Dennis M. Abbott, D.D.S.

The following is the final installment of a three-part series addressing oral health concerns that ideally should be addressed before, during, and after cancer treatment.  This segment focuses on oral health care needs after cancer treatment.

To say a battle with cancer changes one’s life is perhaps one of the most profound understatements ever made!  Few experiences leave their indelible mark on health, relationships, and spirituality as deeply as cancer.  From the moment the diagnosis is verbalized by the physician, lives are changed forever…the life of the patient, the lives of family and friends, the lives of those not even yet born who will benefit from the lessons learned from the care given.  There is little argument to be made - cancer changes lives!

People who have met cancer face-to-face understand that the disease expects much and adaptations in daily life must be made to meet those demands.  So it is with the oral health of the survivors.  Truly, there is still much to learn with regard to cancer survivorship in many areas of health care, and dentistry is no different.  There are, however, tenets of care that must be followed for the cancer survivor.  Some of these simply make life more pleasant; others are fundamental courses of care to which the patients must strictly adhere.

To the cancer survivor, I would say…because your experience with cancer has been a personal journey, there is no single adage that applies to all.  There are, however, recommendations that are applicable to most.  Always consult with your dentist or dental oncologist to customize a continuing care plan that is suited for your needs.  Do not be afraid to begin a dialogue with your oral health care provider.  Let him or her understand what is working for you, and what isn’t.  Together, you and your dental oncologist can develop a regimen that is tailored to your needs and helps ensure your prolonged oral health as you live life as a survivor.

Dental Care Following Chemotherapy

Because many of the direct cytotoxic effects of chemotherapy subside after infusions have ended, much of the oral health care recommendations directed towards the post-chemotherapy patient focus on dealing with possible lingering side effects.  Granted, the severity of enduring complications is usually contingent on the specific chemotherapeutic agents used, their dose, and the duration of treatment.  Usually, however, the patient who has completed chemotherapy will notice a return to normal in the oral cavity.  Dysgeusia (abnormal taste) and dysphagia (difficulty in swallowing) most often resolve without further intervention from the dentist.  As white cells and platelets recover, mucositis is usually no longer an issue.

Xerostomia, or dry mouth, can continue to be a problem for many treated with chemotherapy alone, especially if medication for comorbidities continue after chemo has concluded.  As long as the salivary flow is reduced, as determined by either a “feeling” of dry mouth or quantitative analysis by a dentist or dental oncologist, the xerostomic patient should commit to a professional dental cleaning and recall visit every three months.  Dry mouth can lead to dental complications including rampant caries, periodontal disease, and oral infections.  This condition should continue to be monitored and managed until normal salivary flow has returned and the patient has demonstrated a proficiency in home care that reduces the risk of extensive generalized decay.  

During times of xerostomia, caries control is paramount.  In some cases, it may be necessary to place the patient on microbial reduction therapy.  The level of streptococci mutans can be reduced below a pathological level for three to six months by instructing the patient to use aqueous chlorhexidine gluconate 0.12% as an oral rinse: 1/2 oz. twice a day for two weeks.  (This timeframe of bacterial load reduction has only been demonstrated in non-cancer patients.  Patients battling cancer should continue using aqueous chlorhexidine gluconate on an ongoing basis and should be closely monitored if the oral rinse is reduce or discontinued as rapid recolonization has been documented in this population.)  Similarly, the regular application of fluoride should be considered as long as patient remains at-risk for rampant caries.*

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• Detailed instructions for fluoride application can be found in the second installment of this series.

Dental and Oral Health Care Following Head and Neck Radiation

Dental care following head and neck radiation is perhaps one of the most complicated areas of dental oncology as many of the side effects of radiotherapy linger for the remainder of the patient’s life.  As is the case during treatment, it is imperative that the dental professional be thoroughly familiar with the dose of radiation the patient has received.  An isodose map showing dosage according to anatomical structures must be considered prior to treatment planning for dental and oral health care following radiation.  While most radiation therapy is now administered by intensity modulated radiation therapy (IMRT), some patients may have received treatment through a fixed beam of conventional radiation therapy or brachytherapy, which involves insertion of radioactive wires directly into the tumor.  The dental professional must be familiar with not only the cumulative dose and the structures involved, but also with the radiation modality and the treatment schedule.

Perhaps one of the post-radiation risks most familiar to dental professionals is that of osteoradionecrosis (ORN).  ORN is a late side effect of radiation where damage to the small blood vessels in the mandible, and more rarely the maxilla, impairs the bone’s ability to heal.  Those who have received brachytherapy are particularly at-risk for developing this condition.  Typically, ORN is not seen within the first year following treatment and the risk of ORN increases with time.  Most often, bone necrosis of the jaw in the head and neck cancer survivor follows a traumatic event, such as an extraction or dental surgery; however, spontaneous exposure and necrosis of the bone - especially in the posterior mylohyoid ridge - has been reported.  Although it can occur after lower doses, ORN usually occurs with doses greater than 60 Gy.  All future oral health care treatment planning must consider radiation exposure to the bony structures of the face to minimize the risk for ORN.

Because of the risk of ORN, endodontic therapy should be considered as a viable treatment option for carious lesions with pulpal involvement.  Root banking may be necessary when insufficient tooth structure remains supragingivally.  For carious lesions, fluoridated glass ionomer is the restorative material of choice for the cancer survivor.

Exposure of the salivary glands to therapeutic radiation causes atrophy of the secretory cells resulting in xerostomia, the severity of which is related to the cumulative dose.  Doses as low as 25 Gy can result in dry mouth.  Although IMRT has reduced much of the widespread damage to the salivary glands seen in conventional radiation therapy, xerostomia continues to be the most widespread complication seen in head and neck radiation patients.  The dental professional treating patients with a history of head and neck radiation should realize that long-term survivors who experienced conventional fixed beam radiation may present with more severe xerostomia that is a permanent side effect of their treatment.

Not only does ionizing radiation affect the function of the secretory cells in the glands, it also changes the composition of the saliva when some salivary function is retained.  Serous glands are impaired much more readily than mucous glands.  The result is a saliva that is much more viscous and acidic and lacks much of the protective qualities normally seen.  Clinically, the patient may experience impaired remineralization capacity, taste alteration and difficulty swallowing, difficulties in mastication and speech, and decreased protection against microbes.  These in addition to the increased propensity for dental caries makes xerostomia a side effect that cannot be ignored.  Unfortunately for some head and neck cancer survivors, the damage of the salivary glands is permanent.  These patients require close monitoring by the dental professional and should follow the guidelines for the post-chemotherapy patient as outlined above.  

Fungal infections are more prevalent in this population, and the dentist or dental oncologist must be comfortable diagnosing and treating these conditions should they arise.  When treating a Candida infection, both the patient and the denture should be treated, when applicable.  Fluconazole 100 mg, twice a day, is an effective means of treating a yeast infection in the patient that can be used long term, if necessary.  Nystatin suspension is not recommended due to its high sugar content.  Alternatively, clotrimazole 10 mg troches, five times per day for two weeks, or mycostatin 200 mg oral pastilles, four times per day for two weeks, can be used.  Dentures can be treated using bleach diluted in water (2 teaspoons per 1 cup water) for 30 minutes each day.  

Beyond the teeth and oral mucosal tissues, many lingering side effects often plague the head and neck survivor.  Permanent taste loss can occur at a dose of 60 Gy or higher.  In lower doses, taste loss is often temporary although it may take several months to fully recover.  Decreased salivary flow can cause taste alteration as can damage done by mucositis.  Chemoreceptors on the tongue can take months to years to return to normal function if they have been affected by mucosal ulceration.  Trismus can cause limited opening for three to six months following radiation therapy.  Caused by contraction of the muscles of mastication and the TMJ capsule, trismus can occur with an unpredictable frequency and severity.  Physical therapy (opening the mouth to maximum and closing 20 times, three times per day) can bring some relief and improve opening, but this condition must be considered when planning treatment and formulating an at-home oral hygiene regimen.

Long-term head and neck cancer survivors may also experience occlusion of the carotid arteries.  Consideration must be given to this fact when using dental anesthetics with epinephrine.  The dentist or dental oncologist should be familiar with signs and symptoms of a transient ischemic attack (TIA) or stroke and monitor these patients closely for signs of distress during dental procedures.  Sometimes, head and neck survivors suffer degeneration of cervical vertebrae and may experience fatigue with minimal exertion.  Fibrosis of the musculature in the radiation field may yield unusual results in head and neck examinations.  Careful observation must be made during oral cancer screenings and head and neck examinations as “normal” may feel different to the dental professional examining the patient.  For patients who have just completed treatment, radiation burns may still exist on the skin.  Even long-term, a patient may complain of the tissue that was in the field of radiation as feeling “hot.”  

The dental professional should be prepared to help the head and neck patient understand that many of these changes will affect the way he or she is accustomed to eating.  The patient should avoid sharp or crunchy foods that can cause mucosal damage, hot and spicy foods, foods that are highly acidic, foods that are sticky or highly cariogenic, and drinks that contain alcohol.  Patients should choose foods that are easy to chew and swallow, learn to take small bites and chew slowly, and sip liquids with meals.  While many of these changes were necessary during treatment, most will need to continue these practices for several months following the completion of radiation therapy.  When necessary, the dental professional should be ready to refer the patient to a registered dietician or professional nutrition therapist.  

Other Post-Treatment Oral Health Care Considerations

Patients who have received bisphosphonate therapy via an intravenous route of administration are at risk for developing bisphosophonate-related osteonecrosis of the jaw (BRONJ).  Medications used to treat metastatic disease in the bone include Zometa (zoledronic acid), Aredia (pamidronate), and Xgeva (denosumab).  It is believed that the risk of developing BRONJ is directly related to the dose and duration of the bisphosphonate therapy.  While the specific etiology of BRONJ is not fully understood, the dental professional treating patients with a history of bisphosphonate therapy should understand the risks associated with these medications and care for the patient in a manner similar to patients at risk for ORN.  Since the half-life of some of these medications is in excess of ten years, a history of bisphosphonate therapy should be considered for all future oral health care planning in these patients.

Patients who are post-transplant, either for bone marrow or hematopoietic stem cells, are at high-risk for infection due to continued immunosuppression.  In addition to bacterial and fungal infections, these patients are susceptible to viral infections including herpes simplex virus type 1, herpes varicella zoster virus, and cytomegalovirus.  Moreover, these patients are at-risk for graft-versus-host disease (GVHD) and other autoimmune problems.  GHVD and autoimmune issues can be very complicated.  The dental professional seeing these patients should seek out continued education related to the specific care of autoimmune patients or refer to a dental oncologist experienced in their care.

Caring for patients before, during, or after their fight with cancer can be the most rewarding experience of a lifetime.  More dental professionals are needed to commit to meeting the unique dental and oral health care needs of patients battling cancer.  As the epidemiological forecasts continue to predict an increase in the number of new cancer cases as well as an increase in the population of survivors, now is the time for dental professionals to become part of a cancer care team.  You can make a difference!

Dental Oncology Professionals of North Texas

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Dennis M. Abbott, D.D.S. is the founder and CEO of Dental Oncology Professionals of North Texas, an oral medicine practice dedicated to meeting the unique dental and oral health needs of patients battling cancer. He holds a Bachelor of Arts in biology from Rice University in Houston, and is an honor graduate of Baylor College of Dentistry. After dental school, Dr. Abbott studied immunology, microbiology, and oral medicine at the School of Dental Medicine, State University of New York at Buffalo. In addition to private practice, he is a member of the dental oncology medical staff at Baylor Charles A. Sammons Cancer Center and Baylor University Medical Center in Dallas.  Dr. Abbott also serves as a consultant to the national American Cancer Society in the development of oral monitoring guidelines for post-treatment cancer survivors.

Dr. Abbott has most recently conducted studies focusing on bisphosphonate-related osteonecrosis of the jaw and xerostomia in patients with cancer. He is the previous recipient of the Dentist Scientist Award and the National Research Service Award, both granted by the National Institutes of Health. Dr. Abbott has been a visiting faculty lecturer for the University at Buffalo School of Dental Medicine continuing education program and has lectured throughout the United States.

Dennis M. Abbott, D.D.S.

The following is the first of a three-part series addressing various forms of oral health therapy that ideally should be addressed before, during, and after cancer treatment.  This segment focuses on oral health care needs before the commencement of cancer treatment.

Cancer.  The New Oxford American Dictionary defines it as “the disease caused by an uncontrolled division of abnormal cells in a part of the body;” but for the millions of people it has touched, cancer is so much more.  Cancer is a constant unwanted companion that opens the door to an unchosen journey and demands to be followed.  It affects individuals, families and friends.  Cancer changes lives.

Beyond the emotional toll it imposes, cancer alters the well-being of those it afflicts.  Modern treatment regimens given to combat this disease come with a host of deleterious side effects, many of which occur in the mouth.  Dentists, dental hygienists and dental auxiliaries are in a unique and necessary position to make a positive impact in the lives of patients battling cancer.  

Making a difference begins with a desire to help and a willingness to take a risk.  It is followed by a commitment to learn about the unique oral health care needs of patients engaged in the fight of their lives and put into practice skills that can literally provide comfort and hope.  We, as dental professionals, can and should be a part of a comprehensive cancer care team for an ever-growing number of people facing cancer.

Dental Oncology

Dental oncology is a focus of dentistry dedicated to meeting the unique dental and oral health care needs that arise as a result of cancer therapy.  It is an area of oral medicine devoted to improving the well-being and quality of life of people battling cancer.  Dental oncology goes beyond the scope of general dental treatment to include management of the soft tissues of the mouth and care for oral side effects specific to cancer therapy.  A dental professional knowledgeable in dental oncology plays an important role throughout cancer treatment by preventing and managing mouth sores, dental needs, oral pain and infections.  As a member of the patient’s oncology care team, the dental professional communicates directly with the medical oncologist, radiation oncologist and other team members to provide optimal comprehensive care before, during, and after cancer treatments.

Ideally, a patient’s relationship with a dental professional begins as soon as possible after receiving the diagnosis of cancer.  Most of the present-day treatments for cancer involve the administration of cytotoxic drugs, radiation, myelosuppressive treatments or some combination thereof.  Having a baseline assessment completed before the implementation of immunosuppressive therapies allows the dental professional to have a pre-treatment reference point to compare oral and systemic health at future visits.  

For the newly diagnosed patient with cancer who has not received regular dental and oral health care, a prompt visit to the dentist’s office also allows for immediate attention to unaddressed periodontal issues and unresolved dental needs before immunosuppression begins.  During cancer treatments, bacterial components of calculus, dental plaque and oral biofilm can easily become vehicles for bacteremia or oral infections.  Properly addressing these oral health concerns at this pre-treatment stage can prevent or significantly reduce the severity of oral issues that could complicate or even interrupt the patient’s cancer treatment schedule.

Oral Health Care Before Chemotherapy

Chemotherapy is the treatment of choice for a wide range of cancers.  It can be used either alone or in combination with other treatment modalities.  The goal of chemotherapy is to eradicate the rapidly dividing cancerous cells, but unfortunately these drugs often cannot differentiate between cancer cells and other types of cells that divide rapidly under normal conditions within the body.  These cells include bone marrow, hair, and the mucosa of the entire gastrointestinal tract, including the mouth.  It is the direct cytotoxic effect of the drugs as well as side effects that can cause intraoral complications.  Because chemotherapeutic agents are used to combat cancers of all types, the dental professional is needed to care for patients with most kinds of cancer, not just malignancies relevant to structures within the head or neck.

Optimally, the patient should see a dental professional well enough in advance so that all dental procedures can be completed one week before beginning chemotherapy.  At a minimum, dental procedures that might introduce bacteria into the bloodstream should be completed in this timeframe.  Close communication with the medical oncologist is of paramount importance as each member of the oncology team needs to be aware of the scheduling of all care related to the patient.  Communication should include a summary of the present oral health of the patient, a treatment plan of essential dental care, and an anticipated timeline of when that care can be completed.  The dental professional should also confirm that the medical colleagues on the oncology team understand the nature of anticipated oral complications during treatment and be prepared to function as the expert able to address those oral health issues.

Dental management before chemotherapy should include a thorough baseline dental and periodontal assessment with close attentions paid to conditions that could be problematic during times of immunosuppression.  Preemptive measures should be taken to correct or remove any possible sources of oral trauma.  These might include broken teeth or ill-fitting existing restorations or prostheses.  Non-restorable teeth that pose an infection risk in the short term should be extracted.  This would include any tooth affected by severe periodontal disease or deemed to be of endodontic concern.  Partially-erupted third molars should be evaluated and be extracted if they are at risk for for pericornitis.  A thorough dental prophylaxis including scaling and root planing must be completed.  Decreasing the existing intraoral bacterial load is one of the best preventive services that can be performed for the patient scheduled to undergo chemotherapy.  Carious lesions and tooth-born fractures should be restored.  Resin modified glass ionomer is a good restorative material choice for these patients as xerostomia is anticipated during cancer treatment.  Any orthodontic bands and wires should be removed and orthodontic treatment postponed until cancer treatment is completed.  Oral hygiene instructions should be reviewed, even for regular dental patients.  Educating about possible or anticipated oral issues and reassuring the patient and the family they are not alone in this battle builds confidence and strengthens the dental professional/patient relationship.

Oral Health Before Head and Neck Radiation Therapy

Radiation therapy is routinely used to treat tumors in the head or neck, often in combination with chemotherapy or immunotherapy.  Head and neck radiation, unlike radiotherapy in other parts of the body, creates issues of particular concern for the dental professional.  Patients undergoing head and neck radiation therapy often experience permanent life-changing side effects from their cancer treatment.  Understanding these complications at the pre-treatment assessment positions the dental professional to be of the most service.

The pre-treatment assessment appointment for the patient undergoing head and neck radiation begins with a full-mouth series of radiographs.  A clinical examination including complete periodontal charting must be combined with the radiographic evaluation to assess periodontal condition, to diagnose periapical pathology and to identify teeth requiring immediate attention.  All possible sources of intraoral trauma must be resolved.  Because trauma to irradiated bone poses a risk for osteoradionecrosis, the dental professional must evaluate the current condition of the teeth and periodontium and anticipate the patient’s ability to maintain meticulous oral hygiene for the remainder of his or her life, often in challenging intraoral conditions.  All non-restorable teeth should be extracted.  Those teeth with moderate to severe periodontal disease and partially-erupted third molars within the anticipated field of radiation should also be removed.  Other teeth in the planned field of radiation should be evaluated in light of the patient’s current hygiene status and dental history, the presence of high-risk deleterious habits or co-morbidities (e.g. smoking and diabetes mellitus), the patient’s commitment to regular professional dental visits, and the risk of osteoradionecrosis.  Any decision by the patient to refuse to comply with the dental professional’s recommendation should be well-documented in the patient’s chart.  All remaining teeth must be thoroughly cleaned.  Dental impressions should be taken from which fluoride trays can be fabricated for the patient’s at-home use.  The dental professional should counsel the patient and his or her family concerning the anticipated complications of head and neck radiation therapy and the life-long changes that must be made in oral health care.

Communication between the dental professional and radiation oncologist is extremely important.  The dentist should understand the anticipated scheduling of radiation treatments and must know the amount of radiation planned for each of the jaws.  Similarly, the radiation oncologist should be aware of all necessary dental treatment and the anticipated timeline to complete it.  The timing of dental surgery is of utmost importance:  at least 14 days should be available for healing following any surgery before radiation therapy commences.  The dental professional should understand that tumors of the head and neck are often times fast moving and require expeditious treatment.  Every effort should be made to accommodate head and neck patients for treatment as soon as possible.  There are times, however, when the nature of the tumor may be such that radiation therapy must be initiated immediately and not allow adequate time for dental work to be completed.  In these cases, dental care should be postponed until the completion of radiotherapy and the patient has sufficiently recovered.  Dental care should be avoided while the patient is undergoing radiation therapy, but should be completed as soon after radiotherapy as possible since bone changes associated with radiation worsen over time.

Oral Health Before Bisphosphonate Therapy

Bisphosphonate therapy is used extensively in patients with metastatic bone disease.  These drugs, which include Zometa®(zoledronic acid) and Aredia®(pamidronate), are administered intravenously through a portacath.  They fall into a unique class of drugs that are characterized by their affinity for bone and the ability to inhibit bone resorption through decreased osteoclastic activity.  Because they limit bone turnover, these drugs have been implicated in osteonecrosis following dental surgery subsequent to bisphosphonate therapy.  Drug potency and accumulation seem to be important factors in assessing whether or not a patient is at risk for developing bisphosphonate-related osteonecrosis of the jaw.

If non-restorable teeth exist in a patient who will be undergoing bisphosphonate therapy, they should be removed at least 14 days before the introduction of the drug, if possible.  Partially-erupted third molars and teeth with moderate to severe periodontal disease should be considered for extraction.  Precautions similar to those for patients undergoing head and neck radiation should be considered in evaluating teeth for possible extraction as the half-life bisphosphonates can exceed ten years.  All dental professionals should be aware that a history of bisphosphonate disclosed in a medical history should be carefully considered and evaluated to assess the risk for bisphosphonate-related osteonecrosis of the jaw.

Cancer in The United States Today

According to the North American Association of Central Cancer Registries, the estimated new cancer cases in the United States in 2011 was approximately equivalent to the population of the entire state of Idaho.  From the same source, the estimated number of U.S. deaths in the same year approximated the population of the entire state of Wyoming.  It is important to note that these are annual numbers.  Currently, approximately 12 million people in the United States are living with cancer.  This number does not include cancer survivors considered cancer-free.  In 2010, the national cost for cancer care in the US was over $124 billion.  That number is expected to more than double, and possibly triple, by the year 2020.

Cancer is a significant healthcare concern in the United States and around the world.  As the Baby-Boomer generation continues to age, the incidence rate in the United States is expected to increase.  Cancer treatment has evolved from a required visit to one of just a few major national cancer centers to care that can be received close to home.  With more and more local cancer treatment centers, there is a greater need for local dental professionals to become an integral part of oncology teams and provide the care that these patients so desperately need.

Dental Oncology Professionals of North Texas

web:  www.dopnt.com

Twitter: @DentalOncology

Facebook:  facebook.com/dentaloncology