Planning & Therapy for your Tumour

Dental Advice for Cancer Patients

Quality dental advice for cancer patients can be of great assistance to their well being, but while you are going through the process of diagnosis, treatment planning and therapy for your particular form of tumour, probably the last thing on your mind is dental care.

However, for some of you, this is a very important consideration that you need to address and discuss with your Oncologist and your Dentist.  This short article is to outline the reasons why dental care and preventive dental advice is so important to you.  Please read it as this may help you prevent a very uncomfortable condition and improve your quality of life.

Dental and oral effects of cancer treatment are well known and generally can be managed successfully.  The effects of chemotherapy and radiation therapy may include the following:

• Inflammation and ulceration of the mucous membranes;
• Painful mouth and gums;
• Increase in the risk of developing oral and systemic infections;
• Xerostomia (commonly called “dry mouth”), a condition in which saliva is thickened, reduced or absent;
• Rampant tooth decay;
• Burning, peeling or swelling of the tongue;
• Stiffness in the jaw;
• Impaired ability to eat, speak or swallow;
• Change in taste sensation;
• Poor diet due to difficulty eating.

Dental advice is of particular importance to patients who are going to receive radiotherapy of the head and neck region and patients who are going to be medicated with a group of drugs called Nitrogen-containing Bisphosphonates or a drug called Denosumab used in the treatment of postmenopausal osteoporosis and prevention of adverse events from spreading of solid bone tumours.

Radiotherapy and the Jaws

The radiation used to kill the tumour cells causes fibrous changes in the blood vessels in the irradiated area.  This is particularly true in the bone and therefore irradiated bone, having a less effective blood supply, is less capable of healing and more prone to infection.  Should a dentist remove teeth from a previously irradiated jaw, the extraction sockets are not able to heal and a condition known as Osteo-radio-necrosis (ORN) may occur.   In the case of ORN the bone locally dies off, the wound fails to heal and dead bone is visible through an opening in the soft tissues.  This condition is often very painful and extremely difficult to treat and can last for a prolonged period of time.

As always the best approach is prevention.  It is preferable to carry out a dental assessment of patients before they begin radiotherapy, to include dental examination and dental X-rays, and if there are teeth that appear to have a poor future or if there is acute or chronic infection or extensive gum disease, it would be best to remove those teeth before the irradiation causes these changes in the blood vessels.   In that way, normal healing can take place before therapy starts.

Radiotherapy and the Salivary Glands

Another effect of radiation therapy in the head and neck region can be seen on the salivary glands.  For the same reason as ORN occurs, the radiation causes fibrosis within the salivary glands replacing a large volume of the glandular tissue normally responsible for the production of saliva.  Once this tissue is fibrous, it can no longer manufacture saliva and therefore the mouth will become very dry.  This condition (dry mouth) is called Xerostomia.

Xerostomia has a number of effects.  Saliva contains several enzyme systems and is the first line in the defence of the mouth against bacteria and hence infection.  For patients who have the susceptibility to gum disease, the bacteria are now able to easily overpower the body’s defences due to the missing salivary defences and therefore gum disease can become more severe and progress more quickly leading to bone loss around teeth, loose teeth, infections and abscesses, bad breath and difficulty eating.

Xerostomia also leads to increased susceptibility to dental decay.  Older patients often have experienced some gum recession often associated with ageing, and this exposes the root surface to the oral environment.  Without the protective effects of saliva, the dentine of the root becomes highly susceptible to decay that can progress through the root dentine at an alarming rate.  This is why it is so important that anyone who has received head and neck radiation therapy should attend for regular dental checks so that any decay can be identified early and either treated preventively or restoratively before it leads to tooth loss.

In order to protect patients suffering from Xerostomia, it is imperative they visit a dental Hygienist to discuss the various actions they can take to minimise dental decay and convert their oral environment into one more resistant to decay and having soft tissues that are not irritated by the normal mouthwashes and toothpaste found in the shops.

Such preventative measures include :

• The minimisation of sugar intake frequency (thus reducing the acid production by plaque and reducing the degree of dental decay),
• Optimal mouth cleaning with minimal soft tissue irritation using Biotene Dry Mouth Mouthwash, Toothpaste and Oral Balance Moisturising Gel.  These products, unlike normal toothpaste and mouthwashes, do not contain Sodium Lauryl Sulphate (a detergent that dries out the mouth).  Biotene also aids in the defence against bacterial plaque as it contains LP3 Salivary Enzyme System,
• The use of ToothMousse (a tooth remineralisation gel to help prevent dental decay),
• Chew sugar-free chewing gum after meals to encourage salivary flow to clear sugar residues from the mouth,
• Chew Recaldent chewing gum that assists in remineralisation of teeth and
• The occasional use of an effective antibacterial mouthwash (but not constant use) and ideally use Biotene as this will not sting your mouth and irritate the delicate oral soft tissues.

Xerostomia can also be a major problem for denture wearers.  Wearing a denture requires an adequate volume of good quality saliva to lubricate the soft tissues for the denture to slide on and to help make a seal with the soft tissues.  Dry tissues in the mouth under a denture will be rubbed and can become raw, inflamed and ulcerated.  If the tissues are checked they will be red and spongy due to inflammation.  Full denture wearers are the worst affected.  They need to keep their mouths moist and even drinking or sipping water does not adequately replace saliva.  Water is no substitute for saliva that contains mucus.  It is the mucus that plays the major role in comfortable denture wearing.  Saliva is, therefore, a far better lubricant in the mouth than water and will allow the denture to “stick” to the oral tissues and allow the creation of an air seal under the upper denture that helps it stay in place while you eat, speak and laugh.

It is possible to buy products from your chemist and some supermarkets to replace missing saliva.  If you are considering this you should first discuss the available products with your helpful Pharmacist or your Hygienist.

Bisphosphonate and Denosumab Drug Therapy

These drugs are used to treat both postmenopausal osteoporosis/osteopenia and some bone tumours.  The drugs interfere with the normal balance in the natural turnover of the bone.  This results in increased bone density resulting in a reduced risk of bone fractures in osteoporosis and as a side effect, less space for the minute blood vessels in the bone.  The result is a poorer blood supply to the bone.

Patients who have received intravenous Bisphosphonate therapy and subcutaneous injections of Denosumab (twice yearly) are the most likely to suffer a painful and lasting bone defect with an overlying soft tissue ulcer if they have routine tooth extractions following therapy.

This condition is referred to as Osteonecrosis of the Jaw (ONJ).  Again it is imperative that patients undergoing treatment with these drugs are carefully assessed dentally (both clinically and by dental X-rays) and any poor teeth removed before they start the medication.

If Bisphosphonate drugs are being used for the treatment of Osteopaenia and Osteoporosis it usually involves a lower dose taken as tablets every week or every 2 weeks.   Even this oral form of the drug can result in ONJ but the risk is far lower.  All risks should be carefully assessed and discussed with either your dentist or an Oral & Maxillofacial Surgeon before treatment is planned.

PREVENTION OF COMPLICATIONS AFTER DENTAL EXTRACTIONS INPATIENT HAVING UNDERGONE RADIOTHERAPY OF THE HEAD AND NECK REGION

One way in which tooth extractions can be carried out in patients who have received head and neck radiotherapy is to first improve the blood supply to the jaw bones.  This is achieved using pressurised oxygen therapy also known as Hyperbaric Oxygen Therapy.

By giving oxygen to patients at the increased pressure the body responds by growing more blood vessels (angiogenesis). Hyperbaric Oxygen Therapy involves the patient breathing oxygen in a “Hyperbaric” chamber or pressurised chamber.

This is not a difficult procedure for the patient as they simply sit in the large room in comfort and read their book while they breathe normally.  This treatment is usually provided once per day for 20 days before and 10 days after the extractions.  The treatment improves the blood flow to the jaw-bone and has a lasting effect for around 12 months.  Improved blood flow means that extractions or other oral surgical procedures can then be performed without the risk of ORN.

No short article can be a “Complete Works” on dental care for cancer patients but this one aims to at least bring up some of the more common questions that get asked.  If you find there are questions that remain unanswered, contact the friendly team at NQ Surgical Dentistry today on (07) 4725 1656 or call in to see us at 183 Kings Rd, Pimlico QLD 4812

Dr Colin Priestland BDS, MSc, MGDS RCS (Eng)

Dental Surgeon