Prevalence of bisphosphonate-associated osteonecrosis of the jaws after implementation of primary prevention

Introduction: Depending on the primary disease, for some high-risk subgroups older literature describes incidences of up to 20% for bisphosphonate-associated osteonecrosis of the jaws (BP-ONJ). The aim of this study was to reevaluate the incidence found in the Urology Department of the Johannes Gutenberg University in Mainz during a study conducted in 2008. The 2008 prevalence was 18.6% (8 out of 43). Material and Methods: Inclusion criteria were prostate cancer and a bisphosphonate therapy. The study was conducted in the 2nd half of 2011. No participants from the first study were among the new study group. The main criterion was the existence of BP-ONJ. Results: 2 out of 26 had a BP-ONJ (8%) that had occurred after 25 months on average, whereas the patients without BP-ONJ had an on average intake of 12 months. All patients had received zoledronate except one patient with BP-ONJ who had initially taken pamidronate. All patients were referred to a dentist prior to bisphosphonate treatment. 20 out of 26 went to the dentist. 2 patients out of the 6 who did not go developed BP-ONJ (33%), and 0 out of the 20 (0%) that were screened by a dentist did (p: 0.046). Compared to the former study, the overall prevalence decreased from 19% to 8%; if only the patients who were screened by a dentist are analyzed, prevalence went from 19% to 0%. In 5 out of the 26 patients (19%), a tooth extraction was performed with antibiotic prophylaxis and wound closure. 2 out of these 5 developed BP-ONJ. In the former study, 33% of the patients had had teeth extracted. Conclusion: Through a preventive consultation with a dentist, the prevalence of BP-ONJ could be decreased among patients with prostate cancer. Keywords: Bisphosphonate, bisphosphonate associated osteonecrosis, prevalence, incidence