What are Bisphosphonate Drugs?

Bisphosphonates are a class of drugs that prevent the loss of bone mass. High potency intravenous bisphosphonates have been shown to modify the progression of malignant bone disease in several forms of cancer, including both breast and prostate cancer. Oral bisphosphonates are used to treat osteoporosis, osteitis deformans (Paget’s disease) and other conditions that lead to bone fragility.

After they are taken orally or intravenously, bisphosphonates bind tightly to the surface of the bone directly beneath the bone cells known as osteoclasts, which actively dissolve bone. The drugs then become incorporated into the osteoclasts, stopping them from dissolving bone. As a result, bone production continues, bone loss decreases, bone density is improved and the risk of fracture is reduced.

IV Bisphosphonates

  • Pamidronate (Aredia)
  • Zoledronic Acid (Zometa)
  • Zoledronate (Reclast)
  • Ibandronate (Boniva)

Oral Bisphosphonates

  • Etidronate (Didronel)
  • Tiludronate (Skelid)
  • Aledronate (Fosamax)
  • Risedronate (Actonel)
  • Ibandronate (Boniva)

What is BRONJ?

Bisphosphonate Related Osteonecrosis of the Jaw (BRONJ) can be described as an area of the bone in the jaw that has died and been exposed in the mouth for more than 8 weeks in a person taking any bisphosphonate. Although the exact cause is unknown, BRONJ is considered a side effect of bisphosphonate therapy.

Stages for BRONJ

Stage I – characterized by exposed bone, that shows no disease or inflammation of surrounding soft tissue

Stage 2 – distinguished by painful areas of exposed bone accompanied by soft tissue or bone inflammation

Stage 3 – associated with extensive amount of exposed bone, soft tissue inflammation and pathologic fracture

Risk Factors for BRONJ

Use of bisphosphonates – Although this is a common reason for the development of BRONJ, it is the dosage and length of therapy that are the determining factors. IV bisphosphonates used in cancer treatment are much more potent than oral bisphosphonates used to manage osteoporosis, thus increasing the risk for BRONJ in these patients.

Duration or number of treatments with bisphosphonates – The risk of developing BRONJ appears to increase in relation to the number of treatments with an IV bisphosphonate.

Dental procedures – Patients undergoing routine dental surgical procedures, including tooth extractions, periodontal surgery or dental implant placement, while being treated with bisphosphonates compromise about 60% of BRONJ cases.

Prevention of BRONJ

If you are about to being monthly IV bisphosphonate therapy for the treatment of bone cancer, visit your family dentist for a thorough check up. Take care of all necessary procedures, before treatment starts. If you have removable dentures, make sure they fit well and are comfortable.

If you are currently being treated with either IV or oral bisphosphonates, be sure to tell your family dentist and oral and maxillofacial surgeon the reason for bisphosphonate treatment, the method of treatment (IV or oral), and the dosage level before you schedule a surgical procedure.

Oral hygiene is particularly important if you are being treated with bisphosphonates. It is also crucial that you schedule regular examinations with your family dentist so that any infections or problems can be identified and addressed early.

Management of BRONJ

If you are diagnosed with BRONJ, it is very important that your treatment plan include regular and thorough communication between your physician, family dentist and oral and maxillofacial surgeon. There are a number of treatment options available to your surgeon, who will select what is most appropriate for you. Treatment may include: daily irrigation and antimicrobial rinses; antibiotics to control infection; or surgical debridement for advanced cases.

BRONJ: Bisphosphonate Related Osteonecrosis of the Jaw. AAOMS 2012

Click here for the AAOMS Position Paper on BRONJ