Clinical comparison of patients with osteonecrosis of the jaws, with and without a history of bisphosphonates administration

Bisphosphonate-Related Osteonecrosis of the Jaw and Oral Microbiome: Clinical Risk Factors, Pathophysiology and Treatment Options

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) represents a serious health condition, impacting the lives of many patients worldwide. The condition challenges clinical care due to its complex etiology and limited therapeutic options. A thorough understanding of the pathophysiological and patient-related factors that promote disease development is essential. Recently, the oral microbiome has been implicated as a potential driver and modulating factor of BRONJ by several studies. Modern genomic sequencing methods have provided a wealth of data on the microbial composition of BRONJ lesions; however, the role of individual species in the process of disease development remains elusive. A comprehensive PubMed search was conducted to identify relevant studies on the microbiome of BRONJ patients using the terms "microbiome", "osteonecrosis of the jaws", and "bisphosphonates". Studies focusing on symptoms, epidemiology, pathophysiology, risk factors, and treatment options were included. The principal risk factors for BRONJ are tooth extraction, surgical procedures, and the administration of high doses of bisphosphonates. Importantly, the oral microbiome plays a significant role in the progression of the disease. Several studies have identified alterations of microbial composition in BRONJ lesions. However, there is no consensus regarding bacterial species that are associated with BRONJ across studies. The bacterial genera typically found include Actinomyces, Fusobacterium, and Streptococcus. It is postulated that these microbes contribute to the pathogenesis of BRONJ by promoting inflammation and disrupting normal bone remodeling processes. Current therapeutic approaches are disease-stage-specific and the necessity for more effective treatment strategies remains. This review examines the potential causes of and therapeutic approaches to BRONJ, highlighting the link between microbial colonization and BRONJ development. Future research should seek to more thoroughly investigate the interactions between bisphosphonates, the oral microbiome, and the immune system in order to develop targeted therapies.

Oral bisphosphonates: Adverse effects on the oral mucosa not related to the jaw bones. A scoping review

BACKGROUND

Oral bisphosphonates are widely used in the treatment of bone resorptive diseases. There is an evidence that oral bisphosphonates can exert adverse effects on the oral mucosa independently of their effects on the jaw bones.

OBJECTIVE

To systematically map the literature on adverse effects of oral bisphosphonates on the oral mucosa of adults with bone resorptive diseases.

DESIGN

Scoping review of the literature, including different study designs.

METHODS

Systematic searches of the PubMed, LILACS, Google Scholar and EMBASE databases were conducted. Two independent reviewers screened titles and abstracts according to predetermined criteria.

RESULTS

The search retrieved 26 unique articles, comprising 22 case reports, one case series and three reviews describing a total of 56 cases of oral adverse events related to oral bisphosphonates. 88% of the reported cases were female suffering from comorbidities other than metabolic bone diseases. The improper use of the oral bisphosphonate was the most suspected cause of the adverse effect on the oral mucosa. Its management mainly involved withdrawal of the medication.

CONCLUSION

Adverse effects on the oral mucosa can develop from using oral bisphosphonates. Standardised registration of these adverse effects in university clinics and private practises could provide additional information about their occurrence and severity.

The association between the severity of periodontitis and osteonecrosis of the jaw in patients with different cancer locations: a nationwide population-based study

OBJECTIVES

To determine the relation between the severity of periodontitis and osteonecrosis of the jaw (ONJ) occurrence among different cancer locations and estimate the effect of dental care on ONJ prevention in cancer patients.

MATERIALS AND METHODS

This population-based cross-sectional study was conducted through the Longitudinal Health Insurance Database, Taiwan. Patients with malignancies were collected and subdivided into groups according to their different cancer locations, the severity of periodontitis, and dental care. Multivariable logistic regression analysis was performed to assess the associations between ONJ and ONJ-related factors.

RESULTS

A total of 8,234 ONJ patients and 32,912 control patients were investigated. Lip, oral cavity, and pharynx malignancies had the highest ONJ risk among all cancer locations (OR from 3.07 to 9.56, P < 0.01). There is a linear relationship between different severities of periodontitis and ONJ. Patients with radiotherapy and severe periodontitis had the highest ONJ risk (adjusted OR, 9.56; 95% CI, 5.34-17.1). Patients with good dental care had a lower ONJ risk.

CONCLUSIONS

The periodontal condition and cancer location showed a significant impact on the risk of developing ONJ after adjusting for bisphosphonate use. Good dental care could decrease the risk of ONJ in cancer patients. The severity of periodontitis might be a target to predict the potency of ONJ.

CLINICAL RELEVANCE

Dentists must be vigilant about the increased risk of ONJ in cancer patients with periodontitis, especially in the head and neck cancer population. Good dental care is advised for cancer patients with severe periodontitis.

Overview of Physical and Pharmacological Therapy in Enhancing Bone Regeneration Formation During Distraction Osteogenesis

Distraction osteogenesis (DO) is a kind of bone regeneration technology. The principle is to incise the cortical bone and apply continuous and stable distraction force to the fractured end of the cortical bone, thereby promoting the proliferation of osteoblastic cells in the tension microenvironment and stimulating new bone formation. However, the long consolidation course of DO presumably lead to several complications such as infection, fracture, scar formation, delayed union and malunion. Therefore, it is of clinical significance to reduce the long treatment duration. The current treatment strategy to promote osteogenesis in DO includes gene, growth factor, stem-cell, physical and pharmacological therapies. Among these methods, pharmacological and physical therapies are considered as safe, economical, convenience and effective. Recently, several physical and pharmacological therapies have been demonstrated with a decent ability to enhance bone regeneration during DO. In this review, we have comprehensively summarized the latest evidence for physical (Photonic, Waves, Gas, Mechanical, Electrical and Electromagnetic stimulation) and pharmacological (Bisphosphonates, Hormone, Metal compounds, Biologics, Chinese medicine, etc) therapies in DO. These evidences will bring novel and significant information for the bone healing during DO in the future.

Targeted histological evaluation shows high incidence of actinomyces infection in medication-related osteonecrosis of the jaws

Medication-Related Osteonecrosis of the Jaws (MRONJ) is a difficult-to-treat complication of the therapy of osteoporosis and some malignancies cured with bisphosphonates and antiresorptive drugs. The pathomechanism is unclear, but there is increasing observation that Actinomyces infection may play a role in its development and progression. The aim of our study was to demonstrate that histological examination using a validated triple staining procedure for Actinomyces bacteria strains can detect a high rate of Actinomyces infection in patient's samples with MRONJ. 112 previously hematoxylin-eosin (HE) stained samples submitted with the clinical diagnosis of MRONJ were re-evaluated histologically using an appropriate triple special staining validated for the identification of Actinomyces infection. During the first evaluation, when pathologists did not specifically look for Actinomyces, only 8.93% of the samples were reported as positive. In contrast, re-evaluation with triple staining provided a yield of 93.7% positive samples, therefore, we suggest the triple special staining to be standard in MRONJ histology evaluation. These results show that if the clinician suspects Actinomyces infection and brings this to the attention of the pathologist, it could significantly increase the number of correct diagnoses. It serves as an aid for clinicians in therapeutic success of MRONJ by selecting a long-term adequate antibiotic medication which is suitable for the elimination of actinomyces infection.

Effect of Human Umbilical Cord Matrix-Derived Mesenchymal Stem Cells on Bisphosphonate-Related Osteonecrosis of the Jaw

BACKGROUND

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a severe sequela caused by bisphosphonates (BPs), which are widely used to treat osteoporosis or other malignancies. However, the mechanism underlying BRONJ remains unclear. Recently, human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) have been studied for treatment of diverse diseases and injuries. This study aimed to investigate the therapeutic effects of hUC-MSCs in BRONJ.

METHODS

The therapeutic effects of hUC-MSCs were examined in rat bone marrow (rBM)-derived cells using cell viability, colony-forming, and real-time PCR assays and FACS for analyzing essential proinflammatory and bone regeneration markers in vitro. To demonstrate the in vivo therapeutic and adverse effects of transfused hUC-MSCs, micro-CT, H&E staining, IHC (Angiogenesis marker gene expression) staining, and parathyroid hormone (PTH)/calcium assay were conducted in a BRONJ-induced animal model.

RESULTS

BP-induced cytotoxicity and inflammation in rBM-derived cells decreased, after co-culture with hUC-MSCs. The expression levels of bone regeneration markers (RUNX2, OSX, and BMP-2) significantly increased in BP-treated rBM-derived cells, after co-culture with hUC-MSCs. The BP-induced abnormal shift in RANKL/OPG expression ratio in rBM-derived cells was normalized by hUC-MSCs. Consistent with these in vitro results, transfused hUC-MSCs markedly decreased BRONJ and significantly healed injured mucosa in the BRONJ-induced animal model. The animals exhibited serious destruction of the kidney structure and increases in serum PTH and calcium levels, which were significantly normalized by hUC-MSC transfusion.

CONCLUSION

hUC-MSCs exerted therapeutic effects on BRONJ in vitro and in vivo through their anti-cytotoxicity, anti-inflammatory activity and ability to recover bone regeneration.

The role of antiresorptive drugs and medication-related osteonecrosis of the jaw in nononcologic immunosuppressed patients: A systematic review

Medication related osteonecrosis of the jaw (MRONJ) is a severe condition affecting the jaws of patients exposed to specific drugs, and is primarily described in patients receiving bisphosphonate (BP) therapy. However, more recently it has been observed in patients taking other medications, such as the RANK ligand inhibitor (denosumab) and antiangiogenic drugs. It has been proposed that the existence of other concomitant medical conditions may increase the incidence of MRONJ. The primary aim of this research was to analyze all available evidence and evaluate the reported outcomes of osteonecrosis of the jaws (ONJ) due to antiresorptive drugs in immunosuppressed patients. A multi-database (PubMed, MEDLINE, EMBASE and CINAHL) systematic search was performed. The search generated twenty-seven studies eligible for the analysis. The total number of patients included in the analysis was two hundred and six. All patients were deemed to have some form of immunosuppression, with some patients having more than one disorder contributing to their immunosuppression. Within this cohort the commonest trigger for MRONJ was a dental extraction (n=197). MRONJ complications and recurrence after treatment was sparsely reported in the literature, however a total of fourteen cases were observed. The data reviewed have confirmed that an invasive procedure is the commonest trigger of MRONJ with relatively high frequency of post-operative complications or recurrence following management. However, due to low-quality research available in the literature it is difficult to draw a definitive conclusion on the outcomes analysed in this systematic review.

The risk of osteonecrosis of the jaw and adverse outcomes in patients using antiresorptive drugs undergoing orthodontic treatment: A systematic review

Objectives

Medication-related osteonecrosis of the jaw (MRONJ) is rare. It is a serious adverse effect of certain drugs, of which bisphosphonates (BPs) are the most widely known. The aim of this systematic review was to analyze all published evidence for the reported adverse outcomes as a result of orthodontic treatment in patients undergoing antiresorptive therapy.

Data

All types of studies involving patients undergoing orthodontic treatment and treated with antiresorptive drugs were considered. A meta-analysis was not conducted due to the high amount of variability and heterogeneity in the reporting and presentation of data among the studies meeting the inclusion criteria.

Sources

A systematic search was performed using 4 databases (PubMed, MEDLINE, EMBASE and CINAHL).

Study selection

Seven studies matched the inclusion criteria for this review, reporting a total of 29 patients. MRONJ was only reported in 1 patient. The adverse outcomes following orthodontic treatment included difficulty achieving root parallelism (n = 4), difficulty achieving complete space closure (n = 3), exaggerated tooth mobility post-debond (n = 2), increased duration of orthodontic treatment beyond expected completion (n = 1), sclerotic alveolar bone changes seen on post-op radiographic images (n = 2), and an increased amount of root resorption (n = 1).

Conclusions

The high amount of heterogeneity and limited evidence precluded a valid interpretation and analysis of the results through pooling of data. Additional data with sufficient quality, a reduction of bias, and a greater prospective cohort of patients is crucial to assess adverse effects, mechanisms of action, and associated risk factors in at-risk patients.

Clinical significance

Based on the limited evidence available in the literature, it is unclear whether orthodontic treatment alone can precipitate MRONJ. However, antiresorptive drug therapy may be associated with a sub-optimal treatment outcome.

A systematic review of metastatic cancer presenting in osteonecrosis of the jaws (MC-ONJ) in patients undergoing antiresorptive and/or antiangiogenic therapy for skeletal-related adverse events

INTRODUCTION

Osteonecrosis of the jaw (ONJ) is reported to be primarily associated with patients receiving bisphosphonate therapies but has been found in patients taking a number of other medications. A number of recent reports have noted the presence of metastatic cancers in the histologic analysis of osteonecrotic lesions from the jaw. The aim of the present review is to estimate the frequency and the type of metastatic cancer most commonly found in ONJ specimens in patients undergoing antiresorptive and/or antiangiogenic drug therapy.

MATERIAL AND METHODS

A multidatabase (PubMed, MEDLINE, EMBASE, and CINAHL) systematic search was performed. Any studies involving human participants treated with antiresorptive and antiangiogenic drugs were considered. Where study patients presented with malignant cells within osteonecrotic specimens, further data were collected. Data are presented using descriptive statistics.

RESULTS

A total of 13 studies met the inclusion criteria for this systematic review. Thirty-seven study patients had histologic evidence of malignant cells within medication-related osteonecrosis of the jaw (MRONJ) specimens. The most frequent phenotype of malignant cells found within MRONJ specimens were breast cancer variants (n = 15). The frequency of malignant tumor cells found within the MRONJ specimens was calculated using 4 studies. Out of 604 patients, the frequency was 4.64% (n = 28).

CONCLUSIONS

Based on the limited data available in the literature, it is plausible that not histologically analyzing all ONJ specimens could result in a small number of undiagnosed and untreated malignant diseases. Additional data based on a larger cohort of study patients is necessary to understand the role of MRONJ in metastatic spread and the influence of surgical treatment and reoccurrence.

Actinomyces and MRONJ: A retrospective study and a literature review

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

Medication-Related Osteonecrosis of the Jaws

Medication-related osteonecrosis of the jaw is an oral complication in cancer patients being treated with either antiresorptive or antiangiogenic drugs. The first reports of MRONJ were published in 2003. Hundreds of manuscripts have been published in the medical and dental literature describing the complication, clinical and radiographic signs and symptoms, possible pathophysiology, and management. Despite this extensive literature, the pathobiological mechanisms by which medication-related osteonecrosis of the jaw develops have not yet been fully delineated. The aim of this manuscript is to present current knowledge about the complication ragarding to the definition, known risk factors, and clinical management recommendations. Based on this current state of the science, we also propose research directions that have potential to enhance the management of future oncology patients who are receiving these agents.

Indigenous Microbiota Protects against Inflammation-Induced Osteonecrosis

Medication-related osteonecrosis of the jaw (MRONJ) is a rare intraoral lesion that occurs in patients undergoing long-term and/or high-dose therapy with nitrogen-containing bisphosphonates, a RANKL inhibitor, antiangiogenic agents, or mTOR inhibitors. The presence of pathogenic bacteria is highly associated with advanced stages of MRONJ lesions; however, the exact role of indigenous microbes in MRONJ development is unknown. Here, we report that the normal oral flora in mice protects against inflammation-induced osteonecrosis. In mice that developed osteonecrosis following tooth extraction, there was increased bacterial infiltration when compared with healed controls. Antibiotic-mediated oral dysbiosis led to a local inhibition of bone resorption in the presence of ligature-induced periodontitis (LIP). There was no significant difference in empty lacunae, necrotic bone formation, osteoclast number, and surface area in antibiotic-treated as compared with conventionally colonized mice following extraction of healthy teeth after zoledronic acid infusions. However, extraction of LIP teeth led to increased empty lacunae, necrotic bone, and osteoclast surface area in antibiotic- and zoledronic acid-treated mice as compared with conventionally colonized mice. Our findings suggest that the presence of the indigenous microbiota protects against LIP-induced osteonecrosis.

Risk of Delayed Healing of Tooth Extraction Wounds and Osteonecrosis of the Jaw among Patients Treated with Potential Immunosuppressive Drugs: A Retrospective Cohort Study

Bone-modifying or antiresorptive agents that target osteoclasts, such as bisphosphonates, are known to cause delayed wound healing and osteonecrosis of the jaw (ONJ) following tooth extraction. However, there are no data on whether such adverse events are also caused by drugs that may suppress the immune system, including corticosteroids, immunosuppressants, biological agents, and disease-modifying anti-rheumatic drugs (DMARDs). The aim of this retrospective study was to examine the incidence of delayed post-extraction wound healing and identify risk factors among patients treated with potential immunosuppressive drugs undergoing tooth extraction. We performed a retrospective cohort study involving 101 patients by reviewing their medical records. The underlying diseases of the enrolled patients included dilated cardiomyopathy, hematological malignancy, sarcoidosis, rheumatoid arthritis, and systemic lupus erythematosus. The sample comprised 131 cases of tooth extraction among the 101 patients; delayed post-extraction wound healing occurred in 10 patients (12 cases, 9.2%), including ONJ in three patients (3 cases, 2.3%). The surgical tooth extraction performed for impacted teeth or a residual root (P = 0.009), the number of surgical tooth extraction (P = 0.012), decreased lymphocyte counts (P = 0.008), and decreased eosinophil counts (P = 0.009) were significantly related to delayed wound healing. Thus, among patients taking corticosteroids, immunosuppressants, biological agents, and/or DMARDs, there is a risk of delayed wound healing and ONJ. Moreover, the significant risk factors are low lymphocyte counts, low eosinophil counts, and surgical extraction. It is of particular importance to prevent surgical site infection, when the high-risk patients undergo tooth extraction.

Nitrogen-containing bisphosphonate therapy-Part II: Assessment of alveolar bone tissue inflammatory response in rats-A blind randomized controlled trial

This study aimed to evaluate the alveolar bone tissue inflammatory response in rats undergoing zoledronic acid therapy. The study sample was composed of 28 Wistar rats. Animals from the test group GTa received a weekly intraperitoneal dose of 0.2 mg/kg of zoledronic acid for 3 weeks, while test group GTb received the same dose for 8 weeks. A physiological saline dose, equivalent to that of the medication, was administered to the controls in groups GCa and GCb. A defect was created in the dental crown of the lower first molars using a drill to simulate pulp and periapical injury. Data were evaluated regarding image grey levels by cone-beam computed tomography and histologically by assigning scores for the presence of inflammatory infiltrate, type of infiltrate, vascularization, bone necrosis and dental resorption. Grey levels in the 3-week therapy group (GTa) showed more pronounced changes in comparison with those seen in the GCa group (P < 0.05). Evaluation of the scores demonstrated no association between any of the variables amongst the groups (>0.05). However, bone remodelling decreased in the groups receiving the medication. Bone necrosis was present more frequently in group GTb than in the control group GCb. The results suggest that the drug interfered in the reaction capacity of the alveolar bone tissue as test group GTa showed higher grey levels in comparison to the control group GCa. In addition, there was less bone remodelling activity, with the appearance of bone necrosis zones and intense acute inflammatory infiltrate associated with the 8-week therapy group GTb.

Treatment of stage II medication-related osteonecrosis of the jaw with necrosectomy and autologous bone marrow mesenchymal stem cells

Treatment strategies for medication-related osteonecrosis of the jaw (MRONJ) remain controversial. Although the AAOMS suggests a conservative approach, a surgical management with necrosectomy is often required when conservative management has failed. Moreover, recent studies have shown promising results using an early stage surgical treatment. Over the past decade, cell-based bone regeneration utilizing bone marrow mesenchymal stem cells (MSCs) received increased attention. MSCs are known to promote wound healing and induce new bone formation in compromised tissue. Accordingly, the aim of this study was to assess the role of MSCs in the management of MRONJ. This study included 6 patients referred to our department with the diagnosis of MRONJ. Upon informed consent, the patients underwent surgical resection of necrotic bone followed by MSCs grafting. The MSCs were separated from bone marrow cells aspirated from the iliac crest using a bone marrow aspirate concentrate system. The MSCs were grafted into the defect with autologous thrombin and the defect was covered with a collagen membrane. In all cases, bony edges were rounded and the wound was closed using a three-layered technique. In the follow-up from 12 to 54 months, all patients including those who had impaired conditions, sepsis, or pathological fracture, showed satisfactory healing with no signs of wound infection. This pilot study indicated that surgical management in combination with MSCs transplantation seems to be a promising treatment modality in the therapy of MRONJ.

Analysis of different therapeutic protocols for osteonecrosis of the jaw associated with oral and intravenous bisphosphonates

Introduction

Chemotherapy-associated osteonecrosis of the jaw caused by bisphosphonates is an exposure of necrotic bone with more than eight weeks of evolution that is attributable to bisphosphonates and no prior radiation therapy. Its etiopathogenesis remains unknown, although there are two hypotheses that may explain it: the drug’s mechanism of action, and the risk factors that can lead to osteonecrosis. There is a wide range of treatment options for managing chemotherapy-associated osteonecrosis of the jaw, from conservative treatments to surgical procedures of varying levels of invasiveness, which are sometimes supplemented with adjuvant therapies.

Objectives

The objective of this article is to group the therapeutic options for osteonecrosis of the jaw (ONJ) into seven different protocols and to evaluate their effectiveness in relation to stage of ONJ.

Material and Methods

A literature review was carried out in PubMed following the PRISMA criteria. A total of 47 were collected after compiling a series of variables that define ONJ, applied treatments, and the clinical results obtained.

Results and Discussion

The 47 articles selected have a low to average estimated risk of bias and are of moderate to good quality. According to the data obtained, Protocol 3 (conservative treatment, clinical and radiological follow-up, minimally invasive surgical treatment, and adjuvant therapies) is the most favorable approach for ONJ lesions caused by oral bisphosphonates. For lesions caused by intravenous bisphosphonates, Protocol 2 (conservative treatment, clinical and radiological follow-up, minimally invasive surgical treatment, and no adjuvant therapies) is the best approach. When comparing the different stages of ONJ, Protocol 1 (conservative treatment, clinical and radiological follow-up) promotes better healing of Stage 1 ONJ lesions caused by orally administered bisphosphonates, and Protocol 3 is recommended for Stage II. For ONJ lesions attributable to intravenous bisphosphonates, Protocol 7 (conservative treatment, clinical and radiological follow-up, and adjuvant therapies) provides the best results in Stage 0; in Stages I, II, and III, Protocol 1 gives better results.

Key words:Bisphosphonates, bronj, therapeutic protocol, clinical result.

Evaluation of the predisposing factors and involved outcome of surgical treatment in bisphosphonate-related osteonecrosis of the jaw cases including bone biopsies

Objectives

This study examined the statistical relevance of whether the systemic predisposing factors affect the prognosis of surgical treatment of bisphosphonate-related osteonecrosis of the jaw (BRONJ). All cases had undergone bone biopsies to determine the characteristics of the mechanisms of BRONJ by optical microscopy.

Materials and Methods

The data included 54 BRONJ cases who underwent surgery and in whom bone biopsies were performed. The results of surgery were evaluated and the results were classified into 3 categories: normal recovery, delayed recovery, and recurrence after surgery. The medical history, such as diabetes mellitus, medication of steroids, malignancies on other sites was investigated for an evaluation of the systemic predisposing factors in relation to the prognosis. The three factors involved with the medication of bisphosphonate (BP) were the medication route, medication period, and drug holiday of BP before surgery. The serum C-terminal cross-linking telopeptide (CTX) value and presence of microorganism colony in bone biopsy specimens were also checked. Statistical analysis was then carried out to determine the relationship between these factors and the results of surgery.

Results

The group of patients suffering from diabetes and on steroids tended to show poorer results after surgery. Parenteral medication of BP made the patients have a poorer prognosis after surgery than oral medication. In contrast, the medication period and drug holiday of BP before surgery did not have significance with the results of surgery nor did the serum CTX value and presence of microorganism colony. Necrotic bone specimens in this study typically showed disappearing new bone formation around the osteocytic lacunae and destroyed Howship's lacunae.

Conclusion

Although many variables exist, this study could in part, predict the prognosis of surgical treatment of BRONJ by taking the patient's medical history.

Nitrogen-containing bisphosphonate therapy: assessment of the alveolar bone structure in rats - a blind randomized controlled trial

This study aimed to assess the effect of zoledronic acid exposure on structures of the alveolar bone of rats. The sample was composed of 42 male Wistar rats. Animals in the T1 and T2 groups received weekly doses of 0.2 mg/kg intraperitoneal zoledronic acid for 3 weeks, while animals in the T3 group received the same treatment for 8 weeks. The control groups C1, C2 and C3 received equivalent doses of saline. The first upper molars of Wistar rats in the C2, T2, C3 and T3 groups were extracted. Cone-beam computerized tomography scans were performed, and the image density was analysed by grey levels. The presence and type of inflammatory infiltrate, vascularization and bone necrosis were assigned by histological qualitative scores. Histomorphometric analysis of bone density was performed in the groups without extraction. No significant differences were found in the bone grey density estimated by grey-level value and histomorphometric analysis between the C1 and T1 groups (P > 0.05). The grey levels in the T3 group were lower (P < 0.05) than in the C3 group, corresponding to the bone defect. Histological assessments showed the presence of bone necrosis in the T3 group and lower levels of bone remodelling in the test groups (T2 and T3) compared to the control groups (C2 and C3). The results of qualitative analyses did not differ significantly between the groups (P > 0.05). Zoledronic acid-exposed animals showed maxillary changes including reduced grey levels, the presence of bone necrosis and a higher prevalence of inflammatory signs.

Incidence and risk predictors for osteonecrosis of the jaw in cancer patients treated with intravenous bisphosphonates

INTRODUCTION

The aim of this study was to establish the incidence of bisphosphonate-related osteonecrosis of the jaws (BRONJ) in oncologic patients and to determine risk predictors with respect to this condition.

MATERIAL AND METHODS

This retrospective review included 197 oncologic patients treated from January 2005 to December 2010 with administration of bisphosphonates (BPs) as part of management. Sex, age, type of cancer diagnosed, period of substantial disease, oral surgery, type of bisphosphonate, number of doses, and cases of BRONJ diagnosis were recorded. The cumulative incidence and incidence rate of BRONJ were calculated. The factors that influenced BRONJ were assessed with multivariate logistic regression and with estimations of 95% confidence intervals and odd ratios. Values of p ≤ 0.05 were considered significant.

RESULTS

The BRONJ appeared in 9.64% of patients. The BRONJ incidence rate was 1 in 28 patients per year of BP treatment. Logistic regression showed that the odds of osteonecrosis increased 1.0172-fold with each given dose of BP. The BRONJ risk with zoledronate was 5-fold higher than that with pamidronate or ibandronate. The risk of BRONJ increased by 40-fold after dental surgery.

CONCLUSIONS

Period of BP administration and type of BP used are important risk predictors for the development of BRONJ in oncologic patients treated with intravenous administration of these drugs. Patient-related factors are dental or periodontal events connected with need for oral surgery.

Oral microbiota and host innate immune response in bisphosphonate-related osteonecrosis of the jaw

Bacterial biofilms have emerged as potential critical triggers in the pathogenesis of bisphosphonate (BP)-related osteonecrosis of the jaw (ONJ) or BRONJ. BRONJ lesions have shown to be heavily colonized by oral bacteria, most of these difficult to cultivate and presents many clinical challenges. The purpose of this study was to characterize the bacterial diversity in BRONJ lesions and to determine host immune response. We examined tissue specimens from three cohorts (n=30); patients with periodontal disease without a history of BP therapy (Control, n=10), patients with periodontal disease having history of BP therapy but without ONJ (BP, n=5) and patients with BRONJ (BRONJ, n=15). Denaturing gradient gel electrophoresis of polymerase chain reaction (PCR)-amplified 16S rRNA gene fragments revealed less bacterial diversity in BRONJ than BP and Control cohorts. Sequence analysis detected six phyla with predominant affiliation to Firmicutes in BRONJ (71.6%), BP (70.3%) and Control (59.1%). Significant differences (P<0.05) in genera were observed, between Control/BP, Control/BRONJ and BP/BRONJ cohorts. Enzyme-linked immunosorbent assay (ELISA) results indicated that the levels of myeloperoxidase were significantly lower, whereas interleukin-6 and tumor necrosis factor-alpha levels were moderately elevated in BRONJ patients as compared to Controls. PCR array showed significant changes in BRONJ patients with downregulation of host genes, such as nucleotide-binding oligomerization domain containing protein 2, and cathepsin G, the key modulators for antibacterial response and upregulation of secretory leukocyte protease inhibitor, proteinase 3 and conserved helix-loop-helix ubiquitous kinase. The results suggest that colonization of unique bacterial communities coupled with deficient innate immune response is likely to impact the pathogenesis of ONJ.

Association of dental and periodontal status with bisphosphonate-related osteonecrosis of the jaws. A retrospective case controlled study

INTRODUCTION

To assess the association of oral hygiene, dental caries, and periodontal status with bisphosphonate-related osteonecrosis of the jaws.

MATERIAL AND METHODS

A retrospective case-control study on 81 patients treated for neoplasms with bone metastases. Twenty-nine patients with bone necrosis and 52 controls treated with bisphosphonates were compared using the Oral Hygiene Index, Decay, Missing, Filled Teeth, Community Periodontal Index of Treatment Needs, and Residual Periodontal Bone. The null hypothesis stated that there was no difference in parameters of oral health between patients with and without bone necrosis. Differences of means of above-mentioned variables were compared between the groups with Student's t-test or Mann-Whitney rank sum test and χ(2) test. Value of p ≤ 0.05 was considered significant.

RESULTS

Poorer oral hygiene (OHIs 1.94 vs. 1.32; p = 0.065), more advanced dental caries (DMFT 26.85 vs. 22.87; p = 0.05), and more advanced periodontal disease (CPITN: = 0: 21.05% vs. 42.51%; = 1 13.16% vs. 7.29%; = 2: 0% vs. 15.38%; = 3: 65.79% vs. 28.34%; = 4: 0% vs. 6.48%, Residual periodontal bone 73.1% vs. 80.51%; p = 0,001) were characteristic of patients with bisphosphonate related jaw necrosis when compared with control group. An advanced dental caries or periodontal disease required surgical intervention which directly contributed to the development of the bone necrosis.

CONCLUSIONS

Dental and periodontal disease can lead to bisphosphonate-related osteonecrosis of the jaw. Oncologic patients treated with bisphosphonates should be offered preventive care to reduce dental plaque, calculus, dental caries, and periodontal disease.

Risk factors and indices of osteomyelitis of the jaw in osteoporosis patients: results from a hospital-based cohort study in Japan

BACKGROUND

Several studies have reported osteomyelitis of the jaw (OMJ) as a side effect of bisphosphonates (BPs), and the risk of oral BPs has been recently clarified. However, other systemic risk factors of OMJ remain unclear. Importantly, the possibility of risk classification based on the clinical characteristics of patients has not been explored. Here, we clarified risk factors of OMJ and evaluate the predictive accuracy of risk indices in osteoporosis patients.

METHODS

We performed sub-analysis using a database developed for a retrospective cohort study in patients taking medications for osteoporosis at Kyoto University Hospital. Risk indices for OMJ were constructed using logistic regression analysis, and odds ratios (OR) for OMJ cases and 95% confidence intervals (CI) were estimated. Potential risk factors included in the statistical analysis were age; sex; diabetes; use of oral BPs, corticosteroids, cancer chemotherapy, antirheumatic drugs, and biologic agents; and their interactions. Risk indices were calculated by the sum of potential risk factors of an individual patient multiplied by the regression coefficients. The discriminatory power of the risk indices was assessed by receiver operating characteristic (ROC) analysis.

RESULTS

In analysis of all patients, oral BPs (OR: 4.98, 95% CIs: 1.94-12.75), age (OR: 1.28, 95% CI: 1.06-1.60) and sex-chemotherapy interaction (OR: 11.70, 95% CI: 1.46-93.64) were significant risk factors of OMJ. Areas under the ROC curves of these risk indices provided moderate sensitivity or specificity regardless of group (0.683 to 0.718).

CONCLUSIONS

Our data suggest that oral BP use, age, and sex-chemotherapy are predictors of OMJ in osteoporosis patients. The risk indices are moderately high, and allow the prediction of OMJ incidence.

Is bisphosphonate therapy compromised by the emergence of adverse bone disorders?

Bisphosphonates (BPs) are the preferred class of antiresorptive agents used for the treatment of osteoporosis and bone metastases. Recently, an increasing number of clinical reports concerning osteonecrosis of the jaw and atypical fractures have suggested a link between prolonged use of BPs and these adverse bone events, which are exceptionally difficult to treat. Even though these side effects were mainly observed in patients with metastases, osteoporotic patients might become increasingly affected by these conditions with the increasing use of injectable BPs. Could these severe adverse bone events compromise the use of BPs? The development of these unfavorable conditions as a consequence of oversuppression of bone resorption could raise concern regarding the use of therapeutic strategies involving antiresorptive drugs.

Interleukin-6 concentration changes in plasma and saliva in bisphosphonate-related osteonecrosis of the jaws

AIM

To determine the plasma and saliva levels of IL-6 in patients with bisphosphonate-related osteonecrosis of the jaws (BRONJ) and to investigate whether there is a correlation between more advanced stages of BRONJ and levels of IL-6.

MATERIAL AND METHODS

We studied three groups: group 1 consisted of 30 patients with BRONJ due to intravenous bisphosphonates (ivBP), group 2 consisted of 25 patients treated with ivBP but without BRONJ, and group 3 consisted of 15 healthy controls. In each case, we assayed plasma and saliva IL-6 samples using an ELISA test.

RESULTS

Significantly, higher IL-6 values were found in both saliva and plasma in group 1 vs groups 2 and 3 (P < 0.01). Group 1 showed no differences in plasma or saliva IL-6 according to patient gender (P > 0.05), type of tumor, BRONJ location, etiology of BRONJ, or disease stage (P > 0.05). We found higher plasma and saliva IL-6 values in the more advances stages of BRONJ, although the differences were not statistically significant.

CONCLUSIONS

Plasma and saliva IL-6 values were higher in our patients with BRONJ than in controls and therefore might be a useful tool for monitoring the severity of BRONJ.

Osteopathology associated with bone resorption inhibitors - which role does Actinomyces play? A presentation of 51 cases with systematic review of the literature

BACKGROUND

Bone resorption inhibitor-related osteopathology of the jaw (BRIOJ) is a severe complication in patients treated with bisphosphonates or denosumab. However, the precise pathogenesis of BRIOJ is not yet fully understood. Recent studies discovered the presence of Actinomyces colonies in biopsy material from BRIOJ patients. The aim of this study was to analyze current knowledge concerning the impact of Actinomyces on the pathogenesis of this condition and to present data from our own patients.

METHODS

Data from 51 patients with histopathological diagnoses of BRIOJ were retrospectively analyzed. In addition, a systematic literature search for studies describing the presence of Actinomyces was performed.

RESULTS

Actinomyces was present in 86% of our cases and 63.3% of 371 cases presented in the literature. All of our patients and 85% of patients described in the literature had a clearly defined local focus in association with osteopathology. A clear picture of whether Actinomyces colonizes the previously necrotic bone or contributes to inflammation causing subsequent bone necrosis is lacking in the literature.

CONCLUSION

The pathogenesis of BRIOJ remains unknown; however, there seems to be a role for Actinomyces, and possibly other pathogens, in the development of osteopathology of the jaws, which is not exclusive to bisphosphonate therapy. This study supports the hypothesis that an infectious component is of utmost importance for the pathogenesis of BRIOJ.

Osteonecrosis of the jaw onset times are based on the route of bisphosphonate therapy

PURPOSE

Osteonecrosis of the jaw (ONJ) has been reported to be associated with patients receiving bisphosphonate (BP) therapy. There are many reports that suggest that the time of exposure to BPs is a significant risk factor for ONJ and that the greatest risk occurs after dentoalveolar surgery. The aim of this study was to retrospectively investigate the duration of BP therapy and related events before the onset of ONJ based on an intravenous (IV) or oral route of administration.

MATERIALS AND METHODS

We conducted a retrospective cohort study of patients referred to our institution to identify the onset of ONJ based on the exposure to BP therapy and associated triggers (ie, dentoalveolar surgery or spontaneous occurrence) based on the route of BP administration. Demographic data (ie, age, gender, and race), medical diagnosis related to BP therapy, and information as to whether the BP therapy was continued at the time of ONJ diagnosis were also collected.

RESULTS

We reviewed the records for 114 patients with a history of ONJ. We divided patient cohorts by route of BP administration, with 76 patients having a history of IV BP therapy and 38 patients having a history of oral BP therapy. The overall onset of ONJ was earlier in the IV BP group (median, 3 years) compared with the oral BP group (median, 5 years). There was no statistical difference in the duration to occurrence of ONJ associated with dental extraction compared with spontaneous occurrence for both the IV and oral BP groups.

CONCLUSIONS

The median onset of ONJ for patients undergoing IV BP therapy occurs earlier than the median onset for patients undergoing oral BP therapy, and there was no difference in onset occurring spontaneously and after dental extraction. The significance of these findings suggests that patients who receive IV BP therapy should be closely evaluated after the initiation of BP therapy. The lack of evidence suggesting greater onset after dental extraction may provide clinical support for dentoalveolar surgery that is indicated for patients with a history of BP therapy. Research focusing on the clinical circumstances and physiologic events during early antiresorptive therapy may provide insight as to the critical risk factors.

Posttransplant lymphoproliferative disorder presenting as a nonhealing extraction socket: a case report and review of the literature

Posttransplant lymphoproliferative disorder (PTLD) is a well-recognized complication of long-term immunosuppression following hematopoietic or solid organ transplantation and is associated with significant morbidity and mortality. We present a unique case of PTLD that manifested with a nonhealing dental extraction socket 17 years after renal transplantation. We summarize the existing literature and present a review of an additional 25 cases. These highlight the variable clinical presentations of PTLD within the oral cavity and clear potential for delayed presentation at this anatomical subsite.

Comparison of local and systemic alendronate on distraction osteogenesis

This study compared the effect of systemic and local administration of alendronate on distraction osteogenesis in rabbit mandibles. Thirty New Zealand white rabbits were allocated to 3 groups: 10 rabbits for systemic alendronate; 9 for local alendronate; and 11 as controls. After a 5 day latency period, distraction was performed at a rate of 0.8mm/day for 9 days via a custom-made distractor. Animals were killed at the end of the consolidation period of 28 days. The distracted mandibles were harvested and evaluated by plain radiography, computed tomography (CT), dual energy X-ray absorptiometry (DEXA), and histomorphometry. Histologically, comparing the systemic and local alendronate groups, there were no statistically significant differences in the bone healing parameters, but each group showed a statistically superior effect over the control group (p<0.05). Quantitative CT evaluation showed a significant difference mean in the density of the regeneration between experimental and control groups. There was a significant increase in mean bone mineral density in the experimental groups compared with the control group. Histologic, CT, and DEXA analysis demonstrated that using systemic and local alendronate may be effective in accelerating new bone formation in the distraction gap in rabbit mandibles.

Potential pathophysiological mechanisms in osteonecrosis of the jaw

Bisphosphonates are used in the treatment of hypercalcemia of malignancy, skeletal complications associated with metastastic bone disease, Paget's disease, and osteoporosis. Osteonecrosis of the jaw (ONJ) is a recently described clinical condition that has been associated with the use of nitrogen-containing bisphosphonates. Reports describing this entity first appeared in the literature in 2003. While there have been significant numbers of case reports and a limited number of retrospective and prospective studies examining risk factors associated with ONJ, the pathophysiology of this condition remains elusive. In this review, we explore proposed mechanisms underlying ONJ development and identify potential areas for future investigation.