Every winter and footy season I see the same thing come through the door in Blackburn: a chipped front tooth from a stray elbow, or a teenager who “was wearing a mouthguard” but had one that barely stayed in. Across the City of Whitehorse there’s a huge amount of weekend contact sport — footy, basketball, hockey and soccer, played by families right through Blackburn, Box Hill, Nunawading, Forest Hill and Mitcham — so it’s a question I answer a lot: how should a mouthguard actually fit?
Wearing one at all is a good start. But the fit is what does the protecting. A guard that doesn’t fit properly absorbs less impact, gets uncomfortable, and — the real problem — ends up sitting in the kit bag instead of in the mouth. So here’s how I explain a good fit to patients, and how to tell whether the one you’ve got is doing its job.
The three types, and why fit is the whole story
There are broadly three kinds of mouthguard:
- Stock guards — pre-formed, ready to wear straight out of the packet
- Boil-and-bite guards — the “self-fit” type you soften in hot water and bite into at home
- Custom-made guards — moulded to your own teeth from an impression we take in the chair
Stock guards are the cheapest but tend to fit poorly — bulky, loose, and hard to keep in place. Boil-and-bite guards do a bit better, but they’re only ever as good as the mould you managed to get at your kitchen sink. A custom-made mouthguard is shaped to the exact contours of your teeth and gums, which is why it’s generally the most comfortable and the most protective — and the one I recommend for anyone playing a genuine contact sport week in, week out.
The reason fit matters so much is simple: a guard that fits poorly cushions impact less effectively, and it’s far more likely to be taken out mid-game because it’s annoying. A mouthguard in a pocket protects nobody.
It should cover the teeth and gums properly
A well-fitted mouthguard sits snugly over the upper teeth without you having to clench or bite down to keep it there. If you find yourself holding your jaw shut so it doesn’t move, it isn’t fitting correctly.
A good guard should:
- Sit closely against the upper teeth without shifting
- Cover most of the teeth, stopping short of the very back molars
- Extend slightly over the gum line to help shield the tooth roots
- Avoid running too far onto the palate or too deep under the lip
Too short, and the gums and roots are left exposed when a knock comes. Too long, and it rubs and irritates. A proper fit balances coverage with comfort — protecting the teeth and the soft tissue behind them without getting in the way of normal function.
It should be comfortable to wear
Comfort isn’t a luxury here — it’s what determines whether the guard actually gets worn. A mouthguard shouldn’t feel bulky or sharp, and it shouldn’t make you gag. It should sit clear of the soft palate at the back of the roof of the mouth and let your jaw move naturally.
A correctly fitted guard generally finishes around the back-molar region without pushing further in. If it rubs, causes mouth sores, or is uncomfortable enough to be a distraction, it’ll get pulled out during training — and that’s exactly when a stray knock does its damage. This is the single biggest advantage I see with a custom guard for my younger patients around Blackburn: because it fits, it stays in.
It should let you breathe and speak easily
A properly fitted mouthguard lets you breathe, talk and drink normally — which matters more than people realise during a hard game, when you’re gasping for air and calling to teammates. An ill-fitting guard can restrict airflow or muffle speech, which quietly affects both performance and safety. A good fit leaves enough room inside the mouth — particularly behind the front teeth and along the inner surface of the molars — for your tongue to move and air to flow.
When you should have one in
Wear a mouthguard for:
- Games and competition
- Training sessions and drills (injuries happen just as easily at Tuesday training)
- Any activity with a real risk of falls, collisions or contact
Guards don’t only shield teeth from an outside impact — they also cushion the lips and cheeks against being bitten during a sudden movement, which is a more common injury than most parents expect.
Looking after it
A bit of care keeps a guard hygienic and holding its shape:
- Rinse and gently brush it after every use
- Let it air-dry on a clean surface
- Store it in a ventilated protective case
- Clean the case regularly, with a deeper wash weekly using mild soap and water
- Never use hot water, the dishwasher or harsh chemicals — heat warps the material and ruins the fit
Replace a guard when it’s showing wear, no longer feels comfortable, or has gone loose. For growing kids and teenagers this comes around faster than you’d think, because new teeth and a changing jaw quickly outgrow last season’s fit — worth checking at each routine check-up and clean.
Protecting the smile that’s under there
Mouthguards do a genuinely important job protecting teeth, gums, jaw and soft tissue during contact sport — but how well they do it comes down to fit. A guard that sits securely over the upper teeth, covers the gums, feels comfortable and lets you breathe and speak is the one that actually gets worn, and therefore the one that actually protects.
A shop-bought guard can offer basic short-term cover, but a properly fitted one is part of a preventive approach — the same thinking behind regular check-ups. And if the worst does happen mid-game and a tooth is knocked, chipped or knocked out, that’s a case for emergency dental care straight away, not a Monday-morning wait — the sooner we see a knocked-out tooth, the better the chance of saving it.
If your child plays weekend sport around Whitehorse, or you’re not sure your own guard still fits properly, we can take an impression and make one moulded to your teeth. You’re welcome to book online or call us on (03) 8838 8820. We’re at 129A Canterbury Road, Blackburn — a short walk from Blackburn Station and easy to reach from across the Whitehorse area.