Sir, some of our colleagues may be unaware of the “adverse event” reports of osteonecrosis of the jaw of patients being treated with bisphosphonates. The majority of these reports refer to cancer patients following teeth extraction of other dental surgeries. This has led to warnings and special precautions for use being issued regarding the use of bisphosphonates.

It is suggested that a dental examination with appropriate preventive dentistry should be considered prior to treatment with bisphosphonates in patients with concomitant risk factors (e.g. cancer, chemotherapy, corticosteroids, poor oral hygiene).

While on treatment, these patients should avoid invasive dental procedures if possible. For patients who develop osteonecrosis of the jaw while on bisphosphonate therapy, dental surgery may exacerbate the condition. For patients requiring dental procedures, there are no data available to suggest whether discontinuation of bisphosphonate treatment reduces the risk of osteonecrosis of the jaw. Clinical judgment of the treating physician should guide the management plan of each patient based on individual benefit/risk assessment.

An example of this type of problem is illustrated by a lady born in 1924 who was diagnosed in 1999 with locally advanced breast cancer with widespread metastatic disease present in many bones (not involving the head). She was initially treated with tamoxifen and radiotherapy to the breast, maxilla and supraclavicular fossa. At the end of 2002 she was started on monthly injections of 4 mg IV of Zometa. The patient had a pathological fracture of a femur in 2003 but otherwise remained very active.

The patient had regular dental inspections and was partially dentate with upper and lower partial dentures being worn. At a routine visit in June 2004 the patient complained of having a neuralgic type pain in the right maxilla area for the previous two months. Examination showed upper 6/ to be present and mobile with there being a discharge of pus through the mucosa in the 5/ area. A radiograph was taken and a retained root was found in the 5/ area. Metronidazole was prescribed and a week later the 5/ root was surgically removed.

A month later the patient complained of pain associated with 6/ on biting and of a hole in the gum in the 5/ area. This prompted the practitioner to extract the 6/ and surgically examine the 5/ area in August. Five weeks later the patient presented in pain with a 2 cm by 10 cm area of uncovered bone in the molar and premolar regions of the right maxilla. The area was cleaned and closed using a buccal periosteal release flap.

At the end of November the patient was still having problems and was referred to the local maxillofacial unit regarding this apparent area of bone necrosis. An OPG x-ray revealed an increase in height of the maxillary alveolar bone at the expense of half the maxillary antra bilaterally. Once again the necrotic bone was removed (the pathology being reported as dead membranous bone with no evidence of malignancy and no fungus being present). Sadly this patient recently died of carcinomatosis.

As many patients now regularly receive bisphosphonates (BNF 6.6.2) colleagues will need to be aware of these potential complications and liase with the drug prescriber.