Lack of association between oral bisphosphonates and osteonecrosis using jaw surgery as a surrogate marker.

UNLABELLED: Using jaw surgery as a surrogate marker for osteonecrosis of the jaw, this exploratory study did not find that the risk of jaw surgery was significantly increased with the use of oral bisphosphonates in postmenopausal women.
INTRODUCTION: The objective of this analysis was to explore the potential association between jaw surgery (as a surrogate marker for osteonecrosis of the jaw) and the use of oral bisphosphonates in postmenopausal women.
METHODS: A claims database was used to identify female patients > or = 45 years of age with jaw surgery claims from January 1, 2002 to December 31, 2005. Four controls (patients with no claims for jaw surgery) were matched to each jaw surgery case. Additional patient data collected included oral bisphosphonate prescriptions (including alendronate, risedronate, or ibandronate) and comorbid conditions.
RESULTS: A total of 697 jaw surgery cases and 2,808 controls were identified. Of those jaw surgery cases, 96 (13.8%) received at least one prescription for an oral bisphosphonate. After adjustment for confounding variables, receiving at least one oral bisphosphonate prescription was not shown to significantly increase the risk of jaw surgery (odds ratio(adjusted) = 0.91; 95% confidence interval = 0.70-1.19). When bisphosphonate use was stratified by duration on therapy, no significant increases in the risk of jaw surgery were observed in any group.
CONCLUSIONS: This exploratory analysis did not find a significant association between oral bisphosphonate use and increased risk of jaw surgery, a surrogate marker for osteonecrosis of the jaw.

Dear Editors,

We have carefully read the comments by Yarom and Elad. In response, we would like to point out that in our paper [1] we stated that our study is designed on a previous publication by Zavras and Zhu [2] where the investigators used jaw surgery as a surrogate marker for bisphosphonates-associated osteonecrosis of the jaw (ONJ) in patients with cancer. The design does include the estimated accumulative dose of oral bisphosphonates. Also, the limitations of the study are stated clearly through the relevant sections in our paper. Furthermore, we are puzzled by Yarom and Elad’s comment that “there are major discrepancies between the study design and the conclusions of Pazianas et al.’s study” and also that we claim there to be, based on the findings of our study, no association between oral bisphosphonates and ONJ. We never suggested that; our references were consistently to jaw surgery. Therefore, we believe there is no discrepancy between the study’s design and its conclusions.