Osteonecrosis of the jaw and bisphosphonates in cancer: a narrative review

Piezoelectric Surgery, Er:YAG Laser Surgery and Nd:YAG Laser Photobiomodulation: A Combined Approach to Treat Medication-Related Osteonecrosis of the Jaws (MRONJ)

Medication-related osteonecrosis of the jaw (MRONJ) is a drug complication that can occur in patients taking antiresorptive or antiangiogenic drugs. Although it is a well-documented disease, there is no widely accepted treatment. However, several therapeutic approaches have been proposed. The surgical approach in many advanced cases appears inevitable; however, the results are not yet defined and predictable. This study aimed to propose a combined surgical approach with a piezoelectric device and laser (Er:YAG for bone ablation and Nd:YAG laser for photobiomodulation) in a young patient with breast cancer and bone metastasis under denosumab treatment, affected by spontaneous stage 3 MRONJ with maxillary sinus involvement. The patient under study reported no post-operative discomfort, with painkiller intake limited to the day after surgery. Total mucosal healing was observed without recurrences for more than 4 years after surgery. According to the results of our preliminary study, a combined surgical approach using a piezoelectric device and laser therapy is effective in managing patients affected by MRONJ, leveraging the clinical and biological advantages of these different techniques.

How we manage medication-related osteonecrosis of the jaw

Bone-modifying agents (BMAs) are integral to managing patients with advanced cancer. They improve quality of survival by reducing skeletal-related events, treating hypercalcaemia and chemotherapy-induced bone loss (Coleman in Clin Cancer Res 12: 6243s-6249s, 2006), (Coleman in Ann Oncol 31: 1650-1663, 2020). Two decades ago, medication-related osteonecrosis of the jaw (MRONJ) was first reported following BMA therapy (Marx in J Oral Maxillofac Surg 61: 1115-1117, 2003). The risk of MRONJ extends over a decade following BMA treatment with bisphosphonates, complicating dental care such as extractions. In addition, MRONJ has been reported following additional therapies such as antiangiogenic agents, cytotoxic agents, immunotherapy, and targeted agents. The use of BMAs in the curative and adjuvant cancer setting is increasing, consequently the implication of MRONJ is growing. Over the past 20 years, the literature has consolidated major risk factors for MRONJ, the pathophysiology and management strategies for MRONJ. Our review aims to document the development of MRONJ preventative and management strategies in cancer patients receiving a BMA. The authors advocate the incorporation of dental oncology strategies into contemporary cancer care, to optimise long-term quality of survival after cancer treatment.

Awareness of Medication-Related Osteonecrosis of the Jaws Amongst Patients on Antiresorptive and Antiangiogenic Medications

Background Medication-related osteonecrosis of the jaws (MRONJ) is a rare but severe condition that has garnered increasing attention in recent years. It primarily affects individuals undergoing treatment with antiresorptive and antiangiogenic medications, such as bisphosphonates and denosumab, commonly prescribed for osteoporosis and cancer-related bone metastases. Therefore, the present study aimed to assess awareness and understanding of MRONJ among patients receiving antiresorptive and antiangiogenic medications. Methods A cross-sectional survey was conducted among 110 patients receiving antiresorptive and antiangiogenic medications in a clinical setting. Participants were given a structured questionnaire to assess their awareness of MRONJ. The questionnaire covered aspects such as MRONJ, bisphosphonate usage, and awareness of the condition's potential complications. Demographic information was also collected. Chi-square and Fisher's tests were performed using SPSS statistical software. Results In terms of gender distribution, 63.6% of the participants were female. Concerning age distribution, the majority (43.6%) fell within the 21 to 40 age group, whereas only 5.5% were aged over 60. Regarding educational attainment, a substantial majority (58.2%) of the participants held a bachelor's degree. The study findings reveal that a considerable proportion (35.5%) of participants possess awareness regarding jaw osteonecrosis, and this association is statistically significant (p=0.002). A substantial number of participants administered the medication orally (30.9%), while others utilized various administration routes, including injection (IV and others) (40%), and this difference was also statistically significant (p=0.001). Most participants took bisphosphonates for osteoporosis (41.8%) or cancer (13.6%), both statistically significant (p<0.01). Gender had no significant impact (p>0.01), but age showed potential associations (p=0.07 for awareness, p=0.003 for medication use). Educational backgrounds had no significant link, except for bisphosphonate usage (p<0.01) and side effects reporting (p<0.01). Conclusion Notably, a small percentage of participants demonstrated awareness of this condition, indicating a need for continued education and awareness campaigns. Further research and interventions may be warranted to address the specific needs of different age groups and educational backgrounds in promoting safe and effective medication management.

Medication-Related Osteonecrosis of the Jaw: A Case Report of an Unusual Side Effect of Adalimumab

Background

Medication-related osteonecrosis of the jaw (MRONJ) is a serious adverse drug reaction characterized by progressive bone destruction and necrosis of mandibular and/or maxillary jaw bone that occurs in patients undergoing treatments with antiresorptive drugs such as bisphosphonates or denosumab, antiangiogenic agents such as bevacizumab, or other kinds of monoclonal antibodies such as rituximab and ipilimumab, for different oncologic and nononcologic diseases. The aim of this study was to report a case of MRONJ in a patient affected by rheumatoid arthritis disease in treatment with adalimumab. Case Presentation. A 70-year-old female patient affected by rheumatoid arthritis (RA), who had been undergoing adalimumab (40 mg subcutaneous injection) every two weeks for 5 years, with no history of antiresorptive or antiangiogenic agent administration, came to our attention for intraoral necrotic bone exposures of the anterior mandible. After drug withdrawal and antibiotic cycles, the patient underwent surgical treatment with bone resection and debridement of necrotic tissues. After an observation period of 8 months, a complete healing without signs of recurrence was detected.

Conclusions

Based on this study, a correlation between adalimumab and MRONJ is possible. Therefore, we believe that an oral cavity examination should be done in every patients, before starting therapy with adalimumab, to possibly avoid MRONJ onset. Further studies are required to confirm the role of adalimumab in MRONJ.

Medication-Related Osteonecrosis of the Jaws: A Comparison of SICMF-SIPMO and AAOMS Guidelines

(1) Background: Medication-related osteonecrosis of the jaws (MRONJ) is an adverse drug reaction characterized by progressive bone disruption and necrosis in the mandibular and/or maxillary bones. It occurs in individuals who have received antiresorptive drugs without prior radiotherapy. Since its first reported cases in the USA in 2003, extensive literature has emerged worldwide, leading to significant advancements in understanding MRONJ's pathogenesis and management. (2) Results: This article aims to compare the current national recommendations provided by the Italian Society of Maxillofacial Surgery (SICMF)/Italian Society of Oral Pathology and Medicine (SIPMO) and the American Association of Oral and Maxillofacial Surgeons (AAOMS). (3) Conclusions: Historically, the AAOMS advocated for a more conservative approach compared to the Italian guidelines. However, in their 2022 update, the AAOMS adopted a different perspective based on reported evidence, highlighting the advantages of early surgical treatment. Despite resolving some initial controversies, differences still exist between the two sets of recommendations, particularly regarding diagnosis and staging.

The feasibility of discriminating BRONJ lesion bone with Raman spectroscopy

Background

With the frequent use of Bisphosphonates (BPs), the morbidity of BP-related osteonecrosis of the jaw (BRONJ) is also increasing. However, the prevention and treatment of BRONJ is faced with enormous challenges. This study aimed to illuminate the influence of BP administration in the rat mandible and explore the feasibility of discriminating BRONJ lesion bone with Raman spectroscopy.

Materials and methods

First, we explored the time- and mode-dependent effects of BP administration on the rat mandible with Raman spectroscopy. Second, the BRONJ rat model was constructed, and the lesion and healthy bone components were analyzed using Raman spectroscopy.

Results

When only BPs were administered, no rats showed BRONJ symptoms, and no difference could be found in the Raman spectra. However, when combined with local surgery, six (6/8) rats showed BRONJ symptoms. The Raman spectra also showed a significant difference between the lesion and healthy bone.

Conclusion

In the progression of BRONJ, BPs and local stimulation play an essential role. Both BPs administration and local stimulation need to be controlled to prevent BRONJ. Moreover, BRONJ lesion bone in rats could be discriminated with Raman spectroscopy. This novel method would become a complement in the treatment of BRONJ in the future.

The many facets of micropetrosis - Magnesium whitlockite deposition in bisphosphonate-exposed human alveolar bone with osteolytic metastasis

The lacuno-canalicular space of apoptotic osteocytes eventually becomes mineralised in vivo. This condition is known as micropetrosis and is a fundamental characteristic of ageing bone. Increased prevalence of such hypermineralised osteocyte lacunae is viewed as a structural marker of impaired bone function - both mechanical and biological. Within the lacuno-canalicular space, mineralised apoptotic debris typically occurs as micrometre-sized, spherical nodules of magnesium-rich, carbonated apatite. Moreover, characteristically facetted, rhomboidal nodules of magnesium whitlockite [Mg-whitlockite; Ca₁₈Mg₂(HPO₄)₂(PO₄)₁₂] have been reported in human alveolar bone exposed to the bisphosphonate alendronate. This work provides supporting evidence for Mg-whitlockite formation in the alveolar bone of a 70-year-old male exposed to the bisphosphonate zoledronic acid to suppress osteolytic changes in skeletal metastasis. Backscattered electron scanning electron microscopy (BSE-SEM) revealed spherical and rhomboidal nodules within the lacuno-canalicular space. A variant of spherical nodules exhibited a fuzzy surface layer comprising radially extending acicular crystallites. The rhomboidal nodules ranged between ∼200 nm to ∼2.4 µm across the widest dimension (652 ± 331 nm). Micro-Raman spectroscopy and energy dispersive X-ray spectroscopy confirmed that rhomboidal nodules are compositionally distinct from spherical nodules, exhibiting higher Mg content and lower Ca/P ratio. Formation of Mg-whitlockite within osteocyte lacunae is multifactorial in nature and suggests altered bone biomineralisation. Nevertheless, the underlying mechanism(s) and sequence of events remain poorly understood and warrant further investigation. The possibility to discriminate between carbonated apatite and Mg-whitlockite nodules within osteocyte lacunae, based on particle morphology, attests to the diagnostic potential of BSE-SEM with or without additional analyses of material composition.

Zoledronic acid and denosumab for periprosthetic bone mineral density loss after joint arthroplasty: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Periprosthetic bone mineral density (BMD) loss after total hip arthroplasty (THA) may threaten the survival of implants. Zoledronic acid (ZA) and denosumab were effective in reducing bone loss in conditions associated with accelerated bone turnover by inhibiting osteoclast activity. This meta-analysis aimed to assess the efficiency and safety of ZA and denosumab for periprosthetic BMD loss after THA.

METHODS

A systematic search of randomized controlled trials (RCTs) associated with ZA or denosumab and THA was performed in MEDLINE, PubMed, Embase, the Cochrane Central Register of Controlled Trials, and the Web of Science from 1980 to 2022. Meta-analysis was performed by the Cochrane Review Manager 5 (RevMan) version 5.41. Cochrane risk of bias tool and GRADEpro were applied for methodological quality and overall evidence quality, respectively.

RESULTS

Nine RCTs involving a total of 480 patients were finally included and analyzed. The pooled data that demonstrated significantly less periprosthetic BMD loss in Gruen zone 7 occurred in the intervention group patients than in the control group patients at 3 months (MD = 4.30, 95% CI: 1.78-6.82, P = 0.0008), 6 months (MD = 7.71, 95% CI: 5.41-10.02, P < 0.00001), and 12 months (MD = 8.19, 95% CI: 5.97-10.42, P < 0.00001) after THA. No serious adverse events (AEs) were observed.

CONCLUSION

In the current analysis with evidence on the efficacy and safety of ZA and denosumab, the authors recommend the use of ZA or denosumab treatment for periprosthetic bone mineral density loss.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42022369273.

Zingerone attenuates Ti particle-induced inflammatory osteolysis by suppressing the NF-κB signaling pathway in osteoclasts

Aseptic loosening caused by inflammatory osteolysis is one of the most frequent and serious long-term complications after total joint arthroplasty (TJA). Development of a new therapeutic drug is required due to the lack of effective therapy and serious adverse effects. This study aimed to explore the pharmacological properties of zingerone (ZO) in attenuating osteoclast-mediated periprosthetic osteolysis and how ZO modulates osteoclastogenesis. The nontoxic concentration of ZO was clarified by the CCK-8 method. Then, we explored the efficacy of ZO on suppressing osteoclast differentiation, F-actin ring formation, bone resorption, and NF-κB luciferase activity in vitro as well as osteoprotection in vivo. Polymerase chain reaction and western blotting were applied to detect the underlying mechanisms involved in osteoclastogenesis. ZO showed an obvious inhibitory effect on osteoclastogenesis and bone resorption in a dose-dependent manner by mainly suppressing the activation of NF-κB signaling pathways. Furthermore, ZO administration successfully attenuated titanium (Ti) particle-stimulated periprosthetic osteolysis and osteoporosis by regulating osteoclast formation. Our findings demonstrated the pharmacological properties of ZO in inhibiting osteoclast formation and function by downregulation of NF-κB signaling activation. As a result, these findings could be expected to provide a novel reagent for regulating inflammatory osteolysis caused by prosthetic loosening.

Reporting Criteria for Clinical Trials on Medication-Related Osteonecrosis of the Jaw (MRONJ): A Review and Recommendations

Medication-related osteonecrosis of the jaw (MRONJ) is a complication caused by anti-resorptive agents and anti-angiogenesis drugs. Since we wanted to write a protocol for a randomized clinical trial (RCT), we reviewed the literature for the essential information needed to estimate the size of the active patient population and measure the effects of therapeutics. At the same time, we designed a questionnaire intended for clinicians to collect detailed information about their practices. Twelve essential criteria and seven additional items were identified and compiled from 43 selected articles. Some of these criteria were incorporated in the questionnaire coupled with data on clinical practices. Our review found extensive missing data and a lack of consensus. For example, the success rate often combined MRONJ stages, diseases, and drug treatments. The occurrence date and evaluation methods were not harmonized or quantitative enough. The primary and secondary endpoints, failure definition, and date coupled to bone measurements were not well established. This information is critical for writing a RCT protocol. With this review article, we aim to encourage authors to contribute all their findings in the field to bridge the current knowledge gap and provide a stronger database for the coming years.

Incidence and risk factors associated to Medication-Related Osteo Necrosis of the Jaw (MRONJ) in patients with osteoporosis after tooth extractions. A 12-months observational cohort study

OBJECTIVE

To evaluate the 12-months incidence of MRONJ after tooth extractions and possible related risk factors in patients with osteoporosis treated by means of oral bisphosphonates.

MATERIAL AND METHODS

Forty-five records of osteoporotic patients on therapy with oral bisphosphonates and treated with at least one dental extraction at the Department of Oral Surgery of University of Naples Federico II were selected. All patients were treated using a standardized surgical extraction protocol. At baseline and after 12-months follow-up, the following variables were recorded: "mucosal healing", "gender", "type of drug"; "duration of therapy"; "drug holiday". The collected data were analyzed and a linear regression analysis was performed to assess a possible correlation with onset MRONJ.

RESULTS

A total of 159 tooth extraction in 43 females (95.6%) and in 2 males (4.4%) with a mean age of 67.5 ± 3 years were available for the analysis. The majority part of patients was on therapy with alendronate (23; 51.2%), 11 patients (24.4%) were treated with risedronate and 11 (24.4%) with ibandronate. Before oral surgery, 84% of the patients showed a low-medium risk of MRONJ, while in 16% of the patients a medium-high risk was recorded. After 12-months follow-up, osteonecrosis was observed in 1 patient, with an overall incidence of MRONJ of 0.6%. The linear regression showed a significant correlation with MRONJ onset only for "gender" variable, with a R² of 0.489.

CONCLUSIONS

Within their limitations, the outcomes of the study indicate that the risk of MRONJ after tooth extraction in osteoporotic patients taking bisphosphonates for OS is very low. A prolonged and specific antibiotic and antiseptic therapy, in addition to a surgical procedure as little traumatic as possible, will allow to perform oral surgery safely.

Medication-Related Osteonecrosis of the Jaw in Dental Practice: A Retrospective Analysis of Data from the Milan Cohort

A retrospective analysis was performed with the aim of understanding whether the risk factors showed in the literature for medication-related osteonecrosis of the jaws (MRONJ) in cancer patients are also relevant in osteoporotic patients taking antiresorptive drugs (ARDs). Data were retrospectively pooled from health records of patients on ARDs who requested a dental visit between January 2006 and April 2020 in the Dental Unit at Fondazione Ca’ Granda IRCCS Ospedale Maggiore Policlinico, University of Milan. A total of 434 patients were included. The following variables were collected: sex, age, smoking habit, type of ARD, duration of treatment, route of administration, therapeutic indication, concurrent systemic therapies and pathologies. Statistical analysis confirmed the relevance of chemotherapy, smoking, and immunosuppressive drugs as risk factors. In addition, a higher frequency of MRONJ in osteoporotic patients was reported in our cohort in association with an immunodeficiency disorder of variable origin. In conclusion, the identification of individual risk-profile before dental treatments is crucial for prevention. Anamnesis should include main risk factors, such as immunosuppression, dental extractions, smoking, trauma, and poor dental health. Nevertheless, our suggestion for dental professionals is to conduct a complete medical history of patients who mention long-term per oral therapies with ARDs for osteoporosis. Osteoporotic, as well as cancer patients, may also benefit from periodic monitoring of the ARDs therapy in order to prevent MRONJ.

Bone Metastases: From Mechanisms to Treatment

OBJECTIVES

Bone metastases are of high clinical relevance because they are a frequent complication of most types of common cancers, such as breast and prostate. The metastatic process is complex, requiring the completion of several different steps to allow successful dissemination and homing. In addition, preparation of the metastatic niche changes the constant cycle of bone matrix formation and degradation, leading to the clinical phenotypes of lytic and sclerotic lesions. We review our current knowledge on this topic and briefly explain the current treatment landscape of bone metastasis.

DATA SOURCES

These include PubMed, international guidelines, and clinician experience.

CONCLUSION

Bone metastases remain a clinical challenge that negatively impacts patients prognosis and quality of life. A comprehensive understanding of the complex molecular mechanisms that results in bone metastasis is the basis for successful treatment of affected patients. The disruption of bone matrix metabolism is already recognized as the prerequisite for metastasis formation, but many open questions remain that need to be addressed in future research to establish individually tailored treatment approaches.

IMPLICATIONS FOR NURSING PRACTICE

Patient-centered therapy of bone metastases requires suitable pharmacological options, and importantly a holistic approach in care delivery across the multidisciplinary team. Nurses provide the cornerstone of the multidisciplinary team and provide the closest and the most frequent contact to the patient and their families to provide timely intervention. Nurses require a basic understanding of the complex physiology of metastasis to inform practice.

Spatiotemporally controlled calcitonin delivery: Long-term and targeted therapy of skeletal diseases

Bone is a connective tissue that support the entire body and protect the internal organs. However, there are great challenges on curing intractable skeletal diseases such as hypercalcemia, osteoporosis and osteoarthritis. To address these issues, calcitonin (CT) therapy is an effective treatment alternative to regulate calcium metabolism and suppress inflammation response, which are closely related to skeletal diseases. Traditional calcitonin formulation requires frequent administration due to the low bioavailability resulting from the short half-life and abundant calcitonin receptors distributed through the whole body. Therefore, long-term and targeted calcitonin delivery systems (LCDS and TCDS) have been widely explored as the popular strategies to overcome the intrinsic limitations of calcitonin and improve the functions of calcium management and inflammation inhibition in recent years. In this review, we first explain the physiological effects of calcitonin on bone remodeling: (i) inhibitory effects on osteoclasts and (ii) facilitated effects on osteoblasts. Then we summarized four strategies for spatiotemporally controlled delivery of calcitonin: micro-/nanomedicine (e.g. inorganic micro-/nanomedicine, polymeric micro-/nanomedicine and supramolecular assemblies), hydrogels (especially thermosensitive hydrogels), prodrug (PEGylation and targeting design) and hybrid biomaterials. Subsequently, we discussed the application of LCDS and TCDS in treating hypercalcemia, osteoporosis, and arthritis. Understanding and analyzing these advanced calcitonin delivery applications are essential for future development of calcitonin therapies toward skeletal diseases with superior efficacy in clinic.

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

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

"The use of bisphosphonates to treat skeletal complications in solid tumours"

The skeleton is the most common site of secondary disease in breast cancer and prostate cancer, with up to 80% of patients with advanced disease developing bone metastases (BM). The proportion is also substantial in advanced lung cancer (20%-40%). Because of the high prevalence of cancers of the breast, prostate and lung, these cancers account for more than 80% of cases of metastatic bone disease occurring in solid tumours. Metastatic bone disease is associated with greatly increased bone resorption by osteoclasts, leading to moderate to severe pain and other skeletal complications, with major impact on quality of life (QoL). Skeletal Related Events (SREs) have been defined as: pathological long bone or vertebral fractures; spinal cord compression; need for radiation for pain relief or to prevent fracture/spinal cord compression, need for surgery to bone and hypercalcaemia. More recently, Symptomatic Skeletal Events (SSEs) have been defined to monitor QoL. Although there are currently no curative treatments for metastatic bone disease, patients with breast or prostate cancer and BM are now surviving for several years and sometimes longer, and prevention of SREs is the key aim to optimization of QoL. Since their discovery 50 years ago and their introduction more than 30 years ago into the field of metastatic bone disease, a range of oral and intravenous bisphosphonate drugs have made a major contribution to prevention of SREs. Large trials have clearly demonstrated the clinical value of different bisphosphonate-based drugs (including the oral drugs ibandronate and clodronate and intravenous agents such as zoledronate and pamidronate), in treatment of hypercalcaemia of malignancy and the reduction of SREs and SSEs in a range of cancers. Despite the success of denosumab in reducing osteolysis, bisphosphonates also remain mainstay drugs for treatment of metastatic bone disease. Recognizing the 50th Anniversary of the discovery of bisphosphonates, this review focuses on their continuing value in BM treatment and their future potential, for example in providing a bone-targeting vehicle for cytotoxic drugs.

Racial Disparities in Intravenous Bisphosphonate Use Among Older Patients With Multiple Myeloma Enrolled in Medicare

PURPOSE

Intravenous (IV) bisphosphonates reduce the risk of skeletal-related events in patients with multiple myeloma (MM). However, data describing racial differences in IV bisphosphonate utilization outside of clinical trial settings are limited. We evaluated population-level IV bisphosphonate initiation and discontinuation among patients of age ≥ 65 years with MM.

METHODS

We conducted a retrospective cohort study of patients of age ≥ 65 years diagnosed with first primary MM between 2001 and 2011. Patients were identified using the SEER-Medicare linked database and followed through December 2013. Cumulative incidences of IV bisphosphonate initiation and time to discontinuation among users were compared between racial and ethnic groups. In Fine and Gray competing risk models, we estimated subdistribution hazard ratios (SHRs) and 95% CIs for initiation and discontinuation.

RESULTS

We included 14,231 eligible patients with MM (median age, 76 years; 52% male). Over a median follow-up of 23.1 months, 54% of patients received at least one IV bisphosphonate dose. Our final analytical sample included 10,456 non-Hispanic (NH) Whites, 2,267 NH Blacks, 548 Asian and Pacific islanders, and 815 Hispanic and Latino patients. A higher proportion of White patients (56.1%) newly received IV bisphosphonates after MM diagnosis compared with NH Blacks (45.4%). Compared with White patients, NH Black patients were less likely to initiate IV bisphosphonates (SHR, 0.74; 95% CI, 0.70 to 0.79) and slightly more likely to discontinue treatment (SHR, 1.10; 95% CI, 1.01 to 1.19).

CONCLUSION

Approximately half of the patients with MM of age ≥ 65 years did not receive IV bisphosphonates, with significant delay among racial minority groups. These findings highlight the need for improvement of IV bisphosphonate uptake in patients with MM of age ≥ 65 years.

Better pain control with 8-gray single fraction palliative radiotherapy for skeletal metastases: a Bayesian network meta-analysis

External Beam Radiotherapy (EBRT) allows remarkable pain control in patients with skeletal metastases. We performed a Bayesian network meta-analysis comparing the most commonly used radiotherapy regimens for palliative management in patients with skeletal metastases. The main online databases were accessed in October 2020. All randomized clinical trials evaluating the irradiation of painful bone metastases were considered. The following irradiation patterns were analysed and included in the present network meta-analysis: 8 Gy- and 10 Gy/single fraction, 20 Gy/5 fractions, 30 Gy/10 fractions. The Bayesian hierarchical random-effect model analysis was adopted in all comparisons. The Log Odds-Ratio (LOR) statistical method for dichotomic data was adopted for analysis. Data from 3595 patients were analysed. The mean follow-up was 9.5 (1 to 28) months. The cumulative mean age was 63.3 ± 2.9. 40.61% (1461 of 3595 patients) were female. The 8Gy/single fraction protocol detected reduced rate of “no pain response” (LOR 3.39), greater rate of “pain response” (LOR-5.88) and complete pain remission (LOR-7.05) compared to the other dose patterns. The 8Gy group detected a lower rate of pathological fractures (LOR 1.16), spinal cord compression (LOR 1.31) and re-irradiation (LOR 2.97) compared to the other dose patterns. Palliative 8Gy/single fraction radiotherapy for skeletal metastases shows outstanding results in terms of pain control, re-irradiations, pathological fractures and spinal cord compression, with no differences in terms of survivorship compared to the other multiple dose patterns.

Level of evidence: I, Bayesian network meta-analysis of RCTs.

Targeted nanomedicines for the treatment of bone disease and regeneration

Targeted delivery by either passive or active targeting of therapeutics to the bone is an attractive treatment for various bone related diseases such as osteoporosis, osteosarcoma, multiple myeloma, and metastatic bone tumors. Engineering novel drug delivery carriers can increase therapeutic efficacy and minimize the risk of side effects. Developmnet of nanocarrier delivery systems is an interesting field of ongoing studies with opportunities to provide more effective therapies. In addition, preclinical nanomedicine research can open new opportunities for preclinical bone-targeted drug delivery; nevertheless, further research is needed to progress these therapies towards clinical applications. In the present review, the latest advancements in targeting moieties and nanocarrier drug delivery systems for the treatment of bone diseases are summarized. We also review the regeneration capability and effective delivery of nanomedicines for orthopedic applications.

Bisphosphonate-associated osteonecrosis of the jaw

INTRODUCTION

The purpose of this systematic review was to determine the possible risk factors related to pathophysiology of bisphosphonate-related osteonecrosis of the jaw (BRONJ) and identify adequate treatment strategies available and success rates.

EVIDENCE ACQUISITION

We performed a search for publications about the treatment of BRONJ, published between 2003 and 2018 in the PubMed/Medline data base using the key words: "Bisphosphonate-Associated Osteonecrosis of the Jaw" OR "Bisphosphonate Osteonecrosis" OR "BRONJ", based on the list of MeSH and DeCS.

EVIDENCE SYNTHESIS

According to pre-established criteria for data collection concerning the treatment of BRONJ, we found 19 articles covering a total of 400 patients. Treatments that showed good outcomes were Ozone, PRF, PRP/Debridement/Laser bio-stimulation, Laser surgery and Laser surgery/Laser bio-stimulation. HBO did not achieve good results and was used in only 10 patients. BRONJ is a rare condition in patients with osteoporosis/other pathologies using BP orally. These patients had long exposure time and cumulative doses of BPs until onset of the lesion. The oncological patients were exposed to more potent intravenously administered BPs such as pamidronate and zoledronate. These patients had a shorter exposure time until onset of the lesion.

CONCLUSIONS

The treatment of BRONJ is still under debate and there are promising treatments that need randomized trials with larger numbers of patients to confirm their results. Patients receiving BPs or those who will start treatment should be encouraged to perform preventive dental treatment and maintain good oral hygiene.

Bone metastases: a comprehensive review of the literature

The last report of the World Health Organization (WHO) stated that approximately four million people experience bone pain due to malignant diseases. Among them, metastatic bone pain is one of the most important sources of complaint. The estimated median survival in the presence of bone metastases ranks from 10 to 12 weeks. Bone represents a potential target of distant metastases for the majority of malignant tumours. However, the exact incidence of bone metastases is unknown. Bone metastases have an important socio-economic impact, and due to the enhancement of the overall survivorship, their incidence is increasing. Malignant neoplasms such as lung, thyroid, renal cancer, multiple myeloma, and melanoma often metastasize to the bone. Bone metastases commonly localize to the spinal column, pelvis, shoulder, and distal femur. The proper treatment for painful skeletal metastases is still unknown. Hence, the purpose of this review of the literature was to update current evidence concerning the aetiogenesis, biological behaviour, and treatment algorithms for painful skeletal metastases.

The feasibility of locating the affected bone of BRONJ with indocyanine green

The morbidity of bisphosphonate-related osteonecrosis of the jaw (BRONJ) is also increasing with the use of bisphosphonates (BPs). Removing affected bone accurately is the most effective treatment. This study aimed to explore the feasibility of Indocyanine green (ICG)-based Near-Infrared fluorescence (NIF) imaging to remove BRONJ affected bone. Firstly, the rat model of BRONJ was constructed. And 5 mg/kg ICG were injected via tail vein, after 12 hr, the affected and healthy bone were dissected for ICG-based NIF imaging and quantification detection of fluorescence intensity. Finally, all the bone samples were sent for further pathological examination. All the affected bone tissues in rat BRONJ model were fluorescence developed with ICG. And the fluorescence developed regions were further confirmed as affected bone tissues with pathological examination. The fluorescence intensity in affected bone tissues, adjacent, and opposite bone tissues was 1.93*107 ± 2.08*106, 1.19*106 ± 2.33*105, and 1.24*106 ± 1.57*105, respectively (p < .05). Conclusions It was feasible that the extent of affected bone in rat model with BRONJ could be estimated intraoperative via ICG-based NIF imaging. This novel approach would become an auxiliary method in the treatment of patients with BRONJ in the future.

Saliva diagnostics in patients suffering from bisphosphonate-associated osteonecrosis of the jaw: Results of an observational study

OBJECTIVE

One of the severe side effects of bisphosphonate (BP) therapy is bisphosphonate-associated osteonecrosis of the jaw (BONJ). However, there is no information available about its pathogenesis. Hence, the aim of this observational study was to contribute to discerning this pathogenesis by comparing salivary quantity and quality in patients with BONJ and undergoing BP treatment.

MATERIALS AND METHODS

This study included 60 patients divided into three groups. The first group consisted of 20 patients with established BONJ, the second group had 20 patients undergoing BP treatment, and the third group comprised 20 healthy individuals. These groups were analysed for the flow rate of stimulated saliva, buffer capacity, and salivary pH level.

RESULTS

Reduced salivation was observed in a significantly high number of patients with established BONJ (n = 8) and those undergoing BP treatment (n = 9) in comparison with the healthy control group (n = 4; p = 0.039). Though the distribution of the mean value of stimulated saliva flow rates in patients undergoing BP treatment was lower than in the control group, the difference was not significant. Moreover, there were no significant differences in the salivary pH level and buffer capacity in patients undergoing BP treatment as compared with the healthy control group.

CONCLUSIONS

It is possible that the quantity of human saliva is affected by BP treatment. This reduction in saliva production could have a negative effect on mucosal health and is perhaps a cofactor in the pathogenesis of BONJ.

Management of Osteoporosis in Survivors of Adult Cancers With Nonmetastatic Disease: ASCO Clinical Practice Guideline

PURPOSE

The aim of this work is to provide evidence-based guidance on the management of osteoporosis in survivors of adult cancer.

METHODS

ASCO convened a multidisciplinary Expert Panel to develop guideline recommendations based on a systematic review of the literature.

RESULTS

The literature search of the 2018 systematic review by the US Preventive Services Task Force in the noncancer population was used as the evidentiary base upon which the Expert Panel based many of its recommendations. A total of 61 additional studies on topics and populations not covered in the US Preventive Services Task Force review were also included. Patients with cancer with metastatic disease and cancer survival outcomes related to bone-modifying agents are not included in this guideline.

RECOMMENDATIONS

Patients with nonmetastatic cancer may be at risk for osteoporotic fractures due to baseline risks or due to the added risks that are associated with their cancer therapy. Clinicians are advised to assess fracture risk using established tools. For those patients with substantial risk of osteoporotic fracture, the clinician should obtain a bone mineral density test. The bone health of all patients may benefit from optimizing nutrition, exercise, and lifestyle. When a pharmacologic agent is indicated, bisphosphonates or denosumab at osteoporosis-indicated dosages are the preferred interventions.

Radiographic patterns of multiple myeloma in the jawbones of patients treated with intravenous bisphosphonates

BACKGROUND

The purpose of this study was to evaluate whether intravenous (IV) bisphosphonate (BP) therapy can change the radiographic patterns of multiple myeloma (MM) in the jawbones.

METHODS

The authors evaluated panoramic radiographs obtained from 188 patients with MM for the presence of solitary osteolytic lesions, multiple osteolytic lesions, diffuse osteoporosis, diffuse sclerosis, lamina dura abnormalities, nonhealing alveolar sockets, and bone sequestration. The authors compared results obtained from patients treated with IV BPs with those obtained from patients who had never been exposed to BPs.

RESULTS

Multiple osteolytic lesions (P = .001), diffuse osteoporosis (P = .001), and diffuse sclerosis (P = .0036) occurred more often in the mandible in both groups. Solitary osteolytic lesions occurred less frequently in the BP group (P = .0078). Lamina dura abnormalities (P = .0006) and nonhealing alveolar sockets (P = .0021) were associated with BP treatment.

CONCLUSIONS

IV BP therapy changes the radiographic patterns of MM in the jawbones.

PRACTICAL IMPLICATIONS

The effect of BPs in the maxillofacial area is a matter of concern for health practitioners because this type of medication causes several alterations of the jawbones in patients with cancer.

Antimicrobial photodynamic therapy improves the alveolar repair process and prevents the occurrence of osteonecrosis of the jaws after tooth extraction in senile rats treated with zoledronate

This study evaluated the effects of antimicrobial photodynamic therapy (aPDT) in the alveolar repair of rats with major risk factors for bisphosphonate-related osteonecrosis of the jaws (BRONJ). Senile rats received 0.45 ml of vehicle (VEH and VEH/aPDT) or 0.45 ml of zoledronate (ZOL and ZOL/aPDT) every three days for seven weeks. After three weeks of treatment, the first lower left molar was extracted. VEH/aPDT and ZOL/aPDT were submitted to aPDT on the extraction site at 0, 2 and 4 days postoperatively. Euthanasia was performed 28 days postoperatively and the extraction site was evaluated by clinical, histological, histometric, histochemical and immunohistochemical analysis. ZOL showed tissue repair impairment; lower percentage of newly formed bone tissue (NFBT); higher percentage of non-vital bone tissue (NVBT); fewer mature collagen fibers and increased immunolabeling for tumor necrosis factor (TNFα), interleukin (IL)-1β and IL-6. ZOL/aPDT showed clinical and histological characteristics of the extraction site, percentage of NFBT and percentage of mature collagen fiber similar to VEH. Percentage of NVBT and immunolabeling for inflammatory cytokines in ZOL/aPDT was lower than in ZOL. Immunolabeling for tartarato-resistant acid phosphatase (TRAP) was lower in ZOL and ZOL/aPDT. aPDT in the dental extraction site improves tissue repair process and prevents the occurrence of BRONJ-like lesions after tooth extraction.

Association between biomarkers and medication-related osteonecrosis of the jaws: a systematic review

OBJECTIVES

Our aim was to conduct a systematic review (SR) of the literature assessing the role of human biomarkers in the diagnosis or prognostication of medication-related osteonecrosis of the jaws (MRONJ).

STUDY DESIGN

An electronic search without date or language restriction was carried out in PubMed/MEDLINE, the Cochrane Central Register of Controlled Trials, Web of Science, and LILACS for publications until March 2018. In addition, a manual search in the gray literature was conducted. The search process was performed by 2 independent reviewing authors. Eligibility criteria included randomized and nonrandomized clinical trials, prospective or retrospective cohorts, case controls, and case series evaluating the association between biomarkers and MRONJ. The protocol of this SR was registered in PROSPERO under number CRD42018095886.

RESULTS

The search and selection process yielded 19 studies (2 case series, 6 case-control studies, 9 prospective cohort studies, and 2 retrospective studies) published between 2008 and 2018. Twenty-four biomarkers collected from serum, saliva, and urine were investigated by these studies. Eleven biomarkers were possibly related to MRONJ; however, no consensus is observed in the literature with regard to the sensitivity and clinical effectiveness of these biomarkers.

CONCLUSIONS

Although many biomarkers have been associated with MRONJ, the present SR found scarce clinical evidence supporting the use of these biomarkers for the diagnosis and prognosis of MRONJ.

Application of Autologous Platelet-Rich Plasma on Tooth Extraction Site Prevents Occurence of Medication-Related Osteonecrosis of the Jaws in Rats

This study evaluated the effects of local application of autologous platelet-rich plasma (PRP) on the tooth extraction site of rats presenting the main risk factors for medication-related osteonecrosis of the jaw (MRONJ). For seven weeks, senile rats were submitted to systemic treatment with vehicle (VEH and VEH-PRP) or 100 μg/Kg of zoledronate (ZOL and ZOL-PRP) every three days. After three weeks, the first lower molar was extracted. VEH-PRP and ZOL-PRP received PRP at the tooth extraction site. Euthanasia was performed at 28 days postoperatively. Clinical, histopathological, histometric and immunohistochemical analyses were carried out in histological sections from the tooth extraction site. ZOL showed lower percentage of newly formed bone tissue (NFBT), higher percentage of non-vital bone tissue (NVBT), as well as higher immunolabeling for TNFα and IL-1β. In addition, ZOL presented lower immunolabeling for PCNA, VEGF, BMP2/4, OCN and TRAP. VEH and ZOL-PRP showed improvement in the tooth extraction site wound healing and comparable percentage of NFBT, VEGF, BMP2/4 and OCN. Local application of autologous PRP proved a viable preventive therapy, which is safe and effective to restore tissue repair capacity of the tooth extraction site and prevent the occurrence of MRONJ following tooth extraction.

Micrometer-Sized Magnesium Whitlockite Crystals in Micropetrosis of Bisphosphonate-Exposed Human Alveolar Bone

Osteocytes are contained within spaces called lacunae and play a central role in bone remodelling. Administered frequently to prevent osteoporotic fractures, antiresorptive agents such as bisphosphonates suppress osteocyte apoptosis and may be localized within osteocyte lacunae. Bisphosphonates also reduce osteoclast viability and thereby hinder the repair of damaged tissue. Osteocyte lacunae contribute to toughening mechanisms. Following osteocyte apoptosis, the lacunar space undergoes mineralization, termed "micropetrosis". Hypermineralized lacunae are believed to increase bone fragility. Using nanoanalytical electron microscopy with complementary spectroscopic and crystallographic experiments, postapoptotic mineralization of osteocyte lacunae in bisphosphonate-exposed human bone was investigated. We report an unprecedented presence of ∼80 nm to ∼3 μm wide, distinctly faceted, magnesium whitlockite [Ca₁₈Mg₂(HPO₄)₂(PO₄)₁₂] crystals and consequently altered local nanomechanical properties. These findings have broad implications on the role of therapeutic agents in driving biomineralization and shed new insights into a possible relationship between bisphosphonate exposure, availability of intracellular magnesium, and pathological calcification inside lacunae.

Bone Metastases: An Overview

Bone is a frequent site of metastases and typically indicates a short-term prognosis in cancer patients. Once cancer has spread to the bones it can rarely be cured, but often it can still be treated to slow its growth. The majority of skeletal metastases are due to breast and prostate cancer. Bone metastasis is actually much more common than primary bone cancers, especially in adults. The diagnosis is based on signs, symptoms and imaging. New classes of drugs and new interventions are given a better quality of life to these patients and improved the expectancy of life. It is necessary a multidisciplinary approach to treat patients with bone metastasis. In this paper we review the types, clinical approach and treatment of bone metastases.

Bisphosphonate-related osteonecrosis of the jaw: from the sine qua non condition of bone exposure to a non-exposed BRONJ entity

The present work aimed to review the literature focusing on the diagnostic criteria for bisphosphonate-related osteonecrosis of the jaw (BRONJ) and its implications regarding the management of the disease. Since the report of the first cases, BRONJ concepts, diagnostic criteria and guidelines have been changed. The presence of bone exposure in the oral cavity was at first a sine qua non condition for diagnosis. However, it seems that the great concern now is the possibility of occurrence of BRONJ without this feature. Some authors warn that the bone exposure criterion leads to late diagnosis and poor response to treatment. Meanwhile, some radiographic features, such as bone sclerosis, have been postulated as early signs of the disease. Criticisms have also been raised about the clinical staging system of BRONJ. While there is no consensus on the subject, common sense recommends treating symptomatic patients taking bisphosphonate as having BRONJ despite the absence of bone exposure; and asymptomatic patients must be kept under dental follow-up, since all of them are at risk for BRONJ.

Osteonecrosis of the jaw (ONJ): diagnosis and management in 2015

Osteonecrosis of the jaw (ONJ) has been associated with the use of aminobisphosphonates and denosumab. The vast majority (>90%) of cases occur in the oncology patient population receiving high doses of intravenous bisphosphonates or subcutaneous denosumab. The incidence of ONJ in the osteoporosis patient population is very low and is estimated at 1-90 per 100,000 patient-years of exposure. In the oncology patient population the incidence appears to be related to dose and duration of exposure, and prevalence has been estimated to be as high as 18.6%. A number of risk factors in addition to antiresorptive therapy have been identified. These include the presence of periodontal disease, oral surgical procedures with extractions or implants, radiation therapy, chemotherapy, diabetes, glucocorticoid use, and smoking. Antiangiogenic agents appear to contribute to the risk of ONJ, however, data at this time are limited and further evidence is required prior to confirming a causal relationship. ONJ may be prevented with optimization of oral hygiene, the use of oral antimicrobial mouth rinses, as well as systemic antibiotic therapy. Individuals not responding to conservative management or in the advanced stages of ONJ may be considered for surgery, as data over the past several years have demonstrated surgical success in this patient population. Case reports have indicated that teriparatide may enhance healing. A number of experimental therapies are being evaluated and include the use of bone marrow stem cell intralesional transplantation, local application of platelet-derived growth factor, hyperbaric oxygen, tissue grafting, and low-level laser therapy. This paper summarizes the current research as well as the international consensus on the diagnosis and management of ONJ.

Adjuvant bisphosphonates in early breast cancer: consensus guidance for clinical practice from a European Panel

Bisphosphonates have been studied in randomised trials in early breast cancer to investigate their ability to prevent cancer treatment-induced bone loss (CTIBL) and reduce the risk of disease recurrence and metastasis. Treatment benefits have been reported but bisphosphonates do not currently have regulatory approval for either of these potential indications. This consensus paper provides a review of the evidence and offers guidance to breast cancer clinicians on the use of bisphosphonates in early breast cancer. Using the nominal group methodology for consensus, a systematic review of the literature was augmented by a workshop held in October 2014 for breast cancer and bone specialists to present and debate the available pre-clinical and clinical evidence for the use of adjuvant bisphosphonates. This was followed by a questionnaire to all members of the writing committee to identify areas of consensus. The panel recommended that bisphosphonates should be considered as part of routine clinical practice for the prevention of CTIBL in all patients with a T score of <-2.0 or ≥2 clinical risk factors for fracture. Compelling evidence from a meta-analysis of trial data of >18,000 patients supports clinically significant benefits of bisphosphonates on the development of bone metastases and breast cancer mortality in post-menopausal women or those receiving ovarian suppression therapy. Therefore, the panel recommends that bisphosphonates (either intravenous zoledronic acid or oral clodronate) are considered as part of the adjuvant breast cancer treatment in this population and the potential benefits and risks discussed with relevant patients.

Surgical management of bisphosphonate-related osteonecrosis of the jaw stages II and III

OBJECTIVE

The value of surgery in advanced stages of bisphosphonate-related osteonecrosis of the jaw (BRONJ) is still controversial. Hence, we evaluated the effect of surgical therapy in BRONJ stages II and III in combination with a standardized perioperative adjuvant treatment.

STUDY DESIGN

We included 39 patients who presented with BRONJ in a total of 47 locations and stages II (n = 23) and III (n = 24). All patients had exclusively received a monthly intravenous application of zoledronic acid. Surgical therapy consisted of complete removal of the necrotic jaw, accompanied by a standardized perioperative adjuvant treatment including intravenous antibiotic prophylaxis, gastric feeding, and an antimicrobiologic mouth rinsing.

RESULTS

Overall, 35 (74.5%) of the 47 BRONJ sites were treated successfully, with success defined as complete mucosal healing of the exposed jaw (n = 24) or as relative healing when surgical therapy downscaled BRONJ II or III to asymptomatic BRONJ stage I (n = 11). Interestingly, perioperative adjuvant treatment or bisphosphonate therapy parameters showed no statistical effect on the treatment outcome.

CONCLUSIONS

The results of the present study prove the effectiveness of surgical therapy for BRONJ stage II or III.

Cancer treatment-induced bone loss (CTIBL): pathogenesis and clinical implications

Osteopenia and osteoporosis are often long-term complications of anti-neoplastic treatments, defined as "cancer treatment-induced bone loss" (CTIBL). This pathological condition in oncologic patients results in a higher fracture risk than in the general population, and so has a significant negative impact on their quality of life. Hormone treatment is the main actor in this scenario, but not the only one. In fact, chemotherapies, radiotherapy and tyrosine kinase inhibitors may contribute to deregulate bone remodeling via different mechanisms. Thus, the identification of cancer patients at risk for CTIBL is essential for early diagnosis and appropriate intervention, that includes both lifestyle modifications and pharmacological approaches to prevent bone metabolism failure during anti-tumor treatments.

Changes in cortical bone channels network and osteocyte organization after the use of zoledronic acid

OBJECTIVE

The aim of this study was to evaluate the effects of zoledronic acid (ZA) on the cortical bone channels network (CBCN) and osteocyte organization in relation to the bone channels.

MATERIALS AND METHODS

Eighteen male Wistar rats were divided into control (CG) and test groups (TG). Twelve animals from TG received 3 ZA doses (7.5 µg/kg), and 6 animals from CG did not receive any medication. TG animals were euthanized at 14 (n = 6) and 75 (n = 6) dadys after drug injection. CBCN was analyzed in mandibles and tibias using computational routines. The osteocyte organization was qualitatively evaluated in tibias using a three-dimensional reconstruction of images from serial histological sections.

RESULTS

Significant differences in CBCN of tibia were found between the treated and untreated rats, with a wider range of sizes and shapes of the channels after the use of ZA (channels area p = 0.0063, channels area SD p = 0.0276) and less bone matrix (bone volume p = 0.0388). The alterations in the channels' morphology were more evident at 75 days after the drug injection (channels perimeter p = 0.0286). No differences were found in mandibles CBCN. The osteocyte distribution revealed more variable patterns of cell distribution in ZA groups, with non-homogeneous distribution of cells in relation to the bone channels.

CONCLUSION

Zoledronic acid induces structural changes in CBCN and modifies the osteocyte arrangement in cortical bone in the tibia; also, the variability in the morphology of bone channels became more evident after a certain time of the use of the drug.

The Progression of Bone Mineral Density Abnormalities After Chemotherapy for Childhood Acute Lymphoblastic Leukemia

Although reduced bone mineral density in survivors of childhood acute lymphoblastic leukemia (ALL) is well documented, the degree of demineralization and relation to age are not well described. This is a retrospective chart analysis of 58 patients consecutively treated for ALL without relapse, cranial irradiation, or transplantation. Bone mineral densities were measured by dual-energy x-ray absorptiometry and patients were divided by sex and age (≤5, 6 to 10, and >10 y) at diagnosis. Serial scans for 6 years after therapy were analyzed as Z-scores. Over 6 years after therapy, 93.1% of patients exhibited a decreased Z-score in at least 1 anatomic site. The difference in Z-score among the age cohorts was significant at both the lumbar spine and femoral neck. Patients older than 10 years at diagnosis had the lowest Z-scores: -2.78 and -2.87 for boys and -2.39 and -2.91 for girls at the lumbar spine and femoral neck, respectively. Children after ALL therapy exhibit a significant bone mineral deficit shortly after completion of therapy that persists for at least 6 years. The degree of bone demineralization can be followed up by a dual-energy x-ray absorptiometry scan and is most severe in patients older than 10 years at the initiation of therapy.

Value of nonsurgical therapeutic management of stage I bisphosphonate-related osteonecrosis of the jaw

There is still controversy about the best treatment strategy for patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ) stage I. Therefore, the aim of the present study was to analyse the effect of a nonsurgical treatment protocol in patients with BRONJ stage I. During the study period we included 17 patients (11 male; 6 female) who presented with a total of 24 separate areas of BRONJ, stage I. All patients were exclusively treated with a monthly intravenous regime of zoledronic acid due to an underlying malignant disease. All patients were treated using a standardized nonsurgical protocol consisting of antimicrobial mouth rinsing with chlorhexidine (CHX) (0.12%) three times a day, and daily CHX gel application. In 11 patients (45.8%) the surface area of the exposed jawbone was completely healed by nonsurgical treatment. In seven patients (29.2%), nonsurgical treatment reduced the size of the exposed bone area by a mean of 64.7% (range 20.0-96.8%). None of the patients showed an increase in size of the area of exposed jawbone, or a worsening of the BRONJ from stage I to stages II or III. However, the duration of nonsurgical treatment or the duration of intravenous bisphosphonate therapy did not significantly influence the treatment outcome (p = 0.6628, p = 0.6077, respectively). The results of the present study support the beneficial role of nonsurgical treatment in patients presenting with BRONJ stage I. Surgical therapy of BRONJ should be restricted to patients with advanced stages with clinical symptoms and local signs of infection.

Infection and Medication-related Osteonecrosis of the Jaw

Medication-related osteonecrosis of the jaw (MRONJ), although initially believed to be exclusively associated with bisphosphonates, has been implicated in recent reports with additional drugs, especially the bone antiresorptive denosumab. The pathophysiology has not been fully elucidated, and no causal association between bone antiresorptive regimens and MRONJ has yet been established. However, reduced bone turnover and infection, an almost universal finding, are thought to be central to the pathogenesis of MRONJ. Both bisphosphonates and denosumab, through different pathways of action, significantly reduce the rate of bone turnover and potentially reduce the efficacy of the host defense against infection. Recent evidence questions the simplified etiology of low bone turnover causing MRONJ and offers evidence on the prominent role of infection instead. The management of MRONJ remains a significant clinical challenge, with little progress having been made on treatment. The aim of this article is to explore the current theories on the etiology of MRONJ and to emphasize the importance of infection in the development of this devastating pathology.

Surgical Therapy for Bisphosphonate-Related Osteonecrosis of the Jaw: Six-Year Experience of a Single Institution

PURPOSE

Bisphosphonates are drugs commonly used to treat osteoporosis, hypercalcemia of malignancy, and bone metastases. In some cases, its administration has been associated with osteonecrosis of the jaws. The management of medication-related osteonecrosis of the jaw (MRONJ) has not been completely elucidated, and its treatment can vary from no or limited surgery to more extensive surgery. The objective of the present study was to evaluate the efficacy of surgical therapy for patients presenting with MRONJ.

PATIENTS AND METHODS

A retrospective study was conducted that evaluated all MRONJ cases resulting from bisphosphonate use and treated by surgery from 2006 to 2012. All patients underwent surgery under general anesthesia.

RESULTS

A total of 33 patients with 46 MRONJ sites were evaluated. Most of the patients were women, with an age range of 39 to 83 years (mean 65.6 ± 10.6). Complete healing of the MRONJ region was observed in 40 of the 46 sites (87%), with partial improvement (symptom control and reduction of the exposed bone area) observed in 3 sites (6.5%), for a 93.5% clinical benefit rate. Of the remaining regions, 2 showed no significant changes, and 1 presented with a worse aspect compared with the patient's preoperative condition. Such cases were located in the posterior mandible region. The number of applications and type of bisphosphonate did not influence the treatment response.

CONCLUSION

The surgical approach to treating MRONJ showed a high rate of clinical control. Therefore, surgery should be considered as a therapy for some cases of this condition.

Osteonecrosis of the Jaw in Patients With Metastatic Renal Cell Cancer Treated With Bisphosphonates and Targeted Agents: Results of an Italian Multicenter Study and Review of the Literature

Osteonecrosis of the jaw (ONJ) associated with the use of bisphosphonates has been rarely reported in metastatic renal cell cancer (RCC) patients. Since the introduction of combined therapies consisting of nitrogen-containing bisphosphonates (NBPs) and targeted agents, an increasing number of RCC patients were reported to develop ONJ, suggesting that therapeutic angiogenesis suppression might increase the risk of ONJ in NBPs users. We performed a multicenter retrospective study and reviewed literature data to assess the occurrence and to investigate the nature of ONJ in RCC patients taking NBPs and targeted agents. Nine Italian Centers contributed to the data collection. Patients with exposed and nonexposed ONJ were eligible for the study if they had been taking NBPs and were receiving targeted agents at the time of ONJ diagnosis. Forty-four RCC patients were studied. Patients were mostly male (82%), with a median age of 63 years (range, 45-85 years). Zoledronic acid (93%) and sunitinib (80%) were the most frequently used NBP and antiangiogenic agent, respectively. Other agents included Pamidronate, ibandronate, sorafenib, bevacizumab, mammalian target of rapamycin inhibitors. Forty-nine sites of ONJ were encountered, with the mandible being the preferred site of ONJ (52%); both jaws were affected in 5 cases (12%). The most common precipitating event was dental/periodontal infection (34%), followed by tooth extraction (30%). Oral triggers of ONJ were missing in 10 cases (23%). This unexpectedly high number of ONJ cases, in comparison with literature data, suggests that frequency of ONJ in RCC patients might be largely underestimated and suggests a potential role for targeted agents in the incremental risk of ONJ.