teeth grinding

Welcome to issue seventeen of YOUR DENTAL CARE News.

In this issue we will discuss teeth grinding or bruxism.

 Teeth grinding and short teeth…….

What is Bruxism?

Bruxism is a term used in dentistry to describe the destructive habit of teeth gnashing or grinding against each other in the absence of anything between the teeth.

Effects of Bruxism
Figure 1. Diagram showing the difference in tooth height between a healthy dentition and one affected by bruxism. Courtesy of Scarborough dental.

Teeth should not be in contact during periods of rest. The only time teeth should be in contact is when you are eating and swallowing. During the day when you are not eating the teeth should be apart. Some individuals tend to clench and even rub their teeth together when preoccupied. This can happen when focussed on an activity requiring concentration like driving or parents dealing with strong willed offspring.

The habitual clenching and grinding which takes place during the day is often exacerbated at night during sleep. In the day time excessive clenching pressure and hard grinding of teeth will lead to discomfort and pain. This is enough feedback to stop grinding the teeth. However whilst asleep this feedback mechanism is diminished leading to greater damage to teeth. In extreme cases this will lead to periodic awakening and restless sleep.

Bruxism has also been associated with obstructive sleep apnoea (OSA). The link is growing stronger with recent research indicating OSA can be a major cause for teeth grinding. The current literature show a reduction in bruxism following management of the OSA with a CPAP or mandibular advancement splint.

What are the effects of teeth grinding?

The most obvious signs of teeth grinding is shortening of the teeth. This can happen to all teeth or front only or back molars mainly. The pattern of grinding is quite specific to each individual. Most people who notice their front teeth shortening overtime will most often be bruxers. The severity is dependent on rate of wear and the age of the individual.

Fracturing of teeth including cracks developing in teeth are another sign of teeth grinding. Teeth like any other earthly material has a physical tolerance which when exceeded will lead to failure of the material. Years of abuse from teeth grinding often culminates in periodic tooth breaking which can sometimes be quite sudden in occurrence.

Teeth which are continuously overloaded tend to loosen and will move more when pressure is applied. This is the body trying to create more shock absorption to prevent teeth breaking. Teeth can become sensitive to hot and cold foods because the pulp tissue is inflamed from the trauma of clenching and grinding. In extreme cases the pulp can die leading to toothache.

The muscles responsible for moving the lower jaw and involved in chewing can also become painful. This knotting of the muscle is not unlike the overuse of any other muscle in the body. The muscle becomes tender to pressure and movement of the jaw can lead to pain. Sometimes this is confused with tooth ache. The jaw joints can also become inflamed due to the extreme forces placed on them during periods of bruxing activity at night.

How can I stop myself from clenching and grinding unnecessarily?

night guard
Figure 2. Showing a hard acrylic night guard on a plaster model.

Try to avoid having your teeth together during the day when resting or concentrating. Break yourself out of the habit of clenching to relieve the stress. Instead substitute the habitual response with relaxation or squeezing a stress ball or fist. Clenching and grinding during the day is a learned behavior. You can ‘unlearn’ this pattern but it takes self-awareness, time and continual effort.

The only thing available today to protect teeth from bruxing is a night splint (See Figure 2) worn to protect the teeth and jaw joint during night bruxing. We cannot stop habitual teeth grinding whilst we are asleep. In some individuals hypnosis to create a relaxed state can also help in conjunction with the use of a night splint.

However, if you do have OSA, a night splint or guard can make OSA worse (Please see our article on Diagnosis and management of OSA). So it is a good idea to have a chat to your dentist or medical GP about OSA if you know you snore. A sleep study would be recommended with a sleep physician if you suspect you have OSA. The Mandibular Advancement Splint will help protect your teeth and help with your OSA.

What can be done to repair the damage from teeth grinding?

In cases where teeth have worn down rapidly exposing dentine (the inner softer portion of teeth) a restorative material may be used to cover the vulnerable tooth structure (please refer to our other news articles on cosmetic dentistry to see the types of restorations which can be used). By placing this layer of filling material over the exposed dentine further tooth wear can be avoided. However, if the habit of bruxing persists the restorative material will chip, break or wear down. This will preserve the tooth structure but not the hip pocket!

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If the teeth are to be restored back to their initial shape and height, they will need to be protected with a night splint during sleep. This is the only way to prolong the lifespan of the restorations.

In our next issue we will be looking at the use of sport mouthguards.

Thank you.

Dr Roland Chong

Roland Chong

Roland has over 20 years experience as a general dentist. Roland does all aspects of general dentistry with a special interest in prosthodontics (crown and bridge work) and cosmetic dentistry. A member of the International Team of Implantology, Roland is constantly developing his skills by collaborating with international experts.

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