Saki Hayashida

Evaluation of the Treatment Strategies for Medication-Related Osteonecrosis of the Jaws (MRONJ) and the Factors Affecting Treatment Outcome: A Multicenter Retrospective Study with Propensity Score Matching Analysis†

Medication‐related osteonecrosis of the jaw (MRONJ) is an adverse event that may inhibit the treatment of primary disease and remarkably influence the patients quality of life. The treatment methods for MRONJ, nonsurgical and surgical, are controversial, with no agreement as to which method provides the best outcome and should therefore be recommended. This multicenter retrospective study aimed to investigate the treatment methods and outcome in a large number of patients with MRONJ in Japan, utilizing propensity score matching analysis. A total of 361 patients with MRONJ, at eight hospitals, were registered in this study retrospectively. Various demographic and treatment‐related variables were examined and analyzed to determine their correlation with the treatment outcome. After propensity score matching for treatment methods (nonsurgical versus surgical treatment), 176 patients were analyzed by logistic regression. It was shown that those with low‐dose administration of an antiresorptive agent and surgical treatment had better outcomes. Furthermore, in 159 patients who underwent surgical treatment, those who underwent extensive surgery experienced significantly better treatment outcomes than those who underwent conservative surgery. This is the first study to compare treatment methods for MRONJ using propensity score matching analysis. The results indicated that extensive surgical treatment should be performed as first‐choice therapy for patients with MRONJ.

Efficacy of topical antibiotic administration on the inhibition of perioperative oral bacterial growth in oral cancer patients: a preliminary study

Parenteral antibiotic prophylaxis is the current standard of therapy in clean-contaminated oral cancer surgery. Nevertheless, the incidence of surgical site infection (SSI) in oral oncological surgery is relatively high, especially in major surgery with reconstruction and tracheotomy. The aims of this study were to investigate the perioperative condition related to microorganisms in the oral cavity and to examine the efficacy of the topical administration of tetracycline in reducing the number of bacteria in the oropharyngeal fluid during intubation. The number of oral bacteria was measured during intubation in patients undergoing major oral cancer surgery. The efficacy of the topical administration of tetracycline or povidone iodine gel in reducing the bacteria was then investigated. Bacteria in the oropharyngeal fluid grew from 10(6)CFU/ml to 10(8)CFU/ml during the 3h after intubation (CFU, colony-forming units). When tetracycline was applied to the dorsum of the tongue, oral bacteria decreased immediately to 10(5)CFU/ml, and the number of bacteria in the oropharyngeal fluid was maintained below 10(7)CFU/ml for 7h. The concentration of tetracycline in the oropharyngeal fluid was extremely high for several hours after topical administration. The topical administration of tetracycline could reduce oral bacteria in patients undergoing clean-contaminated oral cancer surgery. This method is expected to be effective in the prevention of SSI.

Factors affecting development of medication-related osteonecrosis of the jaw in cancer patients receiving high-dose bisphosphonate or denosumab therapy: Is tooth extraction a risk factor?

Methods for preventing medication-related osteonecrosis of the jaw (MRONJ) in cancer patients who have received high-dose bisphosphonate (BP) or denosumab (Dmab) have not yet been established. Tooth extraction after starting medication has been believed to be a major risk factor for MRONJ, and therefore this procedure tends to be avoided. This study investigated the risk factors for MRONJ, with a special reference to the correlation between tooth extraction and development of MRONJ. One hundred and thirty-five cancer patients who were administrated high-dose BP or Dmab were enrolled in the study. Demographic factors, general condition, treatment factors, and dental findings were examined retrospectively using medical records and panoramic X-ray findings. The cumulative occurrence rate of MRONJ was calculated using the Kaplan–Meier method, and the correlation between these variables and development of MRONJ was analyzed by univariate and multivariate Cox regression analysis. MRONJ developed in 18 of 135 patients. The 1-, 2-, and 3-year cumulative occurrence rates were 8.6%, 21.5%, and 29.2%, respectively. The duration of medication before first visit to the dental unit and the presence of a tooth with clinical symptoms were significantly correlated with the development of MRONJ. The rate of MRONJ occurrence in patients who had teeth with clinical symptoms, but who did not undergo tooth extraction, became higher 2 years later than that in patients who underwent extraction of teeth with symptoms, although not significant. Early dental examination and effective preventative care to avoid infection/inflammation are important for preventing MRONJ.