Bruxism, commonly known as tooth grinding, involves clenching the upper and lower jaw together and grinding the teeth. This behavior can lead to the removal of healthy enamel from the teeth’s chewing surfaces and may cause facial pain. Those who engage in this behavior are referred to as bruxers. It is prevalent in about 20% of adults while awake and 8% during sleep, and up to 18% of children. Most commonly occurring during the early part of the night’s sleep, the biting force during sleep can be significantly stronger than during wakefulness, sometimes up to six times greater.

Signs and symptoms of night time bruxism include rhythmic crunching or grating sounds, morning headaches and neck stiffness, jaw muscle pain or tightness, teeth clenching upon waking, temporomandibular joint pain and clicking, chronic facial pain, ear discomfort or ringing, increased tooth sensitivity especially in the morning, teeth wear, chipping or fractures, cheek biting or tongue injury, loose teeth, and fatigue in the jaw muscles when chewing.

To treat bruxism, behavioural changes are attempted to help patients rest their tongue, teeth, and lips properly. Additionally, a common approach involves creating a plastic mouth appliance, such as a nightguard, which absorbs the force of biting and helps prevent further dental damage. This appliance also aids in changing the destructive grinding behaviour.