Why you should see the dentists in the Dental Oncology Department before you start radiation therapy?

Radiation therapy can cause many side effects in your mouth.

Some side effects in your mouth include:

• dry mouth
• cavities
• death of bone from radiation
• mouth sores
• taste loss
• thrush
• trismus

You will be referred to a Princess Margaret dentist before your radiation treatment starts. A Princess Margaret dentist can help you prevent or manage these side effects.

What you and the Princess Margaret dentists can do to help manage mouth side effects

Dry mouth

Dry mouth (also called xerostomia) occurs when your body does not make enough saliva (spit) to keep your mouth moist.

Dry mouth may begin as early as 1 week after starting radiation therapy. Dry mouth can be a life-long side effect.

You are more likely to get a cavity when your mouth is very dry. There are many ways to manage dry mouth:

• Use fluoride trays every day.
  Your Princess Margaret dentist will make you fluoride trays to use to apply fluoride gel to your teeth. Fluoride will help prevent cavities from dry mouth. Your Princess Margaret dentist will tell you if you can stop using the fluoride trays.
• Maintain good oral health. Brush and floss your teeth after every meal.
  When your mouth is dry, food is more likely to stick to your teeth. For this reason, it is harder to keep your mouth clean when it is very dry.
• Drink water often.
  This helps keep your mouth moist when you do not have enough saliva. Speak with your Princess Margaret dentist about other products to help you cope with dry mouth

Cavities

You are at higher risk for cavities (holes in the teeth) after your radiation therapy. Cavities can happen within 3 to 6 months after radiation therapy ends.

Reasons you are at higher risk for cavities include:

• Dry mouth (xerostomia).
  A dry mouth leads to more acid in your mouth. More acid in your mouth leads to more cavities. Dry mouth is the main reason you would be at a high risk of cavities after your radiation therapy.
• Higher sugar in your diet.
  During treatment, you may only be able to eat bland foods. Many bland foods, like white bread and crackers (carbohydrates) have a lot of sugar in them.
• Food left in your mouth.
  Because of some mouth side effects, it can be hard to remove food from your mouth. This leftover food in your mouth leads to more cavities.

To lower your risk for cavities:

• Use your daily fluoride gel treatment.
• Brush and floss your teeth after every meal.
• Eat less food with sugar.
• Visit your dentist for regular checkups.

Death of bone from radiation (osteoradionecrosis or ORN)

Osteoradionecrosis (ORN) means the death of bone caused by radiation. ORN is a rare side effect but it is very serious.

ORN often occurs after dental surgery, such as getting teeth pulled at any time after radiation treatment. It is rare, but sometimes osteoradionecrosis can happen on its own or from badly fitted dentures.

Prevent ORN by talking to a Princess Margaret dentist before you start your treatment. The dentist may suggest removing teeth before you start your radiation to prevent ORN in the future.

Remember, you will not be able to have teeth safely pulled after radiation treatment. This is why preventing cavities from radiation (by using your daily fluoride gel treatments) is so important. 

After radiation treatment, you should not have surgery in your mouth without speaking to a Princess Margaret dentist first. Your Princess Margaret dentist and oncologist (cancer doctor) will work together to lower your risk of ORN.

For more information, please ask a member of the Dental Oncology team for a copy of the pamphlet What You Need to Know About Osteoradionecrosis of the Jaw .

Mouth sores

Mouth sores (also called mucositis) is when the lining of your mouth becomes red and sore.

Mouth sores may begin as early as 1 week after you start radiation therapy. Mouth sores will heal soon after you finish radiation therapy.

Speak to a member of your radiation team for help managing mouth sores.

Taste loss

Taste loss is another side effect of radiation therapy. Taste loss may begin as early as half way through your radiation therapy.

Taste loss is usually short term. Most of your sense of taste will return around 1 to 6 months after treatment.

Sometimes taste changes are caused by a condition called hairy tongue. Hairy tongue is when extra protein grows on your taste buds. If you have hairy tongue, Princess Margaret dentists can show you how to remove the extra protein.

Sometimes taste changes happen because of a mouth infection called thrush. Read below to find out more about thrush.

Thrush

Thrush is the most common mouth infection during radiation therapy. Thrush can sometimes look like a white cheesy coating on the tongue.

During radiation, your radiation team will give you a mouth rinse to prevent thrush. However, other mouth conditions like hairy tongue can look like thrush. A Princess Margaret dentist will know if you have thrush or hairy tongue.

There are many treatment options for thrush.

Your dentist may ask you to:

• take an anti-thrush medicine, either in a pill or rinse
• disinfect dentures, if you have dentures

Here are some ways you can prevent thrush:

• Keep your mouth moist.
• If you have dentures, clean your dentures after every meal.
• Do not wear your dentures over night.

Talk to a Princess Margaret dentist if you think you have thrush.

Trismus

Trismus means you are not able to open your mouth fully. This side effect usually starts during or after your radiation therapy treatments are done.

Trismus happens when the muscles that open your mouth are damaged. Trismus causes many problems such as:

• a hard time chewing and eating
• trouble cleaning your teeth
• trouble talking

Regular jaw exercises help you open your mouth again. A Princess Margaret dentist can teach you these exercises. Your radiation team can also refer you to a speech pathologist (an expert in speech and swallowing).

Clinic information

For more information or general questions, contact the number below:
Phone: 416 946 2198

Clinic hours:

Monday to Friday 8:30 am – 4:30 pm
Clinic is closed for lunch every day from 12:00 pm – 1:00 pm