Role of microbiological culture and polymerase chain reaction (PCR) of actinomyces in medication-related osteonecrosis of the jaw (MRONJ).

We hypothesized that local infection plays a critical role in the pathogenesis of medication-related osteonecrosis of the jaw (MRONJ). Recent developments in molecular methods have revolutionized new approaches for the rapid detection of microorganisms including those difficult to culture. The aim of our study is to identify the bacterial profiles in MRONJ by microbiological culture and polymerase chain reactions (PCR). A retrospective analysis was performed on MRONJ patients from 2008 to 2014. The bacterial profile from MRONJ bone samples was determined using microbiological culture and PCR. Ninety five patients fulfilled the inclusion criteria with mean age of 69.85 ± 8.71 years. A female predilection was detected. The mandible was more commonly affected than maxilla. Tooth extraction was the frequent triggering factor. Breast cancer was the primary cause for administration and intravenous bisphosphonates were the most commonly administrated antiresorptive drugs. The majority of patients were classified as stage 2. Posterior teeth were most commonly affected. Based on bone culture results, the most common microorganism were both actinomyces and mixed flora. PCR confirmed the presence of actinomyces in 55 patients. Our data suggest that PCR might be an innovative method for detection of microorganisms difficult to culture using traditional microbiological techniques.

Tooth extraction in patients receiving oral or intravenous bisphosphonate administration: A trigger for BRONJ development?

INTRODUCTION: Scientific debate outlines tooth extraction as a potential trigger for the onset of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Therefore, the aim of this study was to investigate the outcome of tooth extractions in patients receiving bisphosphonate therapy. PATIENTS AND METHODS: A retrospective cohort study was performed on patients with a history of oral or intravenous bisphosphonate administration and tooth extraction between 2007 and 2013 in a single university hospital oral and maxillofacial surgical unit. In all patients, extractions were performed according to the guidelines of the German Society of Oral and Maxillofacial Surgery. The outcome variable was the onset of typical BRONJ signs during postoperative follow-up. RESULTS: In 72 subjects (53 female, 19 male; mean age 67.5 years) receiving oral (n = 27) and/or intravenous (n = 45) bisphosphonates due to malignant tumor (n = 43) or osteoporosis (n = 29), 216 tooth extractions were performed. The mean duration of intake was 36.2 months. In 67 out of 72 patients (93.1%) and 209 out of the 216 extraction sites the postoperative course was uneventful and the wounds healed without complications. Three of the 72 patients (4.2%) developed osteonecrosis of the jaw in four of the 216 extraction sites (1.9%). Duration and route of administration, oral hygiene and steroid intake were identified as potential risk factors for the development of BRONJ. CONCLUSION: Tooth extraction in patients receiving bisphosphonates can be performed in a safe and predictable way, even in high-risk patients, when performed according to established guidelines. It is not tooth extractions themselves, but rather prevailing infectious conditions that may be a key risk factor for the development of BRONJ.