The Case of Medication-Related Osteonecrosis of the Jaw Addressed from a Pathogenic Point of View. Innovative Therapeutic Strategies: Focus on the Most Recent Discoveries on Oral Mesenchymal Stem Cell-Derived Exosomes

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

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

A Review of Novel Strategies for Human Periodontal Ligament Stem Cell Ex Vivo Expansion: Are They an Evidence-Based Promise for Regenerative Periodontal Therapy?

Periodontitis is a gingiva disease sustained by microbially associated and host-mediated inflammation that results in the loss of the connective periodontal tissues, including periodontal ligament and alveolar bone. Symptoms include swollen gingiva, tooth loss and, ultimately, ineffective mastication. Clinicians utilize regenerative techniques to rebuild and recover damaged periodontal tissues, especially in advanced periodontitis. Human periodontal ligament stem cells (hPDLSCs) are considered an appealing source of stem cells for regenerative therapy in periodontium. hPDLSCs manifest the main properties of mesenchymal stem cells, including the ability to self-renew and to differentiate in mesodermal cells. Significant progress has been made for clinical application of hPDLSCs; nevertheless, some problems remain, including the small number of cells isolated from each sample. In recent decades, hPDLSC ex vivo expansion and differentiation have been improved by modifying cell culture conditions, especially with the supplementation of cytokines' or growth factors' mix, chemicals, and natural compounds, or by using the decellularized extracellular matrix. Here, we analyzed the changes in stemness properties and differentiation potential of hPDLSCs when culturing in alternative media. In addition, we focused on the possibility of replacing FBS with human emoderivates to minimize the risks of xenoimmunization or zoonotic transmission when cells are expanded for therapeutic purposes.

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.

Multiple-Drugs-Related Osteonecrosis of the Jaw in a Patient Affected by Multiple Myeloma: A Case Report

A 60-year-old woman suffering from multiple myeloma (MM) was treated with zoledronic acid (bisphosphonate), dexamethasone (corticosteroid), bortezomib (a chemotherapeutic agent), and lenalidomide (thalidomide analog) for about a year and with lenalidomide alone as maintenance therapy for almost two years and developed stage three medication-related osteonecrosis of the jaws (MRONJ) in the upper left dental arch approximately two weeks after tooth extraction, which was treated with a medical nonoperative conservative approach until reversion to stage one. The present case report describing the development of multi-drug-related osteonecrosis of the jaws during the pharmacologic MM maintenance phase draws attention to the complex multidisciplinary and multistage management of MM subjects and also that during disease remission, crucially involving oral healthcare providers for MRONJ prevention and pharmacovigilance. To prevent similar cases, cancer patient management should ensure proper dental care not only before starting but also throughout therapy duration and ensure continuous interdisciplinary consensus between oncologists and dentists. Moreover, also considering the independent negative and potentially synergistic effect on bone metabolism and mucosal healing processes of employed medicaments, additionally combined with the cumulative one of previous intravenous bisphosphonates, further studies should highlight the polypharmacy effect and hopefully aid in patient-specific MRONJ risk assessment in cancer patients.

Medication-Related Osteonecrosis of the Jaws (MRONJ) in Children and Young Patients-A Systematic Review

Medication-related osteonecrosis of the jaw (MRONJ) is defined by the American Association of Oral and Maxillofacial Surgeons (AAOMS) as the presence of an exposed bone area in the maxillofacial region, present for more than eight weeks in patients treated with the use of antiresorptive or antiangiogenic agents, with no history of radiation or metastatic disease. Bisphosphonates (BF) and denosumab (DS) are widely used in adults for the management of patients with cancer and osteoporosis, and recently there has been an increase in their use in child and young patients for the management of disorders such as osteogenesis imperfecta (OI), glucocorticoid-induced osteoporosis, McCune-Albright syndrome (MAS), malignant hypercalcemia, and others. There are differences between case reports in adults compared to child and young patients related to the use of antiresorptive/antiangiogenic drugs and the development of MRONJ. The aim was to analyze the presence of MRONJ in children and young patients, and the relation with oral surgery. A systematic review, following the PRISMA search matrix based on the PICO question, was conducted in PubMed, Embase, ScienceDirect, Cochrane, Google Scholar, and manual search in high-impact journals between 1960 and 2022, publications in English or Spanish, including randomized and non-randomized clinical trials, prospective and retrospective cohort studies, cases and controls studies, and series and case reports. A total of 2792 articles were identified and 29 were included; all of them published between 2007 and 2022, identifying 1192 patients, 39.68% male and 36.24% female, aged 11.56 years old on average, using these drugs mainly for OI (60.15%); 4.21 years on average was the therapy time and 10.18 drug doses administered on average; oral surgery was observed in 216 subjects, reporting 14 cases of MRONJ. We concluded that there is a low presence of MRONJ in the child and youth population treated with antiresorptive drugs. Data collection is weak, and details of therapy are not clear in some cases. Deficiencies in protocols and pharmacological characterization were observed in most of the included articles.

Change in Bone Mineral Density in Stroke Patients with Osteoporosis or Osteopenia

We aimed to investigate the correlation between changes in bone mineral density (BMD) of the lumbar spine (LS) and femoral neck (FN) and osteoporosis-related factors in stroke patients with osteoporosis or osteopenia, and we suggest the need for active rehabilitation treatment. This study included 63 osteoporosis and 34 osteopenia patients who underwent a BMD test following primary stroke onset. The osteoporosis group was followed up with a BMD test after 12 months of bisphosphonate treatment, and the osteopenia group was followed up without medication. The correlation between BMD changes and functional factors was analyzed, biochemical markers were measured, and hematology tests were performed. In the osteoporosis group, a significant increase was observed in LS BMD (p < 0.05), and in the osteopenia group, there was a significant decrease in FN BMD (p < 0.05). The group with a functional ambulatory category of 1 or more showed a significant improvement in BMD (p < 0.05). Comparative analysis was performed on various indicators, but no significant correlation was found between any variable. In stroke patients with osteoporosis or osteopenia, early appropriate drug treatment is important to prevent bone loss and reduce the risk of fractures, and comprehensive rehabilitation treatment, such as appropriate education and training to prevent falls, is essential.

Retrospective Analysis of Treatment Outcomes of Maxillary Sinusitis Associated with Medication-Related Osteonecrosis of the Jaw

Although maxillary sinusitis often occurs in patients with medication-related osteonecrosis of the jaw (MRONJ) of the upper jaw, there have been few reports on the treatment and outcomes for maxillary sinusitis associated with maxillary MRONJ. This study aimed to retrospectively investigate the treatment outcomes of maxillary sinusitis in patients with MRONJ of the upper jaw. There were 34 patients diagnosed with maxillary MRONJ and sinusitis by preoperative computed tomography who underwent surgery in our institution between January 2011 and December 2019. Age, sex, primary disease, stage of MRONJ, class and administration period of an antiresorptive agent, corticosteroid administration, preoperative leukocyte count and serum albumin level, periosteal reaction, sinusitis grade, maxillary sinus surgical procedure, and treatment outcomes of MRONJ and sinusitis were examined. There were 7 male and 27 female patients (average age, 74.7 years). Complete healing of MRONJ was obtained in 29 of 34 patients (85.3%). Maxillary sinusitis resolved or improved in 21 patients (61.8%) but did not change or worsen in 13 patients (38.2%). We found that complete resection of necrotic bone with intraoperative irrigation of the maxillary sinus may provide good treatment outcomes for maxillary sinusitis associated with MRONJ, although our findings were not statistically significant owing to the small number of patients.

Medication-Related Osteonecrosis of the Mandible Treated with Marginal Resection: A Case Report

The aim of this report is to present a successful combined surgical and pharmaceutical treatment in the highest stage of medicine-related osteonecrosis of the jaw (MRONJ). A 70-year-old man treated for metastatic prostate cancer concomitant with hypertension and diabetes presented due to the exposure of the jawbone. Initial imaging studies suggested MRONJ, and the biopsy did not confirm bone metastasis in the oral cavity. Marginal resection of the mandible was performed after the administration of antibiotics and anticoagulants. There was no recurrence of mandibular necrosis during the 3-year follow-up. MRONJ can develop covertly, with scanty clinical symptoms, and can be easily overlooked. Radical combined treatment may, in some cases, prevent further progression of the disease, which was successful in this case.

Quantification of Low Amounts of Zoledronic Acid by HPLC-ESI-MS Analysis: Method Development and Validation

Zoledronic acid (ZA) is used in the treatment of various bone pathologies, but it forms complexes with calcium ions present in body fluids, decreasing ZA bioavailability. Thereby, the study first describes the identification of ZA-calcium complexes that form in calcium-rich environments, in order to establish the bioavailable ZA concentration. Then, a new method for quantification of low ZA amounts in milieus that mimics in vivo conditions by using simulated body fluid and calcium sulfate hemihydrate was described. Almost all analytical methods of ZA quantification described in the literature require compound derivatization. At very low concentrations, derivatization is prone to analyte loss, therefore compromising the analytical results. In our study, we avoided ZA derivatization by using a high-performance liquid chromatography and electrospray ionization mass spectrometry (HPLC-ESI-MS) system, conducting the investigation based on the fragmentation mass extracted ion chromatograms specific to the ZA protonated form. The method was validated by selectivity, precision, accuracy, linearity, signal to noise ratio, and limit of detection and limit of quantification calculation. Experimentally, this method can detect ranges of 0.1–0.5 ng/mL and precisely quantify ZA concentrations as low as 0.1 ng/mL. This method could provide the basis for quantifying low amounts of ZA in the blood during long-term administration.

Targeting of Mevalonate-Isoprenoid Pathway in Acute Myeloid Leukemia Cells by Bisphosphonate Drugs

Metabolic reprogramming represents a hallmark of tumorigenesis to sustain survival in harsh conditions, rapid growth and metastasis in order to resist to cancer therapies. These metabolic alterations involve glucose metabolism, known as the Warburg effect, increased glutaminolysis and enhanced amino acid and lipid metabolism, especially the cholesterol biosynthesis pathway known as the mevalonate pathway and these are upregulated in several cancer types, including acute myeloid leukemia (AML). In particular, it was demonstrated that the mevalonate pathway has a pivotal role in cellular transformation. Therefore, targeting this biochemical process with drugs such as statins represents a promising therapeutic strategy to be combined with other anticancer treatments. In the last decade, several studies have revealed that amino-bisphosphonates (BP), primarily used for bone fragility disorders, also exhibit potential anti-cancer activity in leukemic cells, as well as in patients with symptomatic multiple myeloma. Indeed, these compounds inhibit the farnesyl pyrophosphate synthase, a key enzyme in the mevalonate pathway, reducing isoprenoid formation of farnesyl pyrophosphate and geranylgeranyl pyrophosphate. This, in turn, inhibits the prenylation of small Guanosine Triphosphate-binding proteins, such as Ras, Rho, Rac, Rab, which are essential for regulating cell survival membrane ruffling and trafficking, interfering with cancer key signaling events involved in clonal expansion and maturation block of progenitor cells in myeloid hematological malignancies. Thus, in this review, we discuss the recent advancements about bisphosphonates’ effects, especially zoledronate, analyzing the biochemical mechanisms and anti-tumor effects on AML model systems. Future studies will be oriented to investigate the clinical relevance and significance of BP treatment in AML, representing an attractive therapeutic strategy that could be integrated into chemotherapy.

Mesenchymal Stem Cells Based Treatment in Dental Medicine: A Narrative Review

Application of mesenchymal stem cells (MSC) in regenerative therapeutic procedures is becoming an increasingly important topic in medicine. Since the first isolation of dental tissue-derived MSC, there has been an intense investigation on the characteristics and potentials of these cells in regenerative dentistry. Their multidifferentiation potential, self-renewal capacity, and easy accessibility give them a key role in stem cell-based therapy. So far, several different dental stem cell types have been discovered and their potential usage is found in most of the major dental medicine branches. These cells are also researched in multiple fields of medicine for the treatment of degenerative and inflammatory diseases. In this review, we summarized dental MSC sources and analyzed their treatment modalities with particular emphasis on temporomandibular joint osteoarthritis (TMJ OA).

Non-Interventional Prospective Observational Study of Platelet Rich Fibrin as a Therapy Adjunctive in Patients with Medication-Related Osteonecrosis of the Jaw

BACKGROUND

Medication-related osteonecrosis (MRONJ) of the jaw is a severe and feared side effect of antiresorptive therapy in the oncological setting. With growing evidence that impaired angiogenesis may represent a key factor in pathogenesis, the aim of this study was to evaluate an autologous platelet concentrate as a possible additive in surgical therapy to optimize vascularization and, subsequently, resolution rates.

MATERIAL AND METHODS

A non-interventional, prospective, multicenter study was conducted, and all patients with stage I-III MRONJ, undergoing antiresorptive therapy for an oncological indication, were included. The necrosis was treated surgically without (study arm A) or with (arm B) the addition of an autologous platelet concentrate (platelet-rich fibrin, PRF).

RESULTS

After 5, 14, and 42 days postoperative, wound healing (primary outcome: mucosal integrity) as well as downstaging, pain perception, and oral health-related quality of life (secondary outcome) were assessed via clinical evaluation. Among the 52 patients included, primarily with MRONJ stage I and II, the use of PRF as an additive in surgical therapy did not display a significant advantage for wound healing (p = 0.302), downstaging (p = 0.9), pain reduction (p = 0.169), or quality of life (p = 0.9).

SUMMARY

In conclusion, PRF as an adjunct did not significantly optimize wound healing. Further, no significant changes in terms of downstaging, pain sensation, and oral health-related quality of life were found.

Osteonecrosis of the Jaws in Patients with Hereditary Thrombophilia/Hypofibrinolysis-From Pathophysiology to Therapeutic Implications

Osteonecrosis of the jaws (ONJ) usually has a clear etiology. Local infection or trauma, radiotherapy and drugs that disrupt the vascular supply or bone turnover in the jaws are its major contributors. The thrombotic occlusion of the bone's venous outflow that occurs in individuals with hereditary thrombophilia and/or hypofibrinolysis has a less known impact on jaw health and healing capability. Our research provides the most comprehensive, up-to-date and systematized information on the prevalence and significance of hereditary thrombophilia and/or hypofibrinolysis states in ONJ. We found that hereditary prothrombotic abnormalities are common in patients with ONJ refractory to conventional medical and dental treatments. Thrombophilia traits usually coexist with hypofibrinolysis traits. We also found that frequently acquired prothrombotic abnormalities coexist with hereditary ones and enhance their negative effect on the bone. Therefore, we recommend a personalized therapeutic approach that addresses, in particular, the modifiable risk factors of ONJ. Patients will have clear benefits, as they will be relieved of persistent pain and repeated dental procedures.

Denosumab and invasive cervical root resorption: a case report

This case report describes an adverse side-effect from long-term denosumab therapy in a patient with metastatic breast cancer. The patient presented with extensive external root resorption affecting most of her dentition. There were no other identified risk factors. As the treatment of breast cancer evolves leading to improved survival, and the number of cancer survivors increases, it is expected that dental practitioners will see a growing number of patients who are on long-term denosumab. Comprehensive dental examinations including radiographs, are warranted to identify unusual or unexpected findings such as invasive cervical root resorption. © 2022 Australian Dental Association.

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

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

Human Periodontal Ligament Stem Cells Response to Titanium Implant Surface: Extracellular Matrix Deposition

The major challenge for dentistry is to provide the patient an oral rehabilitation to maintain healthy bone conditions in order to reduce the time for loading protocols. Advancement in implant surface design is necessary to favour and promote the osseointegration process. The surface features of titanium dental implant can promote a relevant influence on the morphology and differentiation ability of mesenchymal stem cells, induction of the osteoblastic genes expression and the release of extracellular matrix (ECM) components. The present study aimed at evaluating the in vitro effects of two different dental implants with titanium surfaces, TEST and CTRL, to culture the human periodontal ligament stem cells (hPDLSCs). Expression of ECM components such as Vimentin, Fibronectin, N-cadherin, Laminin, Focal Adhesion Kinase (FAK) and Integrin beta-1 (ITGB1), and the osteogenic related markers, as runt related transcription factor 2 (RUNX2) and alkaline phosphatase (ALP), were investigated. Human PDLSCs cultured on the TEST implant surface demonstrated a better cell adhesion capability as observed by Scanning Electron Microscopy (SEM) and immunofluorescence analysis. Moreover, immunofluorescence and Western blot experiments showed an over expression of Fibronectin, Laminin, N-cadherin and RUNX2 in hPDLSCs seeded on TEST implant surface. The gene expression study by RT-PCR validated the results obtained in protein assays and exhibited the expression of RUNX2, ALP, Vimentin (VIM), Fibronectin (FN1), N-cadherin (CDH2), Laminin (LAMB1), FAK and ITGB1 in hPDLSCs seeded on TEST surface compared to the CTRL dental implant surface. Understanding the mechanisms of ECM components release and its regulation are essential for developing novel strategies in tissue engineering and regenerative medicine. Our results demonstrated that the impact of treated surfaces of titanium dental implants might increase and accelerate the ECM apposition and provide the starting point to initiate the osseointegration process.

Review of Myeloma Therapies and Their Potential for Oral and Maxillofacial Side Effects

Simple Summary

Myeloma is a common cancer involving the bone marrow. Some of the medications used in the treatment of myeloma, including those that reduce the risk of bone fractures, can increase the chance of side effects occurring in the jawbone. The most serious complication in the jawbone is called medication-related osteonecrosis, meaning part of the jawbone dies. The aim of this review is to highlight some of the medications that are implicated and other risk factors that can contribute to osteonecrosis. Suggestions to prevent this complication from occurring are described. Conventional methods of treating established medication-related osteonecrosis of the jawbone are outlined as well as emerging new treatments.

Abstract

Myeloma is a common haematological malignancy in which adverse skeletal related events are frequently seen. Over recent years, treatment for myeloma has evolved leading to improved survival. Antiresorptive therapy is an important adjunct therapy to reduce the risk of bone fractures and to improve the quality of life for myeloma patients; however, this has the potential for unwanted side effects in the oral cavity and maxillofacial region. Osteonecrosis of the jaw related to antiresorptive medications and other myeloma therapies is not uncommon. This review serves to highlight the risk of osteonecrosis of the jaw for myeloma patients, with some suggestions for prevention and management.

Anxiety Levels Predict Bone Mineral Density in Postmenopausal Women Undergoing Oral Bisphosphonates: A Two-Year Follow-Up

Clinical psychological factors may predict medical diseases. Anxiety level has been associated with osteoporosis, but its role on bone mineral density (BMD) change is still unknown. This study aimed to investigate the association between anxiety levels and both adherence and treatment response to oral bisphosphonates (BPs) in postmenopausal osteoporosis. BMD and anxiety levels were evaluated trough dual-energy X-ray absorptiometry and the Hamilton Anxiety Rating Scale (HAM-A), respectively. Participants received weekly medication with alendronate or risedronate and were grouped according to the HAM-A scores into tertiles (HAM-A 3 > HAM-A 2 > HAM-A 1). After 24 months, BMD changes were different among the HAM-A tertiles. The median lumbar BMD change was significantly greater in both the HAM-A 2 and HAM-A 3 in comparison with the HAM-A 1. The same trend was observed for femoral BMD change. Adherence to BPs was >75% in 68% of patients in the HAM-A 1, 79% of patients in the HAM-A 2, and 89% of patients in the HAM-A 3 (p = 0.0014). After correcting for age, body mass index, depressive symptoms, and the 10-yr. probability of osteoporotic fractures, anxiety levels independently predicted lumbar BMD change (β = 0.3417, SE 0.145, p = 0.02). In conclusion, women with higher anxiety levels reported greater BMD improvement, highlighting that anxiety was associated with adherence and response to osteoporosis medical treatment, although further research on this topic is needed.

Comparison of the Effect of Oral Versus Intravenous Bisphosphonate Administration on Osteoclastogenesis in Advanced-Stage Medication-Related Osteonecrosis of the Jaw Patients

It is yet unknown whether the intravenous administration route alone can fully account for the exacerbation of medication-related osteonecrosis of the jaw (MRONJ). The purpose of this retrospective study was to identify the potential role of the bisphosphonate (BP) administration route as an independent prognostic factor for non-cancerous, stage III MRONJ patients. Bone samples were retrospectively obtained from two groups of osteoporosis patients who underwent surgery for the treatment of stage III MRONJ. Among the subjects, 10 had a history of only oral BP consumption and 10 of intravenous (IV) BP administration. The samples were assessed for osteoclast morphology and immunohistochemical expression of the receptor activator of NF-κB ligand (RANKL), osteoprotegerin (OPG), and potassium calcium-activated channel subfamily N member 4 (Kcnn4). Although the osteoclasts derived from both groups exhibited no significant differences in the mean quantity, diameter, and nuclearity, significantly attenuated tartrate-resistant acid phosphatase activity was noted among the IV BP-induced MRONJ bones compared to those of the oral BP group. Significant suppression of the RANKL/OPG ratio and Kcnn4 expression among the retrieved bones of IV BP group patients was also noted. Our results indicate the potential of the BP administration route as an independent prognostic factor for advanced-stage MRONJ, regardless of the dosage or indication for which the BP was prescribed.

Effect of Inducible BMP-7 Expression on the Osteogenic Differentiation of Human Dental Pulp Stem Cells

BMP-7 has shown inductive potential for in vitro osteogenic differentiation of mesenchymal stem cells, which are an ideal resource for regenerative medicine. Externally applied, recombinant BMP-7 was able to induce the osteogenic differentiation of DPSCs but based on our previous results with BMP-2, we aimed to study the effect of the tetracyclin-inducible BMP-7 expression on these cells. DPSC, mock, and DPSC-BMP-7 cell lines were cultured in the presence or absence of doxycycline, then alkaline phosphatase (ALP) activity, mineralization, and mRNA levels of different osteogenic marker genes were measured. In the DPSC-BMP-7 cell line, the level of BMP-7 mRNA significantly increased in the media supplemented with doxycycline, however, the expression of Runx2 and noggin genes was upregulated only after 21 days of incubation in the osteogenic medium with doxycycline. Moreover, while the examination of ALP activity showed reduced activity in the control medium containing doxycycline, the accumulation of minerals remained unchanged in the cultures. We have found that the induced BMP-7 expression failed to induce osteogenic differentiation of DPSCs. We propose three different mechanisms that may worth investigating for the engineering of expression systems that can be used for the induction of differentiation of mesenchymal stem cells.

Choosing the Right Partner for Medication Related Osteonecrosis of the Jaw: What Central European Dentists Know

Medication-related osteonecrosis of the jaw (MRONJ) is a side effect of antiresorptive drugs. In this online survey, the awareness and knowledge of dentists regarding MRONJ was evaluated, and potential implications for oncologists are discussed. Questionnaires were emailed to dentists from Germany, Austria, Switzerland, and South Tyrol to evaluate disease-related knowledge and management. In addition to the overall score, a separate score was calculated for knowledge (maximum score: 15 points) and management (maximum score: 6 points) questions, and 1197 valid replies with completed questionnaires were received. The mean overall score was 10.45 ± 3.97 points, the mean knowledge score was 7.68 ± 3.05 points, and the mean management score was 2.76 ± 1.77 points. Factors influencing the outcome of the overall score were age, specialization, continuous professional education, and the number of dental screening exams in patients before antiresorptive therapy. Due to the considerable lack of knowledge regarding MRONJ among dentists, MRONJ patients and subjects at risk should be guided towards specialists for dental screening, treatment, and follow-up. This is important from an oncologic point of view to avoid any delay for treatment start of antiresorptives, and to reveal a potentially emerging osteonecrosis at an early stage, thus, avoiding the need for interruption or even cancellation of antiresorptive therapy.