Did You Know that Cancer Treatment Can Affect Your Mouth?

November 30, 2017
Stephen T. Sonis, DMSc, DDS

Stephen T. Sonis, DMD, DMSc, is a professor of oral medicine at the Harvard School of Dental Medicine and a senior surgeon at Brigham and Women’s Hospital and the Dana-Farber Cancer Institute. He has had a longstanding interest in research, teaching, and management of oral complications that arise from cancer treatment. 

Did you know that many cancer treatments can cause side effects in the mouth? share on twitter

The mouth is 1 of the most complex parts of the body, with many types of cells and tissues. Here are some of the ways in which the mouth is unique:

  • It’s the only place where hard tissue—the teeth—touches the outside world.

  • Specialized tissue, nerves, and muscles help you eat, taste, swallow, and speak. 

  • It’s the only place in the body where joints have both ball-and-socket and sliding movements. These are the spots where the jawbones connect with the skull.

  • It has glands that produce saliva for lubrication.

Some types of cancer treatment interfere with these functions. This includes chemotherapy, radiation therapy to the head or neck, and some forms of targeted therapy. Some of the side effects that can affect the mouth are described below.

Surgery is a part of the treatment plan for some cancers of the head and neck. Sometimes, surgery will affect the mouth and its associated structures, like the salivary glands. If you are having surgery, it’s a good idea to discuss possible oral side effects with your health care team.

  • Mouth sores. These are common treatment side effects. Usually, mouth sores occur on the cheeks, tongue, floor of the mouth, and soft palate. Fortunately, most eventually heal on their own. However, it may be uncomfortable when you have one. Tip: Avoid spicy, acidic, hard, and crunchy foods. These foods may irritate the sores. And, ask your doctor for rinses or medicines that can help manage mouth pain.

  • Stiff jaw. Your jaw muscles may become stiff after radiation therapy. Tip: Ask your health care team to teach you stretching and relaxation exercises.

  • Dry mouth. Drugs and radiation therapy to the head and neck can affect the salivary glands. This means your mouth may feel dry because you’re not producing enough saliva. This condition is called xerostomia. Tip: Stay hydrated. Water is the best choice. Avoid caffeinated drinks. Use lubricating mouth rinses before you eat.

  • Dental issues. Saliva helps keep the bacteria in your mouth off your teeth. If you don’t produce enough saliva because of cancer treatment, plaque can build up more easily on your teeth. Plaque can cause tooth decay and gum disease. Tip: Practice good oral hygiene, such as regular brushing and flossing.

Before you start cancer treatment

Visit your dentist at least 4 weeks before starting treatment. The goal will be to solve any current dental issues you may have. That’s because an existing problem could create more problems once you start cancer treatment, even possibly interrupting treatment.

If you need dental surgery, get it done at least 2 weeks before starting radiation therapy or chemotherapy. That way, you will have time to heal.

During cancer treatment

Oral hygiene is important: Brush, floss, and rinse. Repeat. A soft toothbrush is preferred. Ask your dentist what softness toothbrush you should use.

Other tips:

  • Watch what you eat and drink. In particular, stay away from sugar.

  • Don’t use tobacco products.

  • Drink lots of fluids.

  • Ask your health care team about fluoride rinses and gels. These can strengthen your teeth.

  • You may want to consider chewing sugar-free gum.

Keep track of how your mouth feels. Do you have pain? Loss of taste? Numbness? Tell your health care team about any concerns right away. Ask for strategies to treat or soothe these side effects.

A little effort leads to big results

At times, oral hygiene may seem like a low priority, but it’s worth the investment. These practices will greatly reduce your risk of infection and help you have a healthy mouth after treatment ends.


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