Oral Bisphosphonate-Induced Osteonecrosis: Risk Factors, Prediction of Risk Using Serum CTX Testing, Prevention, and Treatment

Bisphosphonate Modulation of the Gene Expression of Different Markers Involved in Osteoblast Physiology: Possible Implications in Bisphosphonate-Related Osteonecrosis of the Jaw

The aim of the present study was to elucidate the role of osteoblasts in bisphosphonates-related osteonecrosis of the jaw (BRONJ). The specific objective was to evaluate the effect on osteoblasts of two nitrogen-containing BPs (zoledronate and alendronate) and one non-nitrogen-containing BP (clodronate) by analyzing modulations in their expression of genes essential for osteoblast physiology. Real-time polymerase chain reaction (RT-PCR) was used to study the effects of zoledronate, alendronate, and clodronate at doses of 10-5, 10-7, or 10-9 M on the expression of Runx-2, OSX, ALP, OSC, OPG, RANKL, Col-I, BMP-2, BMP-7, TGF-β1, VEGF, TGF-βR1, TGF-βR2, and TGF-βR3 by primary human osteoblasts (HOBs) and MG-63 osteosarcoma cells. Expression of these markers was found to be dose-dependent, with no substantive differences between these cell lines. In general, results demonstrated a significant increase in TFG-β1, TGF-βR1, TGF-βR2, TGF-βR3, and VEGF expressions and a significant reduction in RUNX-2, Col-1, OSX, OSC, BMP-2, BMP-7, ALP, and RANKL expressions, while OPG expression varied according to the dose and cell line. The results of this in vitro study of HOBS and MG-63 cell lines indicate that low BP doses can significantly affect the expression of genes essential for osteoblast growth and differentiation and of genes involved in regulating osteoblast-osteoclast interaction, possibly by increasing TGF-β1 production. These findings suggest that osteoblasts may play an important role in BRONJ development, without ruling out other factors.

Short-Term Teriparatide and Recombinant Human Bone Morphogenetic Protein-2 for Regenerative Approach to Medication-Related Osteonecrosis of the Jaw: A Preliminary Study

Our objective was to examine whether adjunct teriparatide administration and local application of recombinant human bone morphogenetic protein-2 (rhBMP-2) is beneficial for the regeneration of jaw bone in patients with medication-related osteonecrosis of the jaw (MRONJ). This study enrolled 17 patients diagnosed with MRONJ. All patients received sequestrectomy under general or local anesthesia with suspension of bisphosphonate. The bone regeneration ratio was compared on cone beam computed tomography (CBCT) scans, acquired immediately post-operation and after 6 months. The patients were divided into groups, based on their treatment regimens: teriparatide combined with rhBMP-2 (parathyroid hormone [PTH]+BMP), rhBMP-2 (BMP), and the control. Biochemical markers were also evaluated at the baseline (T0), 1 month (T1), and 3 months (T2) after surgery. Significant increase was observed in the values of the biochemical markers, serum osteocalcin, and serum C-terminal telopeptide cross-link of type I collagen, within 3 months of surgery in the PTH+BMP group, whereas the mean value in the BMP group did not show a significant change. In all groups, the MRONJ lesions were healed and new bone formation was detected in the CBCT images. The regeneration ratio was significantly greater in the group PTH+BMP than in the BMP and control groups. Significantly greater amount of bone formation was observed in the group PTH+BMP than in the BMP and control groups. Local application of rhBMP-2 alone also had a beneficial effect on bone regeneration but was not more significant than control. Based on these findings, administration of short-term teriparatide with rhBMP-2 in MRONJ patients may maximize the regeneration of bone after surgery. © 2017 American Society for Bone and Mineral Research.

Evaluation of clinical and radiographic indices as predictors of osteoporotic fractures: a 10-year longitudinal study

OBJECTIVES

The aim of the study was to evaluate 2 radiographic and 3 clinical indices as predictors of future osteoporotic fractures.

STUDY DESIGN

In a prospective, longitudinal study with a 10-year fracture follow-up, the 2 radiographic indices mandibular cortical erosion (normal, mild/moderate erosion, and severe erosion of the inferior cortex) and cortex thickness were assessed using panoramic radiographs of 411 women, age 62 to 78 years. The clinical indices were the fracture assessment tool FRAX, the osteoporosis index of risk (OSIRIS), and the osteoporosis self-assessment tool (OST).

RESULTS

The relative risks (RRs) for future fracture were significant for FRAX greater than 15%, 4.1 (95% confidence interval [CI] 2.4-7.2), and for severely eroded cortices, 1.7 (95% CI 1.1-2.8). Cortical thickness less than 3 mm, OSIRIS, and OST were not significant fracture predictors (RR 1.1, 1.4, and 1.5, respectively). For the 5 tested fracture predictors, Fisher's exact test gave the following P values for differences between fracture and nonfracture groups: FRAX <.001, cortical erosion 0.023, OST 0.078, OSIRIS 0.206, and cortical thickness 0.678. The area under the curve was 0.69 for FRAX less than 15%, 0.58 for cortical erosion, and 0.52 for cortical thickness. Adding OSIRIS and OST did not change the area under the curve significantly.

CONCLUSIONS

FRAX and severely eroded cortices predicted fracture but cortical thickness, OSIRIS, and OST did not.

Effects of local alendronate administration on bone defect healing. Histomorphometric and radiological evaluation in a rabbit model

PURPOSE

To performed a histomorphometric and radiological study to evaluate the effects of alendronate sodium administered locally in mandibular bone defects created in rabbits.

METHODS

Two circular defects 5 mm in diameter were created bilaterally in the mandibular corpus of 20 New Zealand rabbits (i.e., four defects per animal). Each defect received one of four treatments: no treatment (EC group), alendronate irrigation (AL group), autogenous bone grafting (AG group), or alendronate irrigation with autogenous bone grafting (AL+AG group). Histomorphometric and radiological assessments were conducted at 4 and 8 weeks after surgery.

RESULTS

Between-group comparisons of the new bone area, the value of the AL+AG group was significantly lower thanthe remaining three groups at 4 weeks postoperatively. In all groups, the new bone area was significantly larger at 8 weeks than at 4 weeks. The residual graft area at 4 and 8 weeks was significantly higher in the AL+AG group than in the AG group, although it was significantly smaller at 8 weeks than at 4 weeks in both these groups.

CONCLUSION

The use of alendronate sodium in conjunction with autogenous bone grafting improves the osteoconductive properties of the graft, enhances graft retention in the defect, and improves ossification.

Safety and efficacy of hydroxyapatite scaffold in the prevention of jaw osteonecrosis in vivo

Two scaffolds of chitosan/sodium alginate/hydroxyapatite (Ch/NaAlg/Hap) 1:1:0.2 and 1:1:0.6 were evaluated in the prevention of bisphosphonate-induced jaw osteonecrosis. Two groups of rats (n = 24, according to the euthanasia time: 15 or 30 days after the last Zoledronic acid (ZA) administration) were subdivided in four subgroups (n = 6): I - Control (saline + teeth extraction); II - ZA 0.6 mg/kg + teeth extraction; III - ZA + teeth extraction + scaffold 1:1:0.2; IV - ZA + teeth extraction + scaffold 1:1:0.6. Jaws were evaluated histologically and blood was evaluated for hematological and biochemical parameters. Histopathology showed significant osteonecrosis in AZ group. The scaffold's implantation, despite the inflammatory process, were able to prevent the osteonecrosis. In the 15-day euthanasia group, an increase in red blood cells and platelets was observed in the subgroup II. Hemoglobin and hematocrit decreased in subgroup IV compared to II. Hepatic transaminases and creatinine concentration increased significantly in subgroup II. Calcium concentration increased in subgroup IV compared to II. In the 30-day euthanasia group, no differences among the groups were observed for any parameter. Scaffolds proved to be efficient and safe to liver and kidney function. Some hematological parameters were altered by the scaffold, but returned to normal concentrations over time. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1799-1808, 2018.

Exposed necrotic bone in 183 patients with bisphosphonate-related osteonecrosis of the jaw: Associated clinical characteristics

BACKGROUND

The main objective of our study was to identify oral symptoms and signs most likely to be associated with the exposure of necrotic bone in bisphosphonate-related osteonecrosis of the jaw (BRONJ).

MATERIAL AND METHODS

The study group consisted of 183 patients with BRONJ. We recorded data on the underlying disease, bisphosphonate used, location of osteonecrosis, symptoms, pain, fistula development, suppuration, infection, exposed necrotic bone, and BRONJ stage.

RESULTS

The mean age of the patients was 68.22 ± 12.19 years. The sample included 118 (64.5%) women. Breast cancer and multiple myeloma were the most common underlying diseases, and 50 patients received oral bisphosphonates for osteoporosis. Dental extractions (69.4%) and mandibular location (74.3%) predominated. The only two variables influencing the possibility of necrotic bone exposure were intravenous bisphosphonate administration and the presence of an intraoral fistula (p < 0.05).

CONCLUSIONS

Intravenous bisphosphonate use and intraoral fistula presence were associated with a major predisposition to bone exposure in patients with BRONJ.

Serum levels of RANKL and OPG, and the RANKL/OPG ratio in bisphosphonate-related osteonecrosis of the jaw: Are they useful biomarkers for the advanced stages of osteonecrosis?

Background

We determined whether serum levels of Receptor Activator for Nuclear Factor κ B Ligand (RANKL), Osteoprotegerin (OPG), and the RANKL/OPG ratio could be useful biomarkers for the severity of oral lesions in bisphosphonate-related osteonecrosis of the jaw (BRONJ).

Material and Methods

A case-control study in which Group 1 consisted of 41 patients with BRONJ due to intravenous bisphosphonates, and Group 2 consisted of 44 healthy control cases. The plasma levels of RANKL and OPG were analyzed by an ELISA assay. The OPG/RANKL ratio was also calculated. We determined if the mean serum values differed among the different stages of BRONJ.

Results

Serum levels of RANKL were lower in Group 1 than in Group 2 (p =0.01), and serum levels of OPG were higher in patients with BRONJ than in the controls (p =0.006). The ratio of RANKL/OPG was greater in the controls than in Group 1 (P >0.01). There were no significant differences in the serum levels of RANKL and OPG among the different stages of osteonecrosis (P > 0.05).

Conclusions

Serum levels of RANKL and OPG, and the RANKL/OPG ratio were not valuable biomarkers for determining the severity of oral lesions in patients with BRONJ.

Key words:Bisphosphonates, RANKL, OPG, Osteonecrosis.

A multicenter retrospective study of the risk factors associated with medication-related osteonecrosis of the jaw after tooth extraction in patients receiving oral bisphosphonate therapy: can primary wound closure and a drug holiday really prevent MRONJ?

Root amputation, extraction of a single tooth, bone loss or severe tooth mobility, and an unclosed wound were significantly associated with increased risk of developing medication-related osteonecrosis of the jaw (MRONJ). We recommend a minimally traumatic extraction technique, removal of any bone edges, and mucosal wound closure as standard procedures in patients receiving bisphosphonates.

INTRODUCTION

Osteonecrosis of the jaws can occur following tooth extraction in patients receiving bisphosphonate drugs. Various strategies for minimizing the risk of MRONJ have been advanced, but no studies have comprehensively analyzed the efficacy of factors such as primary wound closure, demographics, and drug holidays in reducing its incidence. The purpose of this study was to retrospectively investigate the relationships between these various risk factors after tooth extraction in patients receiving oral bisphosphonate therapy.

METHODS

Risk factors for MRONJ after tooth extraction were evaluated using univariate and multivariate analysis. All patients were investigated with regard to demographics; type and duration of oral bisphosphonate use; whether they underwent a discontinuation of oral bisphosphonates before tooth extraction (drug holiday), and the duration of such discontinuation; and whether any additional surgical procedures (e.g., incision, removal of bone edges, root amputation) were performed.

RESULTS

We found that root amputation (OR = 6.64), extraction of a single tooth (OR = 3.70), bone loss or severe tooth mobility (OR = 3.60), and an unclosed wound (OR = 2.51) were significantly associated with increased risk of developing MRONJ.

CONCLUSIONS

We recommend a minimally traumatic extraction technique, removal of any bone edges, and mucosal wound closure as standard procedures in patients receiving bisphosphonates. We find no evidence supporting the efficacy of a pre-extraction short-term drug holiday from oral bisphosphonates in reducing the risk of MRONJ.

Strontium ranelate treatment in a postmenopausal woman with osteonecrosis of the jaw after long-term oral bisphosphonate administration: a case report

Bisphosphonates (BPs) suppress bone resorption and increase bone strength, thus reducing the risk of fracture. Oral BPs are widely used for the prevention and treatment of osteoporosis and osteopenia. Here, we describe the case of a postmenopausal woman who took oral alendronate for >3 years for osteoporosis. The patient presented at the clinic with sharp jaw pain and swelling on the left mandible 4 months after extraction of the third molar. Clinical examinations identified an inflamed mucosal opening with pus over an area of necrotic bone. Initial images of cone beam computed tomography revealed a sequestrum at the extracted socket. The condition did not improve after 1 week of antibiotic treatment; therefore, the alendronate treatment was terminated and the patient was prescribed strontium ranelate instead. The patient gradually recovered and, at the 2-year follow-up, the site of BP-related osteonecrosis of the jaw healed completely as determined by both clinical and cone beam computed tomography measures. The bone mineral densities in the femoral neck and lumbar spine improved after 1 year, and were maintained at the 3-year follow-up. The serum C-terminal cross-linking telopeptide values also gradually increased from the initial 130 pg/mL to 320 pg/mL at the 3-year follow-up. Taken together, this case supports the use of strontium ranelate as an alternative treatment for postmenopausal women who receive long-term oral BP treatments and are at risk for serious complications of BP-related osteonecrosis of the jaw.

Association of Bone Metabolic Markers With Diabetic Retinopathy and Diabetic Macular Edema in Elderly Chinese Individuals With Type 2 Diabetes Mellitus

BACKGROUND

Diabetic retinopathy (DR) is a common and specific microvascular complication of diabetes. The association of bone metabolic markers with the risk of DR and diabetic macular edema (DME) is unclear.

MATERIALS AND METHODS

We investigated the association between bone turnover markers commonly examined in a clinical setting and DR and DME risk in elderly Chinese patients with type 2 diabetes mellitus (T2DM). A total of 408 patients aged 55-70 years with T2DM were included. We first performed univariable logistic regression followed by multivariable logistic regression that included variables selected using purposeful selection.

RESULTS

Fasting blood glucose (P = 0.007) and duration of diabetes (P < 0.0001) were significantly associated with DME in multivariable logistic regression; however, the association of beta C-terminal telopeptide of collagen type I (β-CTx) with DME risk was not statistically significant (P = 0.053). Sex-stratified analysis showed that β-CTx was significantly associated with DME only in female subjects (P = 0.011).

CONCLUSIONS

β-CTx had no significant association with DR. It was significantly associated with DME in female patients with T2DM, but not in male patients with T2DM. More prospective studies with larger sample sizes are warranted to validate our findings.

The effect of chronic dental inflammation on development of Stage 0 medication-related osteonecrosis of the jaw

OBJECTIVE

The pathogenesis of medication-related osteonecrosis of jaw (MRONJ) is poorly understood. The aim of this prospective study was to determine the effect of chronic dental inflammation on the development of Stage 0 MRONJ based on histopathological findings.

METHODS

The study involved patients with a history of bisphosphonate use and an indication for tooth extraction. Before surgery, C-terminal telopeptide test (CTX) values were collected from all patients. All tooth extractions were performed according to a determined protocol. To detect whether any medication-related osteonecrotic changes were present in the non-exposed bone, biopsy samples were taken from the alveolar bone.

RESULTS

A total of 50 patients were included in the study (39 women and 11 men). The patients were mean age of 57.4 ± 12.1 years. In total, 74 teeth were extracted (29 maxillary and 45 mandibular). Histologic examination of three patients (6%) revealed Stage 0 MRONJ. Postoperatively, the complete mucosal healing success rate was 96%. MRONJ risk was not significantly correlated with low CTX value (p = 0.285).

CONCLUSIONS

Chronic inflammation may contribute to Stage 0 MRONJ; however, its role may not be sufficient alone for its development. Application of a predetermined protocol for dentoalveolar processes will help to prevent MRONJ development.

Radiographic evidence of treatment with bisphosphonates

Bony disease is typically evident with radiographic examination. Loss of bone mass consistent with osteoporosis is evident on plain dental radiographs, and it is reasonable to expect that anti-resorptive treatment of osteoporosis would lead to changes in radiodensity of structures visible on dental radiographs. Review of a number of radiographs of patients receiving anti-resorptive (bisphosphonate) treatment appears to confirm increased radiodensity of the structures, which may have implications in risk assessment of complications following dental procedures.

Risk factors of osteonecrosis of the jaw after tooth extraction in osteoporotic patients on oral bisphosphonates

Purpose

The aim of this study was to investigate the incidence of bisphosphonate-related osteonecrosis of the jaw (BRONJ) after tooth extraction in patients with osteoporosis on oral bisphosphonates in Korea and to evaluate local factors affecting the development of BRONJ.

Materials and Methods

The clinical records of 320 patients who underwent dental extraction while receiving oral bisphosphonates were reviewed. All patients had a healing period of more than 6 months following the extractions. Each patient's clinical record was used to assess the incidence of BRONJ; if BRONJ occurred, a further radiographic investigation was carried out to obtain a more definitive diagnosis. Various local factors including age, gender, extraction site, drug type, duration of administration, and C-terminal telopeptide (CTx) level were retrieved from the patients' clinical records for evaluating their effect on the incidence of BRONJ.

Results

Among the 320 osteoporotic patients who underwent tooth extraction, 11 developed BRONJ, reflecting an incidence rate of 3.44%. Out of the local factors that may affect the incidence of BRONJ, gender, drug type, and CTx level showed no statistically significant effects, while statistically significant associations were found for age, extraction site, and duration of administration. The incidence of BRONJ increased with age, was greater in the mandible than the maxilla, and was associated with a duration of administration of more than 3 years.

Conclusion

Tooth extraction in patients on oral bisphosphonates requires careful consideration of their age, the extraction site, and the duration of administration, and close postoperative follow-up should be carried out to facilitate effective early management.

Time to onset of bisphosphonate-related osteonecrosis of the jaws: a multicentre retrospective cohort study

OBJECTIVES

Osteonecrosis of the jaw (ONJ) is a potentially severe adverse effect of bisphosphonates (BP). Although the risk of ONJ increases with increasing duration of BP treatment, there are currently no reliable estimates of the ONJ time to onset (TTO). The objective of this study was to estimate the TTO and associated risk factors in BP-treated patients.

SUBJECTS AND METHODS

Retrospective analysis of data from 22 secondary care centres in seven countries relevant to 349 patients who developed BP-related ONJ between 2004 and 2012.

RESULTS

The median (95%CI) TTO was 6.0 years in patients treated with alendronate (n = 88) and 2.2 years in those treated with zoledronate (n = 218). Multivariable Cox regression showed that dentoalveolar surgery was inversely associated, and the use of antiangiogenics directly associated, with the TTO in patients with cancer treated with zoledronate.

CONCLUSIONS

The incidence of ONJ increases with the duration of BP therapy, with notable differences observed with respect to BP type and potency, route of administration and underlying disease. When data are stratified by BP type, a time of 6.0 and 2.2 years of oral alendronate and intravenous zoledronate therapy, respectively, is required for 50% of patients to develop ONJ. After stratification by disease, a time of 5.3 and 2.2 years of BP therapy is required for 50% of patients with osteoporosis and cancer, respectively, to develop ONJ. These findings have significant implications for the design of future clinical studies and the development of risk-reduction strategies aimed at either assessing or modulating the risk of ONJ associated with BP.

Relationship between disease stage and renal function in bisphosphonate-related osteonecrosis of the jaw

Objectives

Bisphosphonate is the primary cause of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Bisphosphonates are eliminated from the human body by the kidneys. It is anticipated that bisphosphonate levels in the body will increase if the kidney is in a weak state or if there is systemic disease that affects kidney function. The aim of this study was to analyze the relevance of renal function in the severity of BRONJ.

Materials and Methods

Ninety-three patients diagnosed with BRONJ in Pusan National University Dental Hospital from January 2012 to December 2014 were included in this study. All patients underwent a clinical exam, radiographs, and serologic lab test, including urine analysis. The patient's medical history was also taken, including the type of bisphosphonate drug, the duration of administration and drug holiday, route of administration, and other systemic diseases. In accordance with the guidelines of the 2009 position paper of American Association of Oral and Maxillofacial Surgeons, the BRONJ stage was divided into 4 groups, from stage 0 to 3, according to the severity of disease. IBM SPSS Statistics version 21.0 (IBM Co., USA) was used to perform regression analysis with a 0.05% significance level.

Results

BRONJ stage and renal factor (estimated glomerular filtration rate) showed a moderate statistically significant correlation. In the group with higher BRONJ stage, the creatinine level was higher, but the increase was not statistically significant. Other factors showed no significant correlation with BRONJ stage. There was a high statistically significant correlation between BRONJ stage and ‘responder group’ and ‘non-responder group,’ but there was no significant difference with the ‘worsened group.’ In addition, the age of the patients was a relative factor with BRONJ stage.

Conclusion

With older age and lower renal function, BRONJ is more severe, and there may be a decrease in patient response to treatment.

Interrelationship of clinical, radiographic and haematological features in patients under bisphosphonate therapy

OBJECTIVES

To analyze the clinical, radiographic and haematological aspects of patients under bisphosphonate therapy.

METHODS

A retrospective study was conducted where the records of patients taking bisphosphonates were analyzed considering the occurrence of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Evaluation included panoramic and periapical radiographies, haematological examinations and clinical features. Radiographies were analyzed determining the presence or absence of bone sclerosis, osteolysis, persisting alveolar socket, narrowing of the mandibular canal, widening of the periodontal ligament space, periradicular radiolucency, sequestrum and thickening of the lamina dura. Laboratory tests consisted of complete blood count, fasting serum glucose, erythrocyte sedimentation rate (ESR) and serum levels of calcium, phosphorus, alkaline phosphatase, parathormone (PTH) and C-terminal telopeptide of collagen I (CTX).

RESULTS

Alkaline phosphatase and ESR were significantly higher in the BRONJ group, whereas fasting serum glucose, CTX, PTH, calcium and phosphorus did not significantly differ. BRONJ showed association with smoking, tooth extraction, anaemia and leukocytosis. On radiographic analysis, persisting alveolar socket, osteolysis, bone sclerosis and narrowing of the mandibular canal were significantly more prevalent in the BRONJ group. Thickening of the lamina dura, periapical radiolucencies, widening of the periodontal ligament space and sequestrum did not significantly differ between the groups.

CONCLUSIONS

BRONJ is a multifactorial disease with high morbidity, which requires experimental studies to clarify the role of the reported risk factors and clinical radiographic signs to improve its diagnosis.

Antiresorptive agent-related osteonecrosis of the jaw: Position Paper 2017 of the Japanese Allied Committee on Osteonecrosis of the Jaw

Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is an intractable, though rare, complication in cancer patients with bone metastases and patients with osteoporosis who are treated with antiresorptive agents, including bisphosphonates and denosumab. Despite the more than 10 years that have passed since the first cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ) were reported, our understanding of the epidemiology and pathophysiology of ARONJ remains limited, and data supported by evidence-based medicine are still sparse. However, the diagnosis and staging of ARONJ, identification of risk factors, and development of preventive and therapeutic approaches have advanced significantly over the past decade. The Position Paper 2017 is an updated version of the Position Paper 2010 of the Japanese Allied Committee on Osteonecrosis of the Jaw, which now comprises six Japanese academic societies. The Position Paper 2017 describes a new diagnostic definition for ARONJ, as proposed by the American Association of Oral and Maxillofacial Surgeons (AAOMS), summarizes our current understanding of the pathophysiology of ARONJ based on a literature search, and suggests methods for physicians and dentists/oral surgeons to manage the disease. In addition, the appropriateness of discontinuing antiresorptive medications (drug holiday) before, during, and after invasive dental treatments is discussed extensively. More importantly, the manuscript also proposes, for the first time, the importance of interactive communication and cooperation between physicians and dentists/oral surgeons for the successful treatment of ARONJ. The Position Paper 2017 is intended to serve as a guide for improving the management of ARONJ patients in Japan.

Measurement and Clinical Utility of βCTX in Serum and Plasma

Biochemical markers of bone turnover (BTM) are released during bone remodeling and can be measured in blood or urine as noninvasive surrogate markers for the bone remodeling rate. The C-terminal cross-linked telopeptide of type I collagen (βCTX) is released during bone resorption and is specific to bone tissue. Assays have been developed to measure βCTX in blood and in urine; most current use of βCTX measurement for research and in clinical practice is performed on a blood sample. Method-specific differences for serum and plasma βCTX have led to initiatives to standardize or harmonize βCTX commercial assays. βCTX demonstrates significant biological variation due to circadian rhythm and effect of food which can be minimized by standardized sample collection in the fasting state in the morning. While βCTX predicts fracture risk independent of bone mineral density, lack of data has precluded its inclusion in fracture risk calculators. The changes seen in βCTX with antiresorptive therapies have been well characterized and this has led to its widespread use for monitoring therapy in osteoporosis. However, more fracture-based data on appropriate treatment goals for monitoring need to be developed. Evidence is lacking for the use of βCTX in managing "drug holidays" of bisphosphonate treatment in osteoporosis or risk stratifying those at increased risk of developing osteonecrosis of the jaw. βCTX is useful as an adjunct to imaging techniques for the diagnosis of Paget's disease of bone and for monitoring therapy and detecting recurrence. βCTX also shows promise in the management of metastatic bone disease.

Case-Based Review of Osteonecrosis of the Jaw (ONJ) and Application of the International Recommendations for Management From the International Task Force on ONJ

Osteonecrosis of the jaw (ONJ) has been associated with antiresorptive therapy in both oncology and osteoporosis patients. This debilitating condition is very rare and advances in diagnosis and management may now effectively reduce the risk of its development and offer valuable treatment options for affected patients. This paper provides a case-based review of ONJ and application of the International Task Force on ONJ (referred to as the "Task Force") recommendations for the diagnosis and management of ONJ. The Task Force was supported by 14 international societies and achieved consensus from representatives of these multidisciplinary societies on key issues pertaining to the diagnosis and management of ONJ. The frequency of ONJ in oncology patients receiving oncology doses of bisphosphonate (BP) or denosumab is estimated at 1%-15%, and the frequency in the osteoporosis patient population receiving much lower doses of BP or denosumab is estimated at 0.001%-0.01%. Although the diagnosis of ONJ is primarily clinical, imaging may be helpful in confirming the diagnosis and staging. In those with multiple risk factors for ONJ for whom major invasive oral surgery is being planned, interruption of BP or denosumab therapy (in cancer patients) is advised, if possible, before surgery, until the surgical site heals. Major oral surgery in this context could include multiple extractions if surgical extractions are required, not simple forceps extractions. ONJ development may be reduced by optimizing oral hygiene and postoperatively using topical and systemic antibiotics as appropriate. Periodontal disease should be managed before starting oncology doses of BP or denosumab. Local debridement may be successful in disease unresponsive to conservative therapy. Successful surgical intervention has been reported in those with stage 3 disease; less severe disease is best managed conservatively. Teriparatide may be helpful in healing ONJ lesions and may be considered in osteoporosis patients at a high fracture risk in the absence of contraindications. Resumption of BP or denosumab therapy following healing of ONJ lesions is recommended, and there have not been reports of subsequent local recurrence.

Efficacy of the C-terminal telopeptide test in predicting the development of bisphosphonate-related osteonecrosis of the jaw: a systematic review

This systematic review evaluated the efficacy of the morning fasting serum C-terminal telopeptide (CTX) test in predicting the development of bisphosphonate-related osteonecrosis of the jaw (BRONJ). A comprehensive search of studies published up to March 2016, and listed in the PubMed/MEDLINE, Web of Science, and Cochrane Library databases, was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. This review has been registered in the PROSPERO international prospective register of systematic reviews (CRD42016036717). The search identified 542 publications; eight studies were finally deemed eligible for inclusion according to the study criteria. These studies included a total 1442 patients (mean age 66.7 years). The most prescribed drug was alendronate, with osteoporosis being the most frequent indication for the prescription of bisphosphonates. Tooth extraction was the most common trigger for BRONJ. Of all patients evaluated after bisphosphonate treatment, only 24 (1.7%) developed BRONJ. All eight of the selected studies found that CTX levels were not predictive of the development of BRONJ. In conclusion, this systematic review indicates that the CTX test has no predictive value in determining the risk of osteonecrosis in patients taking bisphosphonates.

Diseases having an influence on inhibition of angiogenesis as risk factors of osteonecrosis of the jaw

Objectives

The objective of this study was to retrospectively investigate the association of diseases having an influence on inhibition of angiogenesis such as hypertension, diabetes mellitus type II, hypercholesterolemia, and rheumatoid arthritis (RA) with the development of osteonecrosis of the jaws.

Materials and Methods

The 135 patients were allocated into 4 groups of bisphosphonate-related osteonecrosis of the jaw (BRONJ) group (1A); non-BRONJ group (1B); osteonecrosis of the jaw (ONJ) group (2A); and control group (2B), according to histologic results and use of bisphosphonate. This retrospective study was conducted with patients who were treated in one institute from 2012 to 2013. Fisher's exact test and logistic regression analysis were used to analyze the odds ratios of diseases having an influence on inhibition of angiogenesis for development of ONJ.

Results

The effects of diabetes and hypertension were not statistically significant on development of ONJ. When not considering bisphosphonate use, RA exhibited a high odds ratio of 3.23 (P=0.094), while hyperlipidemia showed an odds ratio of 2.10 (P=0.144) for development of ONJ. More than one disease that had an influence on inhibition of angiogenesis showed a statistically significant odds ratio of 2.54 (P=0.012) for development of ONJ.

Conclusion

Patients without diseases having an influence on inhibition of angiogenesis were at less risk for developing ONJ.

Prevalence of Medication-Related Osteonecrosis of the Jaw in Patients with Breast Cancer, Prostate Cancer, and Multiple Myeloma

Medication-related osteonecrosis of the jaw is a known side-effect of antiresorptive therapy in patients with malignant diseases. Nevertheless, the exact pathogenesis is still unknown and published prevalences show a significant range. The aim of the presented paper was to assess the prevalence of osteonecrosis (ONJ) in breast cancer, prostate cancer, and multiple myeloma patients receiving parenteral antiresorptive therapy. For this reason a PubMed search was performed and 69 matching articles comprising 29,437 patients were included in the analysis. Nine-hundred fifty-one cases of jaw necrosis were described. The overall ONJ-prevalence was 2.09% in the breast cancer group, 3.8% in the prostate cancer group, and 5.16% for multiple myeloma patients.

Bisphosphonate treatment and dental implants: A systematic review

Background

To analyze articles that studied patients submitted to diphosphonates therapy and who received dental implants before, during or after bisphosphonate (BP) treatment, compared to healthy patients, analyzing the increase of failure and loss of implants or bisphosphonate related osteonecrosis of the jaw (BRONJ) incidence.

Material and Methods

The Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement was used in this study. The clinical question in “PICO” format was: In patients under bisphosphonate therapy, do dental implants placement, compared to healthy patients, increase the failure and loss of implants or bisphosphonate related osteonecrosis of the jaw incidence? PubMed/MEDLINE was searched for articles published up until April 15, 2015 using a combination of MeSH terms and their Entry terms.

Results

The search resulted in 375 articles. After selection according to the eligibility criteria, 15 studies fulfilled were included (eight retrospective, one prospective and six case series), with a total of 1339 patients analyzed, 3748 implants placed, 152 loss of implants and 78 cases of BRONJ.

Conclusions

Due to the lack of randomized clinical trials looking at this theme, further studies with longer follow-up are needed to elucidate the remaining questions. Thus, it is wise to be careful when planning dental implant surgery in patients undergoing bisphosphonate therapy because of the risk of developing BRONJ as well as occurring failure of implant. Moreover, complete systemic condition of the patient must be also taking into considering when such procedures are performed.

Key words:Bisphosphonates, diphosphonates, dental implants, osteonecrosis.

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.

Alveolar bone loss in osteoporosis: a loaded and cellular affair?

Maxillary and mandibular bone mirror skeletal bone conditions. Bone remodeling happens at endosteal surfaces where the osteoclasts and osteoblasts are situated. More surfaces means more cells and remodeling. The bone turnover rate in the mandibular alveolar process is probably the fastest in the body; thus, the first signs of osteoporosis may be revealed here. Hormones, osteoporosis, and aging influence the alveolar process and the skeletal bones similarly, but differences in loading between loaded, half-loaded, and unloaded bones are important to consider. Bone mass is redistributed from one location to another where strength is needed. A sparse trabeculation in the mandibular premolar region (large intertrabecular spaces and thin trabeculae) is a reliable sign of osteopenia and a high skeletal fracture risk. Having dense trabeculation (small intertrabecular spaces and well-mineralized trabeculae) is generally advantageous to the individual because of the low fracture risk, but may imply some problems for the clinician.

Computed tomographic assessment of early changes of the mandible in bisphosphonate-treated patients

OBJECTIVES

To compare the computed tomography (CT) features of mandibular cancellous and cortical bones between patients with bisphosphonate (BP) administration and those without and to assess the early changes of the mandible in BP-treated patients.

STUDY DESIGN

Twenty-four BP-treated patients suffering from medication-related osteonecrosis of the jaw (MRONJ) were enrolled in this study. For comparison, 20 patients suffering from osteomyelitis and 20 patients without pathology in the jaw were also enrolled, all of whom did not receive BP treatment. The CT values of the cancellous and cortical bone and the cortical bone widths were measured.

RESULTS

In the MRONJ and osteomyelitis groups, there were significant differences in the CT values of cancellous and cortical bones between the affected and unaffected areas. In patients with stage 0 MRONJ, a significant difference was noted in the cancellous bone CT values between these areas. The cancellous bone CT values at the affected and unaffected areas in the BP-treated group were significantly higher than in the control groups. In patients with stage 0 MRONJ, the cancellous bone CT values at the affected area were also significantly higher than in the healthy patients. The cortical bone widths in the unaffected areas in the BP-treated patients were significantly larger than in healthy patients.

CONCLUSIONS

The cancellous bone CT values were higher in the BP-treated group, including in patients with stage 0 MRONJ, and CT may provide useful quantitative information.

Effects of drug discontinuation after short-term daily alendronate administration on osteoblasts and osteocytes in mice

In order to determine whether osteoclastic bone resorption is restarted after withdrawn of bisphosphonates, we conducted histological examinations on murine osteoclasts, osteoblasts and osteocytes after discontinuation of a daily regimen of alendronate (ALN) with a dosage of 1 mg/kg/day for 10 days. After drug discontinuation, metaphyseal trabecular number and bone volume remained unaltered for the first 4 days. Osteoclast number did not increase, while the number of apoptotic osteoclasts was elevated. On the other hand, tissue non-specific alkaline phosphatase-immunoreactive area was markedly reduced after ALN discontinuation. In addition, osteocytes showed an atrophic profile with empty lacunar areas during and after ALN treatment. Interestingly, as early as 36 h after a single ALN injection, osteocytes show signs of atrophy despite the presence of active osteoblasts. Structured illumination microscopy system showed shortening of osteocytic cytoplasmic processes after drug cessation, suggesting a possible morphological and functional disconnection between osteocytes and osteoblasts. Taken together, it appears that osteoclastic bone resorption is not resumed after ALN discontinuation; also, osteoblasts and osteocytes hardly seem to recover once they are inactivated and atrophied by ALN. In summary, it seems that one must pay more attention to the responses of osteoblasts and osteocytes, rather focusing on the resuming of osteoclastic bone resorption after the ALN discontinuation.

The use of biochemical markers of bone turnover in the clinical management of primary and secondary osteoporosis

The purpose of the present study was to examine of the current role of bone turnover markers (BTMs) in the management of osteoporosis. Perusal of the literature examines the available evidence for the utility of BTMs for decision to treat and for the monitoring of treatment for osteoporosis. There is no evidence for the use of BTMs for fracture risk calculation, decision to treat or for treatment selection. A very abnormal BTM value may be a clue to the presence of bone pathology other than uncomplicated osteoporosis. Whilst changes to BTMs following various osteoporosis treatments are well defined, their utility in monitoring individual patients has been less well established. Some fracture outcome-based data exist for the use of u-NTX target of <21 nmol BCE/mmol for antiresorptive therapy; the equivalent s-CTX level is ~250 ng/L. Suboptimal BTM response to treatment may indicate non-compliance or the presence of secondary causes of osteoporosis which may need addressing. Studies are needed to establish treatment targets based on fracture outcomes for commonly used BTMs for each established osteoporosis therapy.

Assessing the utility of serum C-telopeptide cross-link of type 1 collagen as a predictor of bisphosphonate-related osteonecrosis of the jaw: A systematic review and meta-analysis

BACKGROUND

The authors of this systematic review and meta-analysis assessed the utility of serum C-telopeptide cross-link of type 1 collagen (sCTX), a biomarker of bone resorption, as a predictor of the development of bisphosphonate-related osteonecrosis of the jaw (BRONJ).

TYPES OF STUDIES REVIEWED

The authors searched for studies involving adult participants, written in English, and published through January 20, 2016, using the following electronic databases: the Cochrane Library, MEDLINE via PubMed, and Web of Science. They also searched Google Scholar and the reference lists of all eligible trials and reviews. They identified 16 articles that met their inclusion criteria (9 controlled studies and 7 case series). They applied the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for systematic reviews and meta-analyses. They independently extracted data in duplicate, including the characteristics of study participants, risk factors, control groups, and outcomes. They assessed risk of bias, and they resolved any disagreements between review authors through discussion.

RESULTS

A meta-analysis with 9 controlled studies revealed no significant difference in mean sCTX values between patients with BRONJ and control participants (difference in means, -31.417; 95% confidence interval [CI], -91.560 to 28.726; P = .306). A second meta-analysis with 4 studies showed no significant difference in risk of having an sCTX value below 150 picograms per milliliter for patients with BRONJ compared with control participants (risk ratio, 1.892; 95% CI, 0.636-5.626; P = .251).

CONCLUSIONS AND PRACTICAL IMPLICATIONS

A systematic review of the literature with meta-analysis does not support the use of sCTX levels as a predictor of the development of BRONJ. Further prospective large sample studies are needed to understand the role of sCTX as a predictor for BRONJ.

Do measurements of inflammatory mediators in blood predict recurrence in patients with bisphosphonate-related osteonecrosis of the jaws?

Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is well-recognised, difficult to manage, and often recurs. The aim of this study was to examine the value of preoperative measurements of inflammatory mediators in blood in 212 patients with BRONJ who were studied prospectively. Multiple logistic regression analysis was used to assess the importance of the amounts of substances in the blood that are independently associated with the dependent variable "recurrence of BRONJ". The only factor that significantly influenced the development of recurrent BRONJ was reduction in the white cell count (p<0.0001; hazard ratio 5.324; 95% CI 2.373 to 11.945). Neither white cell counts nor C-reactive protein concentrations within or above the reference ranges were significantly associated with recurrent BRONJ. Patients whose white cell counts were lower than the reference range were at increased risk of recurrent BRONJ. This may be a marker of reduced immunocompetence, and additional prophylactic measures or treatment should be considered for these patients.

Tooth extractions in high-risk patients under bisphosphonate therapy and previously affected with osteonecrosis of the jaws: surgical protocol supported by low-level laser therapy

Trauma during dental surgery is a predisposing factor for medication-related osteonecrosis of the jaws (MRONJ). There are no specific guidelines for the management of dental extractions in patients under bisphosphonate therapy (BPT). The authors proposed in 2013 a successful protocol for tooth extractions in patients under BPT supported by Nd:YAG low-level laser therapy (LLLT). The aim of this study was to validate the safety and efficacy of this protocol reporting the data related to its application in a particular category of patients under BPT at high risk for MRONJ and who were previously affected with MRONJ. Eighty-two tooth extractions were performed in 36 patients previously affected with MRONJ. Antibiotic treatment was administered 3 days before and 2 weeks after tooth extractions. Patients were additionally treated with Nd:YAG LLLT, 5 applications of 1 minute each. Patients were evaluated 3 days and once a week for 2 months after the extractions and every time they received LLLT. In a total of 82 extractions, minimal bone exposure was observed in 2 cases, treated with Er:YAG laser vaporization and then completely healed. The data confirmed that laser biostimulation is a reliable technique that can be considered in the surgical protocol for patients under BPT.