daytime bruxers have some control over the movements of their jaws (voluntary movement). They can therefore more easily get rid of their habit by identifying the cause of their bruxism and trying to release their jaws when they become aware of the action in order to avoid sequelae.

Conversely, nocturnal bruxers grind or clench their teeth completely involuntarily, often during periods of light sleep, while body movements, particularly those of the lower jaw, are more frequent. The pressure exerted on the teeth of nocturnal bruxers is also higher than that exerted by day bruxers.

Usually, neither the squeaking noise nor the pressure exerted wakes up the night bruxer.

Bruxism in children

Young children, who still have their primary teeth, are also affected by bruxism. They may grind or clench their teeth during the day as they explore their teeth. On the other hand, they may seek relief from tooth growth, which leads them to clench teeth to exert counter-pressure on the gums or erupting teeth. Young children can also brux unintentionally at night for various causes.

At the evolutionary level, it is now believed that bruxism allows young children to slowly get rid of their primary teeth.

Bruxism usually stops spontaneously in children when their permanent teeth appear in the mouth. On the other hand, parents of a young chronic burner should monitor their sleeping habits, as a child who burns is more likely to maintain this habit in adulthood if the cause is not treated in the first place.

The occlusal plaque: a preventive solution to teeth grinding

The occlusal plate, also known as the joint plate, is a transparent plastic tray that covers the upper teeth, lower teeth, or both, depending on the appearance of the bruxer. It is the most commonly used device to protect teeth from wear caused by grinding and clenching teeth, as well as to absorb the forces involved.

Causes of teeth grinding

There are many causes of teeth grinding or clenching, and they are still the subject of several studies today. Not all of them have yet been identified by the researchers, but some of them are now recognized and accepted by oral health professionals.

Stress, anxiety, hyperactivity and competitiveness are often related to teeth grinding

The most common cause seems to be psychosocial problems, which are experienced during the day and manifest themselves as stress, anxiety, competitiveness or hyperactivity.

Why can problems that occur during waking have an impact on nocturnal behaviour? Simply because night bruxers would not manage their stress well or the level of stress felt would be higher than average during the day.

It is not so surprising that a creaking or clenching of teeth can occur involuntarily during sleep when an individual mismanages his stress, because one of the manifestations of the stress felt during awakening is precisely a clenching of teeth! These movements can occur when the lower jaw remains taut instead of relaxing at night while the person is sleeping.

One population particularly affected by bruxism is students during their exam periods due to their higher than normal stress level.

Genetics may explain some cases of nocturnal bruxism

Some researchers agree that a genetic component may also explain some of the cases of nocturnal bruxism. It is thought that a disorder in the cerebellum (autonomic nervous system) is the cause of this type of bruxism.

On the other hand, genetics would not be a factor in daytime bruxism, since stress or extreme concentration when performing a task is the most likely cause of the phenomenon.

Sleep patterns and dental malocclusions

Most people who grind their teeth sleep on their backs. This position allows the mandible to move backwards and the tongue to move towards the bottom of the mouth more easily. These two structures then cut off some of the air going into the lungs, causing a decrease in oxygenation that can cause bruxism to appear. At the same time, people who adopt oral respiration would also be at greater risk of burning at night.

Individuals with misaligned teeth or significant malocclusion (gearing of the upper teeth with the lower teeth) are at greater risk of grinding or clenching the teeth and damaging them. The consequences of bruxism are often greater in these individuals.

Traumatisms

Trauma, whether cervical or joint, can contribute to bruxism in some individuals. These traumas can be caused by a whiplash, a car accident or multiple general anesthetics requiring intubations that can negatively affect an individual’s temporomandibular joints (TMJs).

Some drugs increase the chances of bruxism

Finally, some drugs, such as antidepressants, as well as some drugs, such as ecstasy and THC, can increase the chances of suffering from bruxism because of their chemical actions and effects on the brain.

There are also symptoms experienced by bruxers; the most common are described below.

Symptoms

The most obvious symptom of bruxism is the appearance of intense and very unpleasant friction noises from a sleeping person who is burning. Since these noises are heard by a third person, it is called an indirect symptom, because the person who suffers from bruxism is not the one who can detect it.

Sensitivity of the teeth, where they come into contact with each other at rest or during chewing and swallowing;
Pain in the jaw muscles or TMJs, which may range from a sensation of stiffness or abnormal limitation in the opening of the mouth to pain radiating to the ears or face;
Earaches and tinnitus;
Muscle pains in the neck, cheeks and sometimes even in the shoulders;
Chronic headaches, especially in the morning after a night’s sleep;
Fatigue when you wake up, despite the number of hours of sleep.

Dental consequences

Symptom and consequence, premature wear of the enamel and/or dentine of the teeth often betrays bruxism. Worn teeth are more likely to be sensitive to cold or to fracture if wear is high.
It is not uncommon to see teeth so worn that they have lost all their enamel where they touch each other; the yellowish colour that appears in this area is actually dentin, the part of the tooth that is under the enamel. Severe tooth wear is sometimes called « brycosis ».
Depending on the health of the teeth and their wear and tear, it is possible to observe the detachment of small pieces of teeth or the appearance of dental fracture, or even the mobility of some teeth.
Prosthetics, artificial crowns and fillings (fillings) are also at risk of wear and tear or breakage due to clenching or grinding of teeth.
When tooth wear is very severe, damage to or necrosis of the dental nerve can occur, which can lead to the devitalization of worn teeth.

Consequences on temporomandibular joints (TMJs)

Pain and stiffness at TMJs can occur. They can be worse in the morning and last or be aggravated by the stress experienced during the day.
Problems encountered at TMJs can develop over time. Among these, simple creaking or clicking can be heard when the mandible moves.
Other, more serious problems can also occur: a feeling that the jaw remains « stuck » in the open position (dislocation of a condyle), a deviation of the lower jaw on one side when the mouth opens or degenerative arthrosis of the joint.
Difficulties in yawning comfortably can occur and the burner may feel that its mouth is no longer opening as wide as before.

Other bone and muscle consequences

In the most severe cases, bruxism can lead to the destruction of alveolar bone (the bone in which teeth are rooted) and soft tissues, such as the gum. Grinding or clenching your teeth can therefore aggravate an existing periodontal disease, such as gum recession and tooth loosening.
Muscle pain can occur in the orofacial region, as well as in the neck and shoulders; the muscles can even become painful to the touch.
The hypertrophy of the chewing muscles which, by dint of being put to the test, develop abnormally, can occur, much like athletes who develop the muscles they need to perform.

Solutions to bruxism

First of all, a bruxer must be aware of its problem before it can be managed. After this awareness, he must try to obtain a precise diagnosis. Several means can be used for this purpose; polysomnography (sleep study) is the most reliable method, but it is not necessary in a large number of cases.

After being diagnosed with bruxism by a professional, the person who is bruxing must try to determine the cause. Sometimes, depending on the symptoms and cause of the disease, a multidisciplinary approach may be necessary. The health professionals who may be useful in this situation are the ear, nose and throat (ENT) specialist, psychologist, neurologist, pulmonologist, physiotherapist, etc.

The custom-made occlusal plate

The occlusal plaque is custom-made in the dental office from dental impressions taken from the patient. These impressions are used to make models of the teeth and then the joint plate itself.

The models and plate can be manufactured on site or in an external laboratory. In such a case, two appointments are necessary: the first to take the impressions and the second to put the plate in the mouth and adjust it.

The occlusal plate to prevent the upper teeth from touching the lower teeth

The purpose of the occlusal plate is to prevent the upper teeth from touching the lower teeth. The inability to bring them into contact prevents damage that can be caused by clenching or grinding teeth.

There are a variety of occlusal plate models to suit the dentition, occlusion and physiognomy of the burners.

It should be noted that a joint plaque does not cure the cause or consequences of bruxism, but it does act as a preventive measure. It allows the muscles of the jaw to relax and thus reduce the pressure exerted on the TMJs. Over time, the teeth grinding reflex may disappear and the squeezing can no longer do as much damage.

Reduce tooth grinding through relaxation

In the case where stress is potentially involved, the burner has different solutions to hopefully remedy the situation. Stress and anxiety can be managed and controlled with relaxation techniques such as yoga, meditation and also through psychotherapy or hypnosis. These techniques involve an investment of time and sometimes money on the part of the burner, but they can remedy or improve bruxism in a sustainable way.

Adopting a quiet, noiseless environment in the bedroom can help to minimize episodes of bruxism.

Acupuncture is effective in countering stress and anxiety and can be of great help in the management of bruxism, both in children and adults.

Avoid chewing on objects

In order not to accustom the chewing muscles to being active outside meal and snack periods, it is advisable to avoid chewing objects that are not food (e. g. pencils, pens, straws, etc.) or chewing gum. Maintaining the action of chewing during the day can increase the need to clench your teeth at night.

Reduce stimulants, alcohol and caffeine

Stimulants can contribute to bruxism, hence the importance of not smoking before going to bed or consuming alcohol (beer, spirits, wine) or caffeine in all its forms (coffee, energy drinks, soft drinks, chocolate, etc.) a few hours before bedtime.

Carry out stretching exercises of the chewing muscles

In cases where the cause of bruxism is not psychological, there are solutions to minimize its negative impacts, depending on whether the damage is already apparent or not. For example, stretching chewing muscles to relax them can help reduce the pressure when a burner clenches their teeth.

Apply a varnish to the teeth to desensitize them

When tooth wear is severe, an oral health professional can apply a varnish to the teeth to desensitize them and reduce the discomfort of the burner. Fluorinated gels can also be applied by the burning patient as part of their home hygiene care.

Use some muscle relaxants

Drugs that regulate sleep are contraindicated to stop bruxism because the results of studies conclude that they are not really useful. However, some muscle relaxants can be used, as long as they are discussed with a doctor or pharmacist beforehand to avoid becoming dependent on them.

Introduction of calming activities into the daily routine

For young children, the preferred approach is to introduce calming activities into their daily routine to reduce their anxiety and hyperactivity. In some cases, it is possible for a child to wear a mouth guard; the joint plate manufactured to fit perfectly with the dentition is not recommended at an early age, as a child’s dentition is constantly changing.

Orthodontic treatment

Orthodontic treatment to correct a dental malocclusion can reduce the harmful effects of bruxism.

Inject a botulinum toxin into the chewing muscles

A still emerging technique is to inject a botulinum toxin into the most powerful chewing muscles. The injected substance reduces the muscle strength exerted during bruxism episodes, thus limiting damage to the teeth and surrounding tissues. However, long-term results have yet to be determined.

Conclusion on bruxism

No treatment method can guarantee that bruxism will be permanently stopped, as it is an unconscious habit. However, oral health professionals can manage a patient who suffers from it in order to limit the damage it can cause in the medium and long term.