Risk Factors and Indices of Osteomyelitis of the Jaw in Osteoporosis Patients: Results from a Hospital-Based Cohort Study in Japan

Background

Several studies have reported osteomyelitis of the jaw (OMJ) as a side effect of bisphosphonates (BPs), and the risk of oral BPs has been recently clarified. However, other systemic risk factors of OMJ remain unclear. Importantly, the possibility of risk classification based on the clinical characteristics of patients has not been explored. Here, we clarified risk factors of OMJ and evaluate the predictive accuracy of risk indices in osteoporosis patients.

Methods

We performed sub-analysis using a database developed for a retrospective cohort study in patients taking medications for osteoporosis at Kyoto University Hospital. Risk indices for OMJ were constructed using logistic regression analysis, and odds ratios (OR) for OMJ cases and 95% confidence intervals (CI) were estimated. Potential risk factors included in the statistical analysis were age; sex; diabetes; use of oral BPs, corticosteroids, cancer chemotherapy, antirheumatic drugs, and biologic agents; and their interactions. Risk indices were calculated by the sum of potential risk factors of an individual patient multiplied by the regression coefficients. The discriminatory power of the risk indices was assessed by receiver operating characteristic (ROC) analysis.

Results

In analysis of all patients, oral BPs (OR: 4.98, 95% CIs: 1.94-12.75), age (OR: 1.28, 95% CI: 1.06-1.60) and sex-chemotherapy interaction (OR: 11.70, 95% CI: 1.46-93.64) were significant risk factors of OMJ. Areas under the ROC curves of these risk indices provided moderate sensitivity or specificity regardless of group (0.683 to 0.718).

Conclusions

Our data suggest that oral BP use, age, and sex-chemotherapy are predictors of OMJ in osteoporosis patients. The risk indices are moderately high, and allow the prediction of OMJ incidence.     

Bisphosphonates and Osteonecrosis of the Jaw: A Retrospective Study

ObjectiveTo assess the prevalence of osteonecrosis of the jaw (ONJ) in patients receiving bisphosphonate therapy and in those who were bisphosphonate naïve.MethodsWe undertook a retrospective review of medical records of patients at the New York Harbor Health Care System from 1999 through 2004. Charts were selected for review if patients had a Current Procedural Terminology (CPT) code suggestive of ONJ or if they had ever received bisphosphonate therapy.ResultsAmong 1,951 medical records reviewed, we identified 2 patients with ONJ who had received bisphos-phonates and 2 patients with ONJ who were bisphospho-nate naïve. Both patients treated with bisphosphonates had multiple myeloma and were receiving monthly infusions. They had initially received pamidronate before treatment was changed to zoledronic acid. In each case, ONJ was precipitated by a routine dental extraction. The prevalence of ONJ in our patient population receiving intravenously administered bisphosphonates was 1 in 71.5. Of the 2 cases of ONJ in bisphosphonate-naïve patients, osteora-dionecrosis was clearly incriminated in 1 patient and potentially the causative factor in the other patient as well. No patients receiving orally administered bisphosphonates had ONJ, nor did this complication occur in any patients receiving parenteral bisphosphonate therapy for disorders such as osteoporosis or Paget’s disease of bone.ConclusionBisphosphonates remain an important option for management of metabolic bone disease and complications of malignant disease. The overall prevalence of ONJ in patients receiving bisphosphonates seems to be very low; however, patients receiving intense parenteral therapy for an underlying malignant condition appear to have a uniquely elevated risk for the development of this complication. A causal relationship between bisphosphonates and ONJ remains to be proved and merits further investigation. (Endocr Pract. 2007;13:232-238)     

Jaw musculature of the Meiglyptini (Aves: Piciformes: Picidae)

The Meiglyptini comprise eight species of woodpeckers grouped into three genera, two of which contain three species ( Meiglyptes and Mulleripicus), while one genus includes two species ( Hemicircus). The purpose of this study is to describe the mandibular apparatus found in six species of Meiglyptini and to compare them with each other and with other woodpecker species. The results reveal a number of structures that are worth mentioning: (i) the components of the external mandibular adductor system of Hemicircus concretus, particularly the M. adductor mandibulae externus caudalis medialis, are underdeveloped compared with the other investigated species; (ii) the muscles of the internal mandibular system are structurally different among Meiglyptes species and are less developed, both in size and in structure, in H. concretus; (iii) the M . protractor quadrati is vestigial in Meiglyptes species; (iv) the muscles of the protractor system of the quadrate are relatively undeveloped in H. concretus; (v) most of the muscles of the pterygoideus system are structurally differentiated in Meiglyptes species. It appears that the complexity of the mandibular apparatus is associated with the type of food consumed, as the apparatus of the frugivorous species H. concretus is markedly different from that of the insectivorous species.     

The Toxicology of PCB's—An Overview for Clinicians

Polychlorinated biphenyls (PCB''s) have low acute toxicity but are of public health concern because of their persistence in the environment, the bioaccumulation in human and animal tissues, and their potential for chronic or delayed toxicity.Although many questions remain unanswered, it is clear that occupational exposure, at a minimum, can produce dermatologic effects and liver dysfunction. The long half-life of PCB''s and their presence in various human tissues leaves open the possibility of substantial chronic and delayed effects analogous to those seen in animals. PCB''s are potent inhibitors of reproductive function in both rodents and nonhuman primates and produce liver tumors in animal cancer bioassays. As potent inducers of hepatic enzyme systems, PCB''s may have additional unpredictable long-term health effects.These effects have only recently begun to be studied in a rigorous manner, and although the epidemiological evidence is neither complete nor entirely consistent, there can be no question of the necessity to keep human exposures to the lowest feasible levels.