In this article
Medically reviewed by Dr. Nermeen Khazan, BDS — an AHPRA-registered dental practitioner, for clinical accuracy.
A night guard that doesn't fit right isn't just annoying, it's not actually protecting you properly either. Here's how to work out what's going wrong and what to do about it.
It's Too Tight or Won't Fully Seat
If a guard that used to fit fine is suddenly tight, the most common explanation is minor natural tooth movement, which happens gradually to everyone over time even without orthodontic history. A small amount of tightness that eases after a few nights of wear is usually nothing to worry about. But if it won't seat fully no matter what you do, or causes sharp pain when you try, stop forcing it. Continuing to force an ill-fitting guard can put uneven, damaging pressure on individual teeth.
It Feels Loose or Falls Out Overnight
A guard that rocks, feels loose, or comes out while you sleep isn't distributing grinding forces evenly, which defeats the purpose of wearing one at all. This usually means either the guard has warped slightly (heat exposure is the most common cause) or enough time has passed that it's simply reached the end of its useful fit. Either way, a loose guard needs replacing rather than living with it.
It's Causing Sore Spots or Irritation
A specific sore or irritated spot, rather than general adjustment discomfort, usually points to a rough edge or a slightly imprecise area of the fit. This is different from the mild, generalised jaw awareness that's normal in the first few nights with any new guard. A persistent, localised sore spot is worth getting checked rather than pushing through.
When the Fix Is a New Guard, Not a Fix at All
Most fit problems with a night guard aren't something you can adjust at home. Unlike some dental appliances, night guards generally aren't designed to be reshaped or tweaked once made. If yours genuinely doesn't fit, whether from natural changes to your teeth, wear and tear, or heat damage, a fresh set of impressions and a new guard is the actual fix, not a workaround.
Frequently Asked Questions
Why does my night guard suddenly feel tight?
Usually minor, natural tooth movement, which happens gradually to most people over time. Mild tightness that eases after a few nights is normal. Tightness that doesn't improve, or that causes sharp pain, means the fit needs checking.
My night guard keeps falling out while I sleep. What's wrong?
This usually means the guard has warped (often from heat exposure) or has simply reached the end of its useful lifespan. A loose-fitting guard doesn't protect effectively and should be replaced.
Can I adjust my night guard myself if it doesn't fit?
No, this isn't recommended. Night guards aren't designed to be reshaped at home. If the fit is genuinely off, a new impression and a replacement guard is the right fix, not a DIY adjustment.
Is it normal for a new night guard to feel a bit tight at first?
Yes, mild tightness for the first few nights is a normal adjustment period as you and the guard settle in together. This is different from tightness that persists or worsens, which suggests a genuine fit issue.
Time for a Guard That Actually Fits?
Order your custom Jawology night guard from $270 — hundreds cheaper than at the dentist. Soft, mixed or hard, all arch options.
Order Your Night Guard
