Managing Dental Complications in Patients with Head and Neck Cancer
By Luanne Jorewicz
These dental issues most often result from radiation therapy, but surgery and chemotherapy also can cause or exacerbate dental and periodontal problems. Careful attention before, during, and after cancer treatment can minimize these complications.
Dry mouth (xerostomia) is a common side effect of radiation therapy for head and neck cancer. “Most patients receiving radiation treatment for head and neck cancer will have some level of dry mouth, particularly if major salivary glands are within the field of radiation,” said Mark Chambers, D.M.D., a professor in the Department of Head and Neck Surgery and chief of the Section of Oral Oncology and Maxillofacial Prosthodontics at The University of Texas MD Anderson Cancer Center. Unfortunately, xerostomia can become a chronic complication. Some chemotherapy drugs also may cause xerostomia.
By lowering the pH of saliva, xerostomia contributes to tooth decay, plaque buildup, and gum disease. Xerostomia also makes patients more susceptible to fungal infections, particularly candidiasis.
Radiation therapy also may cause blood flow to decrease in treated areas, and the lack of blood to the bone may lead to osteoradionecrosis, a serious and chronic complication. The bone becomes devitalized and develops abscesses, which often defy healing. In patients with osteoradionecrosis of the mandible or maxilla, the jaw’s inability to heal can cause complications if other dental problems necessitate tooth extraction. Jaw fractures, and the resultant tooth damage, also are not uncommon in patients with osteoradionecrosis.
In a study of osteoradionecrosis, Beth Beadle, M.D., Ph.D., an assistant professor in the Department of Radiation Oncology, and her colleagues reviewed the Surveillance, Epidemiology, and End Results–Medicare database to see which side effects had been treated in Medicare recipients who received radiation therapy for head or neck cancer from 1999 to 2007. Of those 1,848 patients, 227 patients (16%) exhibited some degree of jaw complications, although only a small minority of these were severe.
Patients with any type of cancer may experience diminished wound-healing capability owing to immunosuppression from chemotherapy. As levels of white and red blood cells and platelets drop, tooth or gum infections can result in mucositis.
Preventing and managing dental complications
Dr. Beadle said that radiation oncologists meticulously plan their treatment fields to minimize damage to salivary glands and other sensitive areas. Even so, radiation to sensitive areas may be unavoidable when treating nearby tumors, and dental complications remain a major risk for patients receiving radiation to the head and neck.
Preexisting tooth or gum issues or infections ideally are treated 1–2 weeks before cancer treatment begins. These preexisting conditions can lead to more dangerous complications if not resolved. For example, infections or pain may become serious enough to require a break in a patient’s cancer therapy. Infections also could lead to sepsis, which can be life-threatening to patients with compromised immune systems.
During radiation therapy, Dr. Hofstede and other faculty members in the Section of Oral Oncology and Maxillofacial Prosthodontics work closely with the radiation oncology team to address dental issues before they create even greater health risks for the patient. Patients with xerostomia are encouraged to keep their mouths clean to avoid dental caries and periodontal complications.
Repairing surgical damage
Patients whose tumors must be surgically removed sometimes lose a portion of the jawbone. To assist with the patient’s rehabilitation after surgery, Dr. Hofstede may develop a prosthesis, such as a maxillary obturator or a mandibular resection prosthesis, to restore chewing, swallowing, and speech. These prostheses are somewhat like dentures, but they include a replacement for the missing jaw portion. The prosthesis may be held in place by hooks that fit around existing teeth and bones or may attach to dental implants. Because the patient will need to use this prosthesis for the rest of his or her life, Dr. Hofstede’s team will continue to work with the patient to ensure that any changes in status are addressed so that the patient can live as normal a life as possible.
Some patients who undergo newer reconstructive techniques with bone and tissue transfers receive dental implants that are permanently screwed into the reconstructed jaw. Dr. Hofstede said these osseointegrated implants “expand our ability to successfully rehabilitate our patients for a better quality of life.”
Like surgery, radiation therapy to the head and neck presents long-term challenges, even after a patient’s cancer has been successfully treated. As Dr. Chambers said, “Once radiation, always radiation challenges.” For this reason, he said he advises patients who have received such therapy to address dental issues promptly and thoroughly, as these issues can rapidly become health- or life-threatening. For example, while the average person might visit the dentist once a year, most current and former cancer patients are urged to visit their dentists at least twice a year; patients with chronic dental complications resulting from radiation to the head and neck region may need even more frequent appointments. Keeping the mouth clean, acid-free, and healthy can improve the overall health and quality of life for head and neck cancer survivors.
Beadle BM, Liao KP, Chambers MS, et al. Evaluating the impact of patient, tumor, and treatment characteristics on the development of jaw complications in patients treated for oral cancers: A SEER Medicare analysis. Head Neck. 2012 Nov 14. [Epub ahead of print]
For more information, contact Dr. Beth Beadle at 713-563-2300, Dr. Mark Chambers at 713-745-2672, and Dr. Theresa Hofstede and 713-745-4990.
Other articles in OncoLog, November-December 2013 issue: