A few days after braces go on, many people find a small, stinging white or yellow spot on the inside of the lip, right where a bracket sits. That spot is usually a friction ulcer. The cheek and lip lining has not yet adapted to having metal against it, and it usually settles once the rubbing stops and the tissue firms up over the following weeks.
Rubbing, not infection, is the usual cause
The skin inside the mouth is thin and moist. Each time you talk, chew or smile, it slides over the edges of the brackets and any wire ends near the back teeth. That repeated contact can wear through the surface layer and leave a shallow, tender sore. A wire that has slipped and pokes into the cheek, or a bracket that has come loose and twists, can cause the same thing very quickly.
These sores can look a lot like the recurrent canker sores some people get without braces, and the two can overlap. If you are prone to canker sores anyway, braces may set them off more often for a while. Our article on mouth ulcers and canker sores explains the other common triggers.
The early weeks and the days after adjustments are the sore times
Ulcers tend to be most troublesome in the early weeks after braces are fitted. After that, the lining usually becomes tougher where the brackets sit, and new sores become less frequent. A smaller flare can follow a wire change or adjustment, when the teeth are tender and the new wire may sit a little differently. If you are about to start treatment, our guide to the first week with braces covers what else tends to happen early on.
Stopping the rub is what lets an ulcer heal
An ulcer that is rubbed every few seconds struggles to close. The most useful single step is to cover the culprit bracket or wire with orthodontic wax. Dry the bracket with a tissue, roll a pea-sized piece of wax between your fingers and press it firmly over the edge. Replace it after meals and before bed. Our guide to using orthodontic wax has more detail on getting it to stay put.
Other measures help the sore feel better while it heals:
- Rinse gently with warm salt water (about half a teaspoon of salt in a glass of warm water) a few times a day.
- Choose softer, milder food for a few days. Chips, crusty bread, chilli and citrus tend to sting.
- Ask a pharmacist about an ulcer gel or protective paste. Some products contain ingredients that are not suitable for children, so mention the age of the person using it.
- Sip cold water or let a little ice melt near the area for brief relief.
Most friction ulcers heal within a week or two once they are protected.
Fewer sores as treatment goes on
Carrying a small case of wax means you can cover a rough spot the moment you feel it, before it turns into an ulcer. Keeping the brackets clean also reduces irritation, since plaque and food packed around them can inflame the nearby gum and lining. Over the months, many people find they rarely need wax except after adjustments.
If a wire end is poking, wax is only a stopgap. A dentist can trim or tuck the wire in a short visit, which removes the cause instead of padding it. General tenderness from tooth movement is a separate issue from ulcers, and our article on whether braces hurt covers how to manage it.
An ulcer that lasts three weeks needs a look
Ulcers caused by braces should improve steadily once the rubbing is dealt with. Please have it checked by a dentist if an ulcer:
- has not healed after about three weeks
- keeps returning in exactly the same place
- is very painful, growing, or has a raised or hard edge
- comes with fever, swollen glands or general unwellness
A broken bracket or a long wire that cannot be covered is also worth a prompt appointment. Our article on when a mouth ulcer needs attention explains these warning signs in more depth.
Common questions
Should I stop eating certain foods for the whole of treatment?
Not because of ulcers. Avoiding spicy, salty and sharp foods for a few days while a sore heals is enough. The longer-term food rules with braces are about protecting the brackets and wires, not the lining of the mouth.
Can I swallow orthodontic wax by accident?
Small amounts of orthodontic wax are non-toxic, so swallowing a little is not harmful. Simply replace it with a fresh piece.
Will ulcers make treatment take longer?
No. They are a comfort problem rather than a sign that anything is wrong with tooth movement. Overall treatment time depends on the bite and how the teeth respond, as our article on how long braces take explains.
Still sore after a week or two?
If braces keep rubbing in the same place, or a wire needs trimming, the team at Lumi Dental can take a look and make you more comfortable. Read about our general dental care or see what is on our current offers page.
This article is general information only and is not a substitute for personal dental advice. Please see a dentist or orthodontist to discuss your own situation.
