Intravenous Bisphosphonate-Related Osteonecrosis of the Jaw: Bone Scintigraphy as an Early Indicator

Comparison of single photon emission computed tomography-computed tomography, computed tomography and magnetic resonance imaging of medication-related osteonecrosis of jaw by new calculated parameters

BACKGROUND

This study aimed to investigate parameters for medication-related osteonecrosis of jaw (MRONJ) patients using the bone SPECT/CT, especially bone mineral-based parameters.

METHODS

Sixty-three patients with MRONJ (43 osteoporosis and 20 bone metastasises) underwent CT, MRI and SPECT/CT. A commercially available software automatically detected lesion area and calculated the quantitative SPECT/CT parameters as bone mineral-based standardized uptake value (SUV).

RESULTS

Regarding stage of MRONJ patients, bone mineral based maximum SUV of stage 3 was significantly higher than stage 1, 2 (P=0.018). Regarding duration of medication therapy, bone mineral based maximum SUV 1 year or more was significantly higher than less than 1 year (P=0.019). Regarding present of periosteal bone proliferation on CT, bone mineral based maximum SUV was significantly higher than those of absent (P=0.029). Regarding spread of soft tissue inflammation on MRI, bone mineral based maximum SUV of 2 or more was significantly higher than those of less than 2 spaces (P=0.025). Regarding blood pool phase imaging with SPECT, bone mineral based maximum SUV of intense uptake was significantly higher than those of decrease uptake (P=0.002).

CONCLUSIONS

SPECT/CT bone mineral-based parameters indicated significant difference in staging, dosing period, periosteal bone proliferation on CT, spread of soft tissue inflammation on MRI, and blood phase imaging with SPECT. Bone SPECT/CT bone mineral-based parameters are helpful for the assessment of MRONJ.

Correlations between Immune Response and Etiopathogenic Factors of Medication-Related Osteonecrosis of the Jaw in Cancer Patients Treated with Zoledronic Acid

Impairment of the immune response in MRONJ (medication-related osteonecrosis of the jaws) is one of the still unclear etiopathogenic mechanisms of this condition encountered in cancer patients treated with bisphosphonates, with negative effects on the patient's quality of life. The aim of the present study was to correlate the immune response with etiopathogenic factors via immunohistochemical evaluation of the maxillary tissues in zoledronic acid osteonecrosis. The retrospective study included a group of 51 patients with various types of cancers, diagnosed with stage 2 or 3 MRONJ at zoledronic acid and treated surgically. Immunohistochemical expressions of αSMA, CD3, CD4, CD8, CD20, CD79α, CD68, CD204, and tryptase were evaluated. Immunohistochemical markers expressions were statistically analyzed according to the duration of the treatment, the trigger factor, the location of the MRONJ, and the healing status. Analysis of the immune response included T lymphocytes, B lymphocytes, plasma cells, macrophages, and mast cells. The duration of treatment significantly influenced the immunohistochemical expression of most markers (p < 0.05). For an increasing trend in treatment duration, a decreasing trend in marker score was observed, suggesting an inverse correlation. The expression of the markers was different depending on the trigger factor, on MRONJ localization (maxilla/mandible), and the healing status, being more intense in patients cured per primam compared to those who had relapses. The patient's immune response was negatively influenced by the duration of the treatment, the trigger factor, the location of the lesion in the mandible, and the recurrence of MRONJ.

Usefulness of quantitative bone SPECT/CT for evaluating medication-related osteonecrosis of the jaw treatment response

OBJECTIVE

For assessment of therapeutic response in medication-related osteonecrosis of the jaw (MRONJ) cases, the clinical usefulness of quantitative bone single-photon computed tomography-computed tomography (SPECT/CT) results was investigated.

MATERIALS AND METHODS

Sixteen patients (18 lesions) with a clinical diagnosis of MRONJ underwent bone SPECT/CT scanning before and during/after anti-inflammatory therapy given for 3 or more months. The GI-BONE software package was used to determine standard uptake values (SUVs), including maximum (SUVmax), peak (SUVpeak), and mean (SUVmean), and metabolic bone volume (MBV) and also total bone uptake (TBU). In both responders (downstage) and non-responders (upstage or no change), differences in quantitative values between the first and second SPECT/CT examinations were analyzed using a Wilcoxon test.

RESULTS

Following therapy, significant reductions in SUVmax, SUVpeak, SUVmean, MBV and TBU values for 11 lesions were noted in the responders after therapy (p = 0.003, p = 0.006, p = 0.004, p = 0.003, and p = 0.002, respectively). On the other hand, those for the seven lesions in the non-responder group were not significantly different (p = 0.17, p = 0.16, p = 0.26, p = 0.96, and p = 0.12, respectively). Results for SUVmax change showed sensitivity and specificity values of 45.5% and 85.7%, respectively, for differentiating responders from non-responders, with - 37.3% the optimal cutoff value. Those for MBV change were 72.7 and 85.7%, respectively, with - 29.4% the optimal cutoff value. Those for TBU change were 81.8% and 85.7%, respectively, with - 36.3% the optimal cutoff value.

CONCLUSION

The present findings showed that therapeutic response in MRONJ cases could be determined by use of quantitative SUV, MBV, and TBU values based on bone SPECT/CT findings.

Prediction models for early diagnosis of actinomycotic osteomyelitis of the jaw using machine learning techniques: a preliminary study

BACKGROUND

This study aimed to develop and validate five machine learning models designed to predict actinomycotic osteomyelitis of the jaw. Furthermore, this study determined the relative importance of the predictive variables for actinomycotic osteomyelitis of the jaw, which are crucial for clinical decision-making.

METHODS

A total of 222 patients with osteomyelitis of the jaw were analyzed, and Actinomyces were identified in 70 cases (31.5%). Logistic regression, random forest, support vector machine, artificial neural network, and extreme gradient boosting machine learning methods were used to train the models. The models were subsequently validated using testing datasets. These models were compared with each other and also with single predictors, such as age, using area under the receiver operating characteristic (ROC) curve (AUC).

RESULTS

The AUC of the machine learning models ranged from 0.81 to 0.88. The performance of the machine learning models, such as random forest, support vector machine and extreme gradient boosting was significantly superior to that of single predictors. Presumed causes, antiresorptive agents, age, malignancy, hypertension, and rheumatoid arthritis were the six features that were identified as relevant predictors.

CONCLUSIONS

This prediction model would improve the overall patient care by enhancing prognosis counseling and informing treatment decisions for high-risk groups of actinomycotic osteomyelitis of the jaw.

Osteonecrosis of the Jaw and Antiresorptive Agents in Benign and Malignant Diseases: A Critical Review Organized by the ECTS

CONTEXT

Antiresorptive therapy significantly reduces fracture risk in patients with benign bone disease and skeletal-related events (SREs) in patients with bone metastases (BM). Osteonecrosis of the jaw (ONJ) is a rare but severe condition manifested as necrotic bone lesion or lesions of the jaws. ONJ has been linked to the use of potent antiresorptive agents, termed medication-related ONJ (MRONJ).

OBJECTIVE

We aimed to identify the differences various aspects of MRONJ among distinct patient categories and provide recommendations on how to mitigate the risk and optimally manage MRONJ in each of them.

METHODS

A working group of the European Calcified Tissue Society (ECTS) and 2 experts performed an updated detailed review of existing literature on MRONJ incidence, characteristics, and treatment applied in bone diseases with variable severity of skeletal insult, ranging from osteoporosis to prevention of cancer treatment-induced bone loss and SREs in cancer patients with BM.

RESULTS

The risk for MRONJ is much higher in patients with advanced malignancies compared to those with benign bone diseases because of the higher doses and more frequent administration of antiresorptive agents in individuals with compromised general health, along with coadministration of other medications that predispose to MRONJ. The overall risk for MRONJ is considerably lower than the benefits in all categories of patients.

CONCLUSION

The risk for MRONJ largely depends on the underlying bone disease and the relevant antiresorptive regimen applied. Physicians and dentists should keep in mind that the benefits of antiresorptive therapy far outweigh the risk for MRONJ development.

Medication-related osteonecrosis of the jaw: An update

Antiresorptive medications, such as bisphosphonates and denosumab, are an important class of medication used to treat a wide range of diseases from osteoporosis to multiple myeloma. Unfortunately, they are also associated with a rare but devastating side effect - medication-related osteonecrosis of the jaw (MRONJ). First reported in 2003, much research has been done into the area; however, the exact pathophysiology continues to elude clinicians and researchers. What has been ascertained is that intravenous treatment, duration of treatment, and tooth extraction are major risk factors. Staging and treatment guidelines have been proposed; however, there has been no universal acceptance, and clinicians rely on various position papers. Over the next 30 years, the aging population is set to double, and with it, the prescription of antiresorptive medication and incidence of MRONJ will undoubtedly increase. In 2013, Gupta et al. published a paper on bisphosphonate-related osteonecrosis of the jaw; however, there have many changes since then. This paper aims to provide a succinct update on those changes.

Effects of Soft Tissue Closure on Medication-Related Osteonecrosis of the Jaw in a Rabbit Model with Tooth Extraction: A Pilot Study

Objectives

The study investigated the effect of soft tissue closure after tooth extraction on the prevention of medication-related osteonecrosis of the jaw in a rabbit model.

Materials and Methods

Twenty female New Zealand white rabbits were randomly assigned into the experimental group administrated with zoledronic acid (ZA) and control groups treated with saline. Bilateral lower premolar extraction was performed 4 weeks after ZA/saline administration. Immediately after extraction, the wound on the right mandible was closed by suture while the other side was left open. Animals were sacrificed 4 weeks and 8 weeks after tooth extraction. Fluorochrome labeling solutions were injected subcutaneously to evaluate the bone growth rates. The mandibles were harvested and subjected for microcomputed tomography, confocal microscope, and histomorphological examinations.

Results

All extraction sites healed well without any signs of infection. Trabecular thickness (Tb.Th) was significantly higher in the ZA-treated group than in the control group at both week 4 and week 8, while no significant difference was detected in the rest of the assessed parameters. The bone growth rate in mandibles showed gradual reduction in the ZA-treated group. Histological analysis showed that at week 8, the animals in the ZA-treated group had significantly higher incidence of osteonecrosis than that in the control group, while no significance was revealed between the sutured and nonsutured side.

Conclusions

ZA treatment significantly reduces bone growth rates but does not reveal a significant effect on bone mineral density and bone microarchitecture. Soft tissue closure of the extraction socket does not reduce the incidence of ONJ in the ZA-treated rabbit model.

Medication Related Osteonecrosis of the Jaw: 2021 Position Statement of the Korean Society for Bone and Mineral Research and the Korean Association of Oral and Maxillofacial Surgeons

Antiresorptives are the most widely prescribed drugs for the treatment of osteoporosis. They are also used in malignant bone metastases, multiple myeloma, and Paget's disease, and provide therapeutic efficacy on those diseases. However, it was reported that the occurrence of osteonecrosis of the jaw (ONJ) could be related to antiresorptive exposures, and there have been many cases regarding this issue. Therefore, a clearer definition and treatment guidelines were needed for this disease. The American Society for Bone and Mineral Research and the Amnerican Association of Oral and Maxillofacial Surgeons reported statements on bisphosphonate-related ONJ (BRONJ), and a revised version was recently presented. In the revised edition, the diagnosis BRONJ was changed to medication-related ONJ (MRONJ), which reflects consideration of the fact that ONJ also occurs for denosumab, a bone resorption inhibitor of the receptor activator of the nuclear factor-κB ligand antibody family, and bevacizumab, an anti-angiogenesis inhibitor. The Korean Society for Bone and Mineral Research and the Korean Association of Oral and Maxillofacial Surgeons had collectively formed a task force for the preparation of an official statement on MRONJ based on a previous position paper in 2015. The task force reviewed current knowledge and coordinated dental and medical opinions to propose the guideline customized for the local Korean situation.

Usefulness of quantitative bone SPECT/CT for medication-related osteonecrosis of the jaw in clinical settings

OBJECTIVE

This study was conducted to investigate the clinical utility of quantitative bone single-photon computed tomography-computed tomography (SPECT/CT) for detection and classification for medication-related osteonecrosis of the jaw (MRONJ).

MATERIALS AND METHODS

Fifty-nine patients (69 lesions) clinically diagnosed as MRONJ by four specialists of Japanese Society of Oral Surgery according to the AAOMS diagnostic criteria and who underwent bone SPECT/CT were enrolled. One reader determined standard uptake values (SUVs), including maximum (SUVmax), peak (SUVpeak), and mean (SUVmean), as well as metabolic bone volume (MBV), representing total volume above threshold, and total bone uptake (TBU), calculated as MBV × SUVmean, using the GI-BONE software package. One-way repeated-measures analysis of variance and subsequent post hoc analysis were employed to compare quantitative values between clinical stages. To check reproducibility of values, another reader calculated these quantitative values.

RESULTS

Mean SUVmax values for stage 0 (n = 21), 1 (n = 13), 2 (n = 25), and 3 (n = 10) were 5.82 ± 3.20, 5.46 ± 3.79, 8.16 ± 3.93, and 10.57 ± 8.43, respectively, while values for MBV were 9.52 ± 6.33, 11.36 ± 7.32, 12.4 ± 8.21, and 17.84 ± 16.94, respectively, and for TBU were 40.60 ± 46.97, 53.70 ± 77.26, 62.37 ± 42.91, and 102.01 ± 74.52, respectively. There were significant differences for SUVmax, SUVpeak, and SUVmean between clinical stages (p = 0.024, p = 0.027, p = 0.039, respectively). Subsequent post hoc analysis showed that SUVmax and SUVpeak of stage 3 were significantly higher than those of stage 0 (p = 0.046, 0.045, respectively). MBV and TBU showed a tendency to increase with increased stage, though differences between stages were not significant (p = 0.15, p = 0.053, respectively). Little differences of mean SUVmax, SUVpeak, SUVmean, MBV, and TBU between two readers were observed (- 3.10%, - 0.26%, - 4.24%%, 0.69%, and - 3.42%, respectively). The intraclass correlation coefficients (ICCs) of SUVmax, SUVpeak, SUVmean, MBV, and TBU were 0.985, 0.990, 0.980, 0.994, and 0.994, respectively (almost perfect for all values).

CONCLUSION

As objective and reliable indicators, SUVmax and SUVpeak derived from quantitative bone SPECT/CT results are useful for detection of early status disease, as well as staging in MRONJ patients.

Bone Phenotyping Approaches in Human, Mice and Zebrafish - Expert Overview of the EU Cost Action GEMSTONE ("GEnomics of MusculoSkeletal traits TranslatiOnal NEtwork")

A synoptic overview of scientific methods applied in bone and associated research fields across species has yet to be published. Experts from the EU Cost Action GEMSTONE ("GEnomics of MusculoSkeletal Traits translational Network") Working Group 2 present an overview of the routine techniques as well as clinical and research approaches employed to characterize bone phenotypes in humans and selected animal models (mice and zebrafish) of health and disease. The goal is consolidation of knowledge and a map for future research. This expert paper provides a comprehensive overview of state-of-the-art technologies to investigate bone properties in humans and animals - including their strengths and weaknesses. New research methodologies are outlined and future strategies are discussed to combine phenotypic with rapidly developing -omics data in order to advance musculoskeletal research and move towards "personalised medicine".

Medication-Related Osteonecrosis of the Jaw: A Critical Narrative Review

Background: Nearly two decades have passed since a paradoxical reaction in the orofacial region to some bone modifying agents and other drugs was recognized, namely medication-related osteonecrosis of the jaw (MRONJ). Purpose: The aim of this manuscript was to critically review published data on MRONJ to provide an update on key terminology, concepts, and current trends in terms of prevention and diagnosis. In addition, our objective was to examine and evaluate the therapeutic options available for MRONJ. Methods: The authors perused the most relevant literature relating to MRONJ through a search in textbooks and published articles included in several databases for the years 2003–2021. Results and conclusions: A comprehensive update of the current understanding of these matters was elaborated, addressing these topics and identifying relevant gaps of knowledge. This review describes our updated view of the previous thematic blocks, highlights our current clinical directions, and emphasizes controversial aspects and barriers that may lead to extending the accumulating body of evidence related to this severe treatment sequela.

Usefulness of Quantitative Bone SPECT/CT for Evaluating Treatment Response in a Patient with Mandibular Osteomyelitis

We report here a case of mandibular osteomyelitis in a 63-year-old female in which quantitative values determined using bone SPECT/CT were useful to evaluate response to antibiotic therapy, hyperbaric oxygen therapy, and sequestomy. After finishing therapy, the chief complaints were well relieved, and posttreatment Tc-99m HMDP bone SPECT/CT examination showed decreased uptake. The maximum standardized uptake value (SUV), peak SUV, mean SUV, metabolic bone volume, and total bone uptake of the untreated lesion were 6.26, 5.16, 3.97, and 11.86 mL and 42.21, respectively, which were decreased to 4.65, 3.90, 2.77, and 9.67 mL and 26.80, respectively, following hyperbaric oxygen therapy and antibiotic administration, and were moreover decreased to 4.28, 3.67, 2.75, and 6.24 mL and 17.19, respectively, after sequestomy. In comparison with pretreatment situation, those parameters were decreased by −25.7, −24.4, −30.2, −18.5, and −36.5%, respectively, following hyperbaric oxygen therapy and antibiotic administration, and moreover by −31.6, −28.9, −30.7, −47.4, and −59.3, respectively, after sequestomy, likely reflecting treatment response. Quantitative bone SPECT/CT may be useful to evaluate bone inflammatory activity and treatment response in a patient with mandibular osteomyelitis.

Clinical considerations for medication-related osteonecrosis of the jaw: a comprehensive literature review

Background

Medication-related osteonecrosis of the jaw (MRONJ), which was first reported as bisphosphonate-related osteonecrosis of the jaw (BRONJ) in bisphosphonate users, is a rare but severe soft and hard tissue disease induced by several types of medications. There has been a deluge of information about MRONJ, such as epidemiology, risk factors, clinical recommendations for dental treatment to prevent it, and treatment strategies in medication-prescribed users. The aim of this study was to comprehensively review recent articles and provide the current scientific information about MRONJ, especially clinical considerations or recommendations for dental treatment to prevent its occurrence.

Materials and methods

The current literature review was mainly based on 14 systematic reviews with or without meta-analysis, 4 position papers, 1 consensus statement, 1 clinical guideline, and 2 clinical reviews regarding MRONJ after a PubMed database and manual searches according to inclusion and exclusion criteria. Moreover, 53 articles were selected by manual search in regard to all references from selected articles and other articles identified on the PubMed search, irrespective of publication date, and inclusion and exclusion criteria.

Results

The incidence and prevalence of MRONJ are relatively low, although they are clearly higher in cancer patients receiving high-dose antiresorptive agents or angiogenesis inhibitors rather than osteoporosis patients receiving oral bisphosphonates or denosumab. There are many types of local, systemic, and other risk factors for the development of MRONJ. Clinical recommendations are provided for each clinical situation of patients to prevent MRONJ. There are also treatment strategies for MRONJ in each stage.

Conclusions

General dentists should perform appropriate dental treatment to prevent MRONJ in the patients prior to or when receiving medications that could induce MRONJ. Moreover, there are treatment strategies for MRONJ in each stage that oral surgeons could follow. Adequate and updated clinical information regarding MRONJ based on scientific data is required whenever possible.

Various Therapeutic Methods for the Treatment of Medication-Related Osteonecrosis of the Jaw (MRONJ) and Their Limitations: A Narrative Review on New Molecular and Cellular Therapeutic Approaches

Medication-related osteonecrosis of the jaw (MRONJ) is one of the most interesting diseases in the field of maxillofacial surgery. In addition to bisphosphonates, the use of antiresorptive and antiangiogenic agents is known to be the leading cause. However, the exact pathogenesis of MRONJ has not been established, and various hypotheses have been proposed, such as oxidative stress-related theory. As a result, a definitive treatment protocol for MRONJ has not been identified, while various therapeutic approaches are applied to manage patients with MRONJ. Although the surgical approach to treat osteomyelitis of the jaw has been proven to be most effective, there are limitations, such as recurrence and delayed healing. Many studies and clinical trials are being conducted to develop another effective therapeutic modality. The use of some materials, including platelet concentrates and bone morphogenetic proteins, showed a positive effect on MRONJ. Among them, teriparatide is currently the most promising material, and it has shown encouraging results when applied to patients with MRONJ. Furthermore, cell therapy using mesenchymal stem cells showed promising results, and it can be the new therapeutic approach for the treatment of MRONJ. This review presents various treatment methods for MRONJ and their limitations while investigating newly developed and researched molecular and cellular therapeutic approaches along with a literature review.

Effectiveness of Prophylactic Preoperative Antibiotics in Mandible Fracture Repair: A National Database Study

OBJECTIVE

This is the first database study to assess the effectiveness of prophylactic preoperative antibiotics (PPAs) in mandible fracture repair.

STUDY DESIGN

Retrospective cohort.

SETTING

Database study using US inpatient and outpatient insurance claims submitted from July 2006 to March 2015.

METHODS

The IBM MarketScan Commercial Database was queried for adults aged 18 to 64 years who had undergone first-time mandible fracture repair according to Current Procedural Terminology codes for open and closed repair. Primary outcomes included surgical revision, local infection, and osteomyelitis. Rates were compared between cohorts based on whether or not patients had filled antibiotic prescriptions during the preoperative period alone. The effects of drug abuse and type of mandible repair (open vs closed) were explored. Multivariate Poisson regression models were used to calculate adjusted relative risk estimates, and 95% CIs were used to determine statistically significant differences.

RESULTS

A total of 2676 patients were included, with 847 (31.7%) filling PPAs and 1829 (68.3%) filling no antibiotics. Rates were 38.9% for revision, 5.8% for local infection, and 2.1% for osteomyelitis. After multivariate analysis, exposure to PPAs was not associated with surgical revision (adjusted relative risk, 1.04; 95% CI, 0.94-1.15), local infection (1.16; 0.82-1.64), or osteomyelitis (1.21; 0.68-2.14). Patients were more likely to fill PPAs if they underwent open repair (35.3%) versus closed (26.6%) (proportion difference, 8.7%; 95% CI, 5.2%-12.2%), but exposure to antibiotics did not predict outcomes on subgroup analysis.

CONCLUSION

PPAs do not improve mandible repair outcomes, regardless of repair type.

Do various imaging modalities provide potential early detection and diagnosis of medication-related osteonecrosis of the jaw? A review

OBJECTIVE

Patients with medication-related osteonecrosis of the jaw (MRONJ) often visit their dentists at advanced stages and subsequently require treatments that greatly affect quality of life. Currently, no clear diagnostic criteria exist to assess MRONJ, and the definitive diagnosis solely relies on clinical bone exposure. This ambiguity leads to a diagnostic delay, complications, and unnecessary burden. This article aims to identify imaging modalities' usage and findings of MRONJ to provide possible approaches for early detection.

METHODS

Literature searches were conducted using PubMed, Web of Science, Scopus, and Cochrane Library to review all diagnostic imaging modalities for MRONJ.

RESULTS

Panoramic radiography offers a fundamental understanding of the lesions. Imaging findings were comparable between non-exposed and exposed MRONJ, showing osteolysis, osteosclerosis, and thickened lamina dura. Mandibular cortex index Class II could be a potential early MRONJ indicator. While three-dimensional modalities, CT and CBCT, were able to show more features unique to MRONJ such as a solid type periosteal reaction, buccal predominance of cortical perforation, and bone-within-bone appearance. MRI signal intensities of vital bones are hypointense on T₁WI and hyperintense on T₂WI and STIR when necrotic bone shows hypointensity on all T₁WI, T₂WI, and STIR. Functional imaging is the most sensitive method but is usually performed in metastasis detection rather than being a diagnostic tool for early MRONJ.

CONCLUSION

Currently, MRONJ-specific imaging features cannot be firmly established. However, the current data are valuable as it may lead to a more efficient diagnostic procedure along with a more suitable selection of imaging modalities.

Evaluation of segmental mandibular resection without microvascular reconstruction in patients affected by medication-related osteonecrosis of the jaw: a systematic review

Medication-related osteonecrosis of the jaw (MRONJ) is a severe condition that affects the jaw in patients exposed to specific drugs. More often it has been described in association with bisphosphonates (BP), but nowadays it has been observed with the use of other medications, such as denosumab (a RANK ligand inhibitor and monoclonal antibody agent) and antiangiogenic drugs. Managing the condition has unfortunately proven difficult and still remains a major challenge for clinicians and surgeons. The aim of this systematic review was to identify and analyse the evidence on mandibular segmental resection in patients with advanced MRONJ. A multi-database (PubMed, MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials) systematic search was performed. Any type of study on human patients treated with antiresorptive and antiangiogenic drugs was considered. The primary aim was to understand the success of mandibular segmental resection in the short, medium, and long term, and to understand its effects before, during, and after the operation. The search yielded 11 studies that were eligible for analysis with a total of 67 patients. Of the 11 studies, seven reported no complications, and overall, postoperative complications were seen in 16 cases. Recurrence of osteonecrosis was reported in one study. The most common postoperative complication was removal of hardware (n = 11). The mean (SD) follow-up time for eight studies was 35.57 (17.73) months. According to the limited data available in the literature, mandibular segmental resection is a viable treatment that has been used successfully in patients with various stages of MRONJ. The data show a relatively high percentage of recurrence. Additional data based on a larger cohort of patients or case-control studies are necessary to justify routine use of this type of intervention in patients affected by the condition.

Sensory denervation increases potential of bisphosphonates to induce osteonecrosis via disproportionate expression of calcitonin gene-related peptide and substance P

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a serious side effect of systematic administration of bisphosphonates (BPs). Sensory innervation is crucial for bone healing. We established inferior alveolar nerve injury (IANI) and inferior alveolar nerve transection (IANT) models characterized by disorganized periosteum, increased osteoclasts, and unbalanced neuropeptide expression. Zoledronate injection disrupted neuropeptide expression in the IANI and IANT models by decreasing calcitonin gene-related peptide (CGRP) and increasing substance P (SP); associated with this, BRONJ prevalence was significantly higher in the IANT model, followed by the IANI model and the sham control. CGRP treatment significantly reduced BRONJ occurrence, whereas SP administration had the opposite effect. In vitro, RAW 264.7 cells were treated with BPs and then CGRP and/or SP to study changes in zoledronate toxicity; combined application of CGRP and SP decreased zoledronate toxicity, whereas CGRP or SP applied alone showed no effects. These results demonstrate that sensory denervation facilitates the occurrence of BRONJ and that CGRP used therapeutically may prevent BRONJ progression, provided that SP is also present. Further studies are necessary to determine the optimal ratio of CGRP to SP for promoting bone healing and to uncover the mechanism by which CGRP and SP cooperate.

Comparing the Surgical Response of Bisphosphonate-Related Versus Denosumab-Related Osteonecrosis of the Jaws

PURPOSE

The pathophysiology and treatment of medication-related osteonecrosis of the jaws (MRONJ) remain unclear after nearly two decades of recorded observation and discussion. The purpose of this study was to assess outcomes of surgical resection of MRONJ in patients exposed to denosumab.

MATERIALS AND METHODS

A literature review was performed in conjunction with experts at the University of Illinois at Chicago Library. The primary outcome of interest was surgical success defined by maintenance of complete mucosal closure without bone exposure and infection after surgical resection. Secondary interests included demographics, MRONJ stage, location of the focus of osteonecrosis, and the primary underlying disease necessitating antiresorptive treatment. Statistical analysis was performed by χ², analysis of variance, or t test (P < .05 and b = 0.2 or a power of 0.8).

RESULTS

A total of 70 articles were identified and 14 met inclusion criteria. Twenty patients were included (13 women; 7 men); age 61.8 years ± 12.9 (range 19 to 77); and MRONJ stage I (40.0%), II (35.0%), and III (25.0%). Most cases occurred in the mandible (65.0%), followed by the maxilla (30.0%). The success rate of surgical intervention for MRONJ secondary to denosumab was in 16 of 20 (80.0%) patients. Stage I MRONJ lesions achieved mucosal closure in 100% of patients, stage II in 71.4%, and stage III in 60.0%. The surgical success rate was 83.3% in the maxilla and 76.9% in the mandible.

CONCLUSIONS

The surgical success rate for MRONJ secondary to denosumab was 80.0%, similar to that reported in bisphosphonates of 85 to 95%; however, more evidence must be reported and analyzed.

Bone single-photon emission computed tomography-CT peak standardized uptake value for chronic osteomyelitis, osteoradionecrosis and medication-related osteonecrosis of the jaw

INTRODUCTION

Recently, standardized uptake value (SUV) has been applied for the evaluation of SPECT-CT. This study was performed to investigate the bone SPECT-CT peak SUV for chronic osteomyelitis, osteoradionecrosis and medication-related osteonecrosis of the jaw (MRONJ).

METHODS

Sixty-five patients with jaw lesions (12 chronic osteomyelitis, 12 osteoradionecrosis and 41 MRONJ) underwent SPECT-CT after injection of technetium-99m hydroxymethylene diphosphonate. The peak SUV was compared for the chronic osteomyelitis with osteoradionecrosis and MRONJ using GI-BONE software. Statistical analyses for the peak SUV were performed by one-way repeated measures analysis of variance with Tukey's HSD test. A P-value lower than 0.05 was considered as statistically significant.

RESULTS

Peak SUV for chronic osteomyelitis (15.6 ± 4.4) was significantly higher than those for osteoradionecrosis (6.7 ± 2.1, P = 0.000) and MRONJ (10.7 ± 6.1, P = 0.019).

CONCLUSION

The SPECT-CT peak SUV using GI-BONE software can be useful for the evaluation of jaw lesions, such as chronic osteomyelitis, osteoradionecrosis and MRONJ.

Treatment outcomes of adjunctive teriparatide therapy for medication-related osteonecrosis of the jaw (MRONJ): A multicenter retrospective analysis in Japan

BACKGROUND

Therapeutic strategies for patients with medication-related osteonecrosis of the jaw (MRONJ) remain controversial. The aim of the present study was to clarify the effectiveness and safety of teriparatide therapy in Japanese MRONJ patients based on a large number of case series with a multicenter retrospective analysis.

PATIENTS AND METHODS

Between January 2012 and December 2016, 29 patients who were diagnosed with MRONJ at 10 hospitals were treated with teriparatide. The medical records of these patients were retrospectively reviewed to assess the efficacy and safety of teriparatide therapy for MRONJ patients.

RESULTS

Adverse events occurred in 17.2% of patients (5/29). One patient developed severe arthralgia and discontinued teriparatide therapy after 12 days, while others continued the treatment. Among 29 patients, the median period of administration of teriparatide was 14.0 months (range, 0.3-26 months), and treatment outcomes were evaluated as effective in 75.9% of patients with complete resolution in 65.5%. Among patients treated with oral bisphosphonates (BPs), 83.3% were effectively treated with teriparatide and 40% with intravenous BPs. The oral administration of BPs was associated with successful treatment outcomes with teriparatide (p = 0.062).

CONCLUSIONS

Teriparatide therapy has potential as an effective treatment option for MRONJ.

Autofluorescence-guided surgery for the treatment of medication-related osteonecrosis of the jaw (MRONJ): a retrospective single-center study

OBJECTIVE

Medication-related osteonecrosis of the jaw (MRONJ) has become a serious concern for patients under antiresorptive treatment, especially in the oncological setting. Different approaches have been described in the management of MRONJ, including innovative autofluorescence-guided surgery. However, until now, there has been a lack of data regarding the outcome. In this study, we evaluated the efficacy of minimally invasive autofluorescence-guided resection in MRONJ.

STUDY DESIGN

Seventy-five patients with 82 lesions were included in this retrospective, single-center study. All included patients were diagnosed with MRONJ according to the American Association of Oral and Maxillofacial Surgeons guidelines and underwent autofluorescence-guided surgery with a minimum follow-up of 3 months. The primary outcome was complete integrity of the mucosa and absence of bone exposure.

RESULTS

The MRONJ stages were stage 0 (3.7%), stage 1 (3.7%), stage 2 (75.6%), and stage 3 (17%). Overall, complete mucosal healing of all lesions after the first surgery was 81.7% (67 of 82), whereas it was 90.2% (74 of 82) after revision surgery.

CONCLUSIONS

The study showed that autofluorescence-guided surgery is a safe and successful treatment option that can be considered for all stages of MRONJ.

Actinomyces and MRONJ: A retrospective study and a literature review

The AAOMS in 2014 changed from BRONJ to the term Medication-Related Osteonecrosis of the Jaw (MRONJ), because of the growing number of osteonecrosis cases associated with other antiresorptive and antiangiogenic therapies. Even if the drugs involved are different, the histopathological findings are the same. Colonies of Actinomyces are encountered in most cases. The aim of the present study is to report on Actinomyces prevalence among the cases of MRONJ, taking into consideration also antiresorptive and antiangiogenic therapies in the literature and in our sample between 2005 and 2020. The review was performed using the database Medline the linkage between Actinomyces infection and MRONJ. The retrospective study was conducted on patients between with clinical and radiological manifestations of MRONJ May 2005 and February 2020. A total of 42 articles were found, 30 publications have been taken into consideration for the review. A total of 114 patients have been examined at the Padua Hospital. A total of 101 oncological patients presented the histological confirmation of MRONJ. 83 specimens revealed the presence of Actinomyces infection (82.18%). Actinomyces-associated lesions are frequent and present a wide spectrum of clinical manifestation.

Salivary Biomarkers and Their Application in the Diagnosis and Monitoring of the Most Common Oral Pathologies

Saliva is a highly versatile biological fluid that is easy to gather in a non-invasive manner—and the results of its analysis complement clinical and histopathological findings in the diagnosis of multiple diseases. The objective of this review was to offer an update on the contribution of salivary biomarkers to the diagnosis and prognosis of diseases of the oral cavity, including oral lichen planus, periodontitis, Sjögren’s syndrome, oral leukoplakia, peri-implantitis, and medication-related osteonecrosis of the jaw. Salivary biomarkers such as interleukins, growth factors, enzymes, and other biomolecules have proven useful in the diagnosis and follow-up of these diseases, facilitating the early evaluation of malignization risk and the monitoring of disease progression and response to treatment. However, further studies are required to identify new biomarkers and verify their reported role in the diagnosis and/or prognosis of oral diseases.

Early imaging signs of the use of antiresorptive medication and MRONJ: a systematic review

OBJECTIVE

The main aim is to identify, by means of different imaging modalities, the early bone changes in patients "at risk" and in stage 0 MRONJ.

MATERIALS AND METHODS

A search of the literature was performed on PubMed, Embase, Web of Science, and Cochrane Library databases, until June 9, 2020. No language or year restrictions were applied. Screening of the articles, data collection, and qualitative analysis was done. The Newcastle-Ottawa Scale (NOS) was used for observational studies, and the Systematic Review Centre for Laboratory Animal Experimentation's (SYRCLE) risk of bias tool for the animal studies.

RESULTS

A total of 1188 articles were found, from which 47 were considered eligible, whereas 42 were suitable for the qualitative analysis. They correspond to 39 human studies and 8 animal studies. Radiographic findings such as bone sclerosis, osteolytic areas, thickening of lamina dura, persisting alveolar socket, periapical radiolucency, thicker mandibular cortex, widening of the periodontal ligament space, periodontal bone loss, and enhancement of the mandibular canal were identified as early bone changes due to antiresorptive therapy. All those findings were also reported later in Stage 0 patients.

CONCLUSION

The main limitations of these results are the lack of prospective data and comparisons groups; therefore, careful interpretation should be made. It is a fact that radiographic findings are present in antiresorptive-treated patients, but the precise timepoint of occurrence, their relation to the posology, and potential risk to develop MRONJ are not clear.

CLINICAL RELEVANCE

The importance of a baseline radiographic diagnosis for antiresorptive-treated patients.

Calcium Phosphate Ceramics Can Prevent Bisphosphonate-Related Osteonecrosis of the Jaw

Bisphosphonate-associated osteonecrosis of the jaw (BRONJ), a post-surgical non-healing wound condition, is one of the most common side effects in patients treated with nitrogen-containing bisphosphonates. Its physiopathology has been related with suppression of bone turnover, of soft tissue healing and infection. Biphasic calcium phosphates (BCP) are used as a drug delivery vehicle and as a bone substitute in surgical wounds. Due to their capacity to adsorb zoledronate, it was hypothesized these compounds might have a protective effect on the soft tissues in BRONJ wounds. To address this hypothesis, a reproducible in vivo model of BRONJ in Wistar rats was used. This model directly relates chronic bisphosphonate administration with the development of osteonecrosis of the jaw after tooth extraction. BCP granules were placed in the alveolus immediately after tooth extraction in the test group. The animals were evaluated through nuclear medicine, radiology, macroscopic observation, and histologic analysis. Encouragingly, calcium phosphate ceramics were able to limit zoledronate toxicity in vivo and to favor healing, which was evidenced by medical imaging (nuclear medicine and radiology), macroscopically, and through histology. The studied therapeutic option presented itself as a potential solution to prevent the development of maxillary osteonecrosis.

Mitigating osteonecrosis of the jaw (ONJ) through preventive dental care and understanding of risk factors

It is well established that alterations in phosphate metabolism have a profound effect on hard and soft tissues of the oral cavity. The present-day clinical form of osteonecrosis of the jaw (ONJ) was preceded by phosphorus necrosis of the jaw, ca. 1860. The subsequent removal of yellow phosphorus from matches in the early 20th century saw a parallel decline in "phossy jaw" until the early 2000s, when similar reports of unusual jaw bone necrosis began to appear in the literature describing jaw necrosis in patients undergoing chemotherapy and concomitant steroid and bisphosphonate treatment. Today, the potential side effect of ONJ associated with medications that block osteoclast activity (antiresorptive) is well known, though the mechanism remains unclear and the management and outcomes are often unsatisfactory. Much of the existing literature has focused on the continuing concerns of appropriate use of bisphosphonates and other antiresorptive medications, the incomplete or underdeveloped research on ONJ, and the use of drugs with anabolic potential for treatment of osteoporosis. While recognizing that ONJ is a rare occurrence and ONJ-associated medications play an important role in fracture risk reduction in osteoporotic patients, evidence to date suggests that health care providers can lower the risk further by dental evaluations and care prior to initiating antiresorptive therapies and by monitoring dental health during and after treatment. This review describes the current clinical management guidelines for ONJ, the critical role of dental-medical management in mitigating risks, and the current understanding of the effects of predominantly osteoclast-modulating drugs on bone homeostasis.

Bone metabolism of the jaw in response to bisphosphonate: a quantitative analysis of bone scintigraphy images

We examined the changes in the bone metabolism of the jaw in response to BP treatment, and we used bone SPECT-CT to analyze the site-specific bone metabolism between the jaw and other sites of bone. We compared the changes in the bone metabolism of each part of bone in response to BP treatment by performing a quantitative analysis of bone scintigraphy images between patients treated with low-dose BP for osteoporosis (LBP group; n = 17), those treated with high-dose BP for metastatic bone tumor (HBP group; n = 11), and patients with other oral disease who required bone scintigraphy, with no history of BP treatment (control group; n = 40). The study endpoint was the mean standardized uptake value (SUV) of the uptake of Tc-99 m methylene diphosphonate (MDP) in each group. The mean SUVs of the HBP group were significantly lower at the axial bone of the cervical vertebra, thoracic vertebra, sternum, and rib compared to those of the LBP and control groups. The LBP group's mean SUV was significantly higher at the temporal bone, the anodontia part of the alveolar bone in maxilla, the vital teeth part of alveolar bone in the mandible, and the temporomandibular joint. There was no significant difference among the three groups at the mandibular angle and mandibular ramus. Our analyses revealed that the bone metabolism of the jaw and temporal bone in the BP-treated patients was enhanced, and no suppression of bone remodeling in the jaw by BP was observed.

Bisphophonate alterations of the jaw bones in individuals with multiple myeloma

OBJECTIVES

To verify quantitative differences of the mandibular cortical and trabecular bone between patients with multiple myeloma (MM) under bisphosphonate (BP) therapy and a control group never exposed to BP.

METHODS

Clinical and demographic characteristics were collected through medical records and interviews. Mandibular cortical thickness (MCT) and fractal dimension (FD) were measured on cone beam computed tomography (CBCT) images, on the molar region, in both groups. Additionally, FD was measured on periapical digital intraoral radiography and results were compared to CBCT measurements.

RESULTS

There were 33 patients with MM under BP therapy and 28 controls, with no significant differences in gender and age between groups. Pamidronate was used by all MM patients, either associated or not to other types of BP. The median MCT was higher in MM group exposed to BP (5.20 mm) than in controls (3.50 mm, p < 0.001). There were no significant differences in the median FD between patients in the MM group and controls, on CBCT (0.95 vs 0.90, p = 0.814) and periapical digital intraoral radiography (0.98 vs 0.96, p = 0.963), respectively, even when more than one type of BP was used.

CONCLUSIONS

The MCT represents an useful tool in the detection of bone dimensional changes caused by BP, in patients with MM. Additional studies are necessary to improve the knowledge on the quantitative evaluation of trabecular jaw bone, in individuals with MM, under BP therapy.

Anabolics in the management of glucocorticoid-induced osteoporosis: an evidence-based review of long-term safety, efficacy and place in therapy

Introduction

Glucocorticoid-induced osteoporosis is an underrecognized complication of chronic glucocorticoid therapy characterized by a decrease in new bone formation. Anabolic therapies, such as teriparatide, a recombinant human parathyroid hormone, combat the disease by promoting new bone growth.

Aims

This article outlines the pathophysiology of glucocorticoid-induced osteoporosis and details the evidence of efficacy, safety, and patterns of use of teriparatide and other future anabolic therapies.

Evidence review

In multiple clinical trials, teriparatide has been shown to significantly increase lumbar spine bone mineral density (BMD) in patients with glucocorticoid-induced osteoporosis when compared with placebo, alendronate, and risedronate. When compared with alendronate, significantly fewer vertebral fractures were noted in the teriparatide group. Adverse effects noted in clinical trials include nausea, insomnia, flushing, myalgias, and mild hypercalcemia/hyperuricemia. Early studies in rats noted an increased incidence of osteosarcoma; however, an increased rate beyond levels seen in general populations has not been noted in human studies or with long-term pharmacovigilance. Abaloparatide and romosozumab are newer anabolic therapies that have shown some benefit in postmenopausal osteoporosis but have not yet been studied in the chronic glucocorticoid population.

Place in therapy

Major specialty organizations continue to recommend bisphosphonates as first-line therapy in glucocorticoid-induced osteoporosis due to the proven benefit and relative affordability. However, the use of anabolics shows promise to improve outcomes by increasing BMD and reducing fracture-associated morbidity and mortality and has a role for selected populations at high fracture risk.

Metabolomic profiling reveals salivary hypotaurine as a potential early detection marker for medication-related osteonecrosis of the jaw

Medication-related osteonecrosis of the jaw (MRONJ) is a rare but serious adverse event of bone-modifying agents used to prevent bone complications in cancer patients with bone metastasis. Currently, early treatment is the only way to prevent further progression, as the pathogenesis of MRONJ has not yet been elucidated, and a standard treatment has not been established. The aim of this study was to identify a marker for early detection marker of MRONJ by exploring substances in saliva specific to MRONJ at an early stage. We collected salivary samples from 17 patients with MRONJ and conducted metabolomic analyses using capillary electrophoresis mass spectrometry for non-targeted analysis of hydrophilic metabolites. In the screening cohort, we compared the saliva of patients with stage ≥1 advanced MRONJ (n = 9) with that of controls without MRONJ before chemotherapy (n = 9). The top 5 most elevated salivary metabolites were histamine, 3-(4-hydroxyphenyl)propionate, malonate, carnosine, and hypotaurine. In the validation cohort, we analyzed additional patients with stage ≥1 advanced MRONJ (n = 8) and controls without MRONJ after chemotherapy (n = 9), confirming a significant 2.28-fold elevation in the salivary concentration of hypotaurine. These results revealed elevated salivary hypotaurine concentration as a potential marker for the early detection of MRONJ.

Medication-Related Osteonecrosis of the Jaw: MASCC/ISOO/ASCO Clinical Practice Guideline

PURPOSE

To provide guidance regarding best practices in the prevention and management of medication-related osteonecrosis of the jaw (MRONJ) in patients with cancer.

METHODS

Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) and ASCO convened a multidisciplinary Expert Panel to evaluate the evidence and formulate recommendations. Guideline development involved a systematic review of the literature and a formal consensus process. PubMed and EMBASE were searched for studies of the prevention and management of MRONJ related to bone-modifying agents (BMAs) for oncologic indications published between January 2009 and December 2017. Results from an earlier systematic review (2003 to 2008) were also included.

RESULTS

The systematic review identified 132 publications, only 10 of which were randomized controlled trials. Recommendations underwent two rounds of consensus voting.

RECOMMENDATIONS

Currently, MRONJ is defined by (1) current or previous treatment with a BMA or angiogenic inhibitor, (2) exposed bone or bone that can be probed through an intraoral or extraoral fistula in the maxillofacial region and that has persisted for longer than 8 weeks, and (3) no history of radiation therapy to the jaws or metastatic disease to the jaws. In patients who initiate a BMA, preventive care includes comprehensive dental assessments, discussion of modifiable risk factors, and avoidance of elective dentoalveolar surgery (ie, surgery that involves the teeth or contiguous alveolar bone) during BMA treatment. It remains uncertain whether BMAs should be discontinued before dentoalveolar surgery. Staging of MRONJ should be performed by a clinician with experience in the management of MRONJ. Conservative measures comprise the initial approach to MRONJ treatment. Ongoing collaboration among the dentist, dental specialist, and oncologist is essential to optimal patient care.

Three-dimensional radiologic-pathologic correlation of medication-related osteonecrosis of the jaw using 3D bone SPECT/CT imaging

OBJECTIVES

The aim of this study was to assess a three-dimensional (3D) correlation between preoperative 3D bone single photon emission CT (SPECT)/CT, which allows the visualization of radiotracer uptake on 3D volume-rendered CT images, and histopathological characteristics in the medication-related osteonecrosis of the jaw (MRONJ).

METHODS

We conducted a full histopathological assessment of the resected jaws in four patients with Stage 2 or 3 MRONJ. The pathologic results were classified as follows: necrosis without any tissue vascularity (N + V-), necrosis with both vascularity and acute inflammatory cell infiltration due to bacterial infection (N + V+I+), necrosis with regenerative vasculature but no inflammatory cell infiltration (N + V+I-), and chronic inflammation without massive necrosis (N-V +I+). These classifications were correlated with imaging results.

RESULTS

The N + V- areas visually represented the area of necrotic bone exposed to the oral cavity and were consistent with defect area of radioisotope uptake in SPECT/CT. The N + V- areas were surrounded by the N + V+I + areas where increased radiotracer uptake was clearly seen. Also, abnormal uptake was found in both of the N + V+I- and N-V +I+ areas. The extensive surgical resections from necrotic core to bloody viable margins were performed in all cases, although one had the recurrence of MRONJ at the margin showing abnormal uptake that histologically represented the N + V+I- area.

CONCLUSIONS

Radiologic-pathologic correlation of MRONJ could be achieved using 3D SPECT/CT. The presence of regenerative vascularity with necrosis or inflammation seemed to determine bone metabolism in MRONJ. The recurrence of MRONJ was observed in one case, and 3D SPECT/CT had preoperatively depicted the recurrence site.

Molecular imaging of bone metastases using bone targeted tracers

Molecular imaging using bone targeted tracers has been used in clinical practice for almost fifty years and still plays an essential role in the diagnosis and follow-up of bone metastases. It includes both [99mTc]bisphosphonates for bone scan and [18F]NaF for positron emission tomography/computed tomography (PET/CT) which are very sensitive to detect osteoblastic activity, but it is important to consider several aspects to increase the specificity of reported findings (such as specific tracer characteristics and mechanism of action, patient's clinical history, common metastatic patterns, changes after treatment, limitations of the technique, variations and pitfalls). This will enable useful information for clinical management being provided in the report. Furthermore, iatrogenic skeletal adverse events are common and they should also be identified, as they have impact on patient's quality of life. This review makes a brief summary of the mechanism of action of bone targeted tracers, followed by a discussion of classic patterns of bone metastasis, treatment response assessment and iatrogenic skeletal complications. The value of hybrid imaging techniques with bone targeted tracers, including single photon emission computed tomography and PET/CT is also explored. The final part summarizes new bone targeted tracers with superior imaging characteristics that are being developed, and which may further enhance the applications of radionuclide bone imaging.

Glucocorticoid-Induced Bone Fragility Is Prevented in Female Mice by Blocking Pyk2/Anoikis Signaling

Excess of glucocorticoids (GCs) is a leading cause of bone fragility, and therapeutic targets are sorely needed. We report that genetic deletion or pharmacological inhibition of proline-rich tyrosine kinase 2 (Pyk2) prevents GC-induced bone loss by overriding GC effects of detachment-induced bone cell apoptosis (anoikis). In wild-type or vehicle-treated mice, GCs either prevented osteoclast apoptosis or promoted osteoblast/osteocyte apoptosis. In contrast, mice lacking Pyk2 [knockout (KO)] or treated with Pyk2 kinase inhibitor PF-431396 (PF) were protected. KO or PF-treated mice were also protected from GC-induced bone resorption, microarchitecture deterioration, and weakening of biomechanical properties. In KO and PF-treated mice, GC increased osteoclasts in bone and circulating tartrate-resistant acid phosphatase form 5b, an index of osteoclast number. However, bone surfaces covered by osteoclasts and circulating C-terminal telopeptides of type I collagen, an index of osteoclast function, were not increased. The mismatch between osteoclast number vs function induced by Pyk2 deficiency/inhibition was due to osteoclast detachment and anoikis. Further, GC prolongation of osteoclast lifespan was absent in KO and PF-treated osteoclasts, demonstrating Pyk2 as an intrinsic osteoclast-survival regulator. Circumventing Pyk2 activation preserves skeletal integrity by preventing GC effects on bone cell survival (proapoptotic for osteoblasts/osteocytes, antiapoptotic for osteoclasts) and GC-induced bone resorption. Thus, Pyk2/anoikis signaling as a therapeutic target for GC-induced osteoporosis.

Tc-99m hydroxymethylene diphosphonate scintigraphy, computed tomography, and magnetic resonance imaging of osteonecrosis in the mandible: Osteoradionecrosis versus medication-related osteonecrosis of the jaw

Purpose

To present characteristic findings of Tc-99m hydroxymethylene diphosphonate (HMDP) scintigraphy, computed tomography (CT), and magnetic resonance (MR) imaging for osteonecrosis in the mandible, especially osteoradionecrosis (ORN) and medication-related osteonecrosis of the jaw (MRONJ).

Materials and Methods

Thirteen patients with MRONJ and 7 patients with ORN in the mandible underwent Tc-99m HMDP scintigraphy, CT, and MR imaging (T1-weighted images [T1WI], T2-weighted images [T2WI], short inversion time inversion recovery images [STIR]), diffusion-weighted images [DWI], and apparent diffusion coefficient [ADC] mapping). The associations of scintigraphy, CT, and MR imaging findings with MRONJ and ORN were analyzed using the chi-square test with the Pearson exact test.

Results

Thirteen patients with MRONJ and 7 patients with ORN in the mandible showed low signal intensity on T1WI and ADC mapping, high signal intensity on STIR and DWI, and increased uptake on scintigraphy. Periosteal bone proliferation on CT was observed in 69.2% of patients with MRONJ (9 of 13) versus 14.3% of patients with ORN (1 of 7) (P=0.019).

Conclusion

This study presented characteristic imaging findings of MRONJ and ORN on scintigraphy, CT, and MR imaging. Our results suggest that CT can be effective for detecting MRONJ and ORN.

☆Symposium: Imaging modalities for drug-related osteonecrosis of the jaw (5), utility of bone scintigraphy and 18F-FDG PET/CT in early detection and risk assessment of medication-related osteonecrosis of the jaw (secondary publication)

Medication-related osteonecrosis of the jaw (MRONJ) is a significant side effect of antiresorptive and antiangiogenic drugs. Since MRONJ is intractable, early detection is the best way to limit progression. Bone scintigraphy and ¹⁸F- fluorodeoxyglucose positron-emission tomography can detect minimal and subclinical changes in bones earlier than conventional radiological modalities. A differential diagnosis including MRONJ is recommended when abnormally high uptakes are incidentally detected in the jaws of patients who have bone metastases. Quantitative analysis of uptakes, such as bone scan index of the jaw using neural network analysis and maximum standardized uptake value, could differentiate MRONJ from common dental diseases and be useful for the early detection and risk assessment of MRONJ.

Comparative evaluation of SPECT/CT and CBCT in patients with mandibular osteomyelitis and osteonecrosis

OBJECTIVES

Therapy of osteomyelitis and osteonecrosis very often requires surgery. Proper preoperative radiological evaluation of a lesion's localization and extent is a key in planning surgical bone resection. This study aims to assess the differences between single-photon emission computed tomography and cone beam computed tomography when detecting an osteomyelitis/osteonecrosis lesion as well as the lesion's qualitative parameters, extent, and localization.

MATERIAL AND METHODS

Identification of candidates was performed retrospectively following a search for patients with histologically or clinically confirmed osteomyelitis or osteonecrosis. They were matched with a list of patients whose disease extent and localization had been evaluated using single-photon emission computed tomography and cone beam computed tomography in the context of clinical investigations. Subsequently, two experienced examiners for each imaging technique separately performed de novo readings. Detection rate, localization, extent, and qualitative parameters of a lesion were then compared.

RESULTS

Twenty-one patients with mandibular osteomyelitis and osteonecrotic lesions were included. Cone beam computed tomography detected more lesions than single-photon emission computed tomography (25 vs. 23; 100% vs. 92%). Cone beam computed tomography showed significantly greater depth, area, and volume, whereas length and width did not differ statistically between the two groups.

CONCLUSION

Both single-photon emission computed tomography and cone beam computed tomography could sensitively detect osteomyelitis/osteonecrosis lesions. Only single-photon emission computed tomography showed metabolic changes, whereas cone beam computed tomography seemed to display anatomic morphological reactions more accurately. The selection of the most adequate three-dimensional imaging and the correct interpretation of preoperative imaging remains challenging for clinicians.

CLINICAL RELEVANCE

In daily clinical practice, three-dimensional imaging is an important tool for evaluation of osteomyelitis/osteonecrosis lesions. In this context, clinicians should be aware of differences between single-photon emission computed tomography and cone beam computed tomography when detecting and assessing an osteomyelitis/osteonecrosis lesion, especially if a surgical bone resection is planned.

Prevention of tooth extraction-triggered bisphosphonate-related osteonecrosis of the jaws with basic fibroblast growth factor: An experimental study in rats

Osteonecrosis of the jaw induced by administration of bisphosphonates (BPs), BP-related osteonecrosis (BRONJ), typically develops after tooth extraction and is medically challenging. As BPs inhibit oral mucosal cell growth, we hypothesized that suppression of the wound healing-inhibiting effects could prevent BRONJ onset after tooth extraction. Since basic fibroblast growth factor (bFGF) promotes wound healing, but has a short half-life, we examined whether the initiation of BRONJ could be prevented by applying a bFGF-containing gelatin hydrogel over the extraction sockets of BRONJ model rats. Forty-three rats, received two intravenous injections of zoledronic acid 60 μg/kg, once per week for a period of 2 weeks, underwent extraction of a unilateral lower first molar. The rats here were randomly assigned to the bFGF group (n = 15 rats, gelatin hydrogel sheets with incorporated bFGF applied over the sockets); the phosphate-buffered saline (PBS) group (n = 14 rats, gelatin hydrogel sheets without bFGF applied over the sockets); or the control group (n = 14 rats, nothing applied over the sockets). One rat in the bFGF group was sacrificed immediately after tooth extraction. Twenty-one rats were sacrificed at 3 weeks, and the remaining 21 rats were sacrificed at 8 weeks after tooth extractions. The harvested mandibles were analyzed using micro-computed tomography and sections were evaluated qualitatively for mucosal disruption and osteonecrosis. The incidence of osteonecrosis at 8 weeks after tooth extraction was 0% in the bFGF group, 100% in the PBS group, and 85.7% in the control group. The frequency of complete coverage of the extraction socket by mucosal tissue was significantly greater in the bFGF group than in the other groups. These results suggest that application of bFGF in the extraction socket promoted socket healing, which prevented BRONJ development. The growth-stimulating effects of bFGF may have offset the inhibition of wound healing by BP.

Symposium: Imaging modalities for drug-related osteonecrosis of the jaw (1), role of imaging in drug-related osteonecrosis of the jaw: An up-to-date review (secondary publication)

MRONJ/ARONJ is a serious adverse effect of medication, although the incidence of the disease is rare, and there are still controversial issues regarding the pathogenesis of MRONJ/ARONJ. Medications that can lead to MRONJ/ARONJ are commonly used to treat osteoporosis and to prevent bone fractures caused by bone metastasis of malignancies. The long-standing disease state of ONJ deteriorates the quality of life of affected patients. Early detection and prevention of the disease are key to alleviating pain and discomfort. To date, several imaging modalities have been introduced to depict the lesions. Imaging modalities, radiography, CT, MRI and nuclear medicine provide important information for managing this challenging disease.

Treatment outcomes and prognostic factors of medication-related osteonecrosis of the jaw: a case- and literature-based review

OBJECTIVES

The purpose of this study was to investigate the treatment outcomes and prognostic factors of medication-related osteonecrosis of the jaw (MRONJ) in Japanese patients.

PATIENTS AND METHODS

Among 409 cases, treatment outcomes and prognostic factors were investigated in 275 patients. In statistical analyses, the 1-year cumulative curative rate was calculated with the Kaplan-Meier method, and significance was examined with the Wilcoxon test. Cox's proportional hazards regression analysis was used for the multivariate analysis.

RESULTS

Resolution of the disease was achieved in 137 out of 275 MRONJ patients (49.8%). One-year cumulative curative rates were 39.8% in stage 1 patients, 26.3% in stage 2, and 19.0% in stage 3. The 1-year cumulative curative rates of treatment interventions were 17.2% for conservative treatment, 34.5% for sequestrectomy, and 40.7% for extended surgery including bone resection and segmental resection. As the prognostic factors of treatment outcomes, the type of medication, stage of MRONJ, and type of surgical intervention were identified as independent factors in a multivariate analysis.

CONCLUSION

These results suggest that surgical interventions may lead to a good prognosis in MRONJ patients.

CLINICAL RELEVANCE

This study indicated that surgical intervention for MRONJ might lead to improvement of prognosis and quality of life in MRONJ patients.

Highlights from 2017: impactful topics published in the Annals of Nuclear Medicine

The aim of the review is to highlight articles published in 2017 in the Annals of Nuclear Medicine, an official peer-reviewed journal of the Japanese Society of Nuclear Medicine. Among all published manuscripts during the past year, we conducted a subjective selection of the most relevant topics. Fourteen fascinating articles are included in this review, ranging in topic from preclinical to clinical arenas.

Prevalence and Risk Factors of Atypical Femoral Fracture Bone Scintigraphic Feature in Patients Experiencing Bisphosphonate-Related Osteonecrosis of the Jaw

Purpose

Bisphosphonate (BP) is the first-line therapy for the management of osteoporosis. BP-related osteonecrosis of the jaw (BRONJ) and atypical femoral fracture (AFF) are increasingly common comorbidities in patients with osteoporosis under long-term BP treatment. The aim of this study was to evaluate the incidence and risk factors for AFF features on bone scintigraphy in patients with BRONJ.

Methods

Among total of 373 BRONJ patients treated between September 2005 and July 2014, 237 (220 women, 17 men; median age 73 years) who underwent three-phase bone scintigraphy were enrolled for this retrospective study. AFF features on bone scintigraphy and the related clinical factors were assessed.

Results

Among 237 patients with BRONJ, 11 (4.6%) showed AFF features on bone scintigraphy. BP medication duration (p = 0.049) correlated significantly with AFF features on bone scintigraphy in patients with BRONJ. BP intake duration of 34 months was the cutoff value for predicting the presence of AFF features on bone scintigraphy. Among the patients with BRONJ, all those with AFF features on bone scintigraphy were female patients with osteoporosis who were on oral BP medication; however, these factors were not significantly different along with AFF features on bone scintigraphy.

Conclusion

The incidence of AFF features on bone scintigraphy was relatively high in patients with BRONJ. A careful observation of patients presenting with the AFF features on bone scintigraphy may be needed, particularly for female BRONJ patients with osteoporosis who have been on BP medication for over 34 months.

Comparison of the histopathological characteristics of osteomyelitis, medication-related osteonecrosis of the jaw, and osteoradionecrosis

The purpose of this study was to compare the histopathological parameters of chronic/suppurative osteomyelitis, medication-related osteonecrosis of the jaw (MRONJ), and osteoradionecrosis (ORN), and to examine the hypothesis that distinct histological features can be related to a specific disease, allowing for diagnosis based on microscopic evaluation alone. One hundred and ten samples were reviewed by two examiners in a blinded fashion, and a semi-quantitative histomorphometric analysis was performed. The parameters evaluated included the presence or absence of necrotic bone, inflammation, reactive bone formation, bacteria, and osteoclasts. No statistically significant differences were found between groups for any parameter. Necrotic bone was common to all three diagnoses. Inflammation and reactive bone formation were present in all three diagnoses. The presence of bacteria was a prominent feature in all cases. Osteoclasts were scarce in MRONJ and osteomyelitis, and non-existent in ORN. The results of this study failed to identify distinctive microscopic characteristics in any of the three entities that could be used to differentiate between them. Therefore, it is impossible to reach a specific final diagnosis based on microscopic findings alone. The role of microscopic analysis is to serve as an aid to diagnosis that must be complemented by the patient's history and imaging.

GLUCOCORTICOID EXCESS IN BONE AND MUSCLE

Glucocorticoids (GC), produced and released by the adrenal glands, regulate numerous physiological processes in a wide range of tissues. Because of their profound immunosuppressive and anti-inflammatory actions, GC are extensively used for the treatment of immune and inflammatory conditions, the management of organ transplantation, and as a component of chemotherapy regimens for cancers. However, both pathologic endogenous elevation and long-term use of exogenous GC are associated with severe adverse effects. In particular, excess GC has devastating effects on the musculoskeletal system. GC increase bone resorption and decrease formation leading to bone loss, microarchitectural deterioration and fracture. GC also induce loss of muscle mass and strength leading to an increased incidence of falls. The combined effects on bone and muscle account for the increased fracture risk with GC. This review summarizes the advance in knowledge in the last two decades about the mechanisms of action of GC in bone and muscle and the attempts to interfere with the damaging actions of GC in these tissues with the goal of developing more effective therapeutic strategies.

Bisphosphonate-induced osteonecrosis of the jaw in patients with bone metastatic, hormone-sensitive prostate cancer. Risk factors and prevention strategies

Aims and background

Evidence from the literature suggests that osteonecrosis of the jaw is emerging as a serious complication of treatment with bisphosphonates for patients with advanced prostate cancer.

Methods and study design

This study is a series of 60 patients with osseous metastases from prostate cancer under complete androgen deprivation therapy. All patients also received bisphosphonates intravenously every 3 to 4 weeks. Over a period of 3 and a half years, we recorded the incidence, presenting signs and symptoms of osteonecrosis of the jaw among those patients and the diagnostic workup required.

Results

Nine of the 60 patients with metastatic prostate cancer were found to be affected with osteonecrosis of the jaw secondary to bisphosphonate administration at the Urology Department at the University Hospital of Alexandroupolis between January 2006 and August 2009. For diagnostic reasons, all 9 patients underwent computed tomography scan and magnetic resonance imaging of the maxillary region, as well as a three-phase whole body bone scan.

Conclusions

There is evidence that administration of bisphosphonates in patients with advanced prostate cancer may increase the risk of osteonecrosis of the jaw. Guidelines regarding the diagnosis and management of those patients are needed.

Does CBCT alter the diagnostic thinking efficacy, management and prognosis of patients with suspected Stage 0 medication-related osteonecrosis of the jaws?

OBJECTIVES

To evaluate the impact of cone beam CT (CBCT) in the diagnostic thinking efficacy, management and prognosis of patients with suspected Stage 0 medication-related osteonecrosis of the jaw (MRONJ).

METHODS

For 15 patients with suspected Stage 0 MRONJ, clinical photographs, a panoramic radiograph and selected CBCT sections were identified. 13 oral surgeons reviewed the material and answered 10 questions in two different sessions. First session included clinical photographs and panoramic radiographs, while second session also included CBCT images. Questions (Qs) referred to dental disease and bone abnormalities (Qs 1, 2 and 3), differential diagnosis (Qs 4 and 5), patient management (Qs 6 and 7) and prognosis (Qs 8 and 9). Q 10 queried indication (first session) and usefulness (second session) of CBCT images.

RESULTS

Qs 2, 3, 5, 7 and 9 scores increased between sessions, with statistical differences for Qs 2, 3, 5 and 7 (<0.05). Patients 2, 8 and 11 showed a significant increase in the average score of all Qs between sessions, while scores for patient 10 nearly reached statistical significance (p = 0.055). For Q 10, 57.4% of answers reported that CBCT was needed (first session) and was beneficial (second session).

CONCLUSIONS

CBCT had a significant impact in differential diagnosis and management of patients with suspected Stage 0 MRONJ.

Detecting the earliest radiological signs of bisphosphonate-related osteonecrosis

Introduction Oral bisphosphonates are the most commonly prescribed anti-resorptive drugs used in the treatment of osteoporosis, but osteonecrosis of the jaw is a serious complication. The early diagnosis of this destructive side effect is crucial in preventing excessive bone loss, pain and infection.Objective To aid dental practitioners in the early identification of bisphosphonate-related osteonecrosis of the jaw.Method A scoping review was carried out.Data sources We searched MEDLINE via OVID, EMBASE via OVID, Dentistry and Oral Sciences Source (DOSS), Proquest Dissertation and Theses Search, to identify references that described clinical and radiological findings in medication-related osteonecrosis of the jaw (MRONJ).Data selection Nineteen references mentioned the earliest radiological changes in MRONJ with a description of the observations and were included in the analysis.Data synthesis The radiographic signs included osteosclerosis/lysis, widening of the periodontal ligament and thickening of the lamina dura and cortex. To assess the quality of original data on which recommendations had been made, these 19 studies were subjected to a quality appraisal.Conclusion Using bone exposure as a criterion for diagnosis of MRONJ, leads to delayed diagnosis and a poor response to treatment. In those patients at risk of bone exposure with MRONJ, insufficient information is present in the literature to allow the general dental practitioner to reliably identify the radiographic features indicating imminent bone exposure. A well-designed prospective study is needed.