Microbial biofilms are causing jaw-tissue infections in patients taking bisphosphonate drugs, say researchers in the April issue of Journal of Oral and Maxillofacial Surgery.
After seeing an increasing number of reports of osteonecrosis of the jaw (ONJ) in patients who have been taking bisphosphonates to prevent osteoporosis or to treat the bone-wasting effects of cancer, researchers at the University of Southern California (USC) dentistry clinics decided to investigate further.
Four patients who participated in a program at USC to monitor and evaluate patients with ONJ and who were scheduled to undergo sequestrectomy agreed to participate in a study. Researchers evaluated bone samples by using conventional histopathologic techniques and scanning electron microscopy.
The results of the bone sample evaluations showed that large areas were occluded with biofilms comprising mainly bacteria, and occasionally yeast, embedded in extracellular material. The bacteria included species from the genuses Fusobacterium, Bacillus, Actinomyces, Staphylococcus, Streptococcus and Selenomonas, as well as three different species of Treponema, and the yeast was consistent with Candida species. Researchers observed coaggregation between different species within the biofilms.
Researchers conclude that these findings have important clinical and therapeutic implications and may suggest a role for microbial biofilms in the disease process of ONJ.
"Now that we’ve known biofilms are behind the infection of the jaw, we are studying ways to effectively treat or prevent the osteonecrosis," said lead researcher Dr. Parish Sedghizadeh, assistant clinical professor at the USC School of Dentistry.
The study was funded by the USC School of Dentistry with the assistance of a USC Zumberge Research and Innovation Award.
