Osteonecrosis of the jaw in patients treated with oral and intravenous bisphosphonates: experience in Sweden

Investigation of clindamycin concentrations in human plasma and jawbone tissue in patients with osteonecrosis of the jaw: A prospective trial

The aim of this study was to investigate the jawbone concentration of clindamycin (CLI) in patients with an osteonecrosis of the jaw (ONJ). Patients with medication-related ONJ (MRONJ) and osteoradionecrosis (ORN) with an antibiotic treatment with CLI were included. Plasma, vital and necrotic bone samples were collected. Plasma and jawbone samples were analyzed by liquid chromatography-tandem mass spectrometry. Patients with MRONJ exhibited a mean plasma CLI concentration of 9.6 μg/mL (SD ± 3.6 μg/mL) and mean concentrations of 2.3 μg/g CLI (SD ± 1.4 μg/g) and 2.1 μg/g CLI (SD ± 2.4 μg/g) in vital and necrotic bone samples, without statistical significance (p = 0.79). In patients with ORN, mean concentration in plasma was 12.0 μg/mL (SD ± 2.6 μg/mL), in vital bone 2.1 μg/g (SD ± 1.5 μg/g), and in necrotic bone 1.7 μg/g (SD ± 1.2 μg/g). Vital and necrotic bone concentrations did not differ significantly (p = 0.88). The results demonstrate that CLI concentrations are considerably lower than in plasma, but sufficient for most bacteria present in ONJ. Within the limitations of the study, it seems that CLI is a relevant alternative to other antibiotics in the treatment of ONJ because it reaches adequate concentrations in jawbone.

Oral health conditions in patients under antiresorptive therapy are comparable to unexposed during supportive periodontal care

OBJECTIVES

To investigate oral health and oral health-related quality of life (OHRQoL) of patients under antiresorptive therapy (ART) during supportive periodontal care (SPC) considering history of medication-related osteonecrosis of the jaw (MRONJ).

MATERIALS AND METHODS

In this cross-sectional study, 100 patients (50 receiving ART (exposed) and 50 without ART (unexposed)) in regular SPC were enrolled for a clinical oral examination and the evaluation of OHRQoL using the OHIP-G14-questionnaire. History of MRONJ was assessed by anamnesis and reviewing patient records.

RESULTS

There were no statistically significant group differences in age (exposed: 70.00 ± 9.07 versus unexposed: 71.02 ± 8.22 years), sex, distribution of systemic diseases and duration of SPC (on average 8.61 ± 5.73 years). Number of teeth (21.02 ± 5.84 versus 21.40 ± 5.42), DMFT (18.38 ± 3.85 versus 17.96 ± 4.08), probing pocket depth (2.31 ± 0.20 versus 2.38 ± 0.26), clinical attachment level (3.25 ± 0.76 versus 3.46 ± 0.58) and bleeding on probing (15.07 ± 11.53 versus 15.77 ± 13.08) were also not significantly different. The OHIP-G14 sum-score was significantly higher in exposed participants (6.10 ± 6.76 versus 3.62 ± 5.22, p = 0.043). History of MRONJ was prevalent in 8% of patients under ART. Periodontal/peri-implant-related MRONJ were reported in three participants with cancer (n = 1 before and n = 2 after active periodontal therapy). History of MRONJ due to endodontic/restorative reasons was reported in one patient with osteoporosis.

CONCLUSIONS

Patients under ART in SPC demonstrated similar clinical periodontal and dental status but lower OHRQoL compared to unexposed (not statistically significant). Patient awareness of the MRONJ-risk and appropriate preventive measures should be ensured.

CLINICAL RELEVANCE

SPC in osteoporotic patients under ART appeared safe regarding MRONJ, but further investigations on the MRONJ-risk in patients with different risk-profiles are necessary.

STUDY REGISTRATION

clinicaltrials.gov (#NCT04192188).

MRONJ of the Mandible—From Decortication to a Complex Jaw Reconstruction Using a CAD/CAM-Guided Bilateral Scapula Flap

Medication-related osteonecrosis of the jaw (MRONJ) has been an integral part of the maxillofacial patient population for some time. The therapeutic concept ranges from conservative approaches over less extended decortications to major jaw resections, which can result in a considerable loss of quality of life. Based on three case reports, this paper presents the long-term history of patients with MRONJ of the mandible, whose disease ultimately resulted in partial or total mandibular resection and subsequent multisegmental reconstruction using a microvascular anastomosed bone flap. Furthermore, a suitable alternative for complex mandibular reconstruction is demonstrated when using a free fibula flap is not possible. The options are limited, particularly when multisegmental restoration of mandibular continuity is required. One case presents a mandible reconstruction using a CAD/CAM-guided bilateral scapular free flap (CAD/CAM = Computer-Aided Design and Manufacturing), which has not been described for this purpose before. Due to the complexity, computer-assisted surgery and patient-specific implants seem reasonable, which is why a special focus was applied to this topic.

Evaluation of Medication-Related Osteonecrosis of the Jaw (MRONJ) in Terms of Staging and Treatment Strategies by Dental Students at Different Educational Levels

Background: The role of medication-related osteonecrosis of the jaw (MRONJ) as a dento-maxillo-facial pathology is becoming increasingly important due to its growing prevalence. The success of preventive and therapeutic measures relies mainly on the dentist's ability to correctly diagnose the disease. Methods: The aim of this study was to evaluate the skills of dental students of different educational levels in choosing the correct stage, diagnostics, and treatment option for MRONJ based on clinical and radiographic imaging (panoramic radiograph, CBCT). The study was designed as a cross-sectional cohort study. Twenty dental students were asked to complete a questionnaire in their third and fifth year of studies in which they had to correctly stage the disease, choose the radiological diagnostics and recommend the treatment. The control group contained experienced oral and maxillofacial surgeons. Results: With an overall performance of 59% (third year: 145.2/248 points; fifth year: 145.3/248 points), no statistically significant difference between the educational levels could be observed. The classification based on CBCT imaging was significantly more often correct compared to panoramic radiographs (p < 0.001). Conclusions: This study highlights students' lack of knowledge in staging, diagnostics, and treatment of MRONJ, even though the CBCT positively affected decision-making. No significant increase in knowledge could be confirmed through clinical education. This study highlights the need for students to catch up on MRONJ diagnostics and treatment planning. Further expansion of teaching in this disease's context and X-ray diagnostics is needed.

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.

Quantitative Analysis of Multimodal Skeletal SPECT/CT Reconstructions in Diagnosing Medication-related Osteonecrosis of the Jaw

AIM

Our goal was to assess visual and quantitative aspects of multimodal skeletal SPECT/CT reconstructions (recon) in differentiating necrotic and healthy bone of patients with suspected MRONJ.

METHODS

Prior to surgery, 20 patients with suspected MRONJ underwent SPECT/CT of the jaw 3-4 hours after injection of Tc-99m-DPD (622±112.4 MBq). SPECT/CT data were reconstructed using the multimodal xSPECT Bone and xSPECT Quant algorithms as well as the OSEM-algorithm FLASH 3D. For analysis, we divided the jaw into 12 separate regions. Both xSPECT Bone and FLASH 3D datasets were scored on a four-point scale (VIS xSPECT; VIS F3D), based on the intensity of localized tracer uptake. In F3D and xSPECT Quant datasets, local tracer uptake of each region was recorded as semi-quantitative uptake ratio (SQR F3D) or SUVs, respectively. ROC analysis was performed. Postoperative histologic results served as gold standard.

RESULTS

VIS F3D, VIS xSPECT and SQR F3D did not differ significantly in diagnostic accuracy (VIS xSPECT sensitivity=0.64; specificity=0.89). Of the quantitative parameters, SUVpeak yielded the best interobserver reproducibility. SUVpeak was 9.9±7.1 (95%CI: 7.84-11.95) in MRONJ regions, as opposed 3.6±1.8 (95% CI:3.36-3.88) elsewhere, with a cutpoint of 4.5 (sensitivity=0.83; specificity=0.80). Absolute quantitation significantly surpassed VIS and SQR (p<0.05) in accuracy and interobserver agreement (SUVpeak: κ=0.92; VIS xSPECT: κ=0.61; SQR F3D κ=0.66).

CONCLUSION

Absolute quantitation proved significantly more accurate than visual and semi-quantitative assessment in diagnosing MRONJ, with higher interobserver agreement.

Medication-Related Osteonecrosis of the Jaws Initiated by Zoledronic Acid and Potential Pathophysiology

The aim of this systematic review is to present an up-to-date review of available publications investigating the cellular mechanisms initiating the development of medication-related osteonecrosis of the jaw caused by zoledronic acid. Electronic searches of MEDLINE/PubMed and Scopus were conducted on the 3 June 2019. A total of 804 publications were identified, of which 11 met the inclusion criteria and were, therefore, included in this study. All the included studies were in vitro studies investigating various human cells. The current review found that zoledronic acid in various concentrations increased apoptosis and decreased migration and proliferation of epithelial cells, fibroblasts, osteoblasts, endothelial cells and dental pulp stem cells, which can affect local tissue homeostasis. The consequences of zoledronic acid were found to be both time- and dose-dependent. The pathophysiology of medication-related osteonecrosis of the jaw is likely a multifactorial process involving prolonged wound healing, chronic inflammation and altered bone remodelling following the administration of zoledronic acid. Further research is needed to identify the exact pathophysiology to optimise management and treatment.

Characteristics of patients with osteonecrosis of the jaw with oral versus intravenous bisphosphonate treatment

PURPOSE

This retrospective study was aimed to evaluate the clinical characteristics and treatment outcomes in patients with osteonecrosis of the jaw who were receiving oral versus intravenous (IV) bisphosphonate (BP).

MATERIALS AND METHODS

This retrospective study enrolled subjects who had been diagnosed with medication-related osteonecrosis of the jaw (MRONJ) during the period from July 2010 to June 2014. Information regarding the following demographic and clinical characteristics was collected: demographic data, administration route and type of BP, duration of BP medication, primary disease, number of involved sites, location of the lesion, number of surgeries, outcome of treatments, and laboratory test. All the patients were divided into oral and IV BP groups; and the between-group differences were compared.

RESULTS

Total 278 patients were divided into two groups as per the route of BP administration. The proportion of oral BP-related MRONJ group were more dominant over IV BP group (oral BP, n = 251; IV BP, n = 27). In the IV BP group, the average dosing duration (31.4 months) was significantly shorter than that in the oral BP group (53.1 months) (P < 0.001). The average number of involved sites in the oral BP group (1.21 ± 0.48) was smaller than that in the IV BP group (1.63 ± 0.84) (P < 0.001). The average number of surgeries was higher in the IV BP group (1.65 ± 0.95) as compared to that in the oral BP group (0.98 ± 0.73) (P < 0.001). Outcome after the surgery for MRONJ after IV BP was poor than oral BP group.

CONCLUSION

IV administration of BP causes greater inhibition of bone remodeling and could lead more severe inflammation. Therefore, even if the duration of IV administration of BP is shorter than that of oral BP, the extent of the lesion could be more extensive. Therefore, the result suggests that the MRONJ after IV BP for cancer patients needs to be considered as different characteristics to oral BP group for osteoporosis patents.

Prevention and treatment of oral adverse effects of antiresorptive medications for osteoporosis - A position paper of the Brazilian Society of Endocrinology and Metabolism (SBEM), Brazilian Society of Stomatology and Oral Pathology (Sobep), and Brazilian Association for Bone Evaluation and Osteometabolism (Abrasso)

Antiresorptive therapy is the main form of prevention of osteoporotic or fragility fractures. Medication-related osteonecrosis of the jaw (MRONJ) is a relatively rare but severe adverse reaction to antiresorptive and antiangiogenic drugs. Physicians and dentists caring for patients taking these drugs and requiring invasive procedures face a difficult decision because of the potential risk of MRONJ. The aim of this study was to discuss the risk factors for the development of MRONJ and prevention of this complication in patients with osteoporosis taking antiresorptive drugs and requiring invasive dental treatment. For this goal, a task force with representatives from three professional associations was appointed to review the pertinent literature and discuss systemic and local risk factors, prevention of MRONJ in patients with osteoporosis, and management of established MRONJ. Although scarce evidence links the use of antiresorptive agents in the context of osteoporosis to the development of MRONJ, these agents are considered a risk factor for this complication. Despite the rare reports of MRONJ in patients with osteoporosis, the severity of symptoms and impact of MRONJ in the patients' quality of life make it imperative for health care professionals to consider this complication when planning invasive dental procedures.

Actinomyces and MRONJ: A retrospective study and a literature review

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

Incidence of and risk factors for medication-related osteonecrosis of the jaw in women with breast cancer with bone metastasis: a population-based study

OBJECTIVE

The aim of this study was to prospectively determine the incidence of medication-related osteonecrosis of the jaw (MRONJ) and define risk factors in patients with metastatic breast cancer treated with zoledronic acid and/or denosumab.

STUDY DESIGN

In a prospective cohort study performed in Region Skåne, Sweden, from January 1, 2012, until December 31, 2015, all patients with breast cancer who had radiographic evidence of bone metastases and were treated with zoledronic acid or denosumab were included and followed up until May 31, 2018.

RESULTS

Of the 242 patients, MRONJ developed in 16 (6.6%) during the 77 months of study. The incidence of MRONJ in patients treated with zoledronic acid was 4.1%, and in patients treated with denosumab, it was 13.6%. The risk of MRONJ was higher in patients on denosumab than in those treated with zoledronic acid (P = .011). Corticosteroid use was associated with a decreased risk of MRONJ (P = .008), and diabetes was associated with an increased risk of MRONJ (P = .02).

CONCLUSIONS

The incidence of MRONJ is 13.6% (>3 times higher) in denosumab-treated patients with breast cancer compared with that in patients treated with zoledronic acid (4.1%). Corticosteroid use decreased the risk of MRONJ.

Current Concepts of Osteomyelitis: From Pathologic Mechanisms to Advanced Research Methods

Osteomyelitis is an inflammation of the bone and bone marrow that is most commonly caused by a Staphylococcus aureus infection. Much of our understanding of the underlying pathophysiology of osteomyelitis, from the perspective of both host and pathogen, has been revised in recent years, with notable discoveries including the role played by osteocytes in the recruitment of immune cells, the invasion and persistence of S. aureus in submicron channels of cortical bone, and the diagnostic role of polymorphonuclear cells in implant-associated osteomyelitis. Advanced in vitro cell culture models, such as ex vivo culture models or organoids, have also been developed over the past decade, and have become widespread in many fields, including infectious diseases. These models better mimic the in vivo environment, allow the use of human cells, and can reduce our reliance on animals in osteomyelitis research. In this review, we provide an overview of the main pathologic concepts in osteomyelitis, with a focus on the new discoveries in recent years. Furthermore, we outline the value of modern in vitro cell culture techniques, with a focus on their current application to infectious diseases and osteomyelitis in particular.

Knowledge and Attitude of Dentists Regarding Patients Undergoing Bisphosphonate Treatment: a Comparative Questionnaire

Background: Osteonecrosis of the jaw is an uncommon but serious complication related to oral and intravenous bisphosphonate (BP) therapy. Its pathogenesis is not well understood, and there are no universal protocols accepted to treat it.

The aim of our study was to use the same questionnaire as four years ago to evaluate the awareness of dentists in Tîrgu Mureș regarding the dental treatments that can be applied in patients on BP therapy, and to assess how their knowledge on the subject has evolved over these years.

Material and method: We used the same questionnaire-based study as four years ago among dentists in Tîrgu Mureș, raising important issues such as: is the patient asked about current or previous treatments with BPs, do they perform surgical treatment in these patients, do they know under what conditions they can perform this treatment, or do they deem it necessary to contact the prescriber before surgical treatment.

Results: One-hundred twenty questionnaires were returned. The majority of respondents (n = 113, 94.2%) included the question regarding the use of BPs in their medical records. Of all respondents, 48 (40%) perform dental or surgical treatments on patients undergoing BP therapy, 68 (56.7%) do not perform dental or surgical treatments on these patients, and four of the respondents (3.3%) did not know the answer. One hundred (83.3%) respondents always contact the prescriber prior to surgery in these patients, regardless of how BPs are administered.

Conclusions: According to the findings of the present study, many of the respondent doctors have heard about BPs and their complications, but they are not aware of the fundamental concepts of bisphosphonate-related osteonecrosis of the jaw prevention and treatment protocols. In the absence of appropriate protocols, the quality of life of these patients is compromised.

Treatment of diffuse sclerosing osteomyelitis of the jaw with denosumab shows remarkable results-A report of two cases

Denosumab may play a central role in the treatment of diffuse sclerosing osteomyelitis of the mandible. This report describes two patients who had been treated unsuccessfully with antibiotics and steroids for several years. After denosumab treatment, both patients became pain-free and the radiological examination showed less severe osteomyelitis.

Osteonecrosis of the jaw related to non-antiresorptive medications: a systematic review

INTRODUCTION

The reporting of osteonecrosis of the jaw (ONJ) related to anticancer agents without known antiresorptive properties (non-antiresorptives), such as antiangiogenics, tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, immune checkpoint inhibitors, and cytotoxic chemotherapy is increasing.

OBJECTIVE

To review characteristics of ONJ in cancer patients receiving non-antiresorptives.

METHODS

A systematic review of the literature between 2009 and 2017 was conducted by the Bone Study Group of MASCC/ISOO.

RESULTS

Of 6249 articles reviewed and from personal communication, 42 ONJ cases related to non-antiresorptives were identified. No gender predilection was noted. Median age was 60 years and ONJ stage 2 was most common, with predilection for posterior mandible. Exposed bone, pain, and infection were common at diagnosis. In comparison to bone targeting agents (BTAs), radiology, histology, and management were similar, with medication often discontinued. Delayed diagnosis (median 8 weeks) was noted. Important differences included earlier time to ONJ onset (median 20 weeks), absence of trigger event (40%), and greater likelihood of healing and shorter healing time (median 8 weeks) as compared to BTA-related ONJ. Gastrointestinal cancers predominated, followed by renal cell carcinomas compared to breast, followed by prostate cancers in BTA-related ONJ, reflecting different medications.

CONCLUSIONS

Data about non-antiresorptive-related ONJ is sparse. This type of ONJ may have better prognosis compared to the BTA-related ONJ, suggested by greater likelihood of healing and shorter healing time. However, the delay in diagnosis highlights the need for more education. This is the first attempt to characterize ONJ associated with different non-antiresorptives, including BRAF and immune checkpoint inhibitors.

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.

Viewpoints of dentists on the use of bisphosphonates in rheumatology patients

OBJECTIVES

Alhough typically prescribed in oncology, bisphosphonates (BPs) are also employed in rheumatology, particularly for the treatment of osteoporosis, sometimes resulting in complications, such as osteonecrosis of the jaw. Because of different opinions between rheumatologists and dentists on BP use, this study aimed to assess the views of dentists regarding administration of BPs in rheumatology.

METHODS

A questionnaire was sent to 880 dentists from the Auvergne region of France to determine their views on BP treatment.

RESULTS

We obtained 382 (43.4%) responses and analysed 376 (58.7% men). In total, 156 (41.5%) of the responders analysed had attended an in-service training course (ISTC) on the topic. A total of 237 (63.0%) systematically inquired as to whether their patients were undergoing BP treatment; this proportion was higher among those who had been practicing for fewer than 10 years (P < 0.004). For patients receiving BPs, 84.5% of practitioners felt ill at ease about performing dental surgery (n = 318) and 11% felt ill at ease about performing nonsurgical dental care (n = 41); 67% stated that their practice differed depending on the method of BP administration (per os or intravenously). Overall, 53.7% of practitioners felt uncomfortable when asked by a rheumatologist whether a given patient's dental status permitted prescription of BP (n = 202). This proportion was higher among those who had never attended an ISTC (62.6% vs. 50.7%; P < 0.03).

CONCLUSIONS

Dentists feel ill at ease providing dental surgery to patients receiving BPs. Closer collaboration and better information-sharing between rheumatologists and dentists is necessary to facilitate the administration of BPs in rheumatology.

Effectiveness of treatments for medication-related osteonecrosis of the jaw: A systematic review and meta-analysis

BACKGROUND

The effectiveness of management strategies used for the treatment of medication-related osteonecrosis of the jaw (MRONJ) remains poorly understood. The authors evaluated systematically the effectiveness of the various treatment modalities used for MRONJ.

TYPES OF STUDIES REVIEWED

The authors conducted a comprehensive search of MEDLINE, Embase, the Cochrane Library, and Scopus to identify randomized controlled trials, nonrandomized controlled trials, and prospective cohort studies to evaluate comparatively the effectiveness of management strategies for the treatment of MRONJ. The authors conducted the identification of eligible studies in duplicate and synthesized the extracted data by means of a meta-analysis, when feasible.

RESULTS

The authors found 13 studies with a medium-to-high risk of bias that met the inclusion criteria of this review. The authors found that, compared with medical treatment of local antimicrobials with or without systemic antimicrobials, the study investigators associated surgical treatment with higher odds of complete resolution of the condition (2 studies; 76 participants; unadjusted odds ratio, 3.55; 95% confidence interval, 1.12 to 11.19). The effectiveness of other therapies, such as bisphosphonate drug holidays, teriparatide, and hyperbaric oxygen, was uncertain.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

On the basis of the results of an unadjusted analysis, the results of the studies that were deemed to be medium to low quality and to have medium-to-low statistical power suggested that there are higher odds of resolving MRONJ with surgical treatment compared with medical treatment. High-quality research is required for conclusive statements to be made regarding treatment strategies for management of MRONJ.

Uncertainty of current algorithm for bisphosphonate-related osteonecrosis of the jaw in population-based studies: a systematic review

To assess the relevance of previous epidemiologic studies on bisphosphonate-related osteonecrosis of the jaw (BRONJ), we first conducted a systematic review of large population-based observational studies and evaluated the validity of claims-based algorithms for the identification of BRONJ. Studies containing primary observational epidemiologic data regarding bisphosphonate (BP) exposure and outcomes of osteonecrosis of the jaw were systematically reviewed. Using surrogates for identifying potential BRONJ cases from a population-based hospital registry, validation was performed through medical chart review. Positive predictive value (PPV) was estimated for each diagnostic code and for the overall algorithm utilized. Various strategies to increase PPV were also performed. Seventeen studies were systematically reviewed and presented with variations in study quality as well as inconsistent findings. Moreover, there was a high level of methodological heterogeneity. A total of 1920 patients were identified through the ICD-10 algorithm with potential BRONJ, although only 109 cases were confirmed, corresponding to an overall PPV of 5.68% (95% confidence interval [CI] 4.68-6.81). Only K10.2 (inflammatory conditions of the jaw) exhibited a relatively high PPV of 26.18%, which increased to 74.47% after confinement to BP users. Other strategies to increase PPV value were not effective. Our findings showed that the overall PPV for BRONJ identification was very low, indicating low validity of the current algorithm and possible overestimation of ONJ occurrence. There is an urgent need to develop more reliable and specific operational definitions for the identification of BRONJ cases in large population databases. © 2016 American Society for Bone and Mineral Research.

Bacterial diversity in medication-related osteonecrosis of the jaw

OBJECTIVE

The aim was to study the association between microflora and medication-related osteonecrosis of the jaw (MRONJ) by using culture-independent molecular techniques to detect bacteria in necrotic bone lesions.

STUDY DESIGN

Included were 18 consecutive patients with MRONJ, 10 with osteoporosis and 8 cancer patients. Bone biopsies were retrieved from the center of the necrotic bone and from visually healthy bone, and 16 S rRNA gene fragments from bacterial DNA were amplified with polymerase chain reaction.

RESULTS

The study revealed a diversity of bacteria represented by 16 S rRNA sequences in all the necrotic bone samples and in 60% of the visually healthy bone. Eight dominating taxa groups were identified at the genus level: Porphyromonas, Lactobacillus, Tannerella, Prevotella, Actinomyces, Treponema, Streptococcus, and Fusobacterium.

CONCLUSIONS

The necrotic bone lesions contained mainly anaerobic bacteria, representative of periodontal microflora, suggesting that a periodontal infection in combination with antiresorptive treatment could initiate osteonecrosis.

[Clinical analysis of bisphosphonate-related osteonecrosis of the jaw]

OBJECTIVE

The study aims to analyze patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ).

METHODS

Twelve patients treated in the Department of Oral and Maxillofacial Surgery, the First Affiliated Hospital of Me-dical School, Zhejiang University from May 2013 to September 2015 were included. Patients' basic situation, medication, clinical symptoms, therapies, and effects were obtained and analyzed.

RESULTS

The treatment of nine patients focused on the mandible, whereas that of three patients was on the maxilla. The clinical symptoms appeared from 10 to 80 months, with an average of about (28.00±21.42) months. Nine patients had tooth extraction history. After operation (nine patients), eight were treated, one had stable in bone exposure and three patients received conservative treatment.

CONCLUSIONS

Intravenous infusion of bisphosphonates can induce BRONJ. The mandible is commonly involved and tooth extraction is a big inducement. Treatments nowadays seek to relieve clinical symptoms, but prevention is more important.

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.