An occlusal guard — also called a night guard, bite guard, or bruxism appliance — is a custom-fitted dental appliance worn over the teeth to protect against the effects of bruxism (teeth grinding or clenching). It is one of the most commonly prescribed dental appliances.
Why Bruxism Causes Problems
The human jaw can generate up to 600 pounds of force per square inch during sleep. This force, applied repetitively over months and years, causes significant wear of tooth enamel, fracture of teeth and dental restorations, jaw muscle pain and fatigue, temporomandibular joint (TMJ) strain and damage, and headaches (particularly morning headaches from overnight muscle activity).
How an Occlusal Guard Works
An occlusal guard does not stop grinding — it does not address the neurological or sleep-related causes of bruxism. What it does is redistribute the force across a larger surface area and absorb the impact, protecting tooth surfaces from contact. The guard wears down over time instead of the teeth. It also maintains a more relaxed jaw muscle position, reducing muscle tension and joint strain.
Custom vs. Over-the-Counter Guards
Over-the-counter thermoplastic (boil-and-bite) guards are readily available, but they are thicker, less precise in fit, and may interfere with normal jaw positioning. Custom guards are fabricated from impressions or digital scans of your teeth and are designed by your dentist to fit precisely. This improves comfort, compliance, and protective effectiveness.
Hard vs. Soft Guards
Hard acrylic guards are typically used for daytime wear and for patients who grind forcefully. Soft guards are more comfortable for many patients but may stimulate chewing activity in some. Dual-laminate guards (hard outer, soft inner) provide a compromise. Your dentist will recommend the appropriate material based on your grinding pattern and jaw anatomy.