Osteonecrosis of the Jaw Associated with Antiangiogenics in Antiresorptive-Naïve Patient: A Comprehensive Review of the Literature

Novel selective proline-based peptidomimetics for human cathepsin K inhibition

Human cathepsin K (CatK) stands out as a promising target for the treatment of osteoporosis, considering its role in degrading the bone matrix. Given the small and shallow S2 subsite of CatK and considering its preference for proline or hydroxyproline, we now propose the rigidification of the leucine fragment found at the P2 position in a dipeptidyl-based inhibitor, generating rigid proline-based analogs. Accordingly, with these new proline-based peptidomimetics inhibitors, we selectively inhibited CatK against other human cathepsins (B, L and S). Among these new ligands, the most active one exhibited a high affinity (pKi = 7.3 - 50.1 nM) for CatK and no inhibition over the other cathepsins. This specific inhibitor harbors two novel substituents never employed in other CatK inhibitors: the trifluoromethylpyrazole and the 4-methylproline at P3 and P2 positions. These results broaden and advance the path toward new potent and selective inhibitors for CatK.

The adjunctive use of Leukocyte-Platelet Rich Fibrin (L-PRF) in the management of Medication Related Osteonecrosis of the Jaw (MRONJ): a retrospective observational study

PURPOSE

Medication related osteonecrosis of the jaw (MRONJ) is a risk for patients taking anti-resorptive or anti-angiogenic medications. The American Association of Oral and Maxillofacial Surgeons (AAMOS) has classified MRONJ in stages to reflect the severity of the disease and allows implementation of suitable treatment pathways. MRONJ risk is < 5% in cancer patients and < 0.05% in osteoporosis patients. Management is subdivided into operative and non-operative, with advances in the literature investigating adjuvants. Leukocyte-Platelet Rich Fibrin (L-PRF) is an autologous biomaterial consisting of leukocytes and platelets embedded within a fibrin matrix with the ability to release growth factors enabling angiogenesis, bone regeneration and soft tissue healing. This paper's aim is to investigate the effects of L-PRF in conjuction with surgical debridement for management of MRONJ.

METHODS

Twenty-two cases with established MRONJ were treated with either surgical intervention (Group A) or with surgical intervention and L-PRF (Group B), from 2016 to 2023 at Edinburgh Dental Institute (EDI). Treatments were deemed successful when the patients were asymptomatic, displayed complete soft tissue healing with the absence of infection/inflammation, fistula, or exposed bone.

RESULTS

All cases in Group B had healed in contrast to 54.5% not healed in Group A; p value < 0.05 indicating statistical significance.

CONCLUSION

The use of L-PRF as an adjuvant to surgical management of MRONJ is promising with its favourable functional capacity, simple application, and success of treatment outcomes.

Medication-Related Osteonecrosis of the Jaw: A Cross-Sectional Study on the Prevalence of Cutaneous Manifestations and the Primary Care Physician's Role in its Early Diagnosis

BACKGROUND

Medication-related osteonecrosis of the jaw (MRONJ) is a side effect in patients undergoing treatment with bone-modifying agents (BMA) for cancer or osteoporosis. Although most cases are treated by oral medicine specialists, some cases may present extraorally as a fistula in the skin or erythematous swelling localized to the jaw area, causing these patients to consult a primary care physician. This study examined the prevalence and clinical characteristics of extraoral manifestations of MRONJ in a large cohort to raise awareness among primary care physicians of this entity, enabling prompt diagnosis and treatment.

METHODS

Medical records were retrieved of patients diagnosed with MRONJ between 2003 and June 2020 in the Oral Medicine Unit of The Sheba Medical Center, Israel. Data relating to demographics, medical background, type of BMA, and clinical presentation were collected.

RESULTS

In total, 515 patients (378 women [73%] and 137 men [27%]; mean age: 65 years, range: 32-94 years) met the inclusion criteria, among whom 84 (16.5%) presented with extraoral manifestations of MRONJ. Of these 84 patients, 21 (24.7%) presented with extraoral fistulas. Extraoral manifestations were strongly correlated with MRONJ of the mandible (n = 67; P = .0006).

CONCLUSIONS

MRONJ is a significant side effect of BMA therapy. Although MRONJ mostly presents intraorally, some patients may initially present with extraoral manifestations of erythematous swelling or fistulas localized to the jaw area. Primary care physicians should consider MRONJ as a differential diagnosis in such patients.

Medication-Related Osteonecrosis of the Jaw: A Systematic Review and a Bioinformatic Analysis

The objective was to evaluate the current evidence regarding the etiology of medication-related osteonecrosis of the jaw (MRONJ). This study systematically reviewed the literature by searching PubMed, Web of Science, and ProQuest databases for genes, proteins, and microRNAs associated with MRONJ from the earliest records through April 2023. Conference abstracts, letters, review articles, non-human studies, and non-English publications were excluded. Twelve studies meeting the inclusion criteria involving exposure of human oral mucosa, blood, serum, saliva, or adjacent bone or periodontium to anti-resorptive or anti-angiogenic agents were analyzed. The Cochrane Collaboration risk assessment tool was used to assess the quality of the studies. A total of 824 differentially expressed genes/proteins (DEGs) and 22 microRNAs were extracted for further bioinformatic analysis using Cytoscape, STRING, BiNGO, cytoHubba, MCODE, and ReactomeFI software packages and web-based platforms: DIANA mirPath, OmicsNet, and miRNet tools. The analysis yielded an interactome consisting of 17 hub genes and hsa-mir-16-1, hsa-mir-21, hsa-mir-23a, hsa-mir-145, hsa-mir-186, hsa-mir-221, and hsa-mir-424. A dominance of cytokine pathways was observed in both the cluster of hub DEGs and the interactome of hub genes with dysregulated miRNAs. In conclusion, a panel of genes, miRNAs, and related pathways were found, which is a step toward understanding the complexity of the disease.

In Vitro Cytotoxicity of Antiresorptive and Antiangiogenic Compounds on Oral Tissues Contributing to MRONJ: Systematic Review

BACKGROUND

Invasive dental treatment in patients exposed to antiresorptive and antiangiogenic drugs can cause medication-related osteonecrosis of the jaw (MRONJ). Currently, the exact pathogenesis of this disease is unclear.

METHODS

In March 2022, Medline (Ovid), Embase (Ovid), Scopus, and Web of Science were screened to identify eligible in vitro studies investigating the effects of antiresorptive and antiangiogenic compounds on orally derived cells.

RESULTS

Fifty-nine articles met the inclusion criteria. Bisphosphonates were used in 57 studies, denosumab in two, and sunitinib and bevacizumab in one. Zoledronate was the most commonly used nitrogen-containing bisphosphonate. The only non-nitrogen-containing bisphosphonate studied was clodronate. The most frequently tested tissues were gingival fibroblasts, oral keratinocytes, and alveolar osteoblasts. These drugs caused a decrease in cell proliferation, viability, and migration.

CONCLUSIONS

Antiresorptive and antiangiogenic drugs displayed cytotoxic effects in a dose and time-dependent manner. Additional research is required to further elucidate the pathways of MRONJ.

Avoiding implant-related complications in medically compromised patients with or without unhealthy lifestyle/Elevated oxidative stress

Increased human life expectancy broadens the alternatives for missing teeth and played a role in the widespread use of dental implants and related augmentation procedures for the aging population. Though, many of these patients may have one or more diseases. These systemic conditions may directly lead to surgical complications, compromise implant/bone healing, or influence long-term peri-implant health and its response to biologic nuisances. Offering patients credible expectations regarding intra- and postoperative complications and therapeutic prognosis is an ethical and legal obligation. Clear identification of potential types of adverse effects, complications, or errors is important for decision-making processes as they may be related to different local, systemic, and technical aspects. Therefore, the present review structures the underlying biological mechanisms, clinical evidence, and clinical recommendations for the most common systemic risk factors for implant-related complications.

Anti-angiogenic drug aggravates the degree of anti-resorptive drug-based medication-related osteonecrosis of the jaw by impairing the proliferation and migration function of gingival fibroblasts

BACKGROUND

Long-term use of anti-resorptive or anti-angiogenic drugs in cancer patients with odontogenic infections may lead to medication-related osteonecrosis of the jaw (MRONJ). This study investigated whether anti-angiogenic agents aggravate MRONJ occurrence in anti-resorptive-treated patients.

METHODS

The clinical stage and jawbone exposure of MRONJ patients caused by different drug regimens were analyzed to ascertain the aggravation effect of anti-angiogenic drugs on anti-resorptive drug-based MRONJ. Next, a periodontitis mice model was established, and tooth extraction was performed after administering anti-resorptive and/or anti-angiogenic drugs; the imaging and histological change of the extraction socket were observed. Moreover, the cell function of gingival fibroblasts was analyzed after the treatment with anti-resorptive and/or anti-angiogenic drugs in order to evaluate their effect on the gingival tissue healing of the extraction socket.

RESULTS

Patients treated with anti-angiogenic and anti-resorptive drugs had an advanced clinical stage and a bigger proportion of necrotic jawbone exposure compared to patients treated with anti-resorptive drugs alone. In vivo study further indicated a greater loss of mucosa tissue coverage above the tooth extraction in mice treated with sunitinib (Suti) + zoledronate (Zole) group (7/10) vs. Zole group (3/10) and Suti group (1/10). Micro-computed tomography (CT) and histological data showed that the new bone formation in the extraction socket was lower in Suti + Zole and Zole groups vs. Suti and control groups. In vitro data showed that the anti-angiogenic drugs had a stronger inhibitory ability on the proliferation and migration function of gingival fibroblasts than anti-resorptive drugs, and the inhibitory effect was obviously enhanced after combining zoledronate and sunitinib.

CONCLUSION

Our findings provided support for a synergistic contribution of anti-angiogenic drugs to anti-resorptive drugs-based MRONJ. Importantly, the present study revealed that anti-angiogenic drugs alone do not induce severe MRONJ but aggravate the degree of MRONJ via the enhanced inhibitory function of gingival fibroblasts based on anti-resorptive drugs.

Knowledge, attitudes and practices of physicians and dentists on medication-related osteonecrosis of the jaw: a cross-sectional survey

Background Bisphosphonate medication can cause osteonecrosis of the jaw, which is an uncommon but serious complication. This survey explores the knowledge, attitudes and practices of dentists and physicians regarding medication-related osteonecrosis of the jaw (MRONJ).Methods A cross-sectional study was conducted among physicians and dentists of Pakistan's secondary and tertiary care hospitals between March and June 2021. Data were collected through a web-based questionnaire distributed among the eligible clinicians involved in prescribing bisphosphonates to patients or management of osteonecrosis. SPSS Statistics 23.0 was used for the data analysis. The frequencies and proportions of the descriptive variables were reported.Results A response rate of 29% was achieved. Only six dentists (n = 6/61; 9.8%) were aware that mammalian target of rapamycin inhibitors could lead to osteonecrosis. Only one-third (n = 9/26; 34.6%) of physicians informed their patients about the possible side effects of bisphosphonates. The most commonly identified risk factor among them was the duration of the drug (n = 77/87; 88.5%) and the least identified was gender (n = 34/87; 39.0%).Conclusions Our study revealed insufficient knowledge among the respondents about the recently updated established guidelines available on MRONJ. The majority of physicians don't refer patients to dentists before prescribing bisphosphonates and other associated medications.

Medication-Related Osteonecrosis: Why the Jawbone?

Medication-related osteonecrosis of the jaw (MRONJ) has emerged as a complication of anti-resorptive medications. Despite its low incidence rate, this problem has gained attention in recent years due to its devastating consequences and lack of preventive strategy. The fact that MRONJ incidence has been exclusive to the jawbones, despite the systemic effect of anti-resorptive medications, could be a starting point to unravel the multifactorial pathogenesis of this condition. This review aims to negotiate the question of why the jawbone is more susceptible to MRONJ than other skeletal sites. Approaching the problem from this perspective could provide new directions for the prevention of MRONJ and expand our understanding of the unique oral microenvironment.

Oral Side Effects in Patients with Metastatic Renal Cell Carcinoma Receiving the Antiangiogenic Agent Pazopanib-Report of Three Cases

Pazopanib is a potent multi-kinase inhibitor that hinders angiogenesis and blocks tumor growth. It has been approved for the treatment of metastatic renal cell carcinoma (mRCC) and advanced soft tissue sarcoma. There is emerging evidence that bleeding is a common adverse effect of pazopanib and other targeted therapies in patients with mRCC. In addition, jaw osteonecrosis related to pazopanib was recently described in the literature. We report three cases of patients with mRCC who developed adverse oral events related to pazopanib. The first patient, treated with pazopanib as monotherapy, presented with gingival bleeding and oral burning sensation. The other two patients receiving pazopanib as monotherapy and pazopanib followed by sunitinib, respectively, presented complaining about mandibular pain; a diagnosis of medication-related osteonecrosis of the jaw (MRONJ) was rendered in both cases. Gingival bleeding and MRONJ may develop as oral side effects of pazopanib use. The cases presented here aim to alert and inform health care professionals about the risk of adverse oral events in patients with mRCC receiving the antiangiogenic agent pazopanib.

Contribution of Antiangiogenic Agents to the Risk of Medication-related Osteonecrosis of the Jaw in Combination with Antiresorptive Agents: Preliminary Results in a Comparative Prospective Report of 59 Oncologic Cases

AIM

The aim of this preliminary study was to evaluate in an oncological population the association risk of antiangiogenic (AA) agents to antiresorptive (AR) agents on the incidence and the severity of medication-related osteonecrosis of the jaw (MRONJ).

MATERIALS AND METHODS

In this prospective study, we reviewed the medical records and clinical variables of 59 consecutive oncologic patients who developed MRONJ. For all patients, we retrieved the following variables: age, gender, alcohol and tobacco use, type of cancer, use of corticosteroids for >3 months, history of diabetes, MRONJ staging, combination of AR and AA agents, dental history (surgery, prosthesis) or spontaneous, site of MRONJ, delay between AR and AA first intake, and MRONJ development. Patients were divided into two groups according to drugs therapy they underwent: group 1 (G1) including patients treated with AR agents alone and group 2 (G2) including patients receiving antiresorptive-antiangiogenic drugs (AR+AA). The degree and the therapeutical success were defined as primary outcomes and the number, the localization, and the delay in onset of the lesions as secondary outcomes. In order to identify predictive factors of osteonecrosis-free interval time, univariate and multivariate Cox regression was performed. Statistical tests were carried out using the IBM^® SPSS^® Statistics software. All reported P-values are two-tailed and were considered to be significant when less than 0.05.

RESULTS

Among the 47 patients who received AR agent alone (group 1), the mean treatment duration before diagnosis of MRONJ was 39.2 months. In the second group (n = 12), patients developed MRONJ with a comparable mean time of 55 months (P = 0.16). According to the staging of MRONJ at the time of diagnosis, no significant difference (P = 0.736) was observed between the two groups. Moreover, the treatment applied was not statistically different in both the groups and was successful in 36.17% of the patients in group 1 and 58.33% of the patients in group 2. No statistically difference was reported in both the groups (P = 0.16). After statistical analysis, no significant difference in terms of MRONJ localization (P = 0.13) was observed. Finally, the incidence of spontaneous MRONJ was comparable in both the groups. Statistical analysis revealed that total time of treatment was the only factor associated with poor osteonecrosis-free interval time (hazard ratio 0.99; P = 0.001). Interestingly, the combination of an AA and AR agent was not a significant predictor factor of the interval time before the diagnosis of osteonecrosis. Additionally, corticosteroid use, diabetes mellitus, and dental consultation before treatment were not statistically related to poorer osteonecrosis-free interval time rates.

CONCLUSION

In our preliminary study, neither the mean treatment time duration before the diagnosis of MRONJ nor the dose delivered was different in both the groups (AR vs. AR+AA). Moreover, no significant difference was observed between both the groups regarding the localization and the staging of MRONJ at the time of diagnosis. Interestingly, our results demonstrated that the risk of spontaneous MRONJ is statistically comparable in the AR and AR-AA groups. Additionally, the addition of an AA agent did not influence the treatment applied in the two groups of patients.

Use of multikinase inhibitors/lenvatinib concomitant with antiresorptive therapy for bone metastases from radioiodine-resistant differentiated thyroid cancer

Bone is the second most common distant metastasis site in differentiated thyroid cancer (DTC) and is normally associated with the presence of other metastases, which are usually radioiodine‐resistant. The presence of bone metastasis (BM) determines low survival and greater morbidity due to the frequency of skeletal‐related events (SREs), which can be a serious complication of BM. There is evidence that antiresorptive therapy (AT) reduces SREs in other solid tumors, but not yet in DTC BM, for which data are scant. The same is true for systemic therapy with multikinase inhibitors (MKIs). In general, the results for MKI use are well known, although the effect on BM has rarely been evaluated. While MKIs are indicated in current clinical practice guidelines, studies evaluating the benefits and risks of concomitant treatment with MKIs and AT are lacking, and the available data come from small samples in retrospective studies. The objective of this article is to review the latest evidence for concomitant MKIs and AT.

Bone is a common distant metastasis in differentiated thyroid cancer, that is associated with the presence of other metastases, low survival and high morbidity. There is evidence that antiresorptive therapy and multikinase inhibitors reduce skeletal‐related events in other solid tumors, but studies evaluating the benefits and risks of concomitant treatment are lacking in differentiated thyroid cancer. This article reviews the latest evidence.

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.

A patent review on cathepsin K inhibitors to treat osteoporosis (2011 - 2021)

INTRODUCTION

Cathepsin K (CatK) is a lysosomal cysteine protease and the predominant cathepsin expressed in osteoclasts, where it degrades the bone matrix. Hence, CatK is an attractive therapeutic target related to diseases characterized by bone resorption, like osteoporosis.

AREAS COVERED

This review summarizes the patent literature from 2011 to 2021 on CatK inhibitors and their potential use as new treatments for osteoporosis. The inhibitors were classified by their warheads, with the most explored nitrile-based inhibitors. Promising in vivo results have also been disclosed.

EXPERT OPINION

As one of the most potent lysosomal proteins whose primary function is to mediate bone resorption, cathepsin K remains an excellent target for therapeutic intervention. Nevertheless, there is no record of any approved drug that targets CatK. The most notable cases of drug candidates targeting CatK were balicatib and odanacatib, which reached Phase II and III clinical trials, respectively, but did not enter the market. Further developments include exploring new chemical entities beyond the nitrile-based chemical space, with improved ADME and safety profiles. In addition, CatK's role in cancer immunoexpression and its involvement in the pathophysiology of osteo- and rheumatoid arthritis have raised the race to develop activity-based probes with excellent potency and selectivity.

Systematic review of medication related osteonecrosis of the jaw (MRONJ) in patients undergoing only antiangiogenic drug therapy: surgery or conservative therapy?

Osteonecrosis of the jaw is a severe adverse condition affecting patients exposed to specific types of medications. Previous studies have highlighted that osteonecrosis of the jaw is triggered by invasive dental procedures and can be very challenging to manage, especially in patients with cancer. The primary aim of this review was to analyse all available evidence on the management (surgical and/or conservative) of medication related osteonecrosis of the jaws (MRONJ) in patients with a history of antiangiogenic drugs therapy and who had not been previously exposed to any antiresorptive drug treatments. A multi-database search (PubMed, MEDLINE, EMBASE and CINAHL) was performed to identify related multi-language papers published from January 2003 until November 2020. Data were extracted from relevant papers and analysed according to the outcomes selected in this review. The search generated 28 studies eligible for the analysis. The total number of patients included in the analysis was 36. Sixteen patients were treated with anti-vascular endothelial growth factor drugs (anti-VEGF) while the remaining patients were administered a combination of antiangiogenic drugs. The most common MRONJ site was the mandible in 29 patients. MRONJ recurrence after treatment was only reported in six patients, the majority of which were treated conservatively. The data reviewed confirmed that an invasive procedure was the most common trigger of MRONJ with relatively high frequency of postoperative recurrence following treatment. However, due to the low quality of available research in the literature, it is difficult to draw a definitive conclusion on the validity of the presented treatment to manage patients affected by MRONJ associated with angiogenic therapy.

Preclinical models of medication-related osteonecrosis of the jaw (MRONJ)

Medication-related osteonecrosis of the jaw (MRONJ) is a potentially severe adverse event affecting patients with cancer and patients with osteoporosis who have been treated with powerful antiresorptives (pARs) or angiogenesis inhibitors (AgIs). pARs, including nitrogen-containing bisphosphonates (N-BPs; e.g., zoledronic acid, alendronate) and anti-RANKL antibodies (e.g., denosumab), are used to manage bone metastases in patients with cancer or to prevent fragility fractures in patients with osteoporosis. Though significant advances have been made in understanding MRONJ, its pathophysiology is still not fully elucidated. Multiple species have been used in preclinical MRONJ research, including the rat, mouse, rice rat, rabbit, dog, sheep, and pig. Animal research has contributed immensely to advancing the MRONJ field, particularly, but not limited to, in developing models and investigating risk factors that were first observed in humans. MRONJ models have been developed using clinically relevant doses of systemic risk factors, like N-BPs, anti-RANKL antibodies, or AgIs. Specific local oral risk factors first noted in humans, including tooth extraction and inflammatory dental disease (e.g., periodontitis, periapical infection, etc.), were then added. Research in rodents, particularly the rat, and, to some extent, the mouse, across multiple laboratories, has contributed to establishing multiple relevant and complementary preclinical models. Models in larger species produced accurate clinical and histopathologic outcomes suggesting a potential role for confirming specific crucial findings from rodent research. We view the current state of animal models for MRONJ as good. The rodent models are now reliable enough to produce large numbers of MRONJ cases that could be applied in experiments testing treatment modalities. The course of MRONJ, including stage 0 MRONJ, is characterized well enough that basic studies of the molecular or enzyme-level findings in different MRONJ stages are possible. This review provides a current overview of the existing models of MRONJ, their more significant features and findings, and important instances of their application in preclinical research.

Different Presentation and Outcomes in the Surgical Treatment of Advanced MRONJ in Oncological and Nononcological Patients Taking or Not Corticosteroid Therapy

Medication-related osteonecrosis of the jaw (MRONJ) is a severe side effect caused by antiangiogenic antiresorptive drugs used to treat various oncological and non oncological diseases. The clinical and radiological characteristics of MRONJ depend on the type of causative drug, the time of administration, and its dosage. Proven systemic risk factors like anemia, uncontrolled diabetes, corticosteroid therapy, and chemotherapy in neoplastic diseases (e.g., high doses of methotrexate up to 30 mg daily) significantly increase the chances of acquiring MRONJ. The risk factors themselves can affect treatment outcomes. Although the main scientific societies have recently disseminated good practice rules on the patient's prevention, diagnosis, and management, there are still no guidelines on shared therapeutic strategies. In general, if conservative treatment fails, surgical treatment is considered, including local debridement, osteoplasty, and marginal or segmental osteotomy. In literature, cohorts of heterogeneous patients with MRONJ have been analyzed for a long time, resulting in a lack of uniformity of information and difficulties interpreting the data. According to the American Association of Oral and Maxillofacial Surgeons criteria, this retrospective study evaluates the surgical treatment outcomes of 64 patients with stage II-III MRONJ, evaluated at the Department of Maxillofacial Surgery of the University of Turin (Italy). The first objective of this retrospective study is to evaluate treatment results for stages II-III in all cases; the second objective is to evaluate the same results by dividing the sample into different cohorts of patients: first, based on the underlying pathology, i.e., oncological and non oncological, and secondly, based on the drug or combination of drugs they took.

Bevacizumab-associated implant presence-triggered osteonecrosis: A case report and literature review

The effect of bevacizumab-related osteonecrosis of the jaw on previously osseointegrated dental implants has not been adequately studied. Here, we report a case of osteonecrosis of the jaw detected around dental implants placed prior to bevacizumab therapy. A 66-year-old woman undergoing bevacizumab therapy for metastatic triple-negative breast cancer, developed malocclusion following buccal gingival swelling and pain in the #18, #19, and #20 tooth region. The patient visited a local dental clinic, where existing implants in relation to #19 and #20 were removed. Subsequently, the patient visited our department, and intraoral examination revealed necrotic bone in the region corresponding to #19 and #20. Radiographic examination showed a pathological fracture in this region that was considered to result from osteonecrosis of the jaw. Bevacizumab therapy was suspended temporarily till the acute inflammation had subsided. In addition, treatment with antibacterial agents and conservative surgery was considered. Complete soft tissue coverage was observed 14 days following surgery. In recent years, the number of patients receiving bevacizumab treatment has increased. Since bevacizumab-related osteonecrosis of the jaw could occur around previously osseointegrated dental implants as well, this case report suggests an effective treatment regimen based on a combination of antibacterial agents and conservative surgery.

Orthodontic retention: what's on the horizon?

Orthodontic retention remains one of the great challenges in orthodontics. In this article, we discuss what is on the horizon to help address this challenge, including biological approaches to reduce relapse, treating patients without using retainers, technological developments, personalised medicine and the impact of COVID-19 on approaches to orthodontic retention.

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.

Preventing or controlling periodontitis reduces the occurrence of osteonecrosis of the jaw (ONJ) in rice rats (Oryzomys palustris)

INTRODUCTION

Osteonecrosis of the jaw (ONJ) is an adverse event that requires association of both systemic risk factors, such as powerful anti-resorptives (pARs; e.g. zoledronic acid [ZOL]), and local oral risk factors (e.g. tooth extraction, periodontitis). Whereas optimal oral health prior to initiate pARs is recognized as critically important for minimizing ONJ risk, the efficacy of preventive/maintenance measures in patients who are taking pARs is understudied. Rice rats fed a standard diet (STD), rich in insoluble fiber, develop localized periodontitis. STD-rats with localized periodontitis treated with ZOL for 18-24 wk develop ONJ. Hence, we hypothesized that controlling/preventing localized periodontitis in the ZOL-treated rats, reduces ONJ occurrence.

METHODS

We used two approaches to attempt reducing periodontitis prevalence: 1) periodontal cleaning (PC); and 2) replacing the STD-diet with a nutritionally-equivalent diet high in soluble fiber (SF). 75 four-week-old male rats were weight-randomized into five groups (n = 15) in a 24-week experiment. Three groups ate the STD-diet and two the high SF-diet. STD-diet groups received intravenous (IV) vehicle (VEH) q4wks (STD + VEH), 80 μg/kg ZOL q4wks IV (STD + ZOL), or ZOL plus PC q2wks (STD + ZOL + PC). The SF-diet groups received VEH (SF + VEH) or ZOL (SF + ZOL). Jaws were processed for histopathology and evaluated for ONJ prevalence and tissue-level periodontitis.

RESULTS

1) 40% of STD + VEH rats developed maxillary localized periodontitis with no ONJ; 2) 50% of STD + ZOL rats developed ONJ; 3) 7% of STD + ZOL + PC rats developed ONJ (p < 0.01 vs. STD + ZOL); and 4) one SF + ZOL rat developed localized periodontitis, and no SF + VEH or SF + ZOL rats developed ONJ (p < 0.001 vs. STD + ZOL).

CONCLUSIONS

1) Periodontal cleaning in ZOL-treated rats decreases localized periodontitis severity and reduces ONJ prevalence; and 2) feeding a SF-diet to ZOL-treated rats reduces both incidence of localized periodontitis and ONJ. Our data indicates strong oral microbial community shifts according to oral health condition and trends in the shifts associated with diet.

Schemes for Drug-Induced Treatment of Osteonecrosis of Jaws with Particular Emphasis on the Influence of Vitamin D on Therapeutic Effects

Drugs that inhibit bone resorption are prescribed most often by orthopedists, hematologists, or oncologists. Dental practice rarely draws attention to their importance and the effects they carry. The problem concerns mainly older people owing to oncological problems or postmenopausal consequences, but everyone can be at risk. Carefully conducted interviews and analysis of history and disease should always be performed before any action is taken by patients taking this type of medicine. Further action should consider possible complications and, above all, the risk of their occurrence. In this article, the most important issues related to the treatment of drug-induced osteonecrosis of the jaws (ONJ) are raised, including medication-related osteonecrosis of the jaw (MRONJ); conservative treatment, including the use of laser; and the impact of vitamin D supplementation on the overall treatment, prognosis, and prevention before complication, which is osteonecrosis of the jaw in the course of treatment with bisphosphonates and other drugs predisposing to MRONJ, such as denosumab and angiogenesis inhibitors. The degree of osteonecrosis is also critical, as it is possible to avoid surgical procedures for only conservative methods that sometimes bring good results. Surgical treatment of advanced stages is complicated and carries a high risk of error and complications. MRONJ is a disease that is easy to avoid, but it is difficult to treat and treatment sometimes leads only to a partial remission of the disease, not a complete cure.

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.

Comprehensive Study of the Risk Factors for Medication-Related Osteonecrosis of the Jaw Based on the Japanese Adverse Drug Event Report Database

Medication-related osteonecrosis of the jaw (MRONJ) is associated with many drugs, including bisphosphonates (BPs). BPs are associated with atypical femoral fractures and osteonecrosis of the external auditory canal. Thus, many drugs are reported to cause adverse effects on bone. This study aimed to investigate the effects of drugs and patient backgrounds regarding osteonecrosis-related side effects, including MRONJ. This study used a large voluntary reporting database, namely, the Japanese Adverse Drug Event Report database. First, we searched for risk factors related to MRONJ using volcano plots and logistic regression analysis. Next, we searched for bone-necrosis-related side effects using principal component and cluster analysis. Factors that were significantly associated with MRONJ included eight types of BPs and denosumab, prednisolone, sunitinib, eldecalcitol, raloxifene, letrozole, doxifluridine, exemestane, radium chloride, medroxyprogesterone, female, elderly, and short stature. Furthermore, antiresorptive agents (i.e., BPs and denosumab) tended to induce MRONJ and atypical femoral fractures by affecting osteoclasts. We believe these findings will help medical personnel manage the side effects of many medications.

Medication-related osteonecrosis of the jaw: Analysing the range of implicated drugs from the Australian database of adverse event notifications

AIMS

Medication-related osteonecrosis of the jaw (MRONJ) is an uncommon but potentially debilitating condition, characterised by nonhealing jawbone, with or without mucosal exposure, in the presence of certain drugs. Those already strongly associated with MRONJ include antiresorptives denosumab and bisphosphonates; however, a growing range of other non-antiresorptive drugs is implicated. The aim of this study was to analyse all case reports of MRONJ submitted to the publicly available Database of Adverse Event Notification from the Therapeutic Goods Administration in Australia.

METHODS

The Therapeutic Goods Administration was contacted on 6 January 2020 and asked for all reports containing the words "osteonecrosis of the jaw". This was provided in a spreadsheet of de-identified reports received from commencement of the database in 1971 until 1 October 2019.

RESULTS

The drugs implicated in the 419 cases were divided by established drugs with MRONJ and secondary drugs that possibly contribute to MRONJ development. While the majority of cases were associated with denosumab or bisphosphonates (n = 405), there were 14 reports where secondary agents that directly or indirectly affect bone turnover, were also implicated. Some of these secondary drugs, including adalimumab, etanercept, methotrexate and rituximab have previously been associated with MRONJ in published case reports.

CONCLUSIONS

This study contributes to the sparse but growing literature associating an increasing number of drugs with MRONJ, and underscores the importance of considering all possible drugs that elevate a patient's MRONJ risk.

Osteonecrosis of the jaw induced by treatment with anti-PD-1 immunotherapy: a case report

Recognizing rare but clinically significant toxicity of immunotherapy is critical. Here we describe the first detailed case of severe osteonecrosis of the jaw due to anti-PD-1. A 75-year-old man with metastatic melanoma, with no prior radiation or treatment with bone-targeting agents, experienced jaw pain 1 week after his first dose of nivolumab. Imaging studies were negative, and treatment was resumed after pain was controlled. 4 months later, the patient experienced acute exacerbation of pain and malocclusion of the jaw. Imaging showed bilateral fractures of the angle of mandible with extensive disruption of the normal trabecular architecture, requiring total mandibulectomy. The patient's metastatic melanoma responded to treatment and remains controlled >20 months after treatment cessation without further therapy.

Combined Administration of Bisphosphonates, Chemotherapeutic Agents, and/or Targeted Drugs Increases the Risk for Stage 3 Medication-Related Osteonecrosis of the Jaw: A 4-Year Retrospective Study

Objectives

Patients with stage 3 medication-related osteonecrosis of the jaw (MRONJ) suffer from severe complications. Chemotherapeutic agents and targeted drugs are considered to be associated with the development of MRONJ. However, little is known regarding the association of those agents with stage 3 MRONJ. The purpose of this study is to analyze the comprehensive medication history of patients with advanced-stage MRONJ (stage 2 and stage 3) and evaluate the possible risk factors for stage 3 MRONJ. Patients and Methods. Sixty patients with advanced-stage MRONJ were involved in this retrospective study. Patients with developmental maxillofacial anomalies, previous radiation in the head and neck areas, and jaw bone tumors were excluded from the study. All patients were divided into two groups by their MRONJ stage (stage 2 or stage 3). Demographic and clinical characteristics, comprehensive medication data (bisphosphonates, chemotherapeutic agents, targeted drugs, and immunosuppressive agents), and results of serological biomarkers were recorded and compared between two groups. Univariate and multivariate logistic regressions were performed by SPSS 25.0 for evaluating risk factors of stage 3 MRONJ.

Results

Our results indicate that chemotherapy (adjusted OR = 3.43; 95% CI: 1.03 to 11.38), targeted drugs (adjusted OR = 3.69; 95% CI: 1.06 to 12.80), and maxillary lesions (adjusted OR = 4.26; 95% CI: 1.19 to 15.23) increase the risk of stage 3 MRONJ.

Conclusion

The outcome of this study justifies that chemotherapeutic agents and targeted drugs are probably risk factors for stage 3 MRONJ. In addition, the osteonecrosis in maxilla is more easily to develop into stage 3 MRONJ. Intense clinical observation is recommended in MRONJ patients with maxillary osteonecrosis and in those who concurrently administered bisphosphonates, chemotherapeutic agents, and/or targeted drugs. This trial is registered with ChiCTR2000032428.

Delayed Healing of Tooth Extraction Sockets with Ramucirumab Use

Objective

An angiogenesis inhibitor can cause medication-related osteonecrosis of the jaw (MRONJ). To our knowledge, there has been no report that an angiogenesis inhibitor causes delayed healing of tooth extraction socket. Here, we describe a case of delayed healing of tooth extraction sockets associated with an angiogenesis inhibitor, ramucirumab, which showed characteristics similar to MRONJ.

Materials and Methods

A 76-year-old male patient, who was diagnosed with gastric cancer with liver metastasis, received tooth extraction twice during continuous chemotherapy comprising paclitaxel and ramucirumab.

Results

The first extraction was performed 30 days after ramucirumab discontinuation without complication. The second extraction was conducted without ramucirumab discontinuation. Although tooth socket healing was finally achieved, it took about 150 days. Discussion. This case was considered to be delayed healing of dry sockets rather than MRONJ due to ramucirumab. Dentists and oral surgeons need to be aware that angiogenesis inhibitors can cause not only MRONJ but also dry sockets after tooth extraction.

Osteonecrosis of the jaw associated with imatinib therapy in myeloproliferative neoplasm: a rare case report

Medication-related osteonecrosis of the jaw (MRONJ) is a relatively infrequent but very well-known adverse effect of bisphosphonates. This rare complication of bisphosphonates is rarest with the use of certain drugs. Tyrosine kinase inhibitors (TKIs), particularly used in renal cell carcinoma or gastrointestinal tumors as a chemotherapeutic agent, can precipitate this particular medical condition of bone when it is associated with either radiation or bisphosphonates, though, monodrug therapy with TKIs rarely causes MRONJ. This article describes a rare case of necrosis of the jawbone in a patient with a myeloproliferative neoplasm who was receiving the TKI imatinib and had no history of bisphosphonate or radiation therapy to head and neck region.

Retrospective analysis of bacterial colonization of necrotic bone and antibiotic resistance in 98 patients with medication-related osteonecrosis of the jaw (MRONJ)

OBJECTIVES

The aim of our study was to describe microbial flora associated with MRONJ and characterize the susceptibility of pathogens to help guide an effective empiric antibiotic treatment in these patients.

MATERIALS AND METHODS

A retrospective, single-center analysis was performed, using 116 bone samples from 98 patients. The bone samples were homogenized and subjected to routine culture methods. Growing bacteria were differentiated to the species level using whole-cell mass spectrometry and subjected to susceptibility testing.

RESULTS

A highly diverse microbial flora was detected in necrotic bone, with a simultaneous presence of two or more bacterial species in 79% of all patients. In at least 65% of samples, gram-negative isolates were detected. Therefore, bacterial species resistant against β-lactamase inhibitors were present in at least 70% of all patients.

CONCLUSIONS

The empiric choice of antibiotics in MRONJ patients should consider the high rate of gram-negative bacteria and resistance against β-lactam antibiotics.

CLINICAL RELEVANCE

According to recent guidelines and recommendations, systemic antibiotic treatment is a key component in the treatment of all stage 2 and 3 MRONJ patients. We recommend using fluoroquinolones for empiric treatment and emphasize the use of bacterial cultivation and susceptibility testing to enable an effective antibiotic treatment.

Fractal dimension in CBCT images as predictor for MRONJ: a retrospective cohort study

Objective

To estimate boxcounting fractal dimension in a standardized approach in CBCT images of the mandible and maxilla in a group of patients with MRONJ in comparison to a healthy control group.

Material and methods

From our records, a study group consisting of 80 maxillary and mandibular CBCTs in 77 cases of patients having MRONJ was collected. The control group consisted of 84 mandibular and maxillary CBCTs in a total of 78 patients. Using the boxcounting method, fractal dimension (FD) was estimated in a standardized fashion either cranially to the apex of the canine (maxilla) or beneath the tooth apices of the lower molars in the bone area above the mandibular canal (mandible). Intra-observer reproducibility of the FD-measurements was assessed by 6 repeated measurements in 10 individuals. FD values were correlated to age and sex of the individuals as well as to region of interest (ROI) sizes.

Results

FD in the study group (1.684 ± 0.051) was roughly 3.5 % lower than in the control group (1.745 ± 0.026, p < 0.0001). Sex and age had a significant (p < 0.001) influence on FD values in the study group, yet not in the control group. FD values increased with age (study group, spearman-rho: 0.2895, p < 0.05) and also ROI size (both groups, p < 0.0001). Reproducibility was good (intra-class correlation coefficient (ICC): 0.87).

Conclusions

Fractal dimension as assessed by boxcounting seems to be a good descriptor for MRONJ in jaw bones. Influence of age and sex on the outcome values needs to be further investigated in future studies.

Clinical relevance

CBCTs could be assessed with respect to FD to obtain an overview of the disease status of MRONJ patients.

Medication-related osteonecrosis of the jaws associated with intravitreal administration of ranibizumab

Medication-related osteonecrosis of the jaws (MRONJ) is a well-known complication that, in the majority of cases, is related to antiresorptive agents. Numerous articles have described cases of MRONJ in bisphosphonate-naïve patients treated with anti-angiogenic agents administered via various routes. A single case of MRONJ after intravitreal injection of bevacizumab has been reported. We report a case of MRONJ after intravitreal injection of a different anti-angiogenic agent - ranibizumab - for the treatment of neovascular age-related macular degeneration, in a bisphosphonate-naïve patient. Although it may be a rare complication, patients treated with multiple doses of anti-angiogenic agents should be monitored for the possible early diagnosis of MRONJ.

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.

Review and update on drugs related to the development of osteonecrosis of the jaw

Background

Medication-related osteonecrosis of the jaw (MRONJ) is a rare, but serious adverse effect of certain drugs, of which bisphosphonates are the most widely known. This pathology is also associated with other medications such as the biologic antiresorptive agent, denosumab and some antiangiogenics such as sunitinib, bevacizumab or aflibercept. Very recently, new medications have also been associated with osteonecrosis of the jaw (ONJ). The objectives were to update the list of medications associated with ONJ, to analyze the fundamental aspects of this list and to describe the level of evidence available.

Material and Methods

A narrative bibliographic review was made, using the PubMed-MedLine, DOAJ and SCIELO databases. Additional information was obtained through the online Medication Information Centre of the Spanish Agency of Medicines and Medical Devices (AEMPS – CIMA), the websites of the US Food & Drugs Administration (Drugs@FDA) and the European Medicines Agency (EMA).

Results

The latest drugs identified as potential facilitators of this pathology include a number of anti-VEGF based antiangiogenic drugs and anti-TKI and different types of immunomodulators. Neither the level of evidence in this association nor the risk are equal for all these drugs. On the other hand, over the coming years, new drugs will be marketed with similar action mechanisms to those that are recognized as having this adverse effect.

Conclusions

No effective therapy is currently known for the treatment of ONJ. Therefore, in order to prevent new cases of MRONJ, it is essential for all oral healthcare professionals to be fully up-to-date with the etiopathogenic aspects of this pathology and to be aware of those drugs considered to be a risk.

Key words:Osteonecrosis of the jaw, MRONJ, bisphosphonates, antiresorptives, antiangiogenics.

From Osteoclast Differentiation to Osteonecrosis of the Jaw: Molecular and Clinical Insights

Bone physiology relies on the delicate balance between resorption and formation of its tissue. Bone resorption depends on a process called osteoclastogenesis in which bone-resorbing cells, i.e., osteoclasts, are produced by the differentiation of more undifferentiated progenitors and precursors. This process is governed by two main factors, monocyte-colony stimulating factor (M-CSF) and receptor activator of NFκB ligand (RANKL). While the former exerts a proliferating effect on progenitors/precursors, the latter triggers a differentiation effect on more mature cells of the same lineage. Bone homeostasis requires a perfect space–time coordination of the involved signals. When osteoclastogenesis is poorly balanced with the differentiation of the bone forming counterparts, i.e., osteoblasts, physiological bone remodelling can turn into a pathological state, causing the systematic disruption of bone tissue which results in osteopenia or osteolysis. Examples of these conditions are represented by osteoporosis, Paget’s disease, bone metastasis, and multiple myeloma. Therefore, drugs targeting osteoclastogenesis, such as bisphosphonates and an anti-RANKL monoclonal antibody, have been developed and are currently used in the treatment of such diseases. Despite their demonstrated therapeutic efficacy, these agents are unfortunately not devoid of side effects. In this regard, a condition called osteonecrosis of the jaw (ONJ) has been recently correlated with anti-resorptive therapy. In this review we will address the involvement of osteoclasts and osteoclast-related factors in the pathogenesis of ONJ. It is to be hoped that a better understanding of the biological mechanisms underlying bone remodelling will help in the design a medical therapeutic approach for ONJ as an alternative to surgical procedures.

Osteonecrosis of the jaw related to non-antiresorptive medications: a systematic review

INTRODUCTION

The reporting of osteonecrosis of the jaw (ONJ) related to anticancer agents without known antiresorptive properties (non-antiresorptives), such as antiangiogenics, tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, immune checkpoint inhibitors, and cytotoxic chemotherapy is increasing.

OBJECTIVE

To review characteristics of ONJ in cancer patients receiving non-antiresorptives.

METHODS

A systematic review of the literature between 2009 and 2017 was conducted by the Bone Study Group of MASCC/ISOO.

RESULTS

Of 6249 articles reviewed and from personal communication, 42 ONJ cases related to non-antiresorptives were identified. No gender predilection was noted. Median age was 60 years and ONJ stage 2 was most common, with predilection for posterior mandible. Exposed bone, pain, and infection were common at diagnosis. In comparison to bone targeting agents (BTAs), radiology, histology, and management were similar, with medication often discontinued. Delayed diagnosis (median 8 weeks) was noted. Important differences included earlier time to ONJ onset (median 20 weeks), absence of trigger event (40%), and greater likelihood of healing and shorter healing time (median 8 weeks) as compared to BTA-related ONJ. Gastrointestinal cancers predominated, followed by renal cell carcinomas compared to breast, followed by prostate cancers in BTA-related ONJ, reflecting different medications.

CONCLUSIONS

Data about non-antiresorptive-related ONJ is sparse. This type of ONJ may have better prognosis compared to the BTA-related ONJ, suggested by greater likelihood of healing and shorter healing time. However, the delay in diagnosis highlights the need for more education. This is the first attempt to characterize ONJ associated with different non-antiresorptives, including BRAF and immune checkpoint inhibitors.

Medication-related osteonecrosis of the jaw: definition and best practice for prevention, diagnosis, and treatment

Skeletal complications caused by osteoporosis or bone metastases are associated with considerable pain, increased mortality, and reduced quality of life. Furthermore, such events place a burden on health care resources. Agents that prevent bone resorption, such as bisphosphonates or denosumab, can reduce the risk of skeletal-related events and are widely used in patients with osteoporosis or bone metastases of cancer. Medication-related osteonecrosis of the jaw (MRONJ) is a rare, but potentially serious, adverse event associated with high cumulative doses of bisphosphonates or denosumab. However, MRONJ can be treated, and the likelihood of the development of this condition can be reduced through prophylactic dental care and the maintenance of good oral hygiene. Dentists, as part of a multiprofessional team, have a critical role in preventing MRONJ. This review describes the incidence and pathophysiology of MRONJ and provides guidance for dental practitioners with regard to the screening, prophylactic treatment, diagnosis, and management of patients with this condition.