Effects of Simvastatin on Gene Expression and Alkaline Phosphatase Activity in the MG-63 Cell Line Treated With Hyperglycemia for Bone Regeneration

Background Dental implants have become a widespread treatment option for replacing missing teeth. Adequate bone is required for the placement of dental implants, in the absence of which, augmentation by bone regeneration is done. Antiresorptive drugs are used as treatment procedures for bone regeneration. One such antiresorptive drug is simvastatin (SV), a 3-hydroxy-3-methylglutaryl coenzyme used to manage hyperlipidemia. It reduces serum cholesterol levels and has an advantageous effect on new bone formation. Various studies establish that SV stimulates bone morphogenetic protein (BMP)-2 expression and leads to bone formation. SV prevents the production of isoprenoids and mevalonate, which are essential for osteoclastogenesis and contribute to the bone-sparing effect.  Aim The aim of the study was to investigate the osteoregenerative activity of SV in the osteoblast-like cell models, MG-63 cell line, with hyperglycemic conditions. Methodology MG-63 cultures were established under high glucose concentrations during the experiments and cultured with SV concentrations of 1 µM and 3 µM. The quantification of the expression of the genes, namely, BMP-2 and osteocalcin (OCN) was done by real-time quantitative polymerase chain reaction (RTqPCR). The measurement of alkaline phosphatase activity in the SV-treated cells was also determined. Results According to the results of the study, SV had osteoprotective properties resulting from the inhibition of osteoclast stimulation and osteoinductive properties, facilitated by BMP-2 and OCN. In addition, SV at concentrations of 1 µM and 3 µM increased the gene expression of BMP-2 and OCN in the MG-63 cell line. Conclusion The results of this study demonstrated that SV had a significant and direct effect on osteogenesis in osteoblasts in vitro.

Medication-related osteonecrosis of the jaw triggered by endodontic failure in oncologic patients

OBJECTIVES

To describe the association between endodontic treatment failure and medication-related osteonecrosis of the jaw (MRONJ) in a cohort of oncologic patients in therapy with antiresorptive and antiangiogenic drugs.

MATERIALS AND METHODS

Patients were selected as affected by MRONJ in absence of the common local risk factors (oral surgical procedures or ill-fitting dentures) but showing failure of previous endodontic treatment performed at least 6 months before the starting of antiresorptive/antiangiogenic therapies. Jaw lesions were all surgically treated and patients underwent a strict clinical and radiological follow-up.

RESULTS

Among 18 patients, who developed 18 MRONJ, the only detectable local risk factor was the presence of teeth with failed endodontic treatment (more precisely, root canal underfilling in eight cases, root canal overfilling in two cases, root perforation in three cases, root fracture in five cases). All patients completely healed after surgical procedure and no recurrence was observed.

CONCLUSIONS

Endodontic treatment failure should be considered a local risk factor for MRONJ development in oncologic patients. For such reason, it is mandatory to carefully evaluate them prior than the beginning of antiresorptive and antiangiogenic drugs administration.

The Use of Human Amniotic Membrane (hAM) as a Treatment Strategy of Medication-Related Osteonecrosis of the Jaw (MRONJ): A Systematic Review and Meta-Analysis of the Literature

Background and objectives: Although it is very uncommon, medication-induced osteonecrosis of the jaw (also known as MRONJ) can have serious consequences. Traditionally, this adverse event has been recognised in patients who were treated with bisphosphonate (BP) drugs. Nevertheless, in recent years, it has been established that individuals having treatment with various types of medications, such as a receptor activator of nuclear factor kappa-Β ligand inhibitor (denosumab) and antiangiogenic agents, have had the same issue. The purpose of this research is to determine if the application of human amniotic membrane (hAM) may be used as a therapy for MRONJ. Material and Methods: A multi-source database (MEDLINE, EMBASE, AMED, and CENTRAL) systematic search was performed. The major objective of this study is to obtain an understanding of the efficacy of hAM when it is employed as a treatment modality for MRONJ. The protocol of this review was registered in the INPLASY register under the number NPLASY202330010. Results: The authors were able to include a total of five studies for the quality analysis, whereas for the quantity evaluation, only four studies were eligible. A total of 91 patients were considered for the investigation. After treatment with human amniotic membrane (hAM), a recurrence of osteonecrosis was observed in n = 6 cases (8.8%). The combined efficacy of surgical therapy and the use of hAM resulted in an overall success rate of 91.2%. Intraoperative complications were only documented in one article, and they were mostly caused by the positioning of the hAM, which led to wound breakdown at the surgical site. Conclusions: Based on the small amount of data and low-quality research included in this study, using human amniotic membranes to treat MRONJ might represent a feasible option. Nevertheless, further studies with a wider patient population are required to understand the long-term impacts.

Osteonecrosis of the jaws in patients under osteoporosis treatment: a nine-year experience report

Objective

This study aimed to report the experience of medication-related osteonecrosis of the jaws (MRONJ) in osteoporotic patients for nine years, and their associated initiating factors.

Materials and methods

The numbers of invasive oral procedures (IOP) (tooth extraction, dental implant placement, and periodontal procedures) and removable prostheses performed from January 2012 to January 2021 were obtained from the digital records of a large public dental center. There were an estimated 6,742 procedures performed in patients under osteoporosis treatment.

Results

Two cases (0.03%) of MRONJ were registered in nine years amongst patients with osteoporosis who had dental treatment at the center. From the 1,568 tooth extractions, one patient (0.06%) developed MRONJ. There was also one case from the 2,139 removable prostheses delivered (0.05%).

Conclusion

The prevalence of MRONJ associated with osteoporosis treatment was very low. The protocols adopted seem to be adequate for the prevention of this complication. The findings of this study reinforce the rare frequency of MRONJ associated with dental procedures in patients submitted to the pharmacological management of osteoporosis. An integral analysis of systemic risk factors and oral preventive strategies may be considered regularly in the dental treatment of these patients.

Location and Gender Differences in Osteonecrosis of the Jaws in Patients Treated with Antiresorptive and Antineoplastic Drugs Undergoing Dentoalveolar Surgical, Systematic Review with Meta-Analysis and Trial Sequential Analysis

In the treatment and prevention of osteoporosis and more generally of neoplastic and metabolic pathologies affecting bone tissues, antiresorption drugs such as bisphosphonates and monoclonal antibody are used. Bisphosphonates have been linked to cases of osteonecrosis of the jaws since 2003 by Marx, with more and more evidence over the next two decades; together with bisphosphonate drugs, cases relating to the use of monoclonal drugs have been subsequently added. Among the main independent risk factors, we have extraction procedures in oral surgery that can affect both the mandible and the maxilla and the anterior or posterior sectors. The incidence of MRONJ treated with oral bisphosphonates ranges from 0.5% to 3% according to studies; this incidence would appear to be higher in patients treated with antiresorptive agents with neoplastic diseases. Many pathologies including those in which antiresorptive drugs are used show differences in prevalence in relation to sex; similarly, there could be differences in the incidence of cases of osteonecrosis based on gender in patients undergoing dentoalveolar surgery. Therefore, the objective of this systematic review and trial sequential analysis was to identify and quantify whether there is a proportionally greater risk of MRONJ in male or female subjects and whether there is evidence of greater involvement of osteonecrosis at several extraction sites, differentiating them into mandibular or maxilla and in the anterior or posterior sector. The revision protocol followed the indications of the Cochrane Handbook, and were recorded in Prospero, while the drafting of the manuscript was based on PRISMA. The results of the systematic review, after the study identification and selection process, included a total of 24 studies. The results of the meta-analysis reports: odds ratio (random effects model): 1.476 (0.684, 3.184) between male and female; odds ratio (random effects model): 1.390 (0.801, 2.412) between mandible and maxillary, and an odds ratio value of 0.730 (0.250, 2.137) between the anterior and posterior extraction sites. In conclusion, we can see that there was a trend in the onset of MRONJ as a complication of dentoalveolar surgical procedures, which proportionally mostly involved the male sex and the posterior mandibular sectors, however, this trend must be further confirmed by additional studies.

Composition and Properties of Saliva in Patients with Osteoporosis Taking Antiresorptive Drugs

The aim of this study was to examine how the composition and properties of saliva change in people with osteoporosis who have received antiresorptive (AR) treatment, compared to patients with osteoporosis who have not yet received this treatment.

METHODS

The study population consisted of 38 patients with osteoporosis using AR drugs (Group I) and 16 patients with osteoporosis who had never used AR drugs (Group II). The control group consisted of 32 people without osteoporosis. Laboratory tests included determination of pH and concentrations of Ca, PO₄, total protein, lactoferrin, lysozyme, sIgA, IgA, cortisol, neopterin, activity of amylase at rest, and stimulated saliva. The buffering capacity of stimulated saliva was also determined.

RESULTS

There were no statistically significant differences between the saliva of Group I and Group II. No statistically significant correlation was found between the amount of time using AR therapy (Group I) and the tested parameters of the saliva. Significant differences were found between Group I and the control group. The concentrations of PO₄, lysozyme, and cortisol were higher, while concentrations of Ca ions, sIgA, and neopterin were lower, in comparison to the control group. The significant differences between Group II and the control group were smaller, and they concerned only the concentrations of lysozyme, cortisol, and neopterin.

CONCLUSIONS

The saliva of people with osteoporosis subjected to AR therapy and those not subjected to AR therapy did not show statistically significant differences in terms of the examined parameters of the saliva. However, the saliva of patients with osteoporosis taking and not taking AR drugs was significantly different compared to the saliva of the control group.

Clinical and Radiographic Outcomes of Dental Implants in Patients Treated With Antiresorptive Drugs: A Consecutive Case Series

Medication-related osteonecrosis of the jaw (MRONJ) is a serious concern for dentists as well as maxillofacial surgeons. Therefore, the safety of dental implant placement in patient receiving antiresorptive drugs (ARDs) has been the subject of controversial debate for several years and remains a source of uncertainty for surgeons and patients. This consecutive case series assessed the clinical and radiographic outcomes of dental implants placed in patients under antiresorptive therapy. Patients who received at least one dental implant at the Department of Oral and Maxillofacial Surgery, Ludwig Maximilian University (LMU), Munich, Germany, between 2010 and 2019 with a history of current or past antiresorptive medication were included the study. The main outcomes were occurrence of MRONJ, implant success, and survival rate. A total of 16 patients were treated with 39 implants. No implant loss or MRONJ occurred in the respective patients. The reasons for antiresorptive intake were osteoporosis, malignancy, edema of bone marrow, or diffuse sclerosing osteomyelitis (DSO). MRONJ occurred neither around implants nor in other locations. Cumulative implant success was 92.6% (25 of 27). No subjective complaints or postoperative complications were documented. Mean bone loss was 0.60 ± 0.98 mm. The prevalence of peri-implantitis was 30% on patient level and 29.6% on implant level. None of the patients had failed implants. No major complications after implant placement under antiresorptives could be detected. As long as implant surgery follows a specific protocol, implant placement in patients treated with antiresorptive therapy seems to be safe and predictable.

Real-world study of antiresorptive-related osteonecrosis of jaw based on the US food and drug administration adverse event reporting system database

Objective: This study aims to explore the risk signals of osteonecrosis of the jaw induced by antiresorptive drugs and provide references for the clinical safety application. Method: According to the FDA's Adverse Event Reporting System (FAERS), from January 2004 to September 2021, we chose "Osteonecrosis of the jaw (10064658)" and "Exposed bone in jaw (10071014)" as preferred terms, "antiresorptive drugs" as the target drugs, and primary suspect drug as the drug role code in the dataset. We evaluated the association between drugs and adverse events by using reporting odds ratio (ROR) based on disproportionality analysis. We took the High-Level Terms (HLT) of MedDRA® as the classification level of indications to calculate ROR to compare the signal difference of ONJ in different indications. In addition, patients with antiresorptive-induced osteonecrosis of the jaw and the time of onset of the condition following different antiresorptive medications were collected for the study. Results: The FAERS contained 18,421 reports relating to jaw osteonecrosis from January 2004 to September 2021. A total of eight antiresorptive agents were included in the analysis. From high to low, the ROR of ONJ induced by antiresorptive agents (regardless of indication) is pamidronate (ROR = 494.8), zoledronic acid (ROR = 431.9), denosumab (ROR = 194.8), alendronate (ROR = 151.2), risedronate (ROR = 140.2), etidronic acid (ROR = 64.5), ibandronate (ROR = 40.8), and romosozumab (ROR = 6.4). HLT ROR values for "metabolic bone disorders" were the lowest for each drug, while HLT ROR values were high for "tumor-related indications," including breast and nipple neoplasms malignant, plasma cell myelomas, and prostatic neoplasms malignant. The onset time for osteonecrosis of the jaw as median (Q1, Q3), osteoporosis-related indications, and the onset time for ONJ were 730 (368, 1268), 489.5 (236.3, 909.8), 722.5 (314, 1055), 761 (368, 1720), and 153 (50, 346) for zoledronic acid, denosumab, ibandronate, risedronate, and romosozumab, respectively. Cancer-related indications: the onset time for ONJ were 680.5 (255.3, 1283), 488 (245, 851), and 696.5 (347, 1087) for zoledronic acid, denosumab, and pamidronate, respectively. Conclusion: When antiresorptive drugs are used for metastasis, they have the largest risk signal, followed by malignancy, and the smallest is osteoporosis. The onset time of ONJ may not be related to the indications. The onset time of ONJ for BPs was about 2 years, denosumab about 1.3 years, and romosozumab less than 1 year, which may be related to sequential treatment. When used according to the instructions, the risk of ONJ caused by denosumab was higher than that of zoledronic acid, regardless of the indication. Based on these findings, researchers will continue to monitor and identify risk factors.

Analysis of Serum Proteome after Treatment of Osteoporosis with Anabolic or Antiresorptive Drugs

The aim of the study was to explore new markers in serum proteome associated with the response to antiosteoporosis drugs, namely teriparatide and denosumab. We obtained serum samples from 14 patients with osteoporosis, both at baseline and after 6 months of treatment with teriparatide (n = 10) or denosumab (n = 4). Samples were analyzed by nanoliquid chromatography coupled to high-resolution mass spectrometry on a QTOF 5600 (SCIEX) apparatus. The spectrometry data were analyzed with Mascot against the UniProtKB base and then several quality-control filters were applied for the identification of peptides (false discovery rate, FDR q < 0.02) and their quantification (FDR q < 0.05). In the group treated with teriparatide, 28 proteins were identified with significant differences before and after treatment. A pathway analysis by using the Reactome database revealed significant enrichment in the Insulin Like Growth Factor 1 (IGF-I) (FDR q 4 × 10−2) and innate immune system (FDR q 2 × 10−3) pathways. Among patients treated with denosumab, we observed significant differences in the levels of 10 proteins, which were also enriched in the pathways related to the innate immune system (FDR q 3 × 10−2). These results suggest that the innate immune system may be involved in the response to antiosteoporosis drugs.

Recent Progresses in the Treatment of Osteoporosis

Osteoporosis (OP) is a chronic bone disease characterized by aberrant microstructure and macrostructure of bone, leading to reduced bone mass and increased risk of fragile fractures. Anti-resorptive drugs, especially, bisphosphonates, are currently the treatment of choice in most developing countries. However, they do have limitations and adverse effects, which, to some extent, helped the development of anabolic drugs such as teriparatide and romosozumab. In patients with high or very high risk for fracture, sequential or combined therapies may be considered with the initial drugs being anabolic agents. Great endeavors have been made to find next generation drugs with maximal efficacy and minimal toxicity, and improved understanding of the role of different signaling pathways and their crosstalk in the pathogenesis of OP may help achieve this goal. Our review focused on recent progress with regards to the drug development by modification of Wnt pathway, while other pathways/molecules were also discussed briefly. In addition, new observations made in recent years in bone biology were summarized and discussed for the treatment of OP.

Dental Implant Placement in Patients With a History of Medications Related to Osteonecrosis of the Jaws: A Systematic Review

The present systematic review evaluates the safety of placing dental implants in patients with a history of antiresorptive or antiangiogenic drug therapy. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. PubMed, Cochrane Central Register of Controlled Trials, Scopus, Web of Science, and OpenGrey databases were used to search for clinical studies (English only) to July 16, 2019. Study quality was assessed regarding randomization, allocation sequence concealment, blinding, incomplete outcome data, selective outcome reporting, and other biases using a modified Newcastle-Ottawa scale and the Joanna Briggs Institute critical appraisal checklist for case series. A broad search strategy resulted in the identification of 7542 studies. There were 28 studies reporting on bisphosphonates (5 cohort, 6 case control, and 17 case series) and 1 study reporting on denosumab (case series) that met the inclusion criteria and were included in the qualitative synthesis. The quality assessment revealed an overall moderate quality of evidence among the studies. Results demonstrated that patients with a history of bisphosphonate treatment for osteoporosis are not at increased risk of implant failure in terms of osseointegration. However, all patients with a history of bisphosphonate treatment, whether taken orally for osteoporosis or intravenously for malignancy, appear to be at risk of "implant surgery-triggered" medication-related osteonecrosis of the jaw (MRONJ). In contrast, the risk of MRONJ in patients treated with denosumab for osteoporosis was found to be negligible. In conclusion, general and specialist dentists should exercise caution when planning dental implant therapy in patients with a history of bisphosphonate and denosumab drug therapy. Importantly, all patients with a history of bisphosphonates are at risk of MRONJ, necessitating this to be included in the informed consent obtained before implant placement.

Peri-implantitis-like medication-related osteonecrosis of the jaw: Clinical considerations and histological evaluation with confocal laser scanning microscope

Objective

In the recent years, an increasing number of peri‐implant medication‐related osteonecrosis of the jaw (PI‐MRONJ) have been reported in literature, both in oncologic and osteoporotic patients. The aim of this study is to describe 19 cases of patients previously diagnosed as affected by peri‐implantitis, who were treated for PI‐MRONJ, with consideration on clinical and histopathological features.

Materials and Methods

Patients included were affected by postmenopausal osteoporosis and were administered with different antiresorptive drugs. Due to the presence of clinical and radiological signs of peri‐implantitis not healed after non‐surgical periodontal treatment, they were referred to the Complex Operating Unit of Odontostomatology of the University of Bari. Then, after a drug holiday of at least 3 months and cycles of antibiotics, and after other cycles of periodontal treatment, patients underwent the surgical removal of implant fixtures and surrounding bone.

Results

Although the previous diagnosis of peri‐implantitis, the histopathological analysis with both conventional and confocal laser scanner microscopy confirmed the diagnosis of peri‐implantitis‐like MRONJ.

Conclusion

Peri‐implantitis not healed after conventional treatment in patients at risk on MRONJ occurrence should be considered as peri‐implantitis‐like PI‐MRONJ and treated as required in order to get complete healing of the pathological condition, thus avoiding delay in the diagnosis.

Therapeutic Approach in the Treatment of Medication-Related Osteonecrosis of the Jaw: Case Series of 3 Patients and State of the Art on Surgical Strategies

BACKGROUND

Bisphosphonates and receptor activator of nuclear factor kappa-B ligand inhibitors are currently the most widely used antiresorptive therapies in bone metabolism diseases treatment. Unfortunately they can evoke medication-related osteonecrosis of the jaws. The present case series study proposes to evaluate clinical features, evolution and the surgical therapeutic approaches in three patients affected by medication-related osteonecrosis of the jaw and to review the state of art regarding the management of this complication in light of the most recent literature.

METHODS

Three cases of medication-related osteonecrosis of the jaws are discussed, two related to bisphosphonates therapy (ibandronic acid) and one due to denosumab.

RESULTS

All three patients were aged female and had probably a dental trigger agent. The lesions located in posterior mandible were treated in one case with the surgical approach alone and, in the other case, with surgical approach associated with Erb-YAG laser. The lesion related to denosumab was treated with surgical approach and platelet rich fibrin application. A complete healing was always achieved.

CONCLUSIONS

Dentists should be aware of the potential risk of developing medication-related osteonecrosis of the jaws for patients who take or had taken antiresorptive drugs. The side effects of denosumab and bisphosphonates are partly overlapping and currently there is still no consensus about the therapeutic surgical options. Prevention and early detection of the lesions should be the primary strategy.

Osteoporosis: Mechanism, Molecular Target and Current Status on Drug Development

CDATA[Osteoporosis is a pathological loss of bone mass due to an imbalance in bone remodeling where osteoclast-mediated bone resorption exceeds osteoblast-mediated bone formation resulting in skeletal fragility and fractures. Anti-resorptive agents, such as bisphosphonates and SERMs, and anabolic drugs that stimulate bone formation, including PTH analogues and sclerostin inhibitors, are current treatments for osteoporosis. Despite their efficacy, severe side effects and loss of potency may limit the long term usage of a single drug. Sequential and combinational use of current drugs, such as switching from an anabolic to an anti-resorptive agent, may provide an alternative approach. Moreover, there are novel drugs being developed against emerging new targets such as Cathepsin K and 17β-HSD2 that may have less side effects. This review will summarize the molecular mechanisms of osteoporosis, current drugs for osteoporosis treatment, and new drug development strategies.

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

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

Awareness of the risk of developing medication-related osteonecrosis of the jaw among bisphosphonate users

Objective

In this retrospective observational study, we evaluated awareness among patients using bisphosphonates (BPs) regarding the risk of developing medication-related osteonecrosis of the jaw (MRONJ) and whether they received appropriate dental screening and treatment prior to commencing medication.

Methods

Patients using BPs who attended the endodontics clinic at Jordan University Hospital in 2019 were interviewed using a pre-designed questionnaire. Data were analysed using descriptive statistics and chi-squared tests.

Results

In total, 110 patients were interviewed (84 women, 26 men; age 40–78 years). A total of 94 patients were using oral BP and 16 received intravenous (IV) BP. We found that only 12.4% of participants were aware about the risk of MRONJ following BP use, and only one third of them has received information from their prescribing physicians. In total, 5% of participants were referred to a dentist for screening prior to initiating BP treatment. Patients receiving IV BP and those with a university-level education had better awareness about the risk of MRONJ than oral BP users and those with a high school education level.

Conclusion

Patients’ awareness about MRONJ risk was low in our population. Better patient education and collaboration among physicians and dentists are needed prior to starting BP treatment.

Medication-Related Osteonecrosis of Jaws (MRONJ) Prevention and Diagnosis: Italian Consensus Update 2020

The Medication-Related Osteonecrosis of Jaws (MRONJ) diagnosis process and its prevention play a role of great and rising importance, not only on the Quality of Life (QoL) of patients, but also on the decision-making process by the majority of dentists and oral surgeons involved in MRONJ prevention (primary and secondary). The present paper reports the update of the conclusions from the Consensus Conference-held at the Symposium of the Italian Society of Oral Pathology and Medicine (SIPMO) (20 October 2018, Ancona, Italy)-after the newest recommendations (2020) on MRONJ were published by two scientific societies (Italian Societies of Maxillofacial Surgery and Oral Pathology and Medicine, SICMF and SIPMO), written on the inputs of the experts of the Italian Allied Committee on ONJ (IAC-ONJ). The conference focused on the topic of MRONJ, and in particular on the common practices at risk of inappropriateness in MRONJ diagnosis and therapy, as well as on MRONJ prevention and the dental management of patients at risk of MRONJ. It is a matter of cancer and osteometabolic patients that are at risk since being exposed to several drugs with antiresorptive (i.e., bisphosphonates and denosumab) or, more recently, antiangiogenic activities. At the same time, the Conference traced for dentists and oral surgeons some easy applicable indications and procedures to reduce MRONJ onset risk and to diagnose it early. Continuous updating on these issues, so important for the patient community, is recommended.

Pharmacological Therapy of Osteoporosis: What's New?

Osteoporosis and fragility fractures are relevant health issues because of their impact in terms of morbidity, mortality, and socioeconomic burden. Despite this alarming scenario, both underdiagnosis and undertreatment are common features of osteoporotic patients, particularly those who have already sustained a fragility fracture. Pharmacotherapy of osteoporosis is the main treatment option for these patients because of strong evidence about the efficacy of available drugs targeting bone metabolism. However, several issues can interfere with the effectiveness of anti-osteoporotic drugs in clinical practice, such as lack of awareness of both healthcare providers and patients, poor adherence to therapy, and safety in long-term treatment. Therefore, new therapeutic strategies have been proposed to overcome these problems, such as sequential therapy or emerging molecules mainly targeting the stimulation of bone formation. In particular, abaloparatide has been demonstrated to reduce major nonvertebral fracture risk compared with both placebo and teriparatide, although the European Medicines Agency (EMA) refused the marketing authorization because the benefits of this drug did not outweigh its risks. On the other side, EMA has recently approved romosozumab, a monoclonal antibody directed against sclerostin and the only available therapeutic option targeting Wnt signaling, as both bone-forming and antiresorptive intervention to treat osteoporosis and fragility fractures.

The effect of antiresorptive drugs on implant therapy: Systematic review and meta-analysis

OBJECTIVES

A considerable portion of the adult population has received and/or is receiving treatment with antiresorptive drugs (ARDs). It is thus relevant to assess possible side effects of ARD intake in connection to various aspects of implant therapy. The aim of this study was to answer the focused question "In patients with systemic intake of ARDs, what is the outcome and complication rate of implant therapy including associated bone grafting procedures comparing to patients without systemic intake of ARDs?"

MATERIALS AND METHODS

Original studies fulfilled predefined inclusion criteria (e.g., case series, cohort studies, case-control studies, and controlled and/or randomized controlled clinical trials; retro- or prospective design; and ≥10 patients with systemic intake of ARDs). Various patient-, medication-, and intervention-related parameters [i.e., implant loss, grafting procedure complication/failure, peri-implant marginal bone levels/loss, medication-related osteonecrosis of the jaws (MRONJ), and peri-implantitis] were extracted, and meta-analyses and quality assessment were performed.

RESULTS

Twenty-four studies with bisphosphonate (BP) intake (mainly low dose for osteoporosis treatment) and seven studies on hormone replacement therapy (HRT), including ≥10 patients, and controls not taking the medication were identified. Furthermore, seven studies on MRONJ associated with implants were included. Meta-analyses based on four studies reporting on patient level and eight studies reporting on implant level showed no significant differences in terms of implant loss between patients on BPs (mainly low dose for osteoporosis treatment) and controls. Furthermore, low-dose BP intake did not compromise peri-implant marginal bone levels. Based on two studies, no negative effect of HRT was observed on the implant level, while HRT appeared to exert a marginally significant negative effect regarding implant survival on the patient level and regarding peri-implant marginal bone levels. Based on six studies reporting single-patient data, MRONJ in patients on BP for osteoporosis appeared in 70% of the cases >36 months after start of drug intake, while in patients with cancer, MRONJ appeared in 64% of the cases ≤36 months after first BP intake.

CONCLUSION

Low-dose oral BP intake for osteoporosis treatment, in general, does not compromise implant therapy, that is, patients on ARDs do not lose more implants nor get more implant-related complications/failures comparing to implant patients without BP intake. There is almost no information available on the possible effect on implant therapy of high-dose BPs or other widely used ARDs (e.g., denosumab), or on the success or safety of bone grafting procedures. Patients with high-dose ARD intake for management of malignancies, patients on oral BP over a longer period of time, and patients with comorbidities should be considered as high-risk patients for MRONJ.

Non-surgical management of primary hyperparathyroidism

The purpose of this chapter is to discuss the options available for patients with primary hyperparathyrodism (PHPT) not undergoing parathyroidectomy (PTx). Adequate hydration should be recommended in all patients. Calcium intake should not be restricted and vitamin D deficiency should be corrected aiming at a serum concentration of 25OHD of >20 ng/mL or even higher (>30 ng/mL according to some opinion leaders). Pharmacologic therapy is not an alternative to PTx and could be considered in patients who meet the surgical criteria but unwilling to undergo PTx, as well as in patients with an increased risk of surgery or failed surgery. Targeted therapy includes antiresorptive drugs for skeletal protection and cinacalcet for lowering serum calcium. Combined therapy can be an option when appropriate. Pregnant women should be treated conservatively (hydration) and surgery, if needed, performed in the second trimester of pregnancy. Severe hypercalcemia is a life-threatening condition and requires immediate intensive treatment.

Assessment of Bone Quality in Osteoporosis Treatment with Bone Anabolic Agents: Really Something New?

Osteoporosis is a chronic pathologic condition, particularly of the elderly, in which a reduction of bone mineral density (BMD) weakens bone, leading to the so-called fragility fractures, most often of spine and femur. The gold standard exam for the quantitative measurement of BMD is the dual X-ray photon absorptiometry (DXA), a radiological method. However, a relevant number of fragility fractures occurs in the range of normal BMD values, meaning that also qualitative aspects of bone play a role, namely bone architecture and bone geometry. Bone structure is investigated by microCT and histomorphometry, which necessitate an invasive approach with a biopsy, usually taken at the iliac crest, not the typical site of fragility fractures. New tools, trabecular bone score (TBS) and hip structural analysis (HSA), obtained during DXA, can supply informations about bone structure of spine and femur, respectively, in a not invasive way. Therapy of osteoporosis is based on two types of drugs leading to an increase of BMD: antiresorptive and anabolic treatments. The antiresorptive drugs inhibit the osteoclasts, whereas teriparatide and, in part, strontium ranelate ameliorate bone structure. The present review deals with the relation between the anabolic drugs for osteoporosis and the cited new tools which investigate bone architecture and geometry, in order to clarify if they represent a real advantage in monitoring efficacy of osteoporosis' treatment. Data from the studies show that increases of TBS and HSA values after anabolic therapy are small and very close to their least significant change at the end of the usual period of treatment. Therefore, it is questionable if TBS and HSA are really helpful in monitoring bone quality and in defining reduction of individual fragility fracture risk during osteoporosis treatment with bone anabolic agents.

The Osteoclast in Bone Metastasis: Player and Target

Bone metastases are frequently the final fate of breast and prostate cancer patients. According to the definition of metastasis as an incurable disease, to date there are no effective treatments for tumor-associated bone metastases and this represents a real challenge for the researchers in the field. The bone is a heterogeneous environment that represents a fertile soil for tumor cells, supporting their growth. Among the different cell types present in the bone, in this review we will focus our attention on the osteoclasts, which are crucial players in the so called “vicious cycle”, a phenomenon triggered by tumor cells eventually leading to both tumor proliferation as well as bone deregulation, thus fueling the development of bone metastasis. The complex network, linking tumor cells to the bone by activating osteoclasts, represents a fruitful target for the treatment of bone metastases. In this review we will describe how tumor cells perturb the bone microenvironment by actively influencing osteoclast formation and activity. Moreover, we will describe the current antiresorptive drugs employed in the treatment of bone metastases as well as new, targeted therapies able to affect both cancer cells and osteoclasts.

The effect of sequential therapy for postmenopausal women with osteoporosis: A PRISMA-compliant meta-analysis of randomized controlled trials

BACKGROUND

Osteoporosis, more likely to occur in postmenopausal women, is a chronic condition that usually requires a long-term treatment strategy, but the use of either antiresorptive or anabolic drugs should be limited to 18 to 24 months. Discontinuing antiosteoporosis drugs may result in rapidly declining bone mineral density (BMD). Therefore, many patients are treated with the sequential use of 2 or more drugs. However, whether switching treatment from anabolic to antiresorptive drugs or the reverse could maintain or further increase BMD; and whether the sequential therapy could outperform the monotherapy under the same treatment duration still remains unclear. Nowadays, no firm conclusions were drawn.

METHODS

We searched Medline, Embase, and Cochrane Library from January 1, 1974 until February 1, 2016 to identify all randomized controlled trials for evaluating the effectiveness of sequential therapy of antiresorptive and anabolic drugs in postmenopausal osteoporosis women with the BMD changes of lumbar spine, femoral neck, and total hip as the outcomes. We evaluated the methodological quality and abstracted relevant data according to the Cochrane Handbook.

RESULTS

Eight trials involving 1509 patients were included. The pooled data showed that after switching treatment, the alternative drugs maintained the BMD and significantly increased the percentage change in BMD at the lumbar spine (MD, 3.59; 95% CI, 2.26-4.93), femoral neck (MD, 1.44; 95% CI, 0.60-2.27), and total hip (MD, 1.24; 95% CI, -0.12 to 2.60), although change in BMD was not significantly increased at the total hip. The sequential therapy significantly increased BMD from baseline at the lumbar spine (SMD, 0.59; 95% CI, 0.26-0.91), femoral neck (SMD, 0.22; 95% CI, 0.06-0.37), and total hip (SMD, 0.28; 95% CI, 0.01-0.56).

CONCLUSIONS

After switching treatment, sequential therapy further increased BMD. The sequential therapy showed a more significant improvement in BMD compared with any anti-resorptive drug given for the same treatment duration and was as effective as anabolic drugs. Thus, sequential therapy may be recommended as an effective treatment for osteoporotic women. However, more randomized controlled trials are still needed to determine the best sequence and the most appropriate drugs of sequential therapy.

2-(trimethylammonium) ethyl (R)-3-methoxy-3-oxo-2-stearamidopropyl phosphate suppresses osteoclast maturation and bone resorption by targeting macrophage-colony stimulating factor signaling

2-(Trimethylammonium) ethyl (R)-3-methoxy-3-oxo-2-stearamidopropyl phosphate [(R)-TEMOSPho], a derivative of an organic chemical identified from a natural product library, promotes highly efficient megakaryopoiesis. Here, we show that (R)-TEMOSPho blocks osteoclast maturation from progenitor cells of hematopoietic origin, as well as blocking the resorptive function of mature osteoclasts. The inhibitory effect of (R)-TEMOSPho on osteoclasts was due to a disruption of the actin cytoskeleton, resulting from impaired downstream signaling of c-Fms, a receptor for macrophage-colony stimulating factor linked to c-Cbl, phosphoinositol-3-kinase (PI3K), Vav3, and Rac1. In addition, (R)-TEMOSPho blocked inflammation-induced bone destruction by reducing the numbers of osteoclasts produced in mice. Thus, (R)-TEMOSPho may represent a promising new class of antiresorptive drugs for the treatment of bone loss associated with increased osteoclast maturation and activity.

Pharmacological management of osteogenesis

Osteogenesis and bone remodeling are complex biological processes that are essential for the formation of new bone tissue and its correct functioning. When the balance between bone resorption and formation is disrupted, bone diseases and disorders such as Paget's disease, fibrous dysplasia, osteoporosis and fragility fractures may result. Recent advances in bone cell biology have revealed new specific targets for the treatment of bone loss that are based on the inhibition of bone resorption by osteoclasts or the stimulation of bone formation by osteoblasts. Bisphosphonates, antiresorptive agents that reduce bone resorption, are usually recommended as first-line therapy in women with postmenopausal osteoporosis. Numerous studies have shown that bisphosphonates are able to significantly reduce the risk of femoral and vertebral fractures. Other antiresorptive agents indicated for the treatment of osteoporosis include selective estrogen receptor modulators, such as raloxifene. Denosumab, a human monoclonal antibody, is another antiresorptive agent that has been approved in Europe and the USA. This agent blocks the RANK/RANKL/OPG system, which is responsible for osteoclastic activation, thus reducing bone resorption. Other approved agents include bone anabolic agents, such as teriparatide, a recombinant parathyroid hormone that improves bone microarchitecture and strength, and strontium ranelate, considered to be a dual-action drug that acts by both osteoclastic inhibition and osteoblastic stimulation. Currently, anti-catabolic drugs that act through the Wnt-β catenin signaling pathway, serving as Dickkopf-related protein 1 inhibitors and sclerostin antagonists, are also in development. This concise review provides an overview of the drugs most commonly used for the control of osteogenesis in bone diseases.