Pre-treatment dental issues
Dental Preparation for Patients with Head and Neck Cancer Prior to Radiation Therapy.
An MD Anderson Cancer Center perspective
By Jude Richard
For patients who are about to undergo radiation therapy for head and neck cancer, a dental examination before treatment can do more than give them a healthier smile. By precluding many complications that could jeopardize treatment options or delay recovery, a pretreatment dental evaluation can also give patients something to smile about more successful radiation treatment and a smoother recovery.
"When combined with other medical consultations, the dental examination can help the head and neck specialist determine the best and most productive course of treatment," said Jack Martin, D.D.S., chief of the Section of Oncologic Dentistry and Prosthodontics, Department of Head and Neck Surgery, at The University of Texas M. D. Anderson Cancer Center.
The five dental oncologists in the Head and Neck Center at M. D. Anderson each treat 10 to 15 patients a day on an outpatient basis (all together about 650 patient visits a month). Roughly 60% to 80% of these patients have head and neck cancer, and a large percentage, said Dr. Martin, have a poor dental status and a history of tobacco and alcohol use. The dental clinic's location within the Head and Neck Center makes patient referrals more convenient and promotes communication between the dental oncologists and other members of the multidisciplinary treatment team, Dr. Martin said.
The immediate job of the dental oncologists in the Head and Neck Center is to help patients achieve - via a comprehensive oral/dental assessment and, if necessary, dental treatment and prophylaxis - sound oral health, which will allow their disease to respond better to treatment by the head and neck medical team.
According to Rhonda Jacob, D.D.S., a professor in the Department of Head and Neck Surgery, irradiation immediately puts the patient with head and neck cancer at high risk for treatment-related complications including dry mouth (xerostomia), oral infections, oral muscle fibrosis, and jawbone destruction (osteoradionecrosis).
A dental examination before irradiation of head and neck cancers is important, Dr. Martin said, for two reasons: to impress on the patient the need for fluoride therapy and to remove any unrestorable, abscessed, or periodontally diseased teeth in the field of radiation therapy. Many of these patients may also require fabrication of a radiation stent. "In many instances, teeth will need to be extracted before radiation treatment because once the patient has radiation treatment, oral and periodontal surgery may be contraindicated," Dr. Martin said. "When extractions are required, they can be done under local or general anesthesia, depending on the degree of difficulty and the patient's medical status."
In some cases, radiation therapy cannot wait for dental treatment, and the head and neck physician will opt to deal with future dental sequelae as they arise. In most cases, however, dental evaluation and treatment can be done before radiation therapy and should be considered medically necessary, Dr. Martin said.
In patients who have been or are about to be irradiated, the biggest dental problems, said Dr. Jacob, are dental caries and periodontal disease. "In the healthy mouth," she explained, "saliva balances the mouth's acidity and dilutes any sugars that are eaten. Yet, because it is very difficult to exclude the salivary glands from radiation fields in the head and neck and because an irradiated gland can no longer produce saliva, oral acids take advantage and begin to attack the patient's teeth. This greatly increases the chances for dental caries in every tooth." As a result, the patient becomes prone to dental decay, jawbone destruction, and fevers due to these infections, all of which may hinder the recovery from cancer treatment. This is most likely to occur in patients with head and neck cancer whose dental hygiene is poor and in patients who have been irradiated despite having a preexisting dental infection.
To prevent these types of treatment-related complications from occurring, dental oncologists at M. D. Anderson prescribe fluoride and advise patients to visit their regular dentists for routine cleaning and dental work when they return home. According to Dr. Jacob, it is important for community physicians to reiterate this advice to their patients. "Unfortunately," said Dr. Jacob, "most patients tend to be more careful about their dental hygiene at the beginning of and during their therapy. Their dental regimen slips over time as follow-ups become fewer and as fewer people press them to keep up the dental care."
Consequently, she said, community physicians with patients who have been irradiated for head and neck cancer should, ideally, build a relationship with the patient's dentist. "Many of our patients, once they have been treated, placed on fluoride treatment, and sent home, are cared for by their hometown dentists," said Dr. Martin. "We receive calls from their dentists asking if they can make a radiograph, pull a tooth, or perform an endodontic procedure. Being a part of this care is an important part of our function as dental oncologists."
Though its main focus is providing extra- and intraoral prosthetic rehabilitation and preparing patients with head and neck cancer for radiation treatment, the Head and Neck Center's dental clinic also evaluates and, if necessary, treats about 3% of patients receiving chemotherapy at M. D. Anderson. Most of those, said Drs. Martin and Jacob, are patients who have had bone marrow transplants. "Compared with patients who receive radiation therapy," said Dr. Jacob, "cases involving patients receiving chemotherapy pose less of a problem for us since the sequelae of chemotherapy come and go with the cycles of treatment. So, we end up treating a lot of acute, but routine dental infections. During immunosuppressive chemotherapy these dental infections, which are usually self-limiting in a normal situation, can become life threatening."
"On occasion," Dr. Jacob added, "we also see patients who have received head and neck irradiation treatment outside M. D. Anderson, patients previously treated elsewhere who now have advanced dental problems such as osteoradionecrosis, and patients sent to us to receive special prostheses. These patients are sent to us on a 'short-form' registration basis to be seen only by the dental service. We work closely with the referring physicians and dentists to resolve complications related to past or pending cancer therapy."
Dental consultations ordered by the cancer specialist can do more than improve a patient's cancer treatment by improving their oral health, said Dr. Martin. They can also strengthen the physician's relationship with the patient. "In my experience," he said, "most patients appreciate a physician who looks out for them by identifying possible treatment-hindering dental problems and sending them to see a dentist before cancer treatment begins." Dental consultations can also be very cost-effective. "For example," Dr. Martin said, "hyperbaric oxygen is a treatment that allows us to operate on an irradiated jaw that needs dental extractions or has areas of necrosis, but it is very costly for the patient in both time and money--approximately $15,000 for 20 preoperative and 10 postoperative treatments. Even with these treatments, patients may still suffer jawbone loss and require costly jaw reconstruction. In most cases, taking care of the patient's dental problems before irradiation would have made these procedures unnecessary."
In the case of patients who are treated with chemotherapy, pretreatment dental consultation and care could eliminate costly hospital admissions for fevers of undetermined origin. "So," he concluded, "if you compare that cost with the cost of a basic oral examination with dental radiographs (approximately $200), you can see that dental evaluation and treatment before cancer therapy is cost-efficient and, medically, more productive. The patient ultimately returns home healthier in all respects."