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

Prevalence, initiating factor, and treatment outcome of medication-related osteonecrosis of the jaw-a 4-year prospective study

OBJECTIVES

Medication-related osteonecrosis of the jaw (MRONJ) has a wide range of prevalence, and a standard therapy has not yet been established. The aim of this study was to analyze the prevalence and initiating factors of MRONJ and the outcomes of surgical therapy.

STUDY DESIGN

In a prospective cohort study, all patients diagnosed with MRONJ in the Region of Skåne, in Sweden, were included. Predictor variables (comorbidity, site, stage, gender) and initiating factors (tooth extraction, periodontitis) were recorded. Surgical treatment was sequestrectomy or block resection, and the outcome variable was healing after 2 months. To estimate the prevalence, data on the use of bisphosphonate and denosumab were used.

RESULTS

Fifty-five patients with MRONJ were identified. The prevalence of MRONJ was 0.043% among patients treated with oral bisphosphonates, 1.03% among those on intravenous bisphosphonates and 3.64% in those on high-dose denosumab. Periodontal disease preceded development of MRONJ in 41 patients. Fifty patients were treated surgically and followed up for at least 2 months. Remission or healing occurred in 80% of patients treated with sequestrectomy and in 92.5% of patients treated with block resection.

CONCLUSIONS

The prevalence of MRONJ in Sweden is low. Periodontitis is the most common initiating factor. The outcome of treatment of MRONJ is healing in most patients treated surgically.

Risk-reductive dental strategies for medication related osteonecrosis of the jaw among cancer patients: A systematic review with meta-analyses

The purpose of this systematic review with meta-analysis was to assess the effectiveness of dental interventions in preventing or reducing the incidence of medication-related osteonecrosis of the jaw (MRONJ) in cancer patients receiving antiresorptive therapy, compared to similar control groups receiving no intervention. Randomized controlled trials (RCT), case-controls and cohorts on cancer patients with primary outcome being the prevalence of MRONJ were included. Four electronic databases were searched (Cochrane Library, PubMed, EMBASE and Web of Science) up to February 12, 2018. A total of 409 abstracts were assessed and one case-control, one RCT and four cohort studies with 2332 cancer patients met our inclusion criteria. Risk of bias analysis followed Cochrane's handbook. Risk of bias was unclear for the case-control study and high risk for the RCT and all cohort studies. Five studies utilized preventive measures consisting of an initial examination and performing all necessary dental treatment before patients initiated antiresorptive therapy; one study used specialized post-extraction protocols utilizing plasma-rich in growth factors (PRGF) on cancer patients receiving antiresorptive therapy. Though dental preventive measures decreased MRONJ incidence by 77.3% in six studies with 2332 cancer patients (95% CI = 47.4-90.2%; p = .001) compared to control groups, quality of the evidence was low due to high or unclear risk of bias and the observational nature of five of the included studies. In conclusion, high-quality long-term prospective large sample size studies are needed to confirm these results due to high risk of bias and heterogeneous interventions. No funding.

Effects of Zoledronic Acid in Experimental Periapical Lesions in Rats: An Imaging and Histological Analysis

The aim of this study was to assess the imaging and histological features of experimental periapical lesions, including the adjacent alveolar bone, in rats under zoledronic acid treatment. The study used 40 male Wistar rats distributed into 8 groups of 5 animals each: G1: induction of periapical lesion (PL) and weekly intraperitoneal administration (WIPA) of saline solution (0.9% NaCl) for 4 weeks; G2: PL induction and WIPA of zoledronic acid (0.15 mg/kg/week) for 4 weeks; G3: PL induction and WIPA of saline solution for 8 weeks; G4: PL induction and WIPA of zoledronic acid for 8 weeks; G5:WIPA of saline solution for 4 weeks and subsequent PL induction; G6: WIPA of zoledronic acid for 4 weeks and subsequent PL induction; G7: WIPA of saline solution for 8 weeks and subsequent PL induction; G8: WIPA of zoledronic acid for 8 weeks and subsequent PL induction. The administration of zoledronic acid or saline solution continued after PL induction until the euthanasia. Thus, cone beam computed tomography and histological analysis were performed. Statistical analyzes were performed by ANOVA and Kruskal-Wallis test. Groups treated with zoledronic acid showed significantly smaller size of PL than the groups treated with 0.9% NaCl (p<0.05). PLs were formed by chronic inflammation ranging from mild to moderate, with no difference between groups. In all specimens, no mandibular necrosis was observed. In conclusion, the presence of PLs apparently does not represent an important risk factor for the development of bisphosphonate-related osteonecrosis of the jaws.

Microsurgical Reconstruction of the Jaws Using Vascularised Free Flap Technique in Patients with Medication-Related Osteonecrosis: A Systematic Review

Background

Osteonecrosis of the jaw (ONJ) has been reported to be associated with patients receiving primarily bisphosphonate (BP) therapies. However, lately it has been documented that other medications, such as RANK ligand inhibitor (denosumab) and antiangiogenic drug, can cause ONJ. Micro-osseous-vascular reconstruction of the jaws in patients affected by medication-related osteonecrosis of the jaw represents a viable option of treatment for patients affected by stage III of the disease. However, there are still considerable doubts about the success of this procedure in the short, medium, and long term.

Material and Methods

A multidatabase (PubMed/MEDLINE, EMBASE, and CENTRAL) systematic search was performed. Any type of studies considering human patients treated with antiresorptive and antiangiogenic drugs was considered. The aim of the research is to primarily understand the success rate of micro-osseous-vascular reconstruction in the short, medium, and long period of time. This review has also the goal of better understanding any perioperative and postoperative complications resulting from the use of the reconstruction techniques.

Results

Eighteen studies resulted eligible for the study. Fibula free flap is the most commonly utilised vascularised free flap reconstruction technique (80.76%). Ten out of eighteen studies reported no complications. Recurrence of osteonecrosis was registered in five cases (6.41%) after free flap reconstruction. The overall free flap success rate was 96.16%.

Conclusions

Based on the limited data available in literature (Level 4 of the Oxford Evidence-based medicine scale), micro-osseous-vascular reconstruction of the jaws represents a valid treatment in patients with bisphosphonate-related osteonecrosis at stage III of the disease. However, additional data based on a larger cohort of patients are necessary to justify this type of intervention in patient affected by MRONJ.

Could the Combined Administration of Bone Antiresorptive Drug, Taxanes, and Corticosteroids Worsen Medication Related Osteonecrosis of the Jaws in Cancer Patients?

The study presents a report of 58 metastatic cancer patients who developed osteonecrosis of the jaws after being treated with zoledronic acid and taxanes, plus corticosteroids. A retrospective analysis of data registered in the archives of two Italian osteonecrosis of the jaws treatment centers, who are based at the University of Messina and at the University of Palermo, was performed in order to study, in these patients, demographic data and characteristics such as frequency of cancer location, lines of therapy, frequency of cancer drugs, presence/absence of oral trigger, number, location, and stage of jaw osteonecrosis. It was found that the majority of patients developed advanced stages of osteonecrosis, frequently complicated with infection. It was hypothesized that the concurrent administration of chemotherapeutic agents could be eventually considered as a factor able to allow a faster worsening of the clinical manifestation through the exacerbation of soft tissue defects, due to chemotherapy drugs.

Vitamin D supplementation: Hypothetical effect on medication-related osteonecrosis of the jaw

Vitamin D is an important nutrient for bone health and skeleton growth. Few foods are natural sources of this secosteroid; this is the reason why the consumption of vitamin D as a dietary supplement is becoming common in developed countries. For many years vitamin D has been considered crucial in the treatment and prevention of the Global Burden of Disease and in a reduction in mortality among elder people. Many health care providers prescribe these supplements in the management of osteoporosis and metabolic bone diseases; specifically in the primary prevention of fractures. Recently medication-related osteonecrosis of the jaw (MRONJ) has been reported as severe late sequelae of antiresorptive therapies (i.e., bisphosphonates and some monoclonal antibodies). Although MRONJ-related pathophysiology is not fully understood, there are three fundamental theories to explain it: (1) the inhibition of osteoclasts, (2) the inhibition of angiogenesis and (3) the processes of inflammation-infection. Recent advances in Vitamin D research have shown that this secosteroid can play a potential pivotal role in many of the different etiological pathways of MRONJ. Furthermore, there are a large number of co-morbidities between the deficit of this vitamin and other MRONJ concomitant outcomes. Our hypothesis argues that the low-risk and low-cost vitamin D dietary supplementation may prove to be suitable for use as a practical MRONJ prevention strategy. The described framework gives more insight into the study of disease mechanisms, search of potential biomarkers, and therapeutic targets in MRONJ.

Surgically treated osteonecrosis and osteomyelitis of the jaw and oral cavity in patients highly adherent to alendronate treatment: a nationwide user-only cohort study including over 60,000 alendronate users

Osteonecrosis of the jaw (ONJ) is rare (2.53/10,000 person-years) among alendronate users, but long-term and compliant use are associated with an increased risk of surgically treated ONJ. Risk of surgically treated ONJ is higher in patients with rheumatoid diseases and use of proton pump inhibitors.

INTRODUCTION

ONJ is a rare event in users of oral bisphosphonates. Our aims were to evaluate if the risk of surgically treated ONJ increases with longer or more compliant treatment with alendronate for osteoporosis and to identify risk factors for surgically treated ONJ.

METHODS

Open nationwide register-based cohort study containing one nested case-control study. Patients were treatment-naïve incident users of alendronate 1996-2007 in Denmark, both genders, aged 50-94 at the time of beginning treatment (N = 61,990). Participants were followed to 31 December 2013.

RESULTS

Over a mean of 6.8 years, 107 patients received surgery for ONJ or related conditions corresponding to an incidence rate of 2.53 (95% confidence interval (CI) 2.08 to 3.05) per 10,000 patient years. Recent use was associated with an adjusted odds ratio (OR) 4.13 (95% CI 1.94 to 8.79) compared to past use. Similarly, adherent users (medication possession ratio (MPR) >50%) were at two to threefold increased risk of ONJ compared to low adherence (MPR <50%), and long-term (>5 years) use was related with higher risk (adjusted OR 2.31 (95% CI (1.14 to 4.67)) than shorter-term use. History of rheumatoid disorders and use of proton pump inhibitors were independently associated with surgically treated ONJ.

CONCLUSIONS

Our data suggest that recent, long-term, and compliant uses of alendronate are associated with an increased risk of surgically treated ONJ. Nevertheless, the rates remain low, even in long-term adherent users. ONJ risk appears higher in patients with conditions likely to indirectly affect the oral mucosa.

Rapid onset of osteonecrosis of the jaw in patients switching from bisphosphonates to denosumab

OBJECTIVE

The aim of this study was to determine whether osteonecrosis of the jaw (ONJ) developed more rapidly in patients who switched from bisphosphonates (BP) treatment to denosumab than in patients who received only denosumab.

STUDY DESIGN

This was a retrospective cohort study conducted at a tertiary referral center. Thirty-one patients with ONJ met the inclusion criteria.

RESULTS

Twenty-two patients who had been on BP were switched to denosumab (BP + D), whereas 9 patients received only denosumab. Both groups were similar for the known ONJ risk factors, that is, age, diabetes mellitus, and smoking. The number and cumulative doses of denosumab before the onset of ONJ symptoms were significantly lower among the BP + D group compared with the denosumab-only group (P = .025 and .018, respectively). In the BP + D group, ONJ symptoms developed in 9 patients (41%) following the administration of ≤3 denosumab doses compared with ONJ developing in only 1 patient (11%) who was naïve to BP. ONJ developed spontaneously without any known triggering event in 72.7% of patients in the BP + D group and in 77.8% of patients in the denosumab-only group.

CONCLUSIONS

Denosumab-induced ONJ might develop rapidly in patients previously treated with BP. ONJ developed spontaneously in most patients treated with denosumab. In light of our sample being small, there is need for further investigation on our conclusions.

Zoledronate Impairs Socket Healing after Extraction of Teeth with Experimental Periodontitis

Osteonecrosis of the jaws (ONJ) is a rare but severe complication of antiresorptive medications, such as bisphosphonates, used in the treatment of bone malignancy or osteoporosis. Tooth extraction and dental disease have been strongly associated with ONJ development. Here, we investigated molecular and cellular markers of socket healing after extraction of healthy or teeth with experimental periodontitis (EP) in Wistar-Han rats treated with zoledronic acid (ZA). We included 4 experimental groups: vehicle-treated animals with extraction of healthy teeth or teeth with ligature-induced EP and ZA-treated animals with extraction of healthy teeth or teeth with EP. Animals were pretreated with vehicle or ZA for a week, and EP was induced. Four weeks later, the second maxillary molars were extracted; sockets were allowed to heal for 4 wk; animals were euthanized; and maxillae were isolated. Radiographically, extraction sockets in groups 1, 2, and 3 demonstrated normal healing. Contrary incomplete socket healing was noted after extraction of teeth with EP in ZA-treated rats of group 4. Histologically, persistent inflammation and extensive osteonecrosis were seen in group 4. Disorganization of the collagen network, collagen type III predominance, and lack of collagen fiber insertion in the necrotic bone were associated with impaired socket healing. Cells positive for MMP-9, MMP-13, and α-SMA expression were present at the areas of epithelial invagination and adjacent to osteonecrotic bone. Importantly, human biopsies from patients with ONJ showed similar findings. Our data emphasize the importance of dental disease and tooth extraction in ONJ pathogenesis and help delineate an altered profile in wound-healing markers during ONJ development.

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

BACKGROUND

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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