Oral avascular bone necrosis associated with chemotherapy and biphosphonate therapy

A personalized biomimetic dual-drug delivery system via controlled release of PTH1-34 and simvastatin for in situ osteoporotic bone regeneration

Patients with osteoporosis often encounter clinical challenges of poor healing after bone transplantation due to their diminished bone formation capacity. The use of bone substitutes containing bioactive factors that increase the number and differentiation of osteoblasts is a strategy to improve poor bone healing. In this study, we developed an in situ dual-drug delivery system containing the bone growth factors PTH1-34 and simvastatin to increase the number and differentiation of osteoblasts for osteoporotic bone regeneration. Our system exhibited ideal physical properties similar to those of natural bone and allowed for customizations in shape through a 3D-printed scaffold and GelMA. The composite system regulated the sustained release of PTH1-34 and simvastatin, and exhibited good biocompatibility. Cell studies revealed that the composite system reduced osteoblast death, and promoted expression of osteoblast differentiation markers. Additionally, by radiographic analysis and histological observation, the dual-drug composite system demonstrated promising bone regeneration outcomes in an osteoporotic skull defect model. In summary, this composite delivery system, comprising dual-drug administration, holds considerable potential for bone repair and may serve as a safe and efficacious therapeutic approach for addressing bone defects in patients with osteoporosis.

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.

Prognosis by cancer type and incidence of zoledronic acid-related osteonecrosis of the jaw: a single-center retrospective study

PURPOSE

Survival time after bisphosphonate use has been increasingly recognized to be associated with the incidence of medication-related osteonecrosis of the jaw (MRONJ); however, this has not been elucidated sufficiently in the literature. This study aimed to clarify the incidence of MRONJ and the corresponding survival rate of patients treated with zoledronic acid (ZA) for each type of cancer and obtain useful information for the oral/dental supportive care of cancer patients.

METHODS

We evaluated 988 patients who were administered ZA at our hospital; among them, 862 patients with metastatic bone tumors or myeloma were included.

RESULTS

The median survival time (MST) after ZA initiation was 35, 34, 8, 41, 12, and 6 months for patients with breast, prostrate, lung, myeloma, renal, and other cancers, respectively. Patients with cancers that had a short survival time (lung and other cancers [MST = 8 and 6 months, respectively] and cancers with MST < 10 months) did not develop MRONJ; this could be attributed to the shorter duration of ZA administration. The cumulative incidence of MRONJ in breast cancer, prostate cancer, and multiple myeloma was related to the frequency of anti-resorptive drug use and the increased risk over time. In renal cancer, the cumulative incidence of MRONJ increased early, although the MST was 12 months.

CONCLUSION

For the dentists in charge of dental management, it is essential to be aware of prognosis-related factors, predict MRONJ risk for each cancer treatment, and use risk prediction in dental management planning, particularly for cancers with non-poor prognosis.

Impact of COVID-19 disease and its treatment on the development of maxillofacial complications

The novel coronavirus spread worldwide in 2020, causing millions of deaths and disabilities. Even though the virus was considered a respiratory virus, its adverse effects can be detected in several body systems. The article describes COVID-19 disease and its complications in the maxillofacial area. Several complications develop either in response to therapeutic modalities used to treat the underlying disease, or due to overuse of particular medications namely glucocorticoids, antirheumatic agents, interleukin 6-inhibitors, and antibiotics. This article will describe a number of complications ranging from mild complications to severe ones such as osteonecrosis of the upper jaw and facial bones, ophthalmologic and neurological complications. It will also summarize recommendations that will help prevent or minimize these complications.

Bisphosphonate-related osteonecrosis of the jaws and dental surgery procedures in children and young people with osteogenesis imperfecta: A systematic review

BACKGROUND

Bisphosphonates (BPs) contrast the bone fragility and improve bone density in some metastatic cancers and bone diseases, such as Osteogenesis Imperfecta (OI). BPs use has been associated with osteonecrosis of the jaws (BRONJs) in adults needing for invasive dental procedures.

AIM

To conduct a systematic review on BRONJ occurrence after dental surgery in paediatric population under BPs therapy for OI, so as to identify the pre-surgical protocols adopted.

DESIGN

According to PRISMA guidelines, Pubmed, Web of Science (WoS) and Cochrane were investigated on September 2018, and re-checked on July 2019. Inclusion criteria were English-language papers on children/young adults (until 24 years old) reporting dental/oral surgery procedures.

RESULTS

Totally, 60 articles were found. After title/abstract reviews and duplicates exclusion, 22 eligible titles underwent full-text evaluation. Finally, 10 studies were included.

CONCLUSIONS

The lack of BRONJ occurrence in paediatric population suffering OI and treated with BPs, was confirmed, but the reasons are still debated, being the BPs therapies and the surgical strategies various and not standardized. Longitudinal studies should evaluate what happens to those former children once adult, to evaluate the delayed BRONJs onset associated with the occurrence of comorbidities during the adulthood.

Medication-Related Osteonecrosis of the Jaw: MASCC/ISOO/ASCO Clinical Practice Guideline

PURPOSE

To provide guidance regarding best practices in the prevention and management of medication-related osteonecrosis of the jaw (MRONJ) in patients with cancer.

METHODS

Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) and ASCO convened a multidisciplinary Expert Panel to evaluate the evidence and formulate recommendations. Guideline development involved a systematic review of the literature and a formal consensus process. PubMed and EMBASE were searched for studies of the prevention and management of MRONJ related to bone-modifying agents (BMAs) for oncologic indications published between January 2009 and December 2017. Results from an earlier systematic review (2003 to 2008) were also included.

RESULTS

The systematic review identified 132 publications, only 10 of which were randomized controlled trials. Recommendations underwent two rounds of consensus voting.

RECOMMENDATIONS

Currently, MRONJ is defined by (1) current or previous treatment with a BMA or angiogenic inhibitor, (2) exposed bone or bone that can be probed through an intraoral or extraoral fistula in the maxillofacial region and that has persisted for longer than 8 weeks, and (3) no history of radiation therapy to the jaws or metastatic disease to the jaws. In patients who initiate a BMA, preventive care includes comprehensive dental assessments, discussion of modifiable risk factors, and avoidance of elective dentoalveolar surgery (ie, surgery that involves the teeth or contiguous alveolar bone) during BMA treatment. It remains uncertain whether BMAs should be discontinued before dentoalveolar surgery. Staging of MRONJ should be performed by a clinician with experience in the management of MRONJ. Conservative measures comprise the initial approach to MRONJ treatment. Ongoing collaboration among the dentist, dental specialist, and oncologist is essential to optimal patient care.

Zoledronate suppresses VEGF‑induced capillary tube formation and inhibits expression of interferon‑induced transmembrane protein‑1 in human umbilical vein endothelial cells

Interferon‑induced transmembrane protein 1 (IFITM1) is a member of the interferon‑induced transmembrane protein family and has recently been identified as a novel protein participant in angiogenesis. Zoledronate (ZON), a nitrogen‑containing bisphosphonate, is widely used in the treatment of osteoporosis and to prevent bone metastases of certain cancer types. However, the association between ZON and IFITM1 has remained elusive. The present study investigated the effect of ZON on the expression of IFITM1 during vascular endothelial growth factor (VEGF)‑induced capillary tube formation in human umbilical vein endothelial cells. It was observed that cell proliferation and VEGF‑induced tube formation were significantly inhibited by treatment with 10 µM ZON. The expression of IFITM1 increased during VEGF‑induced tube formation. However, the VEGF‑induced increase in IFITM1 expression exhibited a dose‑ and time‑dependent decrease with ZON treatment at the mRNA and protein level. Furthermore, matrix metalloproteinase‑9 activation was markedly decreased by ZON treatment. These results suggest that induction of IFITM1 expression may be involved in the anti‑angiogenic activity of ZON.

Bisphosphonates in multiple myeloma: an updated network meta-analysis

BACKGROUND

Bisphosphonates are specific inhibitors of osteoclastic activity and are used in the treatment of patients with multiple myeloma (MM). While bisphosphonates are shown to be effective in reducing vertebral fractures and pain, their role in improving overall survival (OS) remains unclear. This is an update of a Cochrane review first published in 2002 and previously updated in 2010 and 2012.

OBJECTIVES

To assess the evidence related to benefits and harms associated with use of various types of bisphosphonates (aminobisphosphonates versus non-aminobisphosphonates) in the management of patients with MM. Our primary objective was to determine whether adding bisphosphonates to standard therapy in MM improves OS and progression-free survival (PFS), and decreases skeletal-related morbidity. Our secondary objectives were to determine the effects of bisphosphonates on pain, quality of life, incidence of hypercalcemia, incidence of bisphosphonate-related gastrointestinal toxicities, osteonecrosis of jaw (ONJ) and hypocalcemia.

SEARCH METHODS

We searched MEDLINE, Embase (September 2011 to July 2017) and the CENTRAL (2017, Issue 7) to identify all randomized controlled trial (RCT) in MM up to July 2017 using a combination of text and MeSH terms.

SELECTION CRITERIA

Any randomized controlled trial (RCT) comparing bisphosphonates versus placebo/no treatment/bisphosphonates and observational studies or case reports examining bisphosphonate-related ONJ in patients with MM were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors extracted the data. Data were pooled and reported as hazard ratio (HR) or risk ratio (RR) using a random-effects model. We used meta-regression to explore statistical heterogeneity. Network meta-analysis using Bayesian approach was conducted.

MAIN RESULTS

In this update, we included four new studies (601 participants), resulting in a total of 24 included studies.Twenty RCTs compared bisphosphonates with either placebo or no treatment and four RCTs involved another bisphosphonate as a comparator. The 24 included RCTs enrolled 7293 participants. Pooled results showed that there was moderate-quality evidence of a reduction in mortality with on OS from 41% to 31%, but the confidence interval is consistent with a larger reduction and small increase in mortality compared with placebo or no treatment (HR 0.90, 95% CI 0.76 to 1.07; 14 studies; 2706 participants). There was substantial heterogeneity among the included RCTs (I2 = 65%) for OS. To explain this heterogeneity we performed a meta-regression assessing the relationship between bisphosphonate potency and improvement in OS, which found an OS benefit with zoledronate but limited evidence of an effect on PFS. This provided a further rationale for performing a network meta-analyses of the various types of bisphosphonates that were not compared head-to-head in RCTs. Results from network meta-analyses showed evidence of a benefit for OS with zoledronate compared with etidronate (HR 0.56, 95% CI 0.29 to 0.87) and placebo (HR 0.67, 95% CI 0.46 to 0.91). However, there was no evidence for a difference between zoledronate and other bisphosphonates.The effect of bisphosphonates on disease progression (PFS) is uncertain. Based on the HR of 0.75 (95% CI 0.57 to 1.00; seven studies; 908 participants), 47% participants would experience disease progression without treatment compared with between 30% and 47% with bisphosphonates (low-quality evidence). There is probably a similar risk of non-vertebral fractures between treatment groups (RR 1.03, 95% CI 0.68 to 1.56; six studies; 1389 participants; moderate-quality evidence). Pooled analysis demonstrated evidence for a difference favoring bisphosphonates compared with placebo or no treatment on prevention of pathological vertebral fractures (RR 0.74, 95% CI 0.62 to 0.89; seven studies; 1116 participants; moderate-quality evidence) and skeletal-related events (SREs) (RR 0.74, 95% CI 0.63 to 0.88; 10 studies; 2141 participants; moderate-quality evidence). The evidence for less pain with bisphosphonates was of very low quality (RR 0.75, 95% CI 0.60 to 0.95; eight studies; 1281 participants).Bisphosphonates may increase ONJ compared with placebo but the confidence interval is very wide (RR 4.61, 95% CI 0.99 to 21.35; P = 0.05; six studies; 1284 participants; low-quality evidence). The results from the network meta-analysis did not show any evidence for a difference in the incidence of ONJ (eight RCTs, 3746 participants) between bisphosphonates. Data from nine observational studies (1400 participants) reported an incidence of 5% to 51% with combination of pamidronate and zoledronate, 3% to 11% with zoledronate alone, and 0% to 18% with pamidronate alone.The pooled results showed no evidence for a difference in increase in frequency of gastrointestinal symptoms with the use of bisphosphonates compared with placebo or no treatment (RR 1.23, 95% CI 0.95 to 1.59; seven studies; 1829 participants; low-quality evidence).The pooled results showed no evidence for a difference in increase in frequency of hypocalcemia with the use of bisphosphonates compared with placebo or no treatment (RR 2.19, 95% CI 0.49 to 9.74; three studies; 1090 participants; low-quality evidence). The results from network meta-analysis did not show any evidence for differences in the incidence of hypocalcemia, renal dysfunction and gastrointestinal toxicity between the bisphosphonates used.

AUTHORS' CONCLUSIONS

Use of bisphosphonates in participants with MM reduces pathological vertebral fractures, SREs and pain. Bisphosphonates were associated with an increased risk of developing ONJ. For every 1000 participants treated with bisphosphonates, about one patient will suffer from the ONJ. We found no evidence of superiority of any specific aminobisphosphonate (zoledronate, pamidronate or ibandronate) or non-aminobisphosphonate (etidronate or clodronate) for any outcome. However, zoledronate was found to be better than placebo and first-generation bisposphonate (etidronate) in pooled direct and indirect analyses for improving OS and other outcomes such as vertebral fractures. Direct head-to-head trials of the second-generation bisphosphonates are needed to settle the issue if zoledronate is truly the most efficacious bisphosphonate currently used in practice.

Bisphosphonate-Induced Osteonecrosis of the Jaw

Objective:

To review the risk of osteonecrosis of the jaw associated with bisphosphonates.

Data Sources:

A MEDLINE search (1966–January 2007) and a search of international Pharmaceutical Abstracts (1970–January 2007) were conducted to identify relevant literature. Additional references were reviewed from selected articles.

Study Selection and Data Extraction:

Articles related to bisphosphonate-induced osteonecrosis of the jaw were reviewed and summarized. Inclusion criteria required that articles be either case studies or case series that were reporting actual cases linking osteonecrosis of the jaw with bisphosphonate use. Articles that addressed sites of osteonecrosis not involving the jaw, teaching cases (fictitious patients), and a retrospective claims analysis paper were excluded from consideration.

Data Synthesis:

Bisphosphonates have recently been linked to osteonecrosis of the jaw, with the greatest incidence seen with the intravenous preparations zoledronic acid and pamidronate. Osteonecrosis refers to death of a part of the bone, resulting in decreased bone density. Although the majority of occurrences have been associated with the intravenous bisphosphonates, oral bisphosphonates have also been implicated. Other risk factors noted from reported cases include dental extraction or trauma to the jaw exposing part of the bone. It is difficult to determine an exact incidence of osteonecrosis of the jaw in the general population of patients prescribed bisphosphonates; however, the incidence in cancer patients is approximately 6–7%.

Conclusions:

Although discontinuation of intravenous bisphosphonates in cancer patients has been recommended, stopping oral bisphosphonates prior to dental work cannot be universally endorsed at this time, since it is unknown whether this is effective in reducing the risk of osteonecrosis of the jaw. Treatment of this condition is not well established; therefore, efforts should be directed toward prevention. Pharmacists may further counsel patients to practice good oral hygiene and regularly follow up with their dentist during therapy. Current evidence suggests limited surgical debridement with systemic and local antibiotics as treatments.

Bisphosphonate-related osteonecrosis of the jaws: Report of a case using conservative protocol

Bisphosphonates have been the first-line treatment option for osteometabolic diseases, such as osteoporosis, hypercalcaemia in malignant bone diseases, and in bone metastasis. It is possible to observe a growing number of cases of osteonecrosis of the jaws in patients using this medication, called bisphosphonate-related osteonecrosis of the jaws. The purpose of this study was to report a conservative treatment for bisphosphonate-related osteonecrosis of the jaws--Stage 2, using antibacterial solution and low-level laser therapy. At the end of the treatment, the patient presented improvement of the lesion with the healing of the mucosa. The literature still lacks successful definite protocols, thus the present case may contribute with another option for conservative management for bisphosphonate-related osteonecrosis of the jaws. More research is necessary in order to develop a good protocol management for bisphosphonate-related osteonecrosis of the jaws.

Knowledge and attitudes of Brazilian dental students and dentists regarding bisphosphonate-related osteonecrosis of the jaw

PURPOSE

The aim of this study was to evaluate the knowledge of Brazilian dentists (DEN) and dental students (DS) about bisphosphonates (BP) and bisphosphonate-related osteonecrosis of the jaw (BRONJ).

METHODS

A convenience sample of 104 DEN and 100 DS was randomly selected and invited to answer a questionnaire. The questionnaire was structured on the basis of the main information about BP and the risk factors associated with the development of BRONJ. The data obtained were analyzed by the chi-square and Fisher's exact tests, considering significance of 5%.

RESULTS

Seventy-five (72.1%) DEN and 75 (75%) DS did not know the BP cited in the questionnaire (p < 0.0001), and their commercial brand names were not recognized by 88 (84.6%) DEN and 86 (86%) DS (p < 0.0001). In the same way, 62 (59.6%) DEN (p = 0.04) and 58 (58%) DS (p < 0.0001) did not recognize BRONJ as an oral side effect of BP or point out oral conditions that were not associated with the use of BP.

CONCLUSIONS

Practical initiatives, such as free lectures and workshops, must be taken to broaden the knowledge of DEN and DS about BP and thus contribute to the prevention of BRONJ.

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.

Bisphosphonate-related osteonecrosis of the jaws (Bronj)

Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is an extremely therapy resistant osteomyelitis-like disease exclusively involving the jaw bones of patients in treatment with bisphosphonates (BPs). Objectives: The aim of this study was to evaluate the radiological and clinical findings and management of 51 patients with BRONJ diagnosed from 2004 to 2009 in our Reference Center. Study Design: A prospective study was performed. The patients were examined every 2-6 months, depending on their clinical conditions. Outcome variables were the resolution of symptoms, persistence of bone exposure and /or fistula and the status of the lesional mucosa. Results: The higher prevalence of the disease was noted in 2006 and 2007 and at the time of diagnosis 90% of patients had been treated with iv BPs. The main precipitating event leading to BRONJ was an invasive dental procedure in 61% of patients while no traumatic event could be identified in 16% of patients. The median time of follow-up was 19 months (range: 2-57), during which 31% of patients healed and 39% succumbed. In 78% of patients the therapy was medical, in 16% it consisted in surgical deep curettage and only in 6% it was necessary to perform an osteotomy to avoid a mandibular pathological fracture. All the patients in treatment with oral BPs healed from BRONJ with a median time of conservative treatment of 19 months. Conclusions: Prevention has lead to a progressive reduction in the prevalence of BRONJ. In our experience medical treatment is often sufficient to keep the disease under control and to lead to the healing of the lesions by spontaneous loss of the sequestrum. This approach seems to be very effective in patients who were in treatment with oral Bps preparations; BRONJ seems to have a more benign clinical behaviour in these patients.

Key words:Bisphosphonates, osteonecrosis, treatment, follow-up.

Bisphosphonates in multiple myeloma: a network meta-analysis

BACKGROUND

Bisphosphonates are specific inhibitors of osteoclastic activity and used in the treatment of patients with multiple myeloma (MM). While bisphosphonates are shown to be effective in reducing vertebral fractures and pain, their role in improving overall survival (OS) remains unclear. This is an update of a Cochrane review first published in 2002 and previously updated in 2010.

OBJECTIVES

To assess the evidence related to benefits and harms associated with use of various types of bisphosphonates (aminobisphosphonates versus nonamino bisphosphonates) in the management of patients with MM. Our primary objective was to determine whether adding bisphosphonates to standard therapy in MM improves OS and progression-free survival (PFS), and decreases skeletal-related morbidity. Our secondary objectives were to determine the effects of bisphosphonates on pain, quality of life, incidence of hypercalcemia, incidence of bisphosphonate-related gastrointestinal toxicities, osteonecrosis of jaw and hypocalcemia.

SEARCH METHODS

We searched MEDLINE, LILACS, EMBASE (December 2009 to October 2011) and the Cochrane Controlled Trials Register (all years, latest Issue September 2011) to identify all randomized trials in MM up to October 2011 using a combination of text and MeSH terms. We also handsearched relevant meeting proceedings (December 2009 to October 2011).

SELECTION CRITERIA

Any randomized controlled trial (RCT) assessing the role of bisphosphonates and observational studies or case reports examining bisphosphonate-related osteonecrosis of the jaw in patients with MM were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors extracted the data. Data were pooled and reported as hazard ratio (HR) or risk ratio (RR) under a random-effects model. Statistical heterogeneity was explored using metaregression.

MAIN RESULTS

In this update, we included 2 studies (2464 patients) that were not part of our last Cochrane review published in 2010. In this review we included 16 RCTs comparing bisphosphonates with either placebo or no treatment and 4 RCTs with a different bisphosphonate as a comparator. The 20 included RCTs enrolled 6692 patients. Overall methodological quality of reporting was moderate. Thirty per cent (6/20) of trials reported the method of generating the randomization sequence. Forty per cent (8/20) of trials had adequate allocation concealment. Withdrawals and dropouts were described in 60% (12/20) of trials. Pooled results showed no direct effect of bisphosphonates on OS compared with placebo or no treatment (HR 0.96, 95% CI 0.82 to 1.13; P = 0.64). However, there was a statistically significant heterogeneity among the included RCTs (I(2) = 55%, P = 0.01) for OS. To explain this heterogeneity we performed a metaregression assessing the relationship between bisphosphonate potency and improvement in OS, which found indicating an OS benefit with zoledronate (P = 0.058). This provided a further rationale for performing network meta-analyses of the various types of bisphosphonates that were not compared head to head in RCTs. Results from network meta-analyses showed superior OS with zoledronate compared with etidronate (HR 0.43, 95% CI 0.16 to 0.86) and placebo (HR 0.61, 95% CI 0.28 to 0.98). However, there was no difference between zoledronate and other bisphosphonates. Pooled analysis did not demonstrate a beneficial effect of bisphosphonates compared with placebo or no treatment in improving PFS (HR 0.70, 95% CI 0.41 to 1.19; P = 0.18) There was no heterogeneity among trials reporting PFS estimates (I(2) = 35%, P = 0.20).Pooled analysis demonstrated a beneficial effect of bisphosphonates compared with placebo or no treatment on prevention of pathological vertebral fractures (RR 0.74, 95% CI 0.62 to 0.89; I(2) = 7%), skeletal-related events (SRE) (RR 0.80, 95% CI 0.72 to 0.89; I(2) = 2%) and amelioration of pain (RR 0.75, 95% CI 0.60 to 0.95; I(2) = 63%). The network meta-analysis did not show any difference in the incidence of osteonecrosis of the jaw (5 RCTs, 3198 patients) between bisphosphonates. Rates of osteonecrosis of the jaw in observational studies (9 studies, 1400 patients) ranged from 0% to 51%. The pooled results (6 RCTs, 1689 patients) showed no statistically significant increase in frequency of gastrointestinal symptoms with the use of bisphosphonates compared with placebo or no treatment (RR 1.23, 95% CI 0.95 to 1.60; P = 0.11).The pooled results (3 RCTs, 1002 patients) showed no statistically significant increase in frequency of hypocalcemia with the use of bisphosphonates compared with placebo or no treatment (RR 2.19, 95% CI 0.49 to 9.74). The network meta-analysis did not show any differences in the incidence of hypocalcemia, renal dysfunction and gastrointestinal toxicity between the bisphosphonates used.

AUTHORS' CONCLUSIONS

Use of bisphosphonates in patients with MM reduces pathological vertebral fractures, SREs and pain. Assuming a baseline risk of 20% to 50% for vertebral fracture without treatment, between 8 and 20 MM patients should be treated to prevent vertebral fracture(s) in one patient. Assuming a baseline risk of 31% to 76% for pain amelioration without treatment, between 5 and 13 MM patients should be treated to reduce pain in one patient. With a baseline risk of 35% to 86% for SREs without treatment, between 6 and 15 MM patients should be treated to prevent SRE(s) in one patient. Overall, there were no significant adverse effects associated with the administration of bisphosphonates identified in the included RCTs. We found no evidence of superiority of any specific aminobisphosphonate (zoledronate, pamidronate or ibandronate) or nonaminobisphosphonate (etidronate or clodronate) for any outcome. However, zoledronate appears to be superior to placebo and etidronate in improving OS.

Bisphosphonates in multiple myeloma

BACKGROUND

Bisphosphonates are specific inhibitors of osteoclastic activity and are currently used as supportive therapy for multiple myeloma (MM). However, the exact clinical role of bisphosphonates in MM remains unclear.

OBJECTIVES

This update of the first review published in 2002. We have also analyzed observational studies targeting osteonecrosis of jaw (ONJ).

SEARCH STRATEGY

We searched the literature using the methods outlined in the previous review. We also searched observational studies or case reports examining ONJ.

SELECTION CRITERIA

We selected RCTs with a parallel design related to the use of bisphosphonate in myeloma. We also selected observational studies or case reports examining bisphosphonates related to ONJ.

DATA COLLECTION AND ANALYSIS

We have reported pooled data using either hazard ratio or risk ratio and, when appropriate, as absolute risk reduction and the number needed to treat to prevent or to cause a pathological event. We have assessed statistical heterogeneity and reported I(2) statistic.

MAIN RESULTS

This review includes 17 trials with 1520 patients analyzed in bisphosphonates groups, and 1490 analyzed in control groups. In comparison with placebo/no treatment, the pooled analysis demonstrated the beneficial effect of bisphosphonates on prevention of pathological vertebral fractures (RR= 0.74 (95% CI: 0.62 to 0.89), P = 0.001), total skeletal related events (SREs) (RR= 0.80 (95% CI: 0.72 to 0.89), P < 0.0001) and on amelioration of pain (RR = 0.75 (95% CI: 0.60 to 0.95), P = 0.01). We found no significant effect of bisphosphonates on overall survival (OS), progression-free survival (PFS), hypercalcemia or on the reduction of non-vertebral fractures. The indirect meta-analyses did not find the superiority of any particular type of bisphosphonate over others. Only two RCTs reported ONJ. The identified observational studies suggested that ONJ may be a common event (range: 0% to 51%).

AUTHORS' CONCLUSIONS

Adding bisphosphonates to the treatment of MM reduces pathological vertebral fractures, SREs and pain but not mortality. Assuming the baseline risk of 20% to 50% for vertebral fracture without treatment, we estimate that between eight and 20 MM patients should be treated to prevent vertebral fracture(s) in one patient. Assuming the baseline risk of 31% to 76% for pain amelioration without treatment, we estimate that between five to 13 MM patients should be treated to reduce pain in one patient. Also, with the baseline risk of 35% to 86% for SREs without treatment, we estimate that between six and 15 MM patients should be treated to prevent SRE(s) in one patient. No bisphoshphonate appears to be superior to others.

Zoledronic acid delays wound healing of the tooth extraction socket, inhibits oral epithelial cell migration, and promotes proliferation and adhesion to hydroxyapatite of oral bacteria, without causing osteonecrosis of the jaw, in mice

Nitrogen-containing bisphosphonates such as zoledronic acid (ZOL) and pamidronate have been widely and successfully used for the treatment of cancer patients with bone metastases and/or hypercalcemia. Accumulating recent reports have shown that cancer patients who have received these bisphosphonates occasionally manifest bisphosphonate-related osteonecrosis of the jaw (BRONJ) following dental treatments, including tooth extraction. However, little is known about the pathogenesis of BRONJ to date. Here, to understand the underlying pathogenesis of BRONJ, we examined the effects of ZOL on wound healing of the tooth extraction socket using a mouse tooth extraction model. Histomorphometrical analysis revealed that the amount of new bone and the numbers of blood vessels in the socket were significantly decreased in ZOL-treated mice compared to control mice. Consistent with these results, ZOL significantly inhibited angiogenesis induced by vascular endothelial growth factor in vivo and the proliferation of endothelial cells in culture in a dose-dependent manner. In contrast, etidronate, a non-nitrogen-containing bisphosphonate, showed no effects on osteogenesis and angiogenesis in the socket. ZOL also suppressed the migration of oral epithelial cells, which is a crucial step for tooth socket closure. In addition, ZOL promoted the adherence of Streptococcus mutans to hydroxyapatite and the proliferation of oral bacteria obtained from healthy individuals, suggesting that ZOL may increase the bacterial infection. In conclusion, our data suggest that ZOL delays wound healing of the tooth extraction socket by inhibiting osteogenesis and angiogenesis. Our data also suggest that ZOL alters oral bacterial behaviors. These actions of ZOL may be relevant to the pathogenesis of BRONJ.

Bisphosphonate-associated osteonecrosis of the jaws: the limits of a conservative approach

BACKGROUND

An increasing number of cases of osteonecrosis of the jaws (ONJ) in patients treated with bisphosphonates has been reported in the literature. ONJ significantly affects the patients' quality of life and its management is still extremely difficult.

METHODS

A woman with ONJ secondary to therapy with zoledronic acid came to our attention for recurrent oral infections and orocutaneous fistula unresponsive to antibiotic therapy combined with minor surgical debridements. The patient underwent major surgery to remove the fistula and clean the necrotic bone and soft tissues; a lobed skin platysma flap was used to close the defect. The treatment outcome was good.

CONCLUSION

When ONJ fails to respond to antibiotic therapy and surgical debridements, a more invasive surgical approach may be necessary to guarantee a better quality of life for the patient.

Bisphosphonate Associated Osteonecrosis of the Jaw

In 2003, the first reports describing osteonecrosis of the jaw (ONJ) in patients receiving bisphosphonates (BP) were published. These cases occurred in patients with cancer receiving high-dose intravenous BP; however, 5% of the cases were in patients with osteoporosis receiving low-dose bisphosphonate therapy. We present the results of a systematic review of the incidence, risk factors, diagnosis, prevention, and treatment of BP associated ONJ. We conducted a comprehensive literature search for relevant studies on BP associated ONJ in oncology and osteoporosis patients published before February 2008.All selected relevant articles were sorted by area of focus. Data for each area were abstracted by 2 independent reviewers. The results showed that the diagnosis is made clinically. Prospective data evaluating the incidence and etiologic factors are very limited. In oncology patients receiving high-dose intravenous BP, ONJ appears to be dependent on the dose and duration of therapy, with an estimated incidence of 1%–12% at 36 months of exposure. In osteoporosis patients, it is rare, with an estimated incidence < 1 case per 100,000 person-years of exposure. The incidence of ONJ in the general population is not known. Currently, there is insufficient evidence to confirm a causal link between low-dose BP use in the osteoporosis patient population and ONJ. We concluded BP associated ONJ is associated with high-dose BP therapy primarily in the oncology patient population. Prevention and treatment strategies are currently based on expert opinion and focus on maintaining good oral hygiene and conservative surgical intervention.

Bisphosphonate-induced osteonecrosis of the jaws: review, clinical implications and case report

The introduction of bisphosphonates has increased in the last decade following their indication for metastatic bone diseases, osteoporosis, hypercalcaemia of malignancy and Paget's disease. Although bisphosphonates have been used clinically for more than three decades there have been no documented long-term complications of their effects on the jaws until recently, where there is now growing evidence of the influence of bisphosphonates on osteonecrosis of the jaws. The aim of this paper is to report a case of this newly described complication, to review this phenomenon, including the clinical implications and to reiterate current clinical guidelines for management of patients in which bisphosphonate therapy is indicated. To the best of our knowledge this is the first reported case of bisphosphonate-induced necrosis of the jaw in South Africa.

Bisphosphonate-related osteonecrosis of the jaws: an update on clinical, pathological and management aspects

Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is mainly observed in patients with multiple myeloma and bone metastasis from solid tumors receiving iv bisphosphonate therapy. The reported incidence of BRONJ is significantly higher with the iv preparations zoledronic acid and pamidronate while the risk appears to be minimal for patients receiving oral bisphosphonates. Currently available published incidence data for BRONJ are based on retrospective studies and estimates of cumulative incidence range from 0.8 to 12%. The mandible is more commonly affected than the maxilla (2:1 ratio), and 60-70% of cases are preceded by a dental surgical procedure. The signs and symptoms that may occur before the appearance of clinical evident osteonecrosis include changes in the health of periodontal tissues, non-healing mucosal ulcers, loose teeth and unexplained soft-tissue infection. Although the definitive role of bisphosphonates remains to be elucidated, the inhibition of physiologic bone remodeling and angiogenesis by these potent drugs impairs the regenerative capacity of the bone causing the development of BRONJ. Tooth extraction as a precipitating event is a common observation. The significant benefits that bisphosphonates offer to patients clearly surpass the risk of potential side effects; however, any patient for whom prolonged bisphosphonate therapy is indicated, should be provided with preventive dental care in order to minimize the risk of developing this severe condition. This article provides an update review of current knowledge about clinical, pathological and management aspects of BRONJ.

Osteonecrosis of the jaws associated with use of risedronate: Report of 2 new cases

Use of various bisphosphonates has been associated with the development of osteonecrosis of the jaws (ONJ). At least 865 cases of ONJ attributed to these agents have been reported in the English-language literature. Approximately 96% of these published cases were seen with administration of the intravenous agents pamidronate and zoledronate, whereas only 26 cases have been associated with oral bisphosphonates, 25 of them with alendronate. Only a single case of ONJ associated with the oral bisphosphonate risedronate has been previously cited. We report 2 cases of ONJ attributed to risedronate administration. The patients developed osteonecrosis 15 and 24 months after treatment for osteopenia. A regimen of antibiotics and chlorhexidine mouthrinse resolved the osseous defect in the mandible caused by complete exfoliation of a lingual torus in 1 patient. The other patient required sequestrectomy, repeated courses of antibiotics, surgical debridement, and steroids to promote closure of an oroantral fistula and management of sinusitis after bone grafting and implant placement in the posterior maxilla. A demographic profile of reported oral bisphosphonate users affected by ONJ is also provided. With the millions of patients receiving various oral bisphosphonates for osteopenia and osteoporosis, health care practitioners should be aware of the potential for the onset of osteonecrosis and familiar with its management.

Biphosphonate-associated osteonecrosis can be controlled by nonsurgical management

Sixteen patients with jaw biphosphonate-osteonecrosis and with exposed bone areas were subdivided into 2 treatment groups. The first group (7 patients) underwent superficial or radical surgical therapy, while the second (9 patients) underwent antibiotic treatment. A slight reduction of the necrotic areas was observed in 5 of 7 patients in the first group, whereas no change was observed in the remaining 2 patients at 22- and 24-month follow-up. A slight reduction of the necrotic areas was observed in 7 of 9 patients in the second group, whereas no change was observed in the remaining 2 patients at 5- and 24-month follow-up. The statistical analysis showed that the treatment regimen did not significantly influence the dimensional change in the exposed bone. The preliminary results seem to suggest that biphosphonate-associated osteonecrosis can be well controlled by a nonsurgical protocol consisting in long-term administration of antibiotics.

Bisphosphonate-related osteonecrosis of the jaws: a comprehensive review

BACKGROUND

Bisphosphonate-related osteonecrosis of the jaws (BRONJ) presents the clinician with significant management dilemmas. The purpose of this study was to distil information related to this disorder by comprehensively reviewing the literature.

METHODS

The structure and function of bisphosphonates, and their role in the development of BRONJ will be discussed, as will the possible mechanisms through which this pathology develops. A review of cases presented in the literature will be undertaken, and suggestions offered as to the management of this pathology in terms of surgical and conservative approaches.

RESULTS

Presentation of BRONJ is currently more common in patients taking intravenous forms of bisphosphonates, but there is a fear that the long-term cumulative effects of oral bisphosphonates may see BRONJ increasingly occurring in this patient group.

CONCLUSIONS

Prevention is superior to treatment, and the establishment of meticulous oral hygiene and pre-emptive surgical treatment prior to commencement of bisphosphonate therapy is recommended.

Osteogenesis imperfecta

Osteogenesis imperfecta is a relatively common hereditary connective tissue disorder characterized by bone fragility and fractures. Other frequently affected tissues include tendons, ligaments, skin, sclera, teeth, and middle and inner ear. Molecular studies have demonstrated that most cases result from mutations affecting the genes responsible for the formation of type 1 collagen. The phenotypic presentation varies from mild to lethal. Commonly observed dental abnormalities include dentinogenesis imperfecta and malocclusion. Medical therapies using bisphosphonates have resulted in reduced fracture risk and decreased bone pain. To date, no cases of bisphosphonate-associated osteonecrosis have been reported. With appropriate precautions, the patient with osteogenesis imperfecta can tolerate and benefit from the delivery of necessary dental care to control oral disease, improve function, and improve esthetics.