The first quantitative histomorphological analyses of bone vitality and inflammation in surgical specimens of patients with medication-related osteonecrosis of the jaw

Background The purpose of the study was to categorize the vitality and inflammation of resected bone of patients with medication-related osteonecrosis of the jaw (MRONJ) and to correlate the grade of inflammation with the surgical success. Methods This prospective study includes 44 patients with stage III MRONJ. Necrotic bone was resected in a block fashioned way. After demineralization and staining, histological analyses were performed by measuring the areas of necrotic, vital, and regenerative bone. Areas of chronic and acute inflammation were categorized as non, mild, moderate, and severe and were correlated with surgical success and parameters of inflammation in blood plasma (C-reactive protein and leukocytes). Results An average area of 59.0% was necrotic in the examined specimen. Vital bone was measured with an average area of 40.9%. The stage of chronic inflammation correlated with the amount of vital bone (P < .001) and the success of surgery (P = .002). If acute inflammation was dominant, chronic inflammation areas were found less while necrotic areas were observed more (P < .001). Also, the risk of relapses, wound healing disorders, and the level of C-reactive protein were elevated if acute inflammation was severe or moderate (P = .031). Areas of bone regeneration were seen only in 11.3% of vital bone areas and occurred independently of infection stages. Conclusion If possible, surgery should be delayed in patients with signs of severe acute inflammation. Patients may profit from prolonged pre-operative antibiotic therapy to reduce the level of acute inflammation.