How to remove mouth sores: canker causes, types and treatment

Mouth sores are often small but cause considerable discomfort, especially when eating, drinking, and speaking. You might also refer to them as canker sores or find them similar to ulcers.

The good news is their cause is usually something avoidable. Managed well, you can recover and heal the sore pretty quickly.

In this article, we're exploring different types and offering advice on how to treat mouth sores from braces and other sources. We'll explain:

• The potential causes of oral sores in the mouth.
• How braces and mouth ulcers occur.
• How you can manage sore mouth symptoms effectively. 
• Foods that can contribute to getting sores in your mouth.

Reading this article will help you gain a better understanding of:

• Getting rid of the discomfort that can come with ulcers or sores.
• Ways to keep oral hygiene standards high when dealing with them.
• Ways to avoid worse conditions, like gum disease.

What are mouth sores?

Mouth sores are small lesions in your mouth. They usually occur: on the tongue, lips, gums, inner cheeks, the roof of the mouth and at the corners of the mouth. They can vary in appearance, size, and severity, and may cause pain and discomfort.

Types of mouth sores

As previously mentioned, there are numerous types of mouth sores which can vary in appearance and severity. We explore just some of these types of mouth sores so that you can gain a deeper understanding of what they look like and what might cause them.

Canker sores

Ulcer canker sores (also known as aphthous ulcers), are round in shape with a white or yellow centre and a red border.

These type of mouth sores are not contagious, so they aren't usually a cause for concern. The biggest issue is the pain and discomfort, especially when eating. They usually heal by themselves within a few weeks.

If you're frequently experiencing canker sores, book a check-up with your doctor to ensure you have no underlying health conditions.

Gingivostomatitis

Gingivostomatitis is a type of oral infection that can cause blisters, sores and inflammation to occur in the mouth. It can cause some pain and can come with side effects such as bad breath and fever. It's often the first herpes virus in children and comes from contact through droplets of an infected person.

Cold sores

Cold sores are small, fluid-filled blisters that typically form on the lips or the corners of the mouth. They are common, viral infections, caused by the herpes simplex virus, that can be spread by sharing personal items such as lip products, toothbrushes and utensils.

Mouth sores from orthodontic treatment like braces

Mouth sores caused by orthodontic treatment, such as braces, are common and can be quite uncomfortable. These mouth sores typically occur due to irritation from the braces rubbing against the inside of the cheeks, lips, or gums.

How to prevent mouth sores from braces

Braces are a common culprit of sores in the mouth. This is particularly true at the beginning of brace treatment. Orthodontic wax is a great solution for braces that stick, poke and prick your mouth. You rub it along the braces, which provides relief.

Broken wires, is another common complaint with traditional braces. To keep on top of and heal canker sore ulcers in your mouth regular visits to your dentist is important. You should also avoid hard and harsh foods that could snap, break or erode your brackets.

Other types of mouth sores

While we’ve already outlined some of the more common types of mouth sores, below you’ll find a summary of some of the other types of mouth sores you may come across:

Traumatic ulcers: These are caused by physical injury or trauma to the mouth, such as biting the cheek or the sharp edges of broken teeth, which irritates the cheeks or gums.

Candidiasis: Candidiasis is a fungal infection caused by the yeast Candida, also known as thrush. It leads to white mouth sores, usually on the tongue or inner cheeks. This can occur because certain medications derail your immune system and weaken it.

Lichen planus: This inflammatory, chronic condition can cause white patches, redness and irritation, and open sores.

Leukoplakia: These patches may be precancerous and are often a result of excessive smoking. These types of sores are thick, white patches on the gums, the insides of the cheeks, the bottom of the mouth, and sometimes the tongue.

Symptoms of mouth sores

Mouth sores can present various symptoms depending on the type you have (cold sores, canker sores, etc.). In most cases, you will notice some variation of a lesion or blister on or in your mouth, as well as redness and inflammation. You may even feel pain or discomfort before even seeing the mouth sore.

Below you can learn about some of the specific symptoms you can experience depending on different types of mouth sores:

In the case of cold sores, one of the main symptoms is that you may feel tingling or itching around the mouth before you see the sores appear. These types of sores usually appear as fluid-filled blisters on the lips or in the corners of the mouth.

With canker sores, you may have one or more red bumps with a yellow or white centre that appear on or under your tongue, gums, cheeks or lips. You may feel a slight burning or tingling sensation in the mouth before the sores appear.

With gingivostomatitis, you may notice some sores on the inside of the cheeks, but also additional symptoms such as bad breath and a fever.

What causes mouth sores?

Mouth sores, including cold sores and sores on the tongue, gums, or roof of the mouth, can have various causes. Here are some common reasons why mouth sores may develop:

Infections and viruses: For example, the herpes simplex virus is what causes cold sores. Fungal and bacterial infections are also often what cause mouth sores on the tongue.

Physical irritation to the mouth: Sharp teeth, dental appliances and accidental biting can irritate parts of the mouth, which can lead to sores or ulcers forming.

Nutritional deficiencies: If you are low in minerals or vitamins such as iron, vitamin B12 or folic acid, you may develop mouth sores, especially on the tongue.

Pregnancy and mouth sores: As the hormonal changes increase during pregnancy, you might be susceptible to get them. While it doesn't directly cause them, it can create an environment in your mouth for them to occur.

Can stress cause mouth sores?

Several triggers can increase your likelihood of having mouth sores. Stress, excessive exposure to UV rays, or having a weakened immune system from a different illness can make you more susceptible to developing mouth sores or having recurring sores.

How to get rid of sores inside the mouth

Mouth sores, including canker sores and cold sores, can be painful and bothersome. Here are some tips on how to alleviate the pain caused by mouth sores or remove them completely:

Antiviral medications: If your mouth sore has been caused by a virus, like with cold sores, the best treatment to take is an antiviral medication, which can be prescribed by your doctor.

Topical creams or ointments: a cream or ointment prescribed by your doctor, or from a pharmacy, could prove helpful. You may need to apply it with a cotton swab, depending on the type of treatment. These often provide a cooling or numbing sensation to alleviate the discomfort caused by the sore.

Salt water: swirling a teaspoon of salt in salt water and rinsing your mouth with it can help reduce bacteria and speed up the healing of the affected area.

Cold compresses: Helpful, especially if you have sores on your lips or in the corners of your mouth. It's important to keep your mouth clean to avoid irritation. Try a cold, damp cloth.

Supplements: supplements could be effective at reducing the recurrence. Check with your GP or a functional doctor to see if you have a vitamin deficiency, which can make you prone to canker sores.

Natural ingredients: Apply honey or aloe vera directly to the soft tissue of your cheeks and tongue sores. They both have anti-inflammatory properties, which can help with healing.

As well as these treatments, there are some tips you can follow which can reduce inflammation and help speed up the healing process:

1. Maintain a good oral hygiene routine, brushing and flossing daily to prevent further infection. 
2. Avoid foods that are acidic or spicy, as that could further irritate mouth sores or ulcers. 
3. Drink plenty of water to keep your mouth hydrated and to help flush out any bacteria.

You can alleviate the discomfort caused by mouth sores by following these tips. If sores persist or get worse, make sure you consult with a medical professional so that you can find the right treatment for you.

Avoid mouth sores with clear aligners

Clear aligners, such as those offered at Impress allow you to maintain your usual diet. The clear aligners from Impress are removable so you can eat food and drinks as usual at mealtimes.

Afterwards, brush your teeth with a soft bristle toothbrush, rinsing your mouth with a dentist approved mouth rinse and replace your aligner.

If you have a mouth sore from braces and are wondering how to treat it, you can simply follow the recommendations outlined above. If you want a smarter solution, come and see what Impress can do for you.

Impress clear aligners

Learn about Impress clear aligners or our other treatments by visiting your nearest Impress clinic. Book your free orthodontic evaluation online, through WhatsApp or by calling us on +44 20 3808 1072.

Updated: October 2025