Bisphosphonates increase risk for bone disease after tooth extraction

By Sarah Guy, medwireNews Reporter

The risk for developing osteonecrosis of the jaw (ONJ) after a tooth extraction is significantly higher among patients who receive bisphosphonates (BP) than those who do not, suggest study findings.

The risk was particularly high among patients who received intravenous BP as opposed to oral BP, note the researchers in the International Journal of Oral and Maxillofacial Surgery.

Furthermore, the risk for BP-induced ONJ (BIONJ) was significantly associated with alveolar bone loss among patients who received BP after extraction, suggesting that severe periodontitis may be a risk factor for the condition.

"Preventive and therapeutic treatment of oral bacterial infection before extraction might be important in preventing BIONJ in patients with BP administration," suggest Masashi Yamori (Kyoto University, Japan) and co-investigators.

The team analyzed data from 3216 patients who underwent tooth extraction between April 2006 and June 2009, of whom 126 received BP. In all, 78.6% of patients on BP received them orally, while the remaining 21.4% received BP intravenously.

A total of five patients who received BP developed ONJ compared with one patient who did not, giving a significantly higher cumulative incidence and a crude risk ratio of 122.6 for ONJ associated with BP use.

When stratified by route of administration, intravenous BP resulted in a significantly higher incidence of ONJ than oral administration, with crude risk ratios versus no BP of 457.7 and 31.2, respectively, report the researchers.

The team investigated potential risk factors for BIONJ among patients who received the drug and found that median bone loss scores were significantly higher among those who developed ONJ compared with those who did not, at 1.3 versus 1.6, with higher scores indicating more severe periodontal disease.

To account for the large differences in age and prevalence of cancer or osteoporosis between patients who received BP and those who did not, Yamori and colleagues performed a stratified analysis. They found that the significant risk for ONJ among BP patients remained, with a risk ratio of 200.2 for those aged at least 65 years, versus 12.9 for their same-age, BP-naive counterparts.

"This study provides important information for physicians and dentists concerned with the prevention of ONJ in patients receiving BP," conclude the study authors.

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