Characteristics of bisphosphonate-related osteonecrosis of the jaw after kidney transplantation

Renal transplantation is the definitive treatment of chronic renal failure, and osteoporosis in patients after renal transplantation is caused by the use of high-dose corticosteroids, reduced renal function, and the use of immunosuppressant. While bisphosphonates inhibit osteoclastic activities, they are the drug of choice for the treatment and prevention of osteoporosis. Bisphosphonate-related osteonecrosis of the jaw (BRONJ) becomes a problematic issue. There are few reports on BRONJ in patients after renal transplantation, so many oral bisphosphonates commonly prescribed in patients after renal transplantation to prevent osteoporosis have no warning of BRONJ. We analyzed the records of patients with BRONJ from January 2009 to December 2010. Among the patients with BRONJ, we selected patients who underwent transplantation of the kidney. Demographic data, drug-related factors, and clinical characteristics were evaluated using chart review. A total of 128 patients were categorized as having BRONJ, and there were 3 patients with a history of kidney transplantation. The average age was 54.6 years, and 2 victims were men. All patients received oral bisphosphonates for more than 2 years (range, 2-7 y; average, 58.6 mo). All patients had hypertension, diabetes mellitus, history of high-dose corticosteroids, and taking immunosuppressant drugs. Bisphosphonate-related osteonecrosis of the jaw occurred in the maxilla in all patients, which is classified as stage 3 because of the involved sinus. Extraction was the main provoking factor in all patients. In conclusion, even at a relatively young age, BRONJ in the maxilla can be developed by intake of oral bisphosphonate after kidney transplantation. Dental care for patients before and after undergoing renal transplantation should be emphasized to reduce the risk of BRONJ.