Bruxism: clenching and grinding

Bruxism is repeated activity of the chewing muscles: clenching, grinding or bracing the jaw. It can happen during sleep or while awake, and the two forms have different causes.

Bruxism is not a disease in itself. In many people it causes no problem at all. It matters when it has consequences: pain, worn or cracked teeth, dental work that breaks, or when it is a sign of another problem, such as a sleep disorder.

Sleep bruxism

It happens during micro-arousals from sleep and can’t be controlled voluntarily. Often a partner notices it (the grinding noise). It can be linked to snoring and sleep apnoea, certain medications, coffee, alcohol or smoking.

Awake bruxism

It is usually clenching or muscle tension during concentration, stress or effort, most of the time without noticing. It is the form most often linked to facial muscle pain.

Signs

• worn, cracked or sensitive teeth; fillings or dental work that break
• tired or sore jaws in the morning, headaches on waking
• enlarged masseter muscles, a “square” jawline
• tooth marks on the sides of the tongue or on the cheeks
• grinding noises in sleep, noticed by someone else

Keeping it under control

Bruxism isn’t “cured” for good, but it can be kept under control and its consequences prevented:

• awareness of daytime clenching: “teeth apart, lips together, muscles relaxed”, with small reminders during the day
• sleep hygiene, less coffee and alcohol in the evening, managing stress
• a sleep assessment when there is snoring or daytime tiredness
• an occlusal splint for sleep, to protect the teeth and dental work
• botulinum toxin in selected cases, when muscle pain doesn’t respond to the other measures