Microbial biofilms in osteomyelitis of the jaw and osteonecrosis of the jaw secondary to bisphosphonate therapy

Background. The authors report their observations with respect to microbial biofilms in osteomyelitis of the jaw (OMJ), compare these findings with those for osteonecrosis of the jaw (ONJ) secondary to bisphosphonate therapy and discuss recent findings that the pathogenesis of ONJ may represent a biofilm-mediated infectious disease in the context of bisphosphonate therapy. Methods. In 2004, a program was established at the University of Southern California, Los Angeles, to evaluate, treat and monitor patients who have OMJ and ONJ. Twenty people from this cohort of study patients who were scheduled to undergo surgical debridement or sequestrectomy and who met the authors' inclusion criteria gave informed consent for the study. The authors examined bone samples histopathologically and via scanning electron microscopy, a technique applicable to biofilm characterization. Results. Specimens from all patients with OMJ and ONJ exhibited large surface areas of bone occluded with well-developed biofilms comprising microbial organisms embedded in an extracellular polymeric substance. Actinomyces predominated in OMJ cases, whereas ONJ cases represented more diverse bacterial organisms in addition to fungal organisms not seen in OMJ. The authors observed resorption pits, septic clots, putative nanowires and host inflammatory cells in all specimens. Conclusions. The findings of this study support a role for microbial biofilms in both disease processes. Clinical Implications. Microbial biofilms are a potential target for therapy that includes antibiofilm. modalities in the treatment and prevention of OMJ and ONJ.