The quiet, expensive problem
Nighttime grinding (bruxism) is the single most damaging thing most adults do to their teeth — and most of them don't know they're doing it. By the time we diagnose it, there's usually visible wear, cracked teeth, and a partner who's been quietly complaining about the noise for months.
Here's how to tell if you're a grinder, what the damage actually costs over time, and what a custom night guard actually does.
Why grinding is worse than people realise
Normal chewing force is in the order of tens of pounds per square inch. Grinding generates a far higher sustained force — measurements in dental research vary but consistently show grinding produces multiples of normal chewing force, sustained across hours of sleep. Over years, that's thousands of hours of crushing force on enamel that evolved for intermittent daytime chewing.
The damage is cumulative and largely invisible for the first 10+ years. By the time it becomes visible (flattened teeth, cracks, receding gums), you've already done most of the damage.
The signs you're grinding
Most of these show up in the morning, not during the grinding itself:
- Jaw ache or stiffness on waking — the muscles that clench (masseter) are exhausted
- Morning headaches, especially at the temples — tension radiating from the jaw
- Partner complaining about the noise — grinding is audibly loud when severe
- Flat, worn-looking teeth — especially the canines and front teeth
- Cracked or chipped front teeth with no clear cause
- Sensitive teeth with no cavities — enamel wear exposes dentin
- Clicky, popping jaw — TMJ joint stress
- Scalloped edges on your tongue — it's pressing against teeth at night
- Neck and shoulder tension in the morning — related muscle chains
Why it happens
Honestly, the cause is poorly understood. Strong associations include:
- Stress and anxiety — #1 trigger, and grinders usually notice more grinding in stressful periods
- Sleep apnoea — grinding often accompanies disrupted breathing at night
- Caffeine and alcohol — both increase grinding frequency
- Bite misalignment — minor, but can concentrate grinding forces
- Genetics — runs in families
Why dentists compare night guards to sunscreen: the damage from untreated grinding accumulates silently over decades. A night guard worn in your twenties and thirties is preventative — it stops the wear before it requires major restorative work later. Boring, obvious, and something most grinders simply never get around to doing.
What the damage looks like, stage by stage
- Early stage — microscopic enamel wear. Usually no symptoms. Sometimes partner-reported noise.
- Intermediate — visible flattening of biting edges, occasional morning jaw soreness, sometimes a chipped front tooth.
- Advanced — clear wear patterns, dentine sensitivity, cracks appearing, existing fillings failing under the repeated force.
- Longstanding, untreated — major restorative territory: crowns to rebuild worn teeth, root canals for teeth that have cracked through, sometimes full mouth reconstruction. Largely preventable with earlier intervention.
What a custom night guard actually does
A custom night guard (also called an occlusal splint) is a thin, comfortable plastic tray that covers your upper teeth. You wear it while sleeping. It does three things:
- Protects your enamel — you grind the plastic instead of your teeth. The plastic wears down over years; enamel doesn't grow back.
- Reduces muscle tension — the slight opening of the bite relaxes the clenching muscles. Most patients report less morning jaw ache within a week.
- Protects existing dental work — crowns, veneers, and big fillings are expensive, and grinding cracks them. A night guard pays for itself the first time it saves a crown.
Why chemist boil-and-bite guards are worse than nothing
Hard truth: the $40 chemist night guard is usually counterproductive. Three reasons:
- Wrong thickness — too thick in front, too thin in back. Actually changes your bite over time.
- Poor fit — falls out, gets spat out, or only covers some teeth. Useless protection.
- Wrong material hardness — chemist guards are often too soft, which can actually increase grinding forces (your brain interprets softness as "bite harder").
A properly-made custom guard from a lab, based on a digital scan of your teeth, is a different product entirely. Worth the cost. See our mouthguards page for how we make them.