Discontinuation of bisphosphonate therapy
The literature does not support discontinuing bisphosphonate therapy to enhance the healing process. Bisphosphonates accumulate in a patient's skeleton and could remain active for several years, especially in patients who have been treated with an intravenous bisphosphonate for longer than a year. There is anecdotal evidence that even with discontinuing zoledronic acid therapy for patients who develop BON, the osteonecrotic process clinically progresses and can extend to contiguous sites. However, discontinuing bisphosphonate therapy is advocated by some authors, especially when a procedure to treat BON is planned.[6,9]
Some clinicians believe that discontinuing the drug for patients scheduled for surgery to treat the necrotic area may be beneficial, although this belief is not supported by scientific study. It is recommended that such a drug holiday be maintained until clinical evidence of healing is observed. However, controversy surrounds this issue,[Level of evidence: IV] and further research is needed.
In summary, a potential drug holiday for patients on bisphosphonates must be considered in the context of presence or absence of osteonecrosis. In view of the lack of scientific evidence from randomized controlled studies, risk and benefits of drug discontinuation must be determined by the prescribing physician. In patients who are being treated with bisphosphonate therapy and who need invasive procedures, there is no scientific information that supports a drug holiday and that this will prevent the development of BON. In patients with osteonecrosis who need invasive procedures, a drug holiday may be beneficial. On the other hand, there is emerging evidence that patients with multiple myeloma and osteonecrosis may be maintained on bisphosphonate therapy without the risk of progression of the osteonecrotic process.
It is advisable to discuss with the patient's physician whether discontinuing bisphosphonate therapy will not put the patient's general health at risk. Obtaining an informed consent from the patient before execution of the proposed drug discontinuation and therapy is important.
Spontaneous and asymptomatic BON
Patients may present with asymptomatic exposed necrotic bone anywhere in the oral cavity, although the mylohyoid plate on the posterior mandible and the mandibular tori are the most frequently affected sites. In this case, local measures and effective oral hygiene are important, as is systematic reevaluation of the patient to ensure resolution.
Effects on quality of life
The number of patients who develop BON is small compared with the large number of people who take bisphosphonates. However, some lesions can progress to large sizes and cause severe changes in a patient's quality of life.[1,2] Advanced mandibular lesions, for instance, can cause necrosis of the cortical bone, increasing the risk of fractures. Advanced and nonresponsive infections may require hospitalization and intravenous antibiotic therapy. Advanced cases of BON may require extensive jawbone resection. Therefore, this adverse effect of bisphosphonate therapy may negatively affect quality of life.