Frequency and risk factors associated with osteonecrosis of the jaw in cancer patients treated with intravenous bisphosphonates

Surgical and conservative treatment outcomes of medication-related osteonecrosis of the jaw located at tori: a retrospective study

PURPOSE

Tori and exostoses are considered risk factors for the development of medication-related osteonecrosis of the jaw (MRONJ). The aims of this study were to present the prevalence of MRONJ located at tori in the Copenhagen ONJ Cohort, evaluate the surgical treatment of MRONJ located at tori and explore trauma to tori as an additional risk factor in patients on antiresorptive medication.

METHODS

Data from a consecutive series of 506 patients with MRONJ (Copenhagen ONJ Cohort) were reviewed for the presence of tori and MRONJ located at tori. Demographic and medical data were analyzed, and healing outcomes and pain after the prophylactic removal of tori, surgical treatment of MRONJ located at tori, and conservative treatment of MRONJ located at tori were evaluated and compared using Fisher's exact test.

RESULTS

MRONJ located at tori was frequent and could be identified in 53% of the patients with tori, which accounts for a prevalence of 5.1% in the entire cohort. Of the 28 surgically treated patients, 27 (96.4%) healed uneventfully with no exposed bone after their first or second revision surgery. Fourteen (41.2%) patients with tori underwent therapeutic removal, eight (23.5%) underwent prophylactic removal, and six (17.6%) underwent both therapeutic and prophylactic removals. Two (33.3%) of the six conservatively treated patients healed spontaneously. Both treatment types resulted in a significant decrease in pain.

CONCLUSION

Prophylactic and therapeutic surgical removal of tori are reliable treatments and should be considered if a patient's general health allows surgery.

TRIAL REGISTRATION

The study was approved by the Regional Scientific Ethical Committee (H-6-2013-010) on November 20, 2013, and was retrospectively registered.

A Systematic Review of Laser Photobiomodulation Dosimetry and Treatment Protocols in the Management of Medications-Related Osteonecrosis of the Jaws: A Rationalised Consensus for Future Randomised Controlled Clinical Trials

Medication-related osteonecrosis of the jaw (MRONJ) is a debilitating adverse effect of bisphosphates, antiresorptive therapy or antiangiogenic agents that can potentially increase oxidative stress, leading to progressive osteonecrosis of the jaws. Despite the large number of published systematic reviews, there is a lack of potential MRONJ treatment protocols utilising photobiomodulation (PBM) as a single or adjunct therapy for preventive or therapeutic oncology or non-oncology cohort. Hence, this systematic review aimed to evaluate PBM laser efficacy and its dosimetry as a monotherapy or combined with the standard treatments for preventive or therapeutic approach in MRONJ management. The objectives of the review were as follows: (1) to establish PBM dosimetry and treatment protocols for preventive, therapeutic or combined approaches in MRONJ management; (2) to highlight and bridge the literature gaps in MRONJ diagnostics and management; and (3) to suggest rationalised consensus recommendations for future randomised controlled trials (RCTs) through the available evidence-based literature. This review was conducted according to the PRISMA guidelines, and the protocol was registered at PROSPERO under the ID CRD42021238175. A multi-database search was performed to identify articles of clinical studies published from their earliest records until 15 December 2023. The data were extracted from the relevant papers and analysed according to the outcomes selected in this review. In total, 12 out of 126 studies met the eligibility criteria. The striking inconsistent conclusions made by the various authors of the included studies were due to the heterogeneity in the methodology, diagnostic criteria and assessment tools, as well as in the reported outcomes, made it impossible to conduct a meta-analysis. PBM as a single or adjunct treatment modality is effective for MRONJ preventive or therapeutic management, but it was inconclusive to establish a standardised and replicable protocol due to the high risk of bias in a majority of the studies, but it was possible to extrapolate the PBM dosimetry of two studies that were close to the WALT recommended parameters. In conclusion, the authors established suggested rationalised consensus recommendations for future well-designed robust RCTs, utilising PBM as a monotherapy or an adjunct in preventive or therapeutic approach of MRONJ in an oncology and non-oncology cohort. This would pave the path for standardised PBM dosimetry and treatment protocols in MRONJ management.

Inflammation Can Be a High-Risk Factor for Mucosal Nonunion of MRONJ by Regulating SIRT1 Signaling When Treated with an Oncologic Dose of Zoledronate

Purpose

Zoledronate (ZA) stands as a highly effective antiresorptive agent known to trigger medication-related osteonecrosis of the jaw (MRONJ). Its clinical dosages primarily encompass those used for oncologic and osteoporosis treatments. While inflammation is recognized as a potential disruptor of mucosal healing processes associated with ZA, prior research has overlooked the influence of varying ZA dosages on tissue adaptability. Therefore, a deeper understanding of the specific mechanisms by which inflammation exacerbates ZA-induced MRONJ, particularly when inflammation acts as a risk factor, remains crucial.

Methods

Cell proliferation and migration of human oral keratinocytes (HOK) was analyzed after treatment with different doses of ZA and/or lipopolysaccharide (LPS) to assess their possible effect on mucosal healing of extraction wounds. Mouse periodontitis models were established using LPS, and histological changes in extraction wounds were observed after the administration of oncologic dose ZA. Hematoxylin and eosin (HE) staining and immunofluorescence were used to evaluate mucosal healing.

Results

In vitro, LPS did not exacerbate the effects of osteoporosis therapeutic dose of ZA on the proliferation and migration of HOK cells, while aggravated these with the oncologic dose of ZA treatment by inducing mitochondrial dysfunction and oxidative stress via regulating SIRT1 expression. Furthermore, SIRT1 overexpression can alleviate this process. In vivo, local injection of LPS increased the nonunion of mucous membranes in MRONJ and decreased the expression of SIRT1, PGC-1α, and MnSOD.

Conclusion

Inflammation aggravates oncologic dose of ZA-induced mitochondrial dysfunction and oxidative stress via a SIRT1-dependent pathway, enhancing the risk of impaired mucosal healing in MRONJ. Our study implies that inflammation becomes a critical risk factor for MRONJ development at higher ZA concentrations. Elucidating the mechanisms of inflammation as a risk factor for mucosal non-healing in MRONJ could inform the development of SIRT1-targeted therapies.

Antiresorptive and anti-angiogenic drug therapy in the pediatric population with reference to medication-related osteonecrosis of the jaw

The objective of this study was to identify the prevalence of osteonecrosis of the jaw in a pediatric population with systemic therapeutic exposure to an antiresorptive, anti-angiogenic, and/or immunomodulating drug (ARAID), and in particular in the subgroup of patients who had undergone invasive dental treatment. This was a retrospective cohort study performed at a single center. The investigation included pediatric patients who had undergone systemic therapy with ARAIDs and who began receiving ARAID therapy at ≤16 years of age. The study included 482 patients who received ARAIDs between January 2011 and January 2021. The most common medication class was bisphosphonates (45.0%), followed by mTOR inhibitors (30.1%) and anti-angiogenics (17.8%). No diagnosis of osteonecrosis of the jaw was observed. From this population, 26 patients were noted to have undergone invasive dental treatment. The duration from treatment to the invasive procedure ranged from 0 to 5.9 years. Medication-related osteonecrosis of the jaw is extremely rare among the pediatric population - much less common when compared to the adult population. Prospective cohort studies and continued evaluation will help determine the incidence and prevalence of medication-related osteonecrosis of the jaw in pediatric patients.

Osteonecrosis of the Jaw Associated with Bisphosphonates Infusion for Treatment of Plasma Cell Myeloma-A Retrospective Observational Study of Northern Portuguese Population

Objectives: To verify medication-related osteonecrosis of the jaw (MRONJ) frequency among patients with plasma cell myeloma (PCM) that had been treated with bisphosphonates, to identify predisposing factors that could influence the development of osteonecrosis. Methods: This observational retrospective study was performed at the Department of Hematology of Hospital Center of Porto (CHUP), Portugal. Results: The study population (n = 112) had a 15.2% (n = 17) prevalence of osteonecrosis. Clinically, bone exposure was the most frequently observed sign, present in 100% (n = 17) of the patients, followed by inflammation in 82.4% (n = 14), orofacial pain in 70.6% (n = 12), suppuration in 47.1% (n = 8), and intra or extra-oral fistula in 17.6% (n = 3) of the cases. The most frequent triggering local factor was dental extraction (82.4%). There was a dependence between the presence of extractions and the development of MRONJ (p < 0.001) but not with the time elapsed from the initiation of infusions with BPs and dental extractions (p = 0.499). In the sample of patients with multiple myeloma (MM), 13.8% were found to be more likely to develop MRONJ after an extraction. Conclusions: The most common local predisposing factor was dental extraction. No dependence was observed between the development of osteonecrosis and the time elapsed from the beginning of treatment with bisphosphonates infusions to surgical procedures.

Three-dimensional clinical assessment for MRONJ risk in oncologic patients following tooth extractions

OBJECTIVES

To identify clinical and local radiographic predictors for medication-related osteonecrosis of the jaws (MRONJ) by the assessment of pre-operative CBCT images of oncologic patients treated with anti-resorptive drugs (ARDs) undergoing tooth extractions.

METHODS

This retrospective, longitudinal, case-control study included clinical and imaging data of 97 patients, divided into study and control group. Patients in the study group (n = 47; 87 tooth extractions) had received at least one dose of ARD, undergone tooth extraction(s), and had a pre-operative CBCT. An age-, gender-, and tooth extraction-matched control group (n = 50; 106 tooth extractions) was selected. Three calibrated, blinded, and independent examiners evaluated each tooth extraction site. Statistical analysis used χ2/Fisher's exact/Mann-Whitney U test to contrast control and study group, ARD type used, and sites with or without MRONJ development. p-value ≤ 0.05 was considered significant.

RESULTS

From the study group, 15 patients (32%) and 33 sites (38%) developed MRONJ after tooth extraction. When controls were compared to study sites, the latter showed significantly more thickening of the lamina dura, widened periodontal ligament space, osteosclerosis, osteolysis, and sequestrum formation. In the study group, MRONJ risk significantly increased in patients who had multiple tooth extractions, were smokers, and had shorter drug holidays. Periosteal reaction and sequestrum formation may indicate latent MRONJ lesions. Additionally, patients given bisphosphonates showed considerably more osteosclerosis than those given denosumab.

CONCLUSIONS

Periosteal reaction and sequestrum formation are suspected to be pre-clinical MRONJ lesions. Furthermore, ARD induced bony changes and radiographic variations between ARD types were seen.

Medication-related osteonecrosis of the jaw using periodontitis-induced rat before tooth extraction

OBJECTIVE

This study aimed to investigate the occurrence of medication-related osteonecrosis of the jaw (MRONJ) after tooth extraction due to periodontitis in ovariectomized rats.

METHODS

Twenty-four osteoporosis-induced rats were administered with zoledronic acid (ZA; ZA group) or saline (CONT group). In both groups, tooth extraction was performed after inducing periodontitis, and all animals were sacrificed 8-week after tooth extraction.

RESULTS

Micro-CT of the tibia showed that the bone volume fraction, bone surface density, trabecular number, and bone mineral density were significantly higher in the ZA group than in the CONT group. Histologically, the proliferative zone on the growth plate was thicker in the ZA group than in the CONT group. Micro-CT of the extraction sites revealed that the bone volume fraction was significantly higher in the ZA group than in the CONT group. Radiologically, the ZA group showed partial healing and delayed healing. Histological analysis revealed normal bone healing status with completely healed epithelium in the extraction sites of the CONT group, whereas abnormal empty osteocytes in the necrotic bone and inflammatory infiltration were observed in the ZA group.

CONCLUSION

The incidence of MRONJ increased in the rats administered with ZA.

Risk Factors for Bisphosphonate-Related Osteonecrosis of the Jaws in Bone Metastatic Breast and Prostate Cancer under Zoledronate Treatment: A Retrospective Analysis from 10 Years of Evaluation

OBJECTIVE

This study aims to analyze the risk factors for BRONJ in patients taking zoledronic acid (ZA) for metastatic breast and prostate cancer.

METHODS

For this, a retrospective, quantitative, observational cohort study was conducted using data on adverse effects in the oral cavity in patients during chemotherapy for treatment of solid tumors available in the electronic patient record system of the Haroldo Juaçaba Hospital/Ceará Cancer Institute in the period from 2010, to 2019. Data were tabulated in Excel and exported to SPSS v20.0 software for statistical analysis, with 95% confidence.

RESULTS

Thus, it can be observed that the prevalence of BRONJ in patients under treatment for breast cancer and prostate cancer was <7%, with age <50 years of age (p=0.009), cytotoxic chemotherapy such as methotrexate (p=0.023), paclitaxel (p=0.005), capecitabine (p<0.001), gemcitabine (p=0.007) and bicalutamide (p=0.016), amount of ZA infusions (p<0.001) and hormone therapy (p=0.007), in addition, a slight reduction in survival and increased use of antidepressants (p=0.014) were observed. The reduced overall survival and increased use of antidepressants in patients who developed BRONJ, reinforcing the need for further research to study the mechanisms involved in the unconventional risk factors for BRONJ.

CONCLUSION

Thus, increasing the attention to these patients to prevent this condition from compromising the prognosis of these individuals.

The use of bone-modifying agents in multiple myeloma

Multiple myeloma is a hematological neoplasm characterized by abnormal proliferation of plasma cells in the bone marrow and is usually associated with increased bone pain and skeletal-related events such as pathological fracture and/or spinal cord compression. Myeloma bone disease results in changes in the bone-marrow microenvironment evidenced by increased osteoclastic activity and/or decreased osteoblastic activity, which negatively affect quality of life. Treatment of myeloma bone disease includes bisphosphonates or denosumab (bone-modifying agents). These agents do not induce the formation of new bone or repair existing bone damage, but they can decrease bone pain and the risk of pathological fracture. While these agents improve quality of life, it is not known whether they improve overall survival. This review focuses on different classes of bone-modifying agents, their mechanisms of action, time of initiation, duration of therapy, and potential survival benefits.

Bisphosphonate Osteonecrosis in a Case of Langerhans Cell Histiocytosis: Report of a Case and Review of Literature

Langerhans Cell histiocytosis is a rare multisystem disease originating from dendritic cell lines primarily characterized by osteolytic lesion of the skeleton. Chemotherapy along with bisphosphonates have been used to control the progression of the disease and prevent the osteolysis associated with the disease. Bisphosphonate osteonecrosis of the jaws is a common finding following treatment with bisphosphonates for osteoporosis, metastatic tumors to the bone or the osteolytic lesions of multiple myeloma. The article highlights a rare case of bisphosphonate osteonecrosis of the mandible in a case of long-standing Langerhans cell histiocytosis.

A systematic review assessing occurrence of medication-related osteonecrosis of the jaw following dental procedures

Aim: This study aimed to systematically review existing literature regarding the association between dental procedures—such as tooth extractions and periodontal therapy—and occurrence of medication-related osteonecrosis of the jaw (MRONJ) in individuals using bone-modifying drugs. Methods: Search strategies were performed in PubMed, Scopus, Web of Science and Cochrane Library for a timeframe ending in December 2021. Study selection, data extraction and risk of bias were analyzed independently by two researchers. Three meta-analyses were performed, estimating the crude risk ratio (RR), the adjusted odds ratio (OR) and the adjusted hazard ratio (HR) for the association between tooth extraction and MRONJ. Results: Of the 1,654 studies initially retrieved, 17 were ultimately included. The majority of patients with MRONJ in these studies were female, with a mean age of 64 years. Zoledronic acid was the most commonly used drug among patients with MRONJ, and cancer was the most frequent underlying health condition. Regarding the performed meta-analyses, crude and adjusted analyses demonstrated that tooth extraction increased the risk for MRONJ by 4.28 (95% confidence interval [95%CI]: 1.73–10.58), the OR for MRONJ by 26.94 (95%CI: 4.17–174.17), and the HR for MRONJ by 9.96 (95%CI: 4.04–24.55). Conclusion: It was concluded that performing dental procedures, especially tooth extraction, in patients using bone-modifying drugs increased the risk of MRONJ occurrence and, therefore, should be avoided. Further studies, using adjusted data, are warranted.

The 100 most cited papers on bone metastasis: A bibliometric analysis

•

Citations per article in the most 100 top cited articles ranged from 357 to 2167.

•

The leading country was USA, Canada, and United Kingdom.

•

Clinical management of bone metastasis from different malignancy origins.

•

Intense collaborative activity between countries and institutions was obvious between the selected papers.

Background

Over the past few decades, a vast number of articles focused on bone metastasis have been published. Bibliometric analysis is helpful to determine the qualities and characteristics and to reveal the influential articles in this field.

Methods

All the databases in Web of Science were utilized to identify articles published from 1961 to 2020. The top 100 most cited articles on bone metastases were involved for degree centrality analysis and analyses on publication time and citations, journals, authors, geographical distribution, research institutions, and research keywords.

Results

The selected articles were published mainly from 1986 to 2015. The 100 most cited articles were selected from a total of 67,451 citations out of 90,502 publications with a density of 50.239 citations/year. Citations per article ranged from 357 to 2167. The leading country was USA, followed by Canada and United Kingdom. The most frequently studied themes were clinical management of bone metastasis from different malignancy origins. A co-authorship analysis revealed an intense collaborative activity between countries and institutions.

Conclusions

This study identified the top 100 most cited articles on bone metastasis. Publication time, area, and theme distribution were thoroughly analyzed. The present study highlighted some of the most influential contributions to the field. Clinical and academic communities have shown a sustained interest in the management of bone metastasis.

American Association of Oral and Maxillofacial Surgeons' Position Paper on Medication-Related Osteonecrosis of the Jaws-2022 Update

Strategies for management of patients with, or at risk for, medication-related osteonecrosis of the jaws (MRONJ) - formerly referred to as bisphosphonate-related osteonecrosis of the jaws (BRONJ)-were set forth in the American Association of Oral and Maxillofacial Surgeons (AAOMS) position papers in 2007, 2009 and 2014. The position papers were developed by a committee appointed by the AAOMS Board of Trustees and comprising clinicians with extensive experience in caring for these patients, as well as clinical and basic science researchers. The knowledge base and experience in addressing MRONJ continues to evolve and expand, necessitating modifications and refinements to the previous position papers. Three members of the AAOMS Committee on Oral, Head, and Neck Oncologic and Reconstructive Surgery (COHNORS) and three authors of the 2014 position paper were appointed to serve as a working group to analyze the current literature and revise the guidance as indicated to reflect current knowledge in this field. This update contains revisions to diagnosis and management strategies and highlights the current research status. AAOMS maintains that it is vitally important for this information to be disseminated to other relevant healthcare professionals and organizations.

Adverse events associated with bone-directed therapies in patients with cancer

Bone metastatic disease may lead to serious adverse events in patients with cancer. Bone-directed therapies, including bisphosphonates such as pamidronate and zoledronic acid and the human monoclonal antibody denosumab, are currently approved for the prevention of bone-related adverse events. However, despite the benefits of these drugs, they may cause side effects that are mostly associated with dosages and treatment durations. These side effects range from more frequent, mostly mild, and generally self-limited side effects-such as fever, myalgias, arthralgias, and electrolyte imbalances-to less frequent and more severe side effects such as medication-related osteonecrosis of the jaw and atypical femoral fractures. The purpose of this review is to familiarize clinicians with the literature regarding adverse events associated with bone-directed therapies in patients with cancer. It is important to be aware of these possible adverse events and to educate patients about the predisposing factors associated with side effects from bone-directed therapies and the preventive measures necessary to decrease the risk of occurrence.

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.

Minimizing MRONJ after Tooth Extraction in Cancer Patients Receiving Bone-Modifying Agents

Background: Medication-related osteonecrosis of the jaws (MRONJ) is a mucosal lesion of the maxillofacial region with necrotic bone exposure. MRONJ is believed to be multifactorial. Tooth extraction is debatably a risk factor for MRONJ. The targets of the present study were to examine MRONJ occurrence in patients using bone modifying agents (BMAs) for oncology indications and undergoing a dental extraction, and to assess whether suspected predisposing factors can predict MRONJ. Materials and Methods: This retrospective, cohort study included all patients fitting the inclusion criteria and a large tertiary medical center. Data were obtained from the hospital’s medical records using a structured questionnaire. Results: We performed 103 extractions on 93 patients. Local inflammation/infection of the extraction site was most associated with a complication (p = 0.001) OR = 13.46, 95% CI = (1.71, 105.41), OR = 13.5. When the indication for extraction was periodontal disease, vertical root fracture, or periapical pathosis, the odds of developing MRONJ were 4.29 times higher than for all other indications (p = 0.1), OR = 4.29, 95% CI = (1.16, 15.85). A significant association was found between the time of onset of BMA treatment and time of extraction and the development of MRONJ, OR = 3.34, 95% CI = (1.01, 10.18). Other variables did not correlate with the development of MRONJ. Conclusion: Local inflammation/infection and onset of BMA treatment prior to extraction yield a 10.23 times higher chance of developing MRONJ following tooth extraction. Future protocols should use this information to minimize MRONJ incidence.

Notch signaling enhances bone regeneration in the zebrafish mandible

Loss or damage to the mandible caused by trauma, treatment of oral malignancies, and other diseases is treated using bone-grafting techniques that suffer from numerous shortcomings and contraindications. Zebrafish naturally heal large injuries to mandibular bone, offering an opportunity to understand how to boost intrinsic healing potential. Using a novel her6:mCherry Notch reporter, we show that canonical Notch signaling is induced during the initial stages of cartilage callus formation in both mesenchymal cells and chondrocytes following surgical mandibulectomy. We also show that modulation of Notch signaling during the initial post-operative period results in lasting changes to regenerate bone quantity one month later. Pharmacological inhibition of Notch signaling reduces the size of the cartilage callus and delays its conversion into bone, resulting in non-union. Conversely, conditional transgenic activation of Notch signaling accelerates conversion of the cartilage callus into bone, improving bone healing. Given the conserved functions of this pathway in bone repair across vertebrates, we propose that targeted activation of Notch signaling during the early phases of bone healing in mammals may both augment the size of the initial callus and boost its ossification into reparative bone.

Osteonecrosis of the jaw risk factors in bisphosphonate-treated patients with metastatic cancer

BACKGROUND

A case-control study was performed to define clinical and genetic risk factors associated with osteonecrosis of the jaw in patients with metastatic cancer treated with bisphosphonates.

METHODS

Clinical data and tissues were collected from patients treated with bisphosphonates for metastatic bone disease who were diagnosed with osteonecrosis of the jaw (cases) and matched controls. Clinical data included patient, behavioral, disease, and treatment information. Genetic polymorphisms in CYP2C8 (rs1934951) and other candidate genes were genotyped. Odds ratios from conditional logistic regression models were examined to identify clinical and genetic characteristics associated with case or control status.

RESULTS

The study population consisted of 76 cases and 126 controls. In the final multivariable clinical model, patients with osteonecrosis of the jaw were less likely to have received pamidronate than zoledronic acid (odds ratio = 0.18, 95% Confidence interval: 0.03-0.97, p = .047) and more likely to have been exposed to bevacizumab (OR = 5.15, 95% CI: 1.67-15.95, p = .005). The exploratory genetic analyses suggested a protective effect for VEGFC rs2333496 and risk effects for VEGFC rs7664413 and PPARG rs1152003.

CONCLUSIONS

We observed patients with ONJ were more likely to have been exposed to bevacizumab and zoledronic and identified potential genetic predictors that require validation prior to clinical translation.

Medication-Related Osteonecrosis of the Jaw (MRONJ): A Review of Pathophysiology, Risk Factors, Preventive Measures and Treatment Strategies

Medication-related osteonecrosis of the jaw (MRONJ) is a major problem that can occur in people taking certain medications such bisphosphonates and denosumab. It can be used to treat osteoporosis or cancer. Bisphosphonate exposure, dental diseases and procedures, age, sex, anatomical factors, medical issues, and hereditary factors are all variables that enhance the risk of MRONJ. Even though MRONJ and antiresorptive medications have a close association, the pathophysiology of MRONJ is unknown. Careful dental preparation and oral hygiene instructions significantly minimize the risk of osteonecrosis of the jaw (ONJ). It is ideal to start antiresorptive treatment after the completion of required dental treatment; it is not contraindicated and carries low risk in patients who are on oral antiresorptive medications for less than three years. Drug holidays are one proposed solution to address MRONJ. However, there is still inadequate evidence to support their effectiveness. The objectives of this literature review are to recognize the main diagnostic principles and risk factors and to review the pathophysiology, protective procedures and treatment modalities related to MRONJ.

The following topics are covered in the review: epidemiology, diagnostic criteria, risk factors, pathogenesis and mechanism, MRONJ staging and symptoms, clinical and radiographic findings, treatment strategies, prevention and drug holiday.

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.

Toxicity of zoledronic acid after intravenous administration: A retrospective study of 95 dogs

BACKGROUND

There is a paucity of veterinary literature on the safety or outcome of zoledronic acid (ZA) use in dogs for either bone pain or hypercalcemia.

HYPOTHESIS/OBJECTIVES

The primary aim was to report the adverse events in dogs receiving intravenous administration of ZA.

ANIMALS

Ninety-five dogs with ZA use.

METHODS

A retrospective cohort study was performed; all dogs that received at least 1 dose of ZA and had a serum biochemistry profile performed before and after treatment were reviewed. Diagnosis, indication for treatment, adverse events and survival times were recorded.

RESULTS

Ninety-five dogs met the inclusion criteria. Thirty-one (33%) received multiple intravenous infusions of ZA (range, 2-7), making a total of 166 administrations in all dogs. The dose range was 0.13 to 0.32 mg/kg, given at intervals of 4 to 6 weeks. Thirteen adverse events were recorded in 10 dogs: azotemia (n = 8), vomiting (n = 2), pancreatitis (n = 1), cutaneous ulceration (n = 1), and diarrhea (n = 1). Zoledronic acid could not be confirmed as the cause of azotemia in any case. The change in serum creatinine concentration from dose to dose was not related to the total dose received (P = .46). Five dogs (5%) changed Veterinary Comparative Oncology Group Common Terminology Criteria (VCOG-CTAE) renal/genitourinary grade after administration of ZA; their total dose 0.4 mg/kg (range, 0.26-0.66) was not significantly different to the group which did not change VCOG-CTAE renal/genitourinary grade 0.35 mg/kg (range, 0.2-1.50; P = .93).

CONCLUSIONS AND CLINICAL IMPORTANCE

Multiple doses of ZA were well tolerated in dogs within this study. A small number of dogs developed progressive azotemia which was not associated with cumulative dose.

Risk factors associated with onset of medication-related osteonecrosis of the jaw in patients treated with denosumab

Objectives

While risk factors of bisphosphonate (BP) associated osteonecrosis of the jaw have been properly analyzed, studies focusing on risk factors associated with denosumab (DNO) are sparse. The purpose of this study was to identify risk factors influencing the onset of medication-related osteonecrosis of the jaw (MRONJ) in patients receiving antiresorptive treatment (ART) with DNO by comparing patients suffering from MRONJ and patients without MRONJ. Multiple variables were evaluated including the impact of a previous BP intake.

Materials and methods

A retrospective single-center cohort study with patients receiving DNO was conducted. One-hundred twenty-eight patients were included and divided into three groups: I (control, n = 40) receiving DNO with absence of MRONJ; group II (Test 1, n = 46), receiving DNO with presence of MRONJ; and group III (Test 2, n = 42) sequentially receiving BP and DNO with presence of MRONJ. Patients’ medical history, focusing on the identification of MRONJ risk factors, was collected and evaluated. Parameters were sex, age, smoking habit, alcohol consumption, underlying disease (cancer type, osteoporosis), internal diseases, additional chemo/hormonal therapy, oral inflammation, and trauma.

Results

The following risk factors were identified to increase MRONJ onset significantly in patients treated with DNO: chemo/hormonal therapy (p = 0.02), DNO dosage (p < 0.01), breast cancer (p = 0.03), intake of corticosteroids (p = 0.04), hypertension (p = 0.02), diabetes mellitus (p = 0.04), periodontal disease (p = 0.03), apical ostitis (p = 0.02), and denture use (p = 0.02). A medication switch did not affect MRONJ development (p = 0.86).

Conclusions

Malignant diseases, additional chemotherapy, DNO dosage, and oral inflammations as well as diabetes mellitus and hypertension influence MRONJ onset in patients treated with DNO significantly.

Clinical relevance

Patients receiving ART with DNO featuring aforementioned risk factors have a higher risk of MRONJ onset. These patients need a sound and regular prophylaxis in order to prevent the onset of MRONJ under DNO treatment.

Denosumab-related osteonecrosis of the jaw after tooth extraction and the effects of a short drug holiday in cancer patients: a multicenter retrospective study

Pre-existing inflammation, corticosteroid therapy, periapical periodontitis, longer duration of denosumab therapy, and female sex were significantly associated with an increased risk of denosumab-related osteonecrosis of the jaw after tooth extraction in patients with cancer on oncologic doses of denosumab. A short drug holiday did not protect against this complication.

INTRODUCTION

This study retrospectively investigated the relationship between various risk factors, including brief discontinuation of denosumab, and development of denosumab-related osteonecrosis of the jaw (DRONJ) after tooth extraction in patients with cancer who were receiving oncologic doses of this agent.

METHODS

Data were collected on demographic characteristics, duration of denosumab therapy, whether or not denosumab was discontinued before tooth extraction (drug holiday), duration of discontinuation, presence of pre-existing inflammation, and whether or not additional surgical procedures were performed. Risk factors for DRONJ after tooth extraction were evaluated by univariate and multivariate analyses.

RESULTS

A total of 136 dental extractions were performed in 72 patients (31 men, 41 women) with cancer who were receiving oncologic doses of denosumab. Post-extraction DRONJ was diagnosed in 39 teeth (28.7%) in 25 patients. Tooth extraction was significantly associated with development of DRONJ only in patients with pre-existing inflammation (odds ratio [OR] 243.77), those on corticosteroid therapy (OR 73.50), those with periapical periodontitis (OR 14.13), those who had been taking oncologic doses of denosumab for a longer period (OR 4.69), and in women (OR 1.04). There was no significant difference in the occurrence of DRONJ between patients who had a drug holiday before tooth extraction and those who did not.

CONCLUSIONS

These findings suggest that inflamed teeth should be extracted immediately in patients with cancer who are receiving oncologic doses of denosumab. Drug holidays have no significant impact on the risk of DRONJ.

Medication-Related Osteonecrosis of the Jaw in Patients Treated Concurrently with Antiresorptive and Antiangiogenic Agents: Systematic Review and Meta-Analysis

Introduction

Medication-related osteonecrosis of the jaws (MRONJ) is a known adverse event related to the use of antiresorptive (AR) drugs. More recently, an association between antiangiogenic (AA) drugs and MRONJ has been suggested. This review aimed to investigate the overall prevalence and relative risk of MRONJ in patients treated concurrently with AA and AR agents in comparison with a single AA or AR drug.

Methods

A review protocol was registered with PROSPERO (ID: CRD42020214244). A systematic literature search, study selection, quality assessment, and data extraction were carried out following PRISMA guidelines. Random-effects meta-analysis models were used to summarize relative estimates for the outcomes, namely prevalence and relative risk of MRONJ. Exposure variable included type of drug, specifically AA and AR agents administered either concurrently or individually.

Results

Eleven studies were included in the final qualitative and quantitative syntheses. The overall pooled weighted prevalence of MRONJ with concurrent AA-AR drugs was 6% (95% CI: 3–8%), compared with 0% (95% CI: 0–0%) for AA only and 5% (95% CI: 0–10%) for AR only. However, high heterogeneity was noted among included studies. Retrospective cohort studies showed a higher pooled prevalence of 13% (95% CI: 10–17%) for concurrent AA-AR therapy. The pooled risk ratio for MRONJ revealed a risk with concurrent AA-AR drugs 2.57 times as high as with AR only (95% CI: 0.84–7.87); however, this difference was not statistically significant. Concurrent AA-AR drugs had a risk for MRONJ 23.74 times as high as with AA only (95% CI: 3.71–151.92).

Conclusions

High-quality, representative studies are needed for accurate estimation of relative risk of MRONJ with concurrent AA and AR therapy.

Individualized Bone-Protective Management in Long-Term Cancer Survivors With Bone Metastases

Antiresorptive therapy is an important component of a multimodal approach to treating patients with advanced malignancies and metastatic bone disease. Over the past decade, overall survival of affected patients has improved in most cancer entities, and long-term disease control is a realistic goal in many cases. There are emerging clinical studies showing the benefits of an initial antiresorptive therapy using bisphosphonates or denosumab. However, some adverse events of these therapies, such as osteonecrosis of the jaw, correlate with the cumulative doses given, and there is an increasing clinical need for new antiresorptive concepts to treat long-term survivors. This review summarizes the clinical evidence of antiresorptive therapies across different cancers with bone involvement and presents concepts of dose-reduction protocols for long-term survivors with established metastatic bone disease. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

A retrospective study on the incidence of medication-related osteonecrosis of the jaws (MRONJ) associated with different preventive dental care modalities

Purpose

To assess the efficacy of different preventive dental visits and treatments in reducing the risk of medication-related osteonecrosis of the jaws (MRONJ).

Methods

In this retrospective study, patients diagnosed with MRONJ were divided into 5 groups based on available data: no preventive dental visits (group 0); dental visits and compliance with recommended treatments, at the university hospital’s dental clinic (group 1) or maxillofacial surgery unit (group 2), or at a private dentist’s (group 3); dental visits at one of the above and noncompliance with proposed treatments (group 4); patients judged eligible by the oncologist on panoramic radiography (group 5). Patients were classified on severity of MRONJ according to the Italian SIPMO/SICMF 2.0 staging system. A descriptive analysis was performed on the results. Fisher’s exact test was applied (p < 0.05).

Results

Ninety-three patients diagnosed with MRONJ were considered for the study, but 22 were excluded due to a lack of data, leaving a sample of 71 cases. MRONJ staging was only 0 for some patients (26.92%) in group 0. In all groups, the majority of patients had stage 2 MRONJ. The proportions of cases in stage 3 were 7.69% in group 0, 18.18% in group 3, and 43.48% in group 5. Groups 0 and 3 were somewhat similar as regard MRONJ staging. Most patients in group 5 had MRONJ stage 2 or 3. No statistically significant differences emerged between the groups.

Conclusions

Preventive dental care can reduce the risk of MRONJ providing patients comply with the specialist’s recommendations.

The Role of Autologous Platelet Concentrates in the Treatment of Medication-Related Osteonecrosis of the Jaw

ABSTRACT

The frequent refractory response of patients to the treatment of medication-related osteonecrosis of the jaw (MRJON) has attracted clinicians' attention to several treatments. However, they are at best, palliative, and have a higher failure rate than previous treatments. The present meta-analysis was performed to evaluate the clinical effectiveness of autologous platelet concentrates (APCs) combined with surgery in the treatment of MRONJ. The authors conducted a meta-analysis involving a systematic search of PubMed, EMBASE, Wiley Online Library and the Cochrane Library for eligible studies from their inception to November 2019, in accordance with preselected criteria. The inverse variance method was applied to fixed or random effects models based on the heterogeneity of the studies. Thirteen studies that investigated APCs in the treatment of MRONJ were eligible for inclusion in the meta-analysis of 223 patients and 33 lesions. The pooled success rate of APCs combined with surgery for MRONJ was 90% (95%CI, 80%-97%) and the pooled OR was 7.67 (95%CI, 2.10-27.98), indicating the combination was 7.67 times more effective than surgery alone. The results suggest that the use of APCs is a promising therapeutic regimen, as it provided additional benefits to surgery in the treatment of MRONJ. To achieve the benefits, a tension-free primary closure of the soft tissue is recommended as well. Randomized studies with large sample sizes is warranted to confirm our finding.

The role of bone-modifying agents in myeloma bone disease

Bone disease is common in patients with multiple myeloma (MM), which manifests as bone pain and skeletal-related events (SREs) such as pathological fractures and spinal cord compression. Myeloma bone disease (MBD) can adversely affect the quality of life of patients and have negative effects on morbidity and mortality. The pathogenesis of MBD is complex, and several factors are involved in the dysregulation of bone metabolism and uncoupling of bone remodeling, which result in net bone loss and devastating SREs. Broadly speaking, elevated osteoclast activity, suppressed osteoblast activity, and an aberrant marrow microenvironment play a role in MBD. Interaction of MM cells with the main bone cell osteocytes also promote further bone destruction. This review focuses on the role of bone-modifying agents in the prevention and treatment of MBD. The mainstay of MBD prevention are antiresorptive agents, bisphosphonates and denosumab. However, these agents do not play a direct role in bone formation and repair of existing MBD. Newer agents with anabolic effects such as anti-sclerostin antibodies, parathyroid hormone, anti-Dickkopf-1 antibodies, and others have shown potential in repair of MBD lesions. With the development of several new agents, the treatment landscape of MBD is likely to evolve in the coming years. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

What is the Risk of Developing Medication-Related Osteonecrosis in Patients With Extraction Sockets Left to Heal by Secondary Intention? A Retrospective Case Series Study

PURPOSE

Tooth and root extractions represent trigger factors for medication-related osteonecrosis of the jaw (MRONJ). The best healing modality for postextraction sockets is still debated. The aim of the study was to estimate the incidence of MRONJ after extractions whose sockets were left to heal by secondary intention.

METHODS

A retrospective case series study was performed at the Department of Odontostomatological and Maxillofacial Sciences, Sapienza University of Rome. Only patients who underwent nonsurgical extractions, healed by secondary intention, were included in the study. The following parameters were considered: age, sex, pathologies for which bisphosphonates or other drugs related to MRONJ were prescribed, any local or systemic risk factors, type of drug used, route of administration, number of extractions performed, and number of sessions required to complete the extraction program. The main outcome variable was the occurrence of MRONJ. Statistical analysis was performed with SPSS statistical software.

RESULTS

Two hundred twenty-one patients were treated from 2007 to 2020 with 639 tooth/root extractions. All patients were treated under antibiotic prophylaxis and with anesthesia without vasoconstrictors. No cases of MRONJ occurred. The mean age of patients was 68.02 ± 11.17. Most of the study sample was represented by women (201 = 90.95%) undergoing treatment for osteometabolic pathologies, most frequently postmenopausal osteoporosis. Alendronate was the most frequently prescribed drug, taken mainly orally. Most patients had local and/or systemic risk factors. Each patient had from 1 to 17 tooth/root extractions (mean = 2.87 ± 2.59) during 1 to 4 sessions (mean = 1.41 ± 0.64). Extractions mainly involved single-rooted teeth/roots, equally distributed between the maxilla and mandible.

CONCLUSIONS

Secondary intention healing after nonsurgical tooth extraction does not seem to predispose to MRONJ. It can be advisable to perform extractions under antibiotic prophylaxis using anesthetics without vasoconstrictors and chlorhexidine mouth rinses in the 7 following days.

Infection as an Important Factor in Medication-Related Osteonecrosis of the Jaw (MRONJ)

Medication-related osteonecrosis of the jaw (MRONJ) has become a well-known side effect of antiresorptive, and antiangiogenic drugs commonly used in cancer management. Despite a considerable amount of literature addressing MRONJ, it is still widely accepted that the underlying pathomechanism of MRONJ is unclear. However, several clinical and preclinical studies indicate that infection seems to have a major role in the pathogenesis of MRONJ. Although there is no conclusive evidence for the infection hypothesis yet, available data have shown a robust association between local infection and MRONJ development. This observation is very critical in order to implement policies to reduce the risk of MRONJ in patients under antiresorptive drugs. This critical review was conducted to collect the most reliable evidence regarding the link between local infection and MRONJ pathogenesis.

Tooth extraction in mice administered zoledronate increases inflammatory cytokine levels and promotes osteonecrosis of the jaw

INTRODUCTION

Osteonecrosis of the jaw (ONJ) occurring after invasive dental treatment often adversely affects patients' activities of daily living. Long-term administration of strong anti-bone resorptive agents such as bisphosphonates prior to invasive dental treatment is considered an ONJ risk factor; however, pathological mechanisms underlying ONJ development remain unclear.

MATERIALS AND METHODS

We developed an ONJ mouse model in which a tooth is extracted during treatment with the bisphosphonate zoledronate.

RESULTS

We observed induction of apoptosis in osteocytes, resulting in formation of empty lacunae in jaw bones at sites of tooth extraction but not in other bones of the same mice. We also observed elevated levels of inflammatory cytokines such as TNFα, IL-6 and IL-1 in jaw bone at the extraction site relative to other sites in zoledronate-treated mice. We also report that treatment in vitro with either zoledronate or an extract from Porphyromonas gingivalis, an oral bacteria, promotes expression of inflammatory cytokines in osteoclast progenitor cells. We demonstrate that gene-targeting of either TNFα, IL-6 or IL-1 or treatment with etanercept, a TNFα inhibitor, or a neutralizing antibody against IL-6 can antagonize ONJ development caused by combined tooth extraction and zoledronate treatment.

CONCLUSIONS

Taken together, the cytokine storm induced by invasive dental treatment under bisphosphonate treatment promotes ONJ development due to elevated levels of inflammatory cytokine-producing cells. Our work identifies novel targets potentially useful to prevent ONJ.

Human amniotic membrane: an improvement in the treatment of Medication-related osteonecrosis of the jaw (MRONJ)? A case-control study

The aim of this article is to report the results obtained by the use of HAM in surgical wound healing and the reduction of relapse in patients affected by Medication-related osteonecrosis of the jaw (MRONJ).The study involved patients with the diagnosis of MRONJ, surgically treated between October 2016 and April 2019, in a case-control setting. Enrolled patients were randomly divided into 2 groups. One group will be treated with resective surgery and with the insertion of HAM patch (Group A), while the second group had been treated exclusively with resective surgery (Group B).The patients underwent MRONJ surgical treatment with the placement of amniotic membrane patches at the wound site. Data regarding the long-term complications/functions were evaluated at 3, 6, 12, and 24 months after surgery. Pain measurements were performed before the intervention (T0), 7(T1) and 30(T2) days after surgery. 49 patients were included in the study. 2 patients of GROUP A after 30 days since they were surgically treated showed persistent bone exposure. 5 patients of group B demonstrated a lack of healing of the surgical wound with the persistence of bone exposed to 30 days after surgery. Statistical analysis ruled out any difference in OUTCOME (relapse) between GROUP A and B (p = 0.23). However, the Fisher test highlighted a significant difference between the use of HAM and only surgical treatment in pain at rest (p = 0.032). The use of amniotic membrane implement the patient's quality of life and reduce pain perception. has a learning curve that is fast enough to justify its routine use.

Quality of life in patients affected by medication-related osteonecrosis of the jaws: A systematic review

OBJECTIVE

The aim of this systematic review was to describe the quality of life and oral health-related quality of life of patients affected by medication-related osteonecrosis of the jaw.

STUDY DESIGN

The review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A combination of keywords and MeSH terms was used in PubMed, Scopus, Cochrane Library, Web of Science, and EBSCO up to December 13, 2020.

RESULTS

A total of 1066 results were obtained after duplicate exclusion and 11 articles were included in the final qualitative analysis. Most of the articles described the quality of life in patients with osteonecrosis of the jaw secondary to cancer treatment. The main drugs associated with the disease were bisphosphonates. Surgical treatment of the osteonecrosis improves the quality of life of these patients.

CONCLUSIONS

The present systematic review suggested the negative influence of osteonecrosis of the jaw on the quality of life and oral health-related quality of life among oncologic and osteoporotic patients. The use of quality of life questionnaires in daily practice could be an important tool to better diagnose and manage patients affected by osteonecrosis of the jaws who have received or are receiving drugs associated with this complication.

The Use of Photodynamic Therapy on Medication-Related Osteonecrosis of the Jaws: Animal Study

Background/Aim: Bisphosphonate-related osteonecrosis of the jaw (BRONJ) was first introduced in 2003 and its scope was expanded by the name medication-related osteonecrosis of the jaw (MRONJ), since 2014. This study aimed to evaluate the effects of photodynamic therapy (FDT) on tissue samples by histopathological and histomorphometric examination and serum TRACP-5b (Tartrateresistant acid phosphatase-5b) measurement in rats.

Material and Methods: 24 Sprague-Dawley male rats were divided into 3 groups comprising 8 animals. Zoledronic acid was administered to groups 1 and 2 and 0.9% sodium chloride was administered to group 3 intraperitoneally. After the injections were completed, dental extractions were performed. Photodynamic therapy was applied to group 2, three times a weekfor the two weeks after the extraction. In the 16th week, sacrification was performed. Rats were undergone histopathologic and histomorphometric evaluations.

Results: Photodynamic therapy has led to a decrease in epithelial opening and inflammation and an increase in the formation of new bone. Serum TRACP-5b values were shown to decrease significantly in the presence of osteonecrosis.

Conclusions: PDT was shown to be useful in reducing MRONJ risk in rats. As a serum biomarker, Serum TRACP-5b could be a valuable marker. Additional studies should confirm the findings.

Complementarity of Photo-Biomodulation, Surgical Treatment, and Antibiotherapy for Medication-Related Osteonecrosis of the Jaws (MRONJ)

Background and Objectives: Antiresorptive or anti-angiogenic agents may induce medication-related osteonecrosis of the jaws (MRONJ), which represents a challenge for clinicians. The aim of this study is to design and apply a composed and stage-approach therapy combining antibiotherapy, surgical treatment, and photo-biomodulation (PBM) for the prevention or treatment of MRONJ lesions. Materials and Methods: The proposed treatment protocol was carried out in the Department of Oral & Maxillofacial Surgery of the “Victor Babes” University of Medicine and Farmacy of Timisoara, in 2018–2020. A total of 241 patients who were previously exposed to antiresorptive or anti-angiogenic therapy, as well as patients already diagnosed with MRONJ at different stages of the disease were treated. A preventive protocol was applied for patients in an “at risk” stage. Patients in more advanced stages received a complex treatment. Results: The healing proved to be complete, with spontaneous bone coverage in all the n = 84 cases placed in an “at risk” stage. For the n = 49 patients belonging to stage 0, pain reductions and decreases of mucosal inflammations were also obtained in all cases. For the n = 108 patients proposed for surgery (i.e., in stages 1, 2, or 3 of MRONJ), a total healing rate of 91.66% was obtained after the first surgery, while considering the downscaling to stage 1 as a treatment “success”, only one “failure” was reported. This brings the overall “success” rate to 96.68% for a complete healing, and to 99.59% when downscaling to stage 1 is included in the healing rate. Conclusions: Therefore, the clinical outcome of the present study indicates that patients with MRONJ in almost all stages of the disease can benefit from such a proposed association of methods, with superior clinical results compared to classical therapies.

Incidence of and risk for osteonecrosis of the jaw in Korean osteoporosis patients treated with bisphosphonates: A nationwide cohort-study

PURPOSE

To estimate the incidence of osteonecrosis of the jaw (ONJ) in patients treated with bisphosphonates (BPs) and to identify clinical risk factors that increase the risk for ONJ in Korean osteoporosis patients.

METHODS

We used data acquired from the Korean National Health Insurance Service. Among 2,140,149 participants with osteoporosis in 2012, we selected 164,926 new BP users and 164,926 age- and sex-matched control subjects. The control group included only patients with no prescriptions for BPs between January 1, 2011, and December 31, 2016. Participants were followed for 4 years.

RESULTS

Over the 4-year follow-up period, the cumulative incidence rates of ONJ were 20.9 and 6.9 per 100,000 person-years in the BP and control groups, respectively. The BP group had an increased risk for ONJ compared to the control group after adjusting for multiple variables (hazard ratio [HR] 3.72, 95% CI 2.70-5.11). Advanced age (≥70 years), comorbid diseases such as diabetes, hypertension, and rheumatoid arthritis (RA) were independent risk factors for the development of ONJ. In addition, tooth extraction (HR 9.85), gingivitis, and periodontal disease (HR 4.78) were strongly associated with ONJ.

CONCLUSIONS

ONJ incidence was 21 per 100,000 person-years in osteoporosis patients receiving bisphosphonates. Clinical factors including advanced age, diabetes, RA, dental disease, as well as BP use were significantly associated with ONJ.

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.

Prevalence of medication related osteonecrosis of the jaw in patients treated with sequential antiresorptive drugs: systematic review and meta-analysis

BACKGROUND

Antiresorptive drugs (ARD) are associated with a known serious adverse event, known as medication-related osteonecrosis of the jaws (MRONJ). Transition from one ARD to another has become common clinical practice with the advent of more potent or safer agents; however, the influence of sequential antiresorptive therapy as a risk factor for MRONJ has not been established.

OBJECTIVES

To investigate the prevalence of MRONJ in oncology or osteoporosis patients treated with two or more sequential ARDs as opposed to a single antiresorptive drug.

MATERIAL AND METHODS

Systematic electronic literature searches were conducted using Ovid MEDLINE, Ovid EMBASE, and Cochrane Central Register of Controlled Trials. Two review authors retrieved studies using pre-determined eligibility criteria and conducted quality assessment and data extraction. Fixed or random-effects meta-analysis models were used to summarize relative estimates for prevalence of MRONJ.

RESULTS

A total of 483 titles and abstracts were screened, and 18 full texts were retrieved for review. Twelve studies were included in the final qualitative and quantitative synthesis. Random effects meta-analysis models revealed a weighted pooled MRONJ prevalence of 19% (95% CI 10-27%) for sequential pamidronate-zoledronate therapy, 10% (95% CI 3-22%) for sequential ibandronate-zoledronate therapy. Pooled weighted prevalence of MRONJ was 13% (95% CI 3-22%) for sequential bisphosphonate-denosumab therapy while bisphosphonates only was 5% (95% CI 0-9%) and denosumab only was 4% (95% CI 3-5%).

CONCLUSIONS

The present systematic review suggests an increased prevalence of MRONJ associated with sequential ARD therapy for pamidronate-zoledronate and bisphosphonate-denosumab administration when compared to single ARD therapy.

Update on Equine Odontoclastic Tooth Resorption and Hypercementosis

Equine odontoclastic tooth resorption and hypercementosis (EOTRH) is a progressive, painful disease, affecting incisors, canines, and cheek teeth. Examination findings include gingival inflammation, gingival recession and/or hyperplasia, subgingival swelling, bulbous enlargement of teeth, associated periodontal disease, pathologic tooth fracture, and/or tooth mobility and loss. Current hypotheses include biomechanical stresses and secondary bacterial involvement. Early recognition allows case management, but it is a progressive disease. Owner education is crucial; horses with complete or multiple extractions have a favorable prognosis. Human oral and dental health may be affected by bisphosophonate use; long-term effects of these drugs are currently unknown in horses.

Root canal treatment of compromised teeth as alternative treatment for patients receiving bisphosphonates: 60-month results of a prospective clinical study

AIM

This 60-month prospective study aimed to evaluate tooth survival and healing rates after root canal treatment in patients taking bisphosphonates (BPs). Secondary outcomes were complications and clinical variables observed during and after treatment.

METHODS

Root canal treatment was performed using manual K-file canal instrumentation and a carrier-based filling technique with an epoxy resin-based sealer. Teeth without adequate root/crown integrity were restored by trained operators at the tissue level (TL group) to prevent occlusal/mechanical stress and to enable periapical lesion healing without the risk of root fracture. Other teeth were restored with normal occlusal contacts (OC group). Healthy patients who had undergone one or more root canal treatments of the same type constituted the control group. The relationships of the following variables to survival and health status were examined (chi-squared test and multivariate analysis, P = 0.05): age, gender, smoking habit, tooth location, treatment type, BPs treatment, BPs exposure, initial periapical index (PAI) and occlusal restoration. Survival curves were constructed using Kaplan-Meier analysis, with extraction serving as the end-point.

RESULTS

In total, 65 patients with 109 root canal-treated teeth who were taking BPs were included. At 60 months, data from 57 patients (52F, 5M; median age 65.7 ± 8.6 years) who had undergone 96 root canal treatments were analysed (drop-out rate = 16.9%). The survival rate was 85%, and the success rate was 76%. The control group consisted of 46 patients (21F, 25M; median age 60.3 ± 7.2 years) who had undergone 102 root canal treatments. The survival rate was 88%, with 12 teeth lost during follow-up. The success rate was 73%. In the BP group, 55 teeth were restored normally (OC group) and 41 teeth were restored at the tissue level (TL group). No difference in the success or survival rate was observed between the BP and control groups (P > 0.05). Univariate Kaplan-Meier analysis revealed that only tooth type significantly affected survival status in the BP group. The analysis revealed the clinical relevance of smoking, tooth location and initial PAI on patients' health status (P < 0.05).

CONCLUSION

Root canal treatments and post-endodontic restoration with tissue-level filling procedures represent a safe approach for severely damaged teeth in patients receiving BPs having comparable results to root filled teeth restored with occlusal contacts and to the control group.

Virtual Surgical Planning for Bisphosphonate-Related Osteonecrosis of the Jaw: A Valuable Application in Advanced Cases

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a rare but potentially devastating complication of extended use of bisphosphonates. fibula free flaps (FFFs) are the gold standard of mandibular reconstruction. Virtual surgical planning (VSP) is a technique that utilizes high-definition three-dimensional reconstructions that enable the production of highly accurate intra-operative surgical guides and templates that help guide osteotomies and fibula contouring. 

The aim of this report is to highlight the value of VSP in the surgical management of advanced BRONJ. We report a case study of a woman with advanced BRONJ that required an angle-to-angle mandibular resection with subsequent reconstruction with an FFF. VSP was used to improve the accuracy of the reconstruction and minimize ischemia time.

We present the first reported case of the successful implementation of VSP for the planning of FFF reconstruction for a woman with advanced symptomatic BRONJ that had failed conservative measures.

Surgical treatment of advanced medication-related osteonecrosis of the jaws: Comparison of soft tissue closure techniques and evaluation of side effects

The aim of the study was to evaluate the surgical outcome of patients with advanced medication-related osteonecrosis of the jaw (MRONJ) treated with different flaps for soft tissue closure. Only MRONJ stage III patients with a minimum follow-up of 6 months were included in our prospective study. The soft tissue closure techniques were: Mylohyoid Muscle Flap, Buccal Fat Flap and mucoperiosteal flap alone. Potential risk factors and surgical side effects were analyzed. Relapses occurred in 12 of 44 included cases and 38 reached mucosal integrity within the follow-up. Cases treated with the muscle or fat flap showed better results regarding the recurrence rate (p < 0.001) and soft tissue healing (p = 0.002): only 3 of 33 developed a relapse, and 31 of 33 reached mucosal integrity. The outcome was worse if MRONJ occurred at the front areas of the jaw (p = 0.025). Postoperative, the pain level was reduced significantly (p < 0.001). Partial hypoesthesia of the lip arose in 18 cases. An impairment of the long-term prosthetic rehabilitation has not been seen.Patients with MRONJ stage III undergoing surgery benefit from extensive soft tissue closure.

Clinical profile of individuals with bisphosphonate-related osteonecrosis of the jaw: an integrative review

BACKGROUND

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is still the most prevalent type of osteonecrosis with clinical relevance. In Brazil, bisphosphonate use is high but there is a lack of epidemiological studies on BRONJ.

OBJECTIVE

To determine the clinical profile of BRONJ in a Brazilian population through an integrative review.

DESIGN AND SETTING

Integrative review of BRONJ in a Brazilian population.

METHODS

Cases and clinical research on Brazilians with BRONJ between 2010 and 2019, indexed in PubMed/MEDLINE, Scopus, Web of Science and LILACS were reviewed. Age, sex, type and time of bisphosphonate intake, administration route, related diseases, region of the BRONJ, diagnostic criteria, staging, triggering factor and type of treatment were analyzed.

RESULTS

Fifteen articles on 128 subjects were included. Most patients were women (82.03%); the mean age was 63 years. Intravenous zoledronic acid was mostly used (62.50%), for breast cancer treatment (46.87%). The main localization of BRONJ was the mandible (54.68%), associated mainly with tooth extractions (45.98%). The diagnostic criteria were clinical (100%) and radiographic (89.06%), mostly in stage II (68.08%). The surgical treatments were sequestrectomy (37.50%) and platelet-rich plasma (PRP) (36.71%). Microbial control was done using chlorhexidine (93.75%) and infection control using clindamycin (53.90%).

CONCLUSIONS

BRONJ had higher prevalence in Brazilian women receiving treatment for breast cancer and osteoporosis. The mandible was the region most affected with a moderate stage of BRONJ, particularly when there were histories of tooth extraction and peri-implant surgery. Sequestrectomy with additional drugs and surgical therapy was the treatment most accomplished.

Adult Osteosclerotic Metaphyseal Dysplasia With Progressive Osteonecrosis of the Jaws and Abnormal Bone Resorption Pattern Due to a LRRK1 Splice Site Mutation

Osteosclerotic metaphyseal dysplasia (OSMD) is a rare autosomal recessive sclerosing skeletal dysplasia. We report on a 34-year-old patient with sandwich vertebrae, platyspondyly, osteosclerosis of the tubular bones, pathologic fractures, and anemia. In the third decade, he developed osteonecrosis of the jaws, which was progressive in spite of repeated surgical treatment over a period of 11 years. An iliac crest bone biopsy revealed the presence of hypermineralized cartilage remnants, large multinucleated osteoclasts with abnormal morphology, and inadequate bone resorption typical for osteoclast-rich osteopetrosis. After exclusion of mutations in TCIRG1 and CLCN7 we performed trio-based exome sequencing. The novel homozygous splice-site mutation c.261G>A in the gene LRRK1 was found and co-segregated with the phenotype in the family. cDNA sequencing showed nearly complete skipping of exon 3 leading to a frameshift (p.Ala34Profs*33). Osteoclasts differentiated from the patient's peripheral blood monocytes were extremely large. Instead of resorption pits these cells were only capable of superficial erosion. Phosphorylation of L-plastin at position Ser5 was strongly reduced in patient-derived osteoclasts showing a loss of function of the mutated LRRK1 kinase protein. Our analysis indicates a strong overlap of LRRK1-related OSMD with other forms of intermediate osteopetrosis, but an exceptional abnormality of osteoclast resorption. Like in other osteoclast pathologies an increased risk for progressive osteonecrosis of the jaws should be considered in OSMD, an intermediate form of osteopetrosis. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

Survival in older women with early stage breast cancer receiving low-dose bisphosphonates or denosumab

BACKGROUND

Bisphosphonates and denosumab, as adjuvant therapy in breast cancer, have been associated in some studies with improved cancer outcomes. The potential benefits of these drugs used at the lower doses commonly given for osteoporosis have not been established. The objective of this study was to investigate the association between therapy with bone-modifying agents (BMAs) and survival in older women with early breast cancer.

METHODS

The authors conducted a retrospective cohort study of women aged ≥66 years with breast cancer who were included in the Surveillance, Epidemiology, and End Results and Texas Cancer Registry Medicare-linked databases. Associations were examined between the receipt of BMAs at dosages indicated for osteoporosis within 2 years after diagnosis and overall and breast cancer-specific survival. Cox proportional hazards models and propensity score adjustment and matching were used for the analyses.

RESULTS

Of the 37,724 women included, 7925 (21%) received at least 6 months of a BMA within the first 2 years of breast cancer diagnosis, including bisphosphonates only in 6898 women (80.7%), denosumab only in 1204 (15.2%), and both classes of BMAs in 323 (4.1%). The median follow-up was 64 months. The receipt of a bisphosphonate was associated with improved overall survival (hazard ratio [HR], 0.87; 95% CI, 0.82-0.93) and breast cancer-specific survival (HR, 0.77; 95% CI, 0.64-0.92) after multivariable adjustment. Benefits were primarily seen for patients who had stage II and III disease. No benefits were observed with denosumab (stage II: HR, 1.05 [95% CI, 0.90-1.22]; stage III: HR, 1.09 [95% CI, 0.66-1.82]).

CONCLUSIONS

Bisphosphonates at the doses recommended for osteoporosis are associated with improved survival in older postmenopausal women with early breast cancer.

Influence of ridge preservation procedures on extraction socket healing under antiresorptive therapy: An experimental study in rabbits

BACKGROUND

To assess the influence of ridge preservation procedures on the healing of extraction sockets under antiresorptive therapy.

MATERIAL AND METHODS

A total of 10 Dutch Belted rabbits were randomly allocated to either the intravenous administration of amino-bisphosphonate (zoledronic acid) (Za) (n = 5) or a negative control group (no Za [nZa]) (n = 5). At 6 months, the mandibular and maxillary molars were extracted and the four experimental sites randomly allocated to the following subgroups: (a) socket grafting using a collagen-coated natural bone mineral (BOC) + primary wound closure, (b) coronectomy (CO), or (c) spontaneous healing + primary wound closure (SP). Za medication was continued for another 4 months. Histomorphometrical analyses considered, for example, crestal hard tissue closure of the extraction site (C) and mineralized tissue (MT) formation.

RESULTS

Za-SP was associated with an incomplete median C (31.76% vs 100% in nZa-SP) and signs of bone arrosion along the confines of the socket. BOC had no major effects on increases in C and MT values in the Za group. CO commonly resulted in an encapsulation and partial replacement resorption of residual roots by MT without any histological signs of osteonecrosis.

CONCLUSIONS

(a) Za-SP was commonly associated with a compromised socket healing and signs of osteonecrosis, (b) BOC had no major effect on socket healing in the Za group, and (c) CO at noninfected teeth might be a feasible measure for the prevention of a Za-related osteonecrosis of the jaw.