Radiation therapy is an effective treatment for head and neck cancers, but it can impact healthy oral tissues. Dental procedures, particularly tooth extractions, require careful consideration for those undergoing or having undergone this treatment. Radiation alters oral tissues, increasing the risk of complications.
Understanding the Risk: Osteoradionecrosis
A significant complication associated with dental procedures after head and neck radiation is osteoradionecrosis (ORN). ORN is a condition where bone tissue in the irradiated area dies, becomes exposed, and fails to heal. This occurs because radiation therapy can damage blood vessels, bone cells, and soft tissues in the treated region, leading to reduced blood supply (hypovascularity), fewer cells (hypocellularity), and decreased oxygen levels (hypoxia) in the bone. This compromised environment makes the bone fragile and impairs healing.
Tooth extractions can trigger ORN because they create a wound in a vulnerable area, providing a pathway for bacteria and compromising the impaired healing process. Symptoms of ORN include exposed bone, persistent pain, swelling, infection, numbness or tingling, and in severe cases, jaw fracture or difficulty opening the mouth. While ORN is a rare side effect, affecting approximately 4% to 8% of people with head and neck cancers, its severity highlights the importance of preventive measures and careful management. The risk of ORN is particularly elevated when radiation doses exceed 60 Grays (Gy) to the jawbone.
Timing of Extractions: Before, During, and After Radiation
The timing of tooth extractions relative to head and neck radiation therapy is an important factor in minimizing the risk of complications. Ideally, a comprehensive dental evaluation should be performed several weeks before radiation begins. This allows for the removal of any teeth with a poor long-term prognosis or existing infections within the radiation field, providing an adequate healing period of at least two to three weeks before the start of radiation. This approach aims to eliminate infection and trauma sources to compromised tissues during and after treatment.
During active radiation therapy, tooth extractions are generally avoided due to the acute effects of radiation, such as oral mucositis (inflammation of the mouth lining), which can increase the risk of infection and impair healing. The oral tissues are at their most vulnerable during this period, making any invasive procedure risky. Delaying extractions until after radiation completion is a common strategy, but careful consideration of the post-radiation timeline is still necessary.
After radiation therapy, the risk of ORN remains elevated compared to the general population, and this risk is considered lifelong. While there is no universally agreed “safe” waiting period, many recommendations suggest waiting at least 6 to 12 months post-radiation before performing extractions, if possible. Some studies suggest that the risk of ORN might be reduced if extractions are performed within six months after radiation, before the onset of progressive tissue fibrosis. However, recent research indicates that even extractions performed within four months post-radiation can carry a significant risk of exposed bone and ORN, especially with high radiation doses to the oral cavity or mandible. Therefore, an individualized assessment by a multidisciplinary team, including the oncologist and oral surgeon, is important to weigh the benefits and risks of any post-radiation extraction.
Minimizing Risks and Post-Treatment Care
Minimizing osteoradionecrosis and other complications after radiation therapy involves proactive strategies and careful management. Maintaining comprehensive oral hygiene is important for irradiated patients, including regular brushing with a soft-bristle brush, using antibacterial rinses, and fluoride toothpaste to combat dry mouth and increased caries risk. Regular dental check-ups, at least every three to six months, are also important for early detection and management of any new dental issues.
A multidisciplinary approach involving oncologists, radiation therapists, dentists, and oral surgeons is important for effective patient care. When tooth extractions become necessary after radiation, specific protocols are often implemented to reduce complications.
These may include antibiotic prophylaxis, given both before and after the extraction, to prevent infection. Atraumatic extraction techniques, which minimize trauma to the surrounding bone and soft tissues, are also employed. Additionally, adjunctive therapies like hyperbaric oxygen therapy (HBO) may be considered, particularly for high-risk extractions in heavily irradiated areas. HBO aims to improve tissue oxygenation and promote healing, though its routine use is still debated and often reserved for specific cases.