University of Toronto

Side Effects Post Radiation


Side Effects

These are considered CHRONIC side effects. Once your radiation is completed. The dental clinic will see you 1-month post-radiation. This is another check-up to see how your mouth is healing. We understand that the healing process takes time! Do not expect that you will immediately go back to how everything was before. There will definitely be changes and every one’s healing process is different!

Below is a list of CHRONIC side effects that may occur post-radiation therapy:

1. Dry mouth (xerostomia)

Salivary flow begins to drop off after 1 week of radiation, particularly if all majory salivary glands are included in the radiation field. Xerostomia is a permanent (life-long) side effect.

2. Post-radiation cavities/caries

Because of the decreased salivary flow, the acid content in your mouth is increased. Which means that cavity-producing bacteria outnumber non-cavity producing bacteria. You will now be more prone to getting cavities and this may occur in all teeth at the SAME TIME.

Clinically evident radiation caries may develop within 3 to 6 months after completion of radiation. Excellent oral hygiene and daily application of your fluoride gel will help prevent this from happening.

Avoidance of sugary foods may also be necessary to reduce caries. We understand that if you get a cavity, you may think “Well, just put a filling it”. Sometimes, it gets to a point where you can not just do a filling but have to extract/pull the tooth. This is what we, the dental team, are trying to avoid because of SIDE EFFECT #4.

3. Osteoradionecrosis (ORN)

ORN refers to a condition where part of the irradiated jaw bone becomes exposed and does not heal. The normal bacteria found in the mouth may secondarily infect the exposed bone and this could result in a deep bone infection.

ORN may occur spontaneously, but has also been known to happen where there is inadequate post-extraction healing prior to commencement of radiotherapy, poor or delayed healing when teeth are extracted after radiation, and nutritional factors.

Even trivial trauma, such as denture irritation may lead to the development of ORN. It is a joined effort between your dental team and your commitment to help prevent this from happening!

Altered Taste

Taste can potentially be altered indefinitely. Recovery ranges from 1 to 6 months. Common foods that patients can be adverse to are: caffeine, alcohol, acidic and mint-flavoured items.

"Hairy Tongue"

With a dry mouth, the papillae or taste buds on the top of the tongue may appear longer than usual. This may lead to the appearance of a “hairy tongue” that can vary in colour depending on diet. The longer taste buds have an easier time collecting bacteria and food. Tongue brushing/scraping can help reduce the bacteria and food present on your tongue. Once the taste buds have elongated, they do not return to being short again.

Limited mouth opening (trismus)

Tissues have had radiation can become less elastic over time and become scar tissue or fibrotic. This can affect the ability to open your mouth making dental care challenging. The normal range in opening is approximately 35 – 45mm. Passive mouth-movement exercises can be completed during and after radiation so that you can maintain as much jaw mobility as possible.

Treatment

1. Dry mouth (xerostomia)

There are a lot of products that are over-the-counter that could be tried. The Biotene company makes: a mouthrinse, toothpastes, gel and spray. Oral Science has: xylimelts, chewing gum, mints, and rinses.

Carrying a bottle of water around with you and sipping water throughout the day will be the most important thing you can do to help moisturize your mouth.

2. Post-radiation cavities/caries

Excellent oral hygiene which includes: brushing 2 to 3 times per day, flossing, using your fluoride trays, sipping water, and seeing your dentist on a regular basis will be important.