Bruxism is the medical term for clenching or grinding of the teeth. Almost always it occurs during our sleeping hours. When this is excessive it is sometimes termed TMJ dysfunction or parafunction.

What is the effects of bruxism?

In order of frequency:

  1. We often see evidence of this with removable retainers which can acquire crush marks, holes and splits.
  2. Tooth wear, chipping of teeth, breakages of crowns/bridges/veneers/fillings and splitting of the teeth called 'cracked tooth syndrome'.
  3. Clicking of the jaw joints. Sometimes termed TMJ dysfunction.
  4. Headaches and migraines.
  5. Locking of the jaws or limited mouth opening. Sometimes termed TMJ dysfunction.
  6. Poor sleep quality .
  7. Gum recession.
  8. Cavitation near gums. This is called abfraction , caused by flexion of  teeth near the gums causing micro fractures. LINK


Why do we clench or grind our teeth?

This is not fully understood.

It is very difficult pinning down the cause of bruxism.  During most stressful times, some of us will grind our teeth more during REM sleep. However, some who are apparently not under any pressures or stress will grind the teeth a lot. It was apparent in the year 2020 and 2021 we have seen increasing frequency of grinding in the young compared to other years. This may be due to uncertainties caused by covid with schooling and its impact, particularly in the exam years.

Evidence suggests the control of jaw muscles are close the areas, or a change in the distribution of neurotransmitters in the brain that are active during our REM (Rapid Eye Movement) sleep. This can activate the part of the brain controlling the jaw muscles causing clenching/grinding.

We all clench or grind our teeth at some stage. It occurs during our REM when we are in our deep sleep cycle. We are not  aware of teeth grinding unless it causes secondary effects of jaw joint clicking, pain or other symptoms mentioned above. 

Grinding of the teeth produces huge pressures causing noises that could be heard from a distance! Try grinding the teeth and produce the noise while awake - it is quite difficult and rather uncomfortable. This illustrates the magnitude of the forces generated. Research shows the forces are 40X in REM sleep then those generated during our waking hours. These pressures can cause disruption to the joint architecture or its associated structures that can be difficult to correct when advanced. Early management should be considered. It commonly produces wearing away of teeth as seen below at Evolution Orthodontics:

Moderate incisor wear in a young patient.

Pre treatment: Advanced wearing of teeth producing severe tooth loss.

Post Treatment: After treatment by  Pankaj Amin


A normal TMJ with disc in normal position:


Clicking TMJ with disc displacement:



How is bruxism treated?

There are many opinions about bruxism or TMJ dysfunction and as a consequence different ways to manage bruxism. Unfortunately, we are not able to stop grinding.

  1. In the early stage: there may be joint clicking. This is when the disk in the joint ( see diagram below ) has been displaced and the joint trips over the edge creating the noise. In this case, the jaw opening should be limited ( no opening wide when yawning ) and a diet that is less chewy - no dry baguettes. The idea here is for the area to heal and recover.
  2. Next stage: Is a bite guard. This is normally the favoured step is there is evidence of tooth wear. Bite guards cover the teeth protect the teeth from bruxism. At Evolution Orthodontics there are two recommended designs:
  3. A thin vacuum formed retainer for mild cases.
  4. An SCI (Sleep Clench Inhibitor).  It is the most clinically effective FDA-approved treatment when there is TMJ dysfunction with more significant symptoms e.g clicking, locking of the jaw joint or excessive wear.

An SCI has three key components:












The pencil test

Studies show the intensity of the pressures generated in the muscles is reduced by an average of 85% when an SCI is worn. Take a pencil and place it between your molars or canines. With your hands, feel the temporalis muscle bulge in the temple area.Then transfer the pencil between your incisors and press the temporalis at the same spot on your temples again: can you feel the difference? 


We do not recommend soft bite guards as the 'bouncy' nature of the device has been shown to causes more grinding. Nor do we recommend surgery as it carries high risks due to the presence of numerous important structures in and near the joints which can be damaged.

Tooth wear and broken teeth

Your teeth should last you a lifetime and not wear down. However, bruxism is a destructive condition. Normal chewing and eating does not cause wear or damage to your teeth. If you suffer from bruxism, you are putting your teeth and gums under massive amounts of pressure. During sleep, there is no feedback mechanism to tell your brain that your teeth are hurting because of too much pressure, hence we can put up to 40 times the amount of pressure on our teeth whilst we sleep - it is no surprise to see a lot of damage.


Mahesh Patel

First published: 23rd January 2019

Last Modified:   14th Feb 2022

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