Bisphosphonates are an important and very commonly prescribed class of drugs that are widely used to treat certain resorptive bone diseases such as osteoporosis, Paget's Disease, and hypercalcemia associated with certain malignancies (i.e. multiple myeloma and bone metastasis from the breast or prostate). In fact, these drugs are so common that total US prescriptions for oral bisposphonates exceed 30 million every year.
Unfortunately, bisphosphonates have also been recognized to be associated with an adverse event known as osteonecrosis of the jaws (ONJ), which manifests as localized death of bone tissue mandible (more commonly) or maxilla. A diagnosis of BRONJ is reliant on three criteria:
- the patient has an area of exposed bone in the jaw persisting for more than 8 weeks,
- the patient must have no history of radiation therapy to the head and neck (osteonecrosis can also occur as a result of prolonged radiation and chemotherapy treatment),
- the patient must be taking or have taken bisphosphonates.
Both the dose and length of exposure to the bisphosphonates are positively linked to the risk of developing BRONJ, with IV administration providing the biggest risk. Additionally, the newer generations of oral drugs, which contain nitrogen groups, are riskier than previous generations.
The clinical presentation of BRONJ will typically include at least one of the following:
- Pain or altered sensation
- Erythema and/or suppuration
- Halitosis
Because the exact mechanism of BRONJ is unknown to date, treatment is still problematic and outcomes can be unpredictable. Therefore, proper recognition of risk factors and application of preventive dental treatment procedures are vital cornerstones of appropriate dental care in these cases.
Both of these axioms applied in the case of Mr. T. Due to his history of multiple myeloma, he was classified by his OMFS as being high risk for bisphosphonate-associated ONJ. As such, the team decision was made to treat him with more preventive measures. More commonly, these measures would include caries control, conservative periodontal and restorative treatments. But in his case, this meant nonsurgical endodontic treatment of a tooth that in 99.9% of cases would be extracted.
After proper review of informed consent and alternatives with Mr. T, #30 was treated with NSRCT. After local anesthesia was administered, the rubber dam clamp was placed on the intact #31 in order to minimize trauma to the bone in the area. Additionally, the gums that had overgrown into the tooth were carefully resected, with special attention paid to avoid any contact with the bone. Once proper isolation was achieved using FastDam, the roots were endodontically treated and then sealed individually with core material, so that risk of contamination by saliva would be minimized. Finally, when both roots were complete, all remaining supra-gingival tooth structure was reduced and prepared in a manner similar to overdenture abutments, and the tooth was hemisected to avoid the risk of future fracture.
The patient was satisfied with the outcome and reported minimal post-operative pain. Additionally, one month follow up with Mr. T revealed no issues and that the tissues in the area were healthy and symptom-free.
