The Frequency of Medication-related Osteonecrosis of the Jaw and its Associated Risk Factors

Bone complications of cancer treatment

With the advancements in conventional treatment modalities such as radiation, chemotherapy, and surgery, as well as the emergence of immunotherapy, the overall cure rate for solid tumor malignancies has experienced a significant increase. However, it is unfortunate that exposure to cancer treatments can have detrimental effects on the function of osteoblasts and osteoclasts, disturbing bone metabolic homeostasis in patients, as well as causing damage to bone marrow cells and other bone tissues. Consequently, certain tumor treatment options may pose a risk for subsequent bone diseases. Common bone disorders associated with cancer treatment include osteonecrosis, bone loss, and secondary bone tumors. (1)Cancer treatment-related osteonecrosis is primarily linked to the use of radiation therapy and certain chemicals, such as bisphosphonates, denosumab, antiangiogenic agents, and immunomodulators. It has been observed that high-dose radiation therapy is more likely to result in osteonecrosis. (2)Chemicals and hormones, particularly sex hormones, glucocorticoids, and thyroid hormones or thyrotropic hormones, are among the factors that can contribute to cancer treatment-related bone loss. (3)Secondary bone tumors differ from metastases originating from primary tumors, and radiotherapy plays a significant role in their development, while chemotherapy may also exert some influence. Radiogenic secondary bone tumors are predominantly malignant, with osteosarcoma being the most common type. Chemotherapy may be a risk factor for the relatively rare occurrence of secondary Ewing sarcoma of the bone. These treatment-related bone disorders have a considerable adverse impact on the prognosis of cancer patients. Hence, it is imperative to prioritize the bone health of patients undergoing cancer treatment and give it further attention.

Examination of certain single-nucleotide polymorphisms of interleukins 1A and 1B in medication-related osteonecrosis of the jaw - An ambirectional cohort study

AIM

The aim of this study was to examine particular single-nucleotide polymorphisms (IL-1A-889 C/T - rs1800587, IL-1B +3953 C/T - rs 1143634) of interleukins 1A and 1B in the development and prognosis of medication-related osteonecrosis of the jaw.

MATERIALS AND METHODS

DentiGen Parodontitis Tests were applied for collecting samples. This test is suitable for sampling oral mucosa cells in order to detect interleukins 1A and 1B single nucleotide polymorphisms (IL-1A-889, IL-1B+3953). Genetic samples were evaluated in the Istenhegyi Genediagnostic Center using the DNA-hybridization method. Genetic samples were collected in the patient group and the control group. The role of gene polymorphisms in the development of the disease was investigated by comparing the genetic results for the patient and control groups. The investigation of gene polymorphisms in disease prognosis is based on stage improvement, recovery, and relapses following treatment.

RESULTS

In total, 91 patients with MRONJ and 59 healthy controls were included in the study. 51 patients in the patient group and 37 controls had unfavorable allelic variants. No association (Mp = 1.42, SDp = 0.496, Mc = 1.35, SDc = 0.482, p = 0.52) was found between unfavorable polymorphisms and the development of the MRONJ. In the patient group, surgical therapy was required in 79 cases. Stage improvement was detected in 78 cases, recovery in 67 cases, and relapse in 33 cases. No stage improvement was found in one case, recovery in nine cases, or relapse in 34 cases. Of the 79 patients requiring surgical therapy, 49 had unfavorable allelic variants. No connection was found between the polymorphisms examined and stage improvement (Mp = 1.37, SDp = 0.486, Mnp = 2, SDnp = -, p = 0.800) or recovery (Mp = 1.39, SDp = 0.491, Mnp = 1.44, SDnp = 0.527, p = 0.990). However, a significant association (Mp = 1.21, SDp = 0.415, Mnp = 1.58, SDnp = 0.502, p < 0.001) was found between relapses and the presence of unfavorable allelic variants.

CONCLUSION

Within the possible limitations of this study, it can be assumed that the analysis of certain single-nucleotide polymorphisms of interleukin-1 may have the potential to help define the risk stratification of MRONJ after surgical therapy.

Management of Medication-Related Osteonecrosis of the Jaw: An Overview of National and International Guidelines

There is variability amongst clinicians in the management of medication-related osteonecrosis of the jaw (MRONJ) though numerous guidelines are available. The aim of this critical review is to appraise current international and national guidelines on MRONJ to evaluate areas of consensus or inconsistency, identify areas lacking evidence, and discuss recommendations with agreement and variability across guidelines. A literature search was performed to identify all national and international guidelines published until May 2022 on the prevention and treatment of MRONJ. Included guidelines were compared and critically appraised with Appraisal of Guidelines for Research and Evaluation II (AGREE II). The included sixteen guidelines were published from ten different countries, two of which had international collaborations. AGREE II assessment found four guidelines of high quality. There is consensus to optimise oral health prior to and during therapy, to conservatively manage established MRONJ in earlier stages and consider surgery at advanced stages. There is disparity on strategies to reduce the risk of osteonecrosis such as the avoidance of invasive dental procedures, therapy suspension, and techniques to reduce the impact of invasive surgery. The authors recommend an international lead in the development of dental guidelines to establish a global standardised management approach aiming for better health equality.

Is maxillary sinusitis and radiographic maxillary sinus opacification associated with an altered microbiology of MRONJ?

OBJECTIVE

Maxillary sinusitis can be a sequela of medication-related osteonecrosis of the jaw (MRONJ). This study aims to characterize the microbiome of maxillary MRONJ with concurrent maxillary sinusitis and radiographic maxillary sinus opacification to determine if there is a relationship between the microbiome of MRONJ and sinus disease.

STUDY DESIGN

This retrospective case series was conducted using electronic health records from the University of Pennsylvania and affiliated hospitals. The target population was surgically managed maxillary MRONJ patients. The primary predictor variables were tissue culture results. The primary outcomes were maxillary sinusitis or maxillary sinus opacification. Statistical analysis was performed using chi-squared tests at the 95% confidence interval.

RESULTS

Thirty-nine subjects were selected: 25 had sinus opacification and 11 had sinusitis. Resident bacteria were present in 90% of subjects, nonresident bacteria in 74%, and opportunistic organisms in 15%. There were significantly more subjects with chronic sinusitis microbes (79%) than without. There were significantly more gram-positive anaerobes, specifically Propionibacterium, as well as the gram-negative facultative anaerobe, Capnocytophaga, in subjects with concurrent sinusitis.

CONCLUSIONS

Maxillary MRONJ with concurrent maxillary sinusitis may be associated with gram-positive anaerobic species, Propionibacterium, and Capnocytophaga colonization. Maxillary MRONJ patients may benefit from sinus evaluation and concurrent surgical intervention.

A Comparison of 18 F-FDG PET/CT and 68 Ga-PSMA PET/CT in Detecting Osteonecrosis of the Jaw in a Patient With Prostate Cancer

ABSTRACT

Medication-related osteonecrosis of the jaw (ONJ) is rare adverse effect of zoledronic acid. We present ONJ detected in a 65-year-old man with prostate cancer who underwent 18 F-FDG PET/CT for metabolic characterization and to exclude a second primary malignancy of the liver lesion observed in 68 Ga-PSMA PET/CT. ONJ has high metabolic activity on 18 F-FDG PET/CT and no PSMA receptor activation on the 68 Ga-PSMA PET/CT. In this case, we wanted to underline the importance of 18 F-FDG PET/CT imaging of medication-related ONJ in patients receiving zoledronic acid therapy and to emphasize that rapid and appropriate treatment can be provided.

A Case Report of Ibandronic Acid Induced Non-Exposed BRONJ Involving the Maxillary Sinus

Background

The aim of this case report is to present an interesting case of bisphosphonate-related osteonecrosis of the jaw, involving the maxilla and the maxillary sinus, as a result of per os administration of ibandronic acid.

Methods

A female patient, 62 years old, was referred to the Department of Dentoalveolar Surgery, Surgical Implantology and Radiology, School of Dentistry, Aristotle University of Thessaloniki, Greece, complaining about pain in the first quadrant. Her medical history revealed per os bisphosphonate administration for the past four years. Subsequently, the cone-beam computed tomography examination revealed a small sequestrum of bone, surrounded by radiolucency, in proximity with the sinus floor. The clinical examination didn't reveal any pathological clinical signs.

Results

Based on the radiological examination, a surgical approach was implemented to remove the necrotic bone, irrigate the alveolar process and the sinus with saline, and finally achieve primary closure, after which, the patient healed uneventfully. The osteonecrosis was attributed to the bisphosphonate administration.

Conclusions

Bisphosphonate-related osteonecrosis of the jaw without obvious or with minor implication of gingival tissues is a diagnostic challenge indicating an early stage of this adverse reaction. Imaging is critical for the early detection of those cases. After careful choice of the case the proper surgical intervention could be effective to eliminate a future advancement of bone destruction. The prevention of osteonecrosis of the jaw can be achieved through the provision of adequate education to dental medicine practitioners, medical doctors, and patients.

Awareness, perceptions and attitudes toward medication-related osteonecrosis of the jaw among physicians who treat osteoporosis

Osteoporosis is the most common indication for antiresorptive drugs (ARDs). Medication-related osteonecrosis of the jaw (MRONJ) is a severe complication of ARDs. Multiple risk factors can increase the risk of MRONJ, one of which is the duration of ARD intake, which is usually prolonged for osteoporosis cases. Prevention of MRONJ relies on collaborative care between treating physicians and dental practitioners. Therefore, knowledge about MRONJ and its prevention strategies is crucial for both teams.

Aim

This study aimed to assess the knowledge and attitudes of physicians toward MRONJ in osteoporosis patients. Another aim was to develop recommendations for the prevention of MRONJ.

Materials and methods

Through an online survey, basic information such as the practice location, training, knowledge, perceptions, and attitudes of physicians regarding ARDs and MRONJ in osteoporosis patients was collected. Statistical analysis was performed for all variables, and their correlations were explored.

Results

A total of 221 physicians participated in the survey: 34.8% were rheumatologists, 25.3% were endocrinologists, 8.6% were family medicine physicians, 5.9% were orthopedists, and 5.9% were internal medicine physicians. Of them, 58.0% reported more than 6 years of experience. Only 78.7% were aware of MRONJ and recognized that bisphosphonates (BPs) can contribute to MRONJ. In contrast, 56.0% recognized denosumab as a causative factor for MRONJ. Duration of ARD therapy and pre- and post-ARD dental care were known to influence the risk of MRONJ by 62% and 65.6% of the participants, respectively. Only 41.6% and 31.2% of participants informed patients about MRONJ prior to BP and denosumab therapy, respectively. Only 25.3% and 20.8% referred patients to dentists before BP and denosumab therapy, respectively. Overall, 65.6% of the participants had a negative attitude toward MRONJ, and 34.4% had a positive attitude. A positive attitude was mostly observed among rheumatologists (55.8%) compared to other specialists (p <0.001). More years of experience were associated with a higher level of knowledge and positive attitude.

Conclusion

The findings of this study identified a notable gap in the awareness, knowledge and attitudes of physicians regarding MRONJ in osteoporosis patients. Continuing education programs about ARDs and MRONJ risk are highly recommended.

Association Between Malignant Diseases and Medication-Related Osteonecrosis of the Jaw (MRONJ): A Systematic Review and Meta-Analysis

PURPOSE

The aim was to identify whether malignant diseases increase the risk of medication-related osteonecrosis of the jaw (MRONJ) occurrence when patients are exposed to bisphosphonate, antiresorptive or antiangiogenic drugs. To analyze related factors.

METHODS

A systematic literature searching was performed in PubMed, Embase, and Google Scholar for studies with information about whether patients have malignant diseases. Patients involved must be treated with MRONJ-related drugs and at high risk of developing MRONJ.

RESULTS

A total of 6 cohort studies and 3 case-control studies were included. Analysis according 9 studies shows that malignant diseases have significant influence on MRONJ occurrence (risk ratio (RR): 2.62; 95% confidence interval (95% CI): 1.58-4.33; P =0.0002). Subgroup analysis according 6 cohort studies also shows that malignant diseases significantly affect MRONJ occurrence (RR: 3.50; 95% CI: 1.63-7.52; P =0.001). Chemotherapy have no obvious influence on MRONJ occurrence (RR: 1.64; 95% CI: 0.79-3.39; P =0.18). Intravenous drug administration significantly influences MRONJ occurrence (RR: 2.67; 95% CI: 1.27-5.58; P =0.009).

CONCLUSIONS

Patients with malignant diseases have higher risk of MRONJ occurrence when exposed to bisphosphonate, antiresorptive, or antiangiogenic drugs. Cumulative dosages from intravenous drugs administration contribute to MRONJ developing. Prevention of MRONJ in patients with malignancy should be emphasized.

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.

Roles of osteoclasts in alveolar bone remodeling

Osteoclasts are large multinucleated cells from hematopoietic origin and are responsible for bone resorption. A balance between osteoclastic bone resorption and osteoblastic bone formation is critical to maintain bone homeostasis. The alveolar bone, also called the alveolar process, is the part of the jawbone that holds the teeth and supports oral functions. It differs from other skeletal bones in several aspects: its embryonic cellular origin, the form of ossification, and the presence of teeth and periodontal tissues; hence, understanding the unique characteristic of the alveolar bone remodeling is important to maintain oral homeostasis. Excessive osteoclastic bone resorption is one of the prominent features of bone diseases in the jaw such as periodontitis. Therefore, inhibiting osteoclast formation and bone resorptive process has been the target of therapeutic intervention. Understanding the mechanisms of osteoclastic bone resorption is critical for the effective treatment of bone diseases in the jaw. In this review, we discuss basic principles of alveolar bone remodeling with a specific focus on the osteoclastic bone resorptive process and its unique functions in the alveolar bone. Lastly, we provide perspectives on osteoclast-targeted therapies and regenerative approaches associated with bone diseases in the jaw.

A systematic review assessing occurrence of medication-related osteonecrosis of the jaw following dental procedures

Aim: This study aimed to systematically review existing literature regarding the association between dental procedures—such as tooth extractions and periodontal therapy—and occurrence of medication-related osteonecrosis of the jaw (MRONJ) in individuals using bone-modifying drugs. Methods: Search strategies were performed in PubMed, Scopus, Web of Science and Cochrane Library for a timeframe ending in December 2021. Study selection, data extraction and risk of bias were analyzed independently by two researchers. Three meta-analyses were performed, estimating the crude risk ratio (RR), the adjusted odds ratio (OR) and the adjusted hazard ratio (HR) for the association between tooth extraction and MRONJ. Results: Of the 1,654 studies initially retrieved, 17 were ultimately included. The majority of patients with MRONJ in these studies were female, with a mean age of 64 years. Zoledronic acid was the most commonly used drug among patients with MRONJ, and cancer was the most frequent underlying health condition. Regarding the performed meta-analyses, crude and adjusted analyses demonstrated that tooth extraction increased the risk for MRONJ by 4.28 (95% confidence interval [95%CI]: 1.73–10.58), the OR for MRONJ by 26.94 (95%CI: 4.17–174.17), and the HR for MRONJ by 9.96 (95%CI: 4.04–24.55). Conclusion: It was concluded that performing dental procedures, especially tooth extraction, in patients using bone-modifying drugs increased the risk of MRONJ occurrence and, therefore, should be avoided. Further studies, using adjusted data, are warranted.

Interventions for managing medication-related osteonecrosis of the jaw

BACKGROUND

Medication-related osteonecrosis of the jaw (MRONJ) is a severe adverse reaction experienced by some individuals to certain medicines commonly used in the treatment of cancer and osteoporosis (e.g. bisphosphonates, denosumab, and antiangiogenic agents), and involves the progressive destruction of bone in the mandible or maxilla. Depending on the drug, its dosage, and the duration of exposure, this adverse drug reaction may occur rarely (e.g. following the oral administration of bisphosphonate or denosumab treatments for osteoporosis, or antiangiogenic agent-targeted cancer treatment), or commonly (e.g. following intravenous bisphosphonate for cancer treatment). MRONJ is associated with significant morbidity, adversely affects quality of life (QoL), and is challenging to treat. This is an update of our review first published in 2017.

OBJECTIVES

To assess the effects of interventions versus no treatment, placebo, or an active control for the prophylaxis of MRONJ in people exposed to antiresorptive or antiangiogenic drugs. To assess the effects of non-surgical or surgical interventions (either singly or in combination) versus no treatment, placebo, or an active control for the treatment of people with manifest MRONJ.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched four bibliographic databases up to 16 June 2021 and used additional search methods to identify published, unpublished, and ongoing studies.  SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing one modality of intervention with another for the prevention or treatment of MRONJ. For 'prophylaxis of MRONJ', the primary outcome of interest was the incidence of MRONJ; secondary outcomes were QoL, time-to-event, and rate of complications and side effects of the intervention. For 'treatment of established MRONJ', the primary outcome of interest was healing of MRONJ; secondary outcomes were QoL, recurrence, and rate of complications and side effects of the intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results, extracted the data, and assessed the risk of bias in the included studies. For dichotomous outcomes, we reported the risk ratio (RR) (or rate ratio) and 95% confidence intervals (CIs).

MAIN RESULTS

We included 13 RCTs (1668 participants) in this updated review, of which eight were new additions. The studies were clinically diverse and examined very different interventions, so meta-analyses could not be performed. We have low or very low certainty about available evidence on interventions for the prophylaxis or treatment of MRONJ. Prophylaxis of MRONJ Five RCTs examined different interventions to prevent the occurrence of MRONJ. One RCT compared standard care with regular dental examinations at three-month intervals and preventive treatments (including antibiotics before dental extractions and the use of techniques for wound closure that avoid exposure and contamination of bone) in men with metastatic prostate cancer treated with zoledronic acid. The intervention seemed to lower the risk of MRONJ (RR 0.10, 95% CI 0.02 to 0.39, 253 participants). Secondary outcomes were not evaluated. Dentoalveolar surgery is considered a common predisposing event for developing MRONJ and five RCTs tested various preventive measures to reduce the risk of postoperative MRONJ. The studies evaluated plasma rich in growth factors inserted into the postextraction alveolus in addition to standardised medical and surgical care versus standardised medical and surgical care alone (RR 0.08, 95% CI 0.00 to 1.51, 176 participants); delicate surgery and closure by primary intention versus non-traumatic tooth avulsion and closure by secondary intention (no case of postoperative MRONJ in either group); primary closure of the extraction socket with a mucoperiosteal flap versus application of platelet-rich fibrin without primary wound closure (no case of postoperative MRONJ in either group); and subperiosteal wound closure versus epiperiosteal wound closure (RR 0.09, 95% CI 0.00 to 1.56, 132 participants).  Treatment of MRONJ Eight RCTs examined different interventions for the treatment of established MRONJ; that is, the effect on MRONJ cure rates.  One RCT analysed hyperbaric oxygen (HBO) treatment used in addition to standard care (antiseptic rinses, antibiotics, and surgery) compared with standard care alone (at last follow-up: RR 1.56, 95% CI 0.77 to 3.18, 46 participants).  Healing rates from MRONJ were not significantly different between autofluorescence-guided bone surgery and conventional bone surgery (RR 1.08, 95% CI 0.85 to 1.37, 30 participants). Another RCT that compared autofluorescence- with tetracycline fluorescence-guided sequestrectomy for the surgical treatment of MRONJ found no significant difference (at one-year follow-up: RR 1.05, 95% CI 0.86 to 1.30, 34 participants).  Three RCTs investigated the effect of growth factors and autologous platelet concentrates on healing rates of MRONJ: platelet-rich fibrin after bone surgery versus surgery alone (RR 1.05, 95% CI 0.90 to 1.22, 47 participants), bone morphogenetic protein-2 together with platelet-rich fibrin versus platelet-rich fibrin alone (RR 1.10, 95% CI 0.94 to 1.29, 55 participants), and concentrated growth factor and primary wound closure versus primary wound closure only (RR 1.38, 95% CI 0.81 to 2.34, 28 participants).   Two RCTs focused on pharmacological treatment with teriparatide: teriparatide 20 μg daily versus placebo in addition to standard care (RR 0.96, 95% CI 0.31 to 2.95, 33 participants) and teriparatide 56.5 μg weekly versus teriparatide 20 μg daily in addition to standard care (RR 1.60, 95% CI 0.25 to 1.44, 12 participants).

AUTHORS CONCLUSIONS

Prophylaxis of medication-related osteonecrosis of the jaw One open-label RCT provided some evidence that dental examinations at three-month intervals and preventive treatments may be more effective than standard care for reducing the incidence of medication-related osteonecrosis of the jaw (MRONJ) in individuals taking intravenous bisphosphonates for advanced cancer. We assessed the certainty of the evidence to be very low. There is insufficient evidence to either claim or refute a benefit of the interventions tested for prophylaxis of MRONJ in patients with antiresorptive therapy undergoing dentoalveolar surgery. Although some interventions suggested a potential large effect, the studies were underpowered to show statistical significance, and replication of the results in larger studies is pending. Treatment of medication-related osteonecrosis of the jaw The available evidence is insufficient to either claim or refute a benefit, in addition to standard care, of any of the interventions studied for the treatment of MRONJ.

Medication-related osteonecrosis of the jaw after dental clearance: Prevalence in an oncology center

Objective

Study design

Results

Conclusion

Oral Complications in Cancer Patients–Medication-Related Osteonecrosis of the Jaw (MRONJ)

Medication-Related Osteonecrosis of the Jaw (MRONJ) was first reported in 2003. Despite the progress in the understanding of this oral complication in cancer patients for the past 18 years, there is still discussion about the best way to define MRONJ, prevent the complication, how to diagnose, and the options of treatment available. The initial reports associated MRONJ to bisphosphonates and denosumab, medications that work as bone-modifying agents. Later, other agents such as the antiangiogenics, have also been reported to cause the oral complication, either alone or in combination with antiresorptives. Initially, these medications were prescribed to patients with osteoporosis and cancers patients with bone metastasis. Today, because of the effect of the medications in the bone remodeling system, patients with several other diseases such as giant cell tumors, rheumatoid arthritis, Paget's disease of bone, fibrous dysplasia, osteogenesis imperfecta, are managed with these medications, significantly increasing the population of individuals at risk for developing MRONJ. This mini review focused on the cancer patient. It updates the dental clinician on the recent scientific literature about MRONJ and provides information on how to diagnose and manage patients being treated with these medications, suggests protocols to prevent the development of MRONJ, and present ways to manage those patients who develop the oral complication.

[Bisphosphonate-related osteonecrosis of the jaws]

The number of patients with metabolic osteopathies and oncological diseases occurring with the formation of bone metastases is constantly growing and requires special attention not only of oncologists, but also maxillofacial surgeons, dental surgeons and periodontists, due to severe complications from the oral cavity, against the background of antiresorptive therapy with bisphosphonates. These drugs are associated with the development of necrotic processes of the jaw bones and surrounding tissues. It is worth noting the fact that the development of complications after taking these drugs leads to a significant increase in the suffering of patients. The importance of an integrated approach to the treatment and prevention of such complications is extremely important, as it reduces the risk of possible complications and improves the quality of life of this group of patients.

Prevalence, Incidence Rate, and Risk Factors of Medication-Related Osteonecrosis of the Jaw in Patients With Osteoporosis and Cancer: A Nationwide Population-Based Study in Japan

PURPOSE

Medication-related osteonecrosis of the jaw (MRONJ) is a rare but severe adverse event of antiresorptive agents. However, the precise prevalence and factors associated with the development of MRONJ remain unknown. The present study was performed to describe the prevalence, incidence rate, and risk factors of developing MRONJ.

METHODS

We conducted a population-based retrospective cohort study using the National Database of Health Insurance, an administrative claims database of all patients in Japan. We identified patients who newly began using antiresorptive drugs from April 2015 to December 2018. The primary outcome was the development of MRONJ. We calculated the prevalence and incidence rate of MRONJ and performed a time-dependent Cox proportional hazard regression analysis to examine risk factors for developing MRONJ.

RESULTS

We identified 2,819,310 patients who newly used antiresorptive drugs during the study period. Of these patients, 2,664,104 (94.5%) had osteoporosis and 155,206 had cancer. Among the patients with osteoporosis, 1,603 (0.06%) developed MRONJ; the incidence rate was 22.9 per 100,000 person-years. Among the patients with cancer, 2,274 (1.47%) developed MRONJ; the incidence rate was 1,231.7 per 100,000 person-years. The occurrence of MRONJ was associated with poor oral conditions (including tooth extraction), age, male sex, drug type, concomitant drug use, comorbidities, cancer type, and geographic location.

CONCLUSIONS

The overall prevalence and incidence rate were low, but they were still higher than those in previous studies. Poor oral conditions were more closely related to the development of MRONJ than other factors. These findings suggest that improving poor oral hygiene may be essential to prevent MRONJ.

The incidence of medication-related osteonecrosis of the jaw following tooth extraction in patients prescribed oral bisphosphonates

Aims To determine the incidence of medication-related osteonecrosis of the jaw in patients prescribed oral bisphosphonate medication following dental extraction in a dedicated clinic within the Department of Oral Surgery of King's College Hospital. The effect of factors such as sex, duration of therapy, medical comorbidities and site of extraction, which have previously been reported to significantly affect the risk of developing osteonecrosis of the jaw, was also examined.Materials and methods Data were gathered from the dental records of patients who had extractions over an eight-year period and were included in this retrospective study. Patients with previous or current exposure to intravenous bisphosphonates, denosumab, novel-targeted chemotherapies used in the oncology setting or radiotherapy to the head and neck were excluded from this study.Results The incidence of medication-related osteonecrosis of the jaw following tooth extraction in this group of 652 was 0.8%. A significantly increased risk of developing medication-related osteonecrosis of the jaw was evident in patients prescribed oral bisphosphonates for four years or more (p = 0.02), with an incidence in this group of 1.6%.Conclusion This study demonstrates that, following dental extraction, patients who are prescribed oral bisphosphonates are at risk of developing medication-related osteonecrosis of the jaw and that this risk increases significantly when the patient has been taking the bisphosphonate for four years or more.

Risk factors associated with onset of medication-related osteonecrosis of the jaw in patients treated with denosumab

Objectives

While risk factors of bisphosphonate (BP) associated osteonecrosis of the jaw have been properly analyzed, studies focusing on risk factors associated with denosumab (DNO) are sparse. The purpose of this study was to identify risk factors influencing the onset of medication-related osteonecrosis of the jaw (MRONJ) in patients receiving antiresorptive treatment (ART) with DNO by comparing patients suffering from MRONJ and patients without MRONJ. Multiple variables were evaluated including the impact of a previous BP intake.

Materials and methods

A retrospective single-center cohort study with patients receiving DNO was conducted. One-hundred twenty-eight patients were included and divided into three groups: I (control, n = 40) receiving DNO with absence of MRONJ; group II (Test 1, n = 46), receiving DNO with presence of MRONJ; and group III (Test 2, n = 42) sequentially receiving BP and DNO with presence of MRONJ. Patients’ medical history, focusing on the identification of MRONJ risk factors, was collected and evaluated. Parameters were sex, age, smoking habit, alcohol consumption, underlying disease (cancer type, osteoporosis), internal diseases, additional chemo/hormonal therapy, oral inflammation, and trauma.

Results

The following risk factors were identified to increase MRONJ onset significantly in patients treated with DNO: chemo/hormonal therapy (p = 0.02), DNO dosage (p < 0.01), breast cancer (p = 0.03), intake of corticosteroids (p = 0.04), hypertension (p = 0.02), diabetes mellitus (p = 0.04), periodontal disease (p = 0.03), apical ostitis (p = 0.02), and denture use (p = 0.02). A medication switch did not affect MRONJ development (p = 0.86).

Conclusions

Malignant diseases, additional chemotherapy, DNO dosage, and oral inflammations as well as diabetes mellitus and hypertension influence MRONJ onset in patients treated with DNO significantly.

Clinical relevance

Patients receiving ART with DNO featuring aforementioned risk factors have a higher risk of MRONJ onset. These patients need a sound and regular prophylaxis in order to prevent the onset of MRONJ under DNO treatment.

Review and Update of the Risk Factors and Prevention of Antiresorptive-Related Osteonecrosis of the Jaw

Antiresorptive-related osteonecrosis of the jaw (ARONJ) is a rare but serious adverse event of bisphosphonate or denosumab administration; it is associated with severe pain and a deteriorated quality of life. Since its first report in 2003, there have been many studies on its definition, epidemiology, pathophysiology, diagnosis, and treatment. Nevertheless, the epidemiology and mechanisms underlying this condition have not yet been fully delineated and several risk factors are known. Moreover, as there is no effective treatment currently available for osteonecrosis of the jaw, prevention is essential. Furthermore, close cooperation between prescribing physicians and dentists is important. The aim of this review was to provide up-to-date information regarding the risk factors and prevention of ARONJ from a physician's perspective.

Conservative Management of Severe Medication-Related Osteonecrosis of the Jaw With Pathological Fracture

ABSTRACT

Medication-related osteonecrosis of the jaw (MRONJ) is a well-known risk following dental extraction in patients taking certain medications. Pathological fracture secondary to MRONJ often requires complex operative intervention.This case demonstrates the conservative management of pathological fracture secondary to MRONJ in a patient with multiple comorbidities. The patient developed MRONJ with pathological fracture following extraction of the mandibular second molar. The patient presented with significant surgical risk factors, having hypertension and a recent stroke, causing dense left hemiparesis, subsequently resulting in transition to high-level nursing care. Given the high risk of reconstructive surgery, nonoperative management was undertaken. Following a course of long-term antibiotics with resolution of signs of infection, the case was managed conservatively with chlorhexidine-based mouthwash and soft diet.With routine clinico-radiographic assessment and optimal oral health care, the pathological fracture did not require operative intervention. Healing progressed well with no clinical complications and radiographic evidence of good healing at 6- and 12-month follow-up on orthopantomogram.A role for conservative management of pathological fractures secondary to MRONJ yet exists, especially in the elderly population. This case highlights the importance of developing treatment plans based on individual patient context and clinical assessment.

A retrospective study on the incidence of medication-related osteonecrosis of the jaws (MRONJ) associated with different preventive dental care modalities

Purpose

To assess the efficacy of different preventive dental visits and treatments in reducing the risk of medication-related osteonecrosis of the jaws (MRONJ).

Methods

In this retrospective study, patients diagnosed with MRONJ were divided into 5 groups based on available data: no preventive dental visits (group 0); dental visits and compliance with recommended treatments, at the university hospital’s dental clinic (group 1) or maxillofacial surgery unit (group 2), or at a private dentist’s (group 3); dental visits at one of the above and noncompliance with proposed treatments (group 4); patients judged eligible by the oncologist on panoramic radiography (group 5). Patients were classified on severity of MRONJ according to the Italian SIPMO/SICMF 2.0 staging system. A descriptive analysis was performed on the results. Fisher’s exact test was applied (p < 0.05).

Results

Ninety-three patients diagnosed with MRONJ were considered for the study, but 22 were excluded due to a lack of data, leaving a sample of 71 cases. MRONJ staging was only 0 for some patients (26.92%) in group 0. In all groups, the majority of patients had stage 2 MRONJ. The proportions of cases in stage 3 were 7.69% in group 0, 18.18% in group 3, and 43.48% in group 5. Groups 0 and 3 were somewhat similar as regard MRONJ staging. Most patients in group 5 had MRONJ stage 2 or 3. No statistically significant differences emerged between the groups.

Conclusions

Preventive dental care can reduce the risk of MRONJ providing patients comply with the specialist’s recommendations.

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

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

Medication-Related Osteonecrosis of the Jaw—A Continuing Issue

Introduction: Medication-related osteonecrosis of the jaw (MRONJ) is a condition that is becoming more common in the everyday practice of both dental and maxillofacial surgeons. Materials and methods: This paper aims to provide a comprehensive and easy to read by clinicians presentation of comprehensive, accessible, and up-to-date data on MRONJ. The individual chapters focus on the etiology, epidemiology, diagnosis, prevention, treatment, and recurrence of MRONJ. Results and discussion: It has been observed over the years that among drugs that increase the risk of the disease, apart from bisphosphonates, angiogenesis inhibitors and anti-RANKL monoclonal antibodies should also be included. A thorough physical and subjective examination, periodic correction of dental prostheses, and an adequate preparation for even the simplest of procedures in the oral cavity area can prevent or minimize the risk of MRONJ. Conclusions: It is extremely difficult to treat once it occurs and oftentimes is a recurring problem that leads to a multitude of symptoms that gradually decrease the quality of a patient’s life.

Frequency of osteonecrosis in bisphosphonate users submitted to dental procedures: A systematic review

OBJECTIVE

To determine the frequency of osteonecrosis of the jaw in bisphosphonate users submitted to dental procedures.

METHODS

This systematic review searched the sources: MEDLINE, EMBASE, Web of Science, Scopus, and Virtual Health Library, with no restriction on language or publication date. Reviewers, in pairs and independently, selected the studies, extracted their data, and assessed the risk of bias. Meta-analyses were pooled using the DerSimonian and Laird random effects model.

RESULTS

A total of 27 studies (5391 participants) were included. The most reported bisphosphonates were zoledronate (n = 17 studies) and alendronate (n = 19) for treating cancers (n = 11) and osteoporosis (n = 16), respectively. Twelve studies were of low methodological quality. The frequency of osteonecrosis was 2.7% (95% CI: 0.9-5.2%) and proved higher for intravenous [6.9% (0.7-17.3%)] than oral [0.2% (0.9-5.2%)] bisphosphonate use. No association between longer treatment duration and greater frequency of osteonecrosis was observed.

CONCLUSIONS

Higher frequency of osteonecrosis was observed in intravenous bisphosphonate users submitted to dental extraction. Further studies collecting more detailed information on the bisphosphonates used and of greater methodological rigor are warranted to confirm these findings and better inform prescribers, dental surgeons, and other professionals on risks of bisphosphonate use in this patient group.

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.

Alendronate-induced Perturbation of the Bone Proteome and Microenvironmental Pathophysiology

Objectives: Bisphosphonates (BPs) are powerful inhibitors of osteoclastogenesis and are used to prevent osteoporotic bone loss and reduce the risk of osteoporotic fracture in patients suffering from postmenopausal osteoporosis. Patients with breast cancer or gynecological malignancies being treated with BPs or those receiving bone-targeted therapy for metastatic prostate cancer are at increased risk of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Although BPs markedly ameliorate osteoporosis, their adverse effects largely limit the clinical application of these drugs. This study focused on providing a deeper understanding of one of the most popular BPs, the alendronate (ALN)-induced perturbation of the bone proteome and microenvironmental pathophysiology. Methods: To understand the molecular mechanisms underlying ALN-induced side-effects, an unbiased and global proteomics approach combined with big data bioinformatics was applied. This was followed by biochemical and functional analyses to determine the clinicopathological mechanisms affected by ALN. Results: The findings from this proteomics study suggest that the RIPK3/Wnt/GSK3/β-catenin signaling pathway is significantly perturbed upon ALN treatment, resulting in abnormal angiogenesis, inflammation, anabolism, remodeling, and mineralization in bone cells in an in vitro cell culture system. Conclusion: Our investigation into potential key signaling mechanisms in response to ALN provides a rational basis for suppressing BP-induced adverse effect and presents various therapeutic strategies.

Bisphosphonates in Dentistry – State of the Art

Bisphosphonates remain the most used and most effective drugs for the treatment of systemic bone diseases followed by bone resorption. Although their side effects in a form of alveolar bone osteonecrosis have been reported, bisphosphonates have a potential of being used in the treatment of the most common oral diseases followed by alveolar bone resorption such as peri-implantitis, periapical lesions, and periodontitis. The aim of this article was to review the most recent research regarding the use of bisphosphonates in the field of dentistry. The results of studies indicate that bisphosphonate use in the treatment of peri-implantitis, periapical lesions, and periodontitis can reduce alveolar bone resorption and contribute to bone preservation. However, the most beneficial way of their application in the treatment of these oral diseases remain to be determined.

Human amniotic membrane: an improvement in the treatment of Medication-related osteonecrosis of the jaw (MRONJ)? A case-control study

The aim of this article is to report the results obtained by the use of HAM in surgical wound healing and the reduction of relapse in patients affected by Medication-related osteonecrosis of the jaw (MRONJ).The study involved patients with the diagnosis of MRONJ, surgically treated between October 2016 and April 2019, in a case-control setting. Enrolled patients were randomly divided into 2 groups. One group will be treated with resective surgery and with the insertion of HAM patch (Group A), while the second group had been treated exclusively with resective surgery (Group B).The patients underwent MRONJ surgical treatment with the placement of amniotic membrane patches at the wound site. Data regarding the long-term complications/functions were evaluated at 3, 6, 12, and 24 months after surgery. Pain measurements were performed before the intervention (T0), 7(T1) and 30(T2) days after surgery. 49 patients were included in the study. 2 patients of GROUP A after 30 days since they were surgically treated showed persistent bone exposure. 5 patients of group B demonstrated a lack of healing of the surgical wound with the persistence of bone exposed to 30 days after surgery. Statistical analysis ruled out any difference in OUTCOME (relapse) between GROUP A and B (p = 0.23). However, the Fisher test highlighted a significant difference between the use of HAM and only surgical treatment in pain at rest (p = 0.032). The use of amniotic membrane implement the patient's quality of life and reduce pain perception. has a learning curve that is fast enough to justify its routine use.

Underprescription of medications in older adults: causes, consequences and solutions-a narrative review

PURPOSE

Under-prescription is defined as the omission of a medication that is indicated for the treatment of a condition or a disease, without any valid reason for not prescribing it. The aim of this review is to provide an updated overview of under-prescription, summarizing the available evidence concerning its prevalence, causes, consequences and potential interventions to reduce it.

METHODS

A PubMed search was performed, using the following keywords: under-prescription; under-treatment; prescribing omission; older adults; polypharmacy; cardiovascular drugs; osteoporosis; anticoagulant. The list of articles was evaluated by two authors who selected the most relevant of them. The reference lists of retrieved articles were screened for additional pertinent studies.

RESULTS

Although several pharmacological therapies are safe and effective in older patients, under-prescription remains widespread in the older population, with a prevalence ranging from 22 to 70%. Several drugs are underused, including cardiovascular, oral anticoagulant and anti-osteoporotic drugs. Many factors are associated with under-prescription, e.g. multi-morbidity, polypharmacy, dementia, frailty, risk of adverse drug events, absence of specific clinical trials in older patients and economic factors. Under-prescription is associated with negative consequences, such as higher risk of cardiovascular events, worsening disability, hospitalization and death. The implementation of explicit criteria for under-prescription, the use of the comprehensive geriatric assessment by geriatricians, and the involvement of a clinical pharmacist seem to be promising options to reduce under-prescription.

CONCLUSION

Under-prescription remains widespread in the older population. Further studies should be performed, to provide a better comprehension of this phenomenon and to confirm the efficacy of corrective interventions.

Medication-related osteonecrosis of the jaw: Analysing the range of implicated drugs from the Australian database of adverse event notifications

AIMS

Medication-related osteonecrosis of the jaw (MRONJ) is an uncommon but potentially debilitating condition, characterised by nonhealing jawbone, with or without mucosal exposure, in the presence of certain drugs. Those already strongly associated with MRONJ include antiresorptives denosumab and bisphosphonates; however, a growing range of other non-antiresorptive drugs is implicated. The aim of this study was to analyse all case reports of MRONJ submitted to the publicly available Database of Adverse Event Notification from the Therapeutic Goods Administration in Australia.

METHODS

The Therapeutic Goods Administration was contacted on 6 January 2020 and asked for all reports containing the words "osteonecrosis of the jaw". This was provided in a spreadsheet of de-identified reports received from commencement of the database in 1971 until 1 October 2019.

RESULTS

The drugs implicated in the 419 cases were divided by established drugs with MRONJ and secondary drugs that possibly contribute to MRONJ development. While the majority of cases were associated with denosumab or bisphosphonates (n = 405), there were 14 reports where secondary agents that directly or indirectly affect bone turnover, were also implicated. Some of these secondary drugs, including adalimumab, etanercept, methotrexate and rituximab have previously been associated with MRONJ in published case reports.

CONCLUSIONS

This study contributes to the sparse but growing literature associating an increasing number of drugs with MRONJ, and underscores the importance of considering all possible drugs that elevate a patient's MRONJ risk.

Osteonecrosis of the jaw in a patient under treatment of osteoporosis with oral bisphosphonate

Although uncommon in patients under oral therapy, bisphosphonate-related osteonecrosis of the jaw (BRONJ) can be a very severe issue. Early intervention with surgical resection should be the preferable method of treating any stage of the disease, resulting in better outcomes and decreasing the morbidity of this condition. A 77-year-old female patient attended the Special Care Dentistry Centre of the University of São Paulo Faculty of Dentistry (CAPE FOUSP) complaining mainly of "an exposed bone that appeared after tooth extraction performed six months earlier". The patient was diagnosed with osteonecrosis associated with bisphosphonate (sodium ibandronate) and surgically treated with removal of bone sequestration and antibiotic therapy. The patient was followed up for six years (a total of 6 appointments), presenting good general health and no sign of bone exposure. Imaging findings showed no changes related to BRONJ either.

Osteonecrosis of the jaw induced by treatment with anti-PD-1 immunotherapy: a case report

Recognizing rare but clinically significant toxicity of immunotherapy is critical. Here we describe the first detailed case of severe osteonecrosis of the jaw due to anti-PD-1. A 75-year-old man with metastatic melanoma, with no prior radiation or treatment with bone-targeting agents, experienced jaw pain 1 week after his first dose of nivolumab. Imaging studies were negative, and treatment was resumed after pain was controlled. 4 months later, the patient experienced acute exacerbation of pain and malocclusion of the jaw. Imaging showed bilateral fractures of the angle of mandible with extensive disruption of the normal trabecular architecture, requiring total mandibulectomy. The patient's metastatic melanoma responded to treatment and remains controlled >20 months after treatment cessation without further therapy.

Combined Administration of Bisphosphonates, Chemotherapeutic Agents, and/or Targeted Drugs Increases the Risk for Stage 3 Medication-Related Osteonecrosis of the Jaw: A 4-Year Retrospective Study

Objectives

Patients with stage 3 medication-related osteonecrosis of the jaw (MRONJ) suffer from severe complications. Chemotherapeutic agents and targeted drugs are considered to be associated with the development of MRONJ. However, little is known regarding the association of those agents with stage 3 MRONJ. The purpose of this study is to analyze the comprehensive medication history of patients with advanced-stage MRONJ (stage 2 and stage 3) and evaluate the possible risk factors for stage 3 MRONJ. Patients and Methods. Sixty patients with advanced-stage MRONJ were involved in this retrospective study. Patients with developmental maxillofacial anomalies, previous radiation in the head and neck areas, and jaw bone tumors were excluded from the study. All patients were divided into two groups by their MRONJ stage (stage 2 or stage 3). Demographic and clinical characteristics, comprehensive medication data (bisphosphonates, chemotherapeutic agents, targeted drugs, and immunosuppressive agents), and results of serological biomarkers were recorded and compared between two groups. Univariate and multivariate logistic regressions were performed by SPSS 25.0 for evaluating risk factors of stage 3 MRONJ.

Results

Our results indicate that chemotherapy (adjusted OR = 3.43; 95% CI: 1.03 to 11.38), targeted drugs (adjusted OR = 3.69; 95% CI: 1.06 to 12.80), and maxillary lesions (adjusted OR = 4.26; 95% CI: 1.19 to 15.23) increase the risk of stage 3 MRONJ.

Conclusion

The outcome of this study justifies that chemotherapeutic agents and targeted drugs are probably risk factors for stage 3 MRONJ. In addition, the osteonecrosis in maxilla is more easily to develop into stage 3 MRONJ. Intense clinical observation is recommended in MRONJ patients with maxillary osteonecrosis and in those who concurrently administered bisphosphonates, chemotherapeutic agents, and/or targeted drugs. This trial is registered with ChiCTR2000032428.

Management of Medication-Related Osteonecrosis of the Jaw (MRONJ) Using Leukocyte- and Platelet-Rich Fibrin (L-PRF) and Photobiomodulation: A Retrospective Study

Background. The aim of this study was to compare retrospectively the effect of three different treatment protocols on the healing outcome in patients with established medication-related osteonecrosis of the jaw (MRONJ). Methods. A total of 34 MRONJ patients were recruited from the Department database and were divided according to the treatment protocols in a study group (G1) and two control groups (G2 and G3). G1 was treated with antibiotic therapy, surgery, leukocyte- and platelet-rich fibrin (L-PRF), and photobiomodulation; G2 was treated with antibiotic therapy and surgery; G3 was treated with antibiotic therapy and photobiomodulation. Various clinical variables and treatment protocols were analyzed to determine their correlation with the healing outcome at three and six months of follow-up. Results. There was a significant association between the different treatment protocols and the outcomes at both three and six months follow-up (p = 0.001 and p = 0.002, respectively). No significant association was observed between the outcomes and MRONJ localization, MRONJ stage, duration of drug treatment, gender, diabetes, corticosteroid therapy, smoking habits, underlying disease, and history of chemotherapy at both three and six months follow-up. Conclusions. Our results show that the combination of antibiotic therapy, surgery, L-PRF, and photobiomodulation may effectively contribute to MRONJ management.

Pathogenesis and multidisciplinary management of medication-related osteonecrosis of the jaw

Medication-related osteonecrosis of the jaw (MRONJ) is a serious side effect of bone-modifying agents and inhibits angiogenesis agents. Although the pathogenesis of MRONJ is not entirely clear, multiple factors may be involved in specific microenvironments. The TGF-β1 signalling pathway may have a key role in the development of MRONJ. According to the clinical stage, multiple variables should be considered when selecting the most appropriate treatment. Therefore, the prevention and management of treatment of MRONJ should be conducted in patient-centred multidisciplinary team collaborative networks with oncologists, dentists and dental specialists. This would comprise a closed responsibility treatment loop with all benefits directed to the patient. Thus, in the present review, we aimed to summarise the pathogenesis, risk factors, imaging features, clinical staging, therapeutic methods, prevention and treatment strategies associated with MRONJ, which may provide a reference that can inform preventive strategies and improve the quality of life for patients in the future.

Bone-Specific Drugs and Osteonecrosis of Sites Other Than the Jaw: A Nationwide Cohort Study

Bone-specific drugs (BSDs) increase the risk of osteonecrosis of the jaw (ONJ), but whether they increase the risk of osteonecrosis at other sites is not known. Two studies, a cohort study and a case-control study, were conducted using registry data on everyone who was residing in Sweden on December 31, 2005, and who was 50 years of age or older at the time (n = 3,523,912). In the cohort study, individuals prescribed a BSD during the period 2006-2017 (n = 217,387) were 1:1 matched with nonusers on birth year, sex, hip fracture status, and Swedish or foreign origin. In the case-control study, individuals diagnosed with osteonecrosis during 2006-2017 (n = 12,614) were 1:1 matched with individuals without a diagnosis of osteonecrosis on birth year, sex, and Swedish or foreign background. In the cohort study, osteonecrosis was diagnosed in 983 BSD users and 214 nonusers (adjusted hazard ratio [aHR] 4.02; 95% CI, 3.32-4.87), during a mean treatment time of 2.8 years. A similar association was observed in a subcohort where all individuals diagnosed with cancer (HR 4.82; 95% CI, 2.52-9.22). The greatest difference in incidence between BSD users and nonusers was observed in patients with a femoral neck fracture that was not treated with total hip arthroplasty or hemiarthroplasty (incidence rate difference, 77.8 cases per 10,000 person-years, p < .05). The risk of osteonecrosis was higher in users of denosumab (HR 1.93; 95% CI, 1.33-2.79) and users of zoledronic acid (HR 1.95; 95% CI, 1.31-2.91) than in users of other BSDs. The increased risk of osteonecrosis decreased after the end of therapy (p < .001 for time trend). The results were confirmed in the case-control study. In summary, use of BSDs, especially more potent BSDs, is associated with increased risk of osteonecrosis of sites other than the jaw. This increased risk decreases after the final dose of BSD. © 2020 American Society for Bone and Mineral Research.

Medication-Related Osteonecrosis of the Jaws

Medication-related osteonecrosis of the jaw is an oral complication in cancer patients being treated with either antiresorptive or antiangiogenic drugs. The first reports of MRONJ were published in 2003. Hundreds of manuscripts have been published in the medical and dental literature describing the complication, clinical and radiographic signs and symptoms, possible pathophysiology, and management. Despite this extensive literature, the pathobiological mechanisms by which medication-related osteonecrosis of the jaw develops have not yet been fully delineated. The aim of this manuscript is to present current knowledge about the complication ragarding to the definition, known risk factors, and clinical management recommendations. Based on this current state of the science, we also propose research directions that have potential to enhance the management of future oncology patients who are receiving these agents.

Therapeutic approach and management algorithms in medication-related osteonecrosis of the jaw (MONJ): recommendations of a multidisciplinary group of experts

BACKGROUND

The justification for this consensus is the absence of local protocols on Medication-Related Osteonecrosis of the Jaws (MONJ), for prevention, evaluation, and treatment, involving physicians and dentists, leading to suspension of antiresorptive treatments, despite their benefit in the prevention of fragility fractures (40-70%). These fractures cause disability and mortality (80% and 20-30%, respectively), as opposed to the low risk associated with MONJ in osteoporotic (0.01-0.03%) and oncological patients (1.3-1.8%).

PURPOSE

To provide management recommendations through algorithms that guide health professionals to prevent, diagnose, and treat MONJ in different clinical scenarios.

METHOD

A technical multidisciplinary team composed of specialists with extensive experience in osteoporosis or osteonecrosis of the jaw from Fundación Santa Fé (Bogotá, Colombia) and the Asociación Colombiana de Osteoporosis y Metabolismo Mineral was selected. Three rounds were carried out: definition of questions, answers using Delphi methodology, and the discussion of questions in order to have an agreement. The whole group participated in two phases, and the developer group in the total number of rounds. A literature review was conducted to obtain academic support to design questions with clinical relevance.

RESULTS AND CONCLUSIONS

The consensus group generated definitions and recommendations useful for doctors and dentists, following clinical algorithms involving four scenarios: osteoporosis patient who requires dental procedures and has not received antiresorptives, osteoporosis patient who are under treatment with antiresorptives, cancer patients, and MONJ-instituted patients. The therapeutic approach in osteoporosis and cancer patients, in invasive dental procedures, must be relied on the risk-benefit treatment.

Skeletal Site-Specific Response of Jawbones and Long Bones to Surgical Interventions in Rats Treated with Zoledronic Acid

Bisphosphonates (BPs) have been extensively used for management of bone diseases with pathologically high resorption. Despite the great clinical benefits, a severe complication known as medication-related osteonecrosis of the jaw (MRONJ) has been reported. It is found that most of the reported MRONJ cases were limited in the jawbones/craniofacial bones instead of long bones. The present study aims to investigate the differential bone response to surgical procedures between jawbones and long bones exposed to BPs. Forty-eight skeletal mature Sprague Dawley female rats were administered oncologic dose of zoledronic acid (ZA) or normal saline for 4 weeks and then subjected to tooth extraction on the mandible and maxilla, and a bone defect creation on the femur. After surgical procedures, ZA or saline treatment were continued until sacrifice at week 2, week 4, and week 8, post-operatively. The samples were subjected to micro-computerized tomography (micro-CT) and histological assessment. Osteonecrosis was only found in jawbones in ZA-treated rats. ZA-treated rats showed significantly higher bone mineral density with greater bone volume in all surgical sites than that in the controls. The length of exposure of ZA did not seem to affect trabecular microstructure, and it only showed higher bone volume and BMD with longer healing time which is expected in the healing process.

Role of osteoclasts in oral homeostasis and jawbone diseases

The jawbone is a unique structure as it serves multiple functions in mastication. Given the fact that the jawbone is remodeled faster than other skeletal bones, bone cells in the jawbone may respond differently to local and systemic cues to regulate bone remodeling and adaptation. Osteoclasts are bone cells responsible for removing old bone, playing an essential role in bone remodeling. Although bone resorption by osteoclasts is required for dental tissue development, homeostasis and repair, excessive osteoclast activity is associated with oral skeletal diseases such as periodontitis. In addition, antiresorptive medications used to prevent bone homeostasis of tumors can cause osteonecrosis of the jaws that is a major concern to the dentist. Therefore, understanding of the role of osteoclasts in oral homeostasis under physiological and pathological conditions leads to better targeted therapeutic options for skeletal diseases to maintain patients' oral health. Here, we highlight the unique features of the jawbone compared to the long bone and the involvement of osteoclasts in the jawbone-specific diseases.

Bilateral Bone Ridge Splitting in Maxilla with Immediate Implant Placement in a Patient with Osteoporosis: A Clinical Report with 2-Year Follow-up

Every year, a higher percentage of bisphosphonates is prescribed for osteoporosis treatment which can lead to bone osteonecrosis after several surgical procedures in the oral cavity. This report describes an approach to restore two missing teeth, employing bilateral bone ridge splitting in the maxilla with immediate placement of implants in a patient using bisphosphonates in the management of osteoporosis. Two titanium implants with a width of 3.45 mm and a length of 10 mm were placed in the maxillary ridge with a diameter of 4.4 mm and 3.0 mm in positions 15 and 24 according to the classification of the World Dental Federation. The implants were placed immediately by bone splitting, using a piezosurgery device and guided bone regeneration with an alloplastic material and a collagen membrane. Five months later, the implants were uncovered and the final porcelain crowns were cemented. 24 months later, the control through clinical and radiographical examinations showed no bone loss in the collar part of the implants and the proper status of the peri-implant soft tissue without any signs of inflammation. Piezosurgery is a useful and safe method of ridge splitting in a very thin ridge (4.5 and 3.0 mm).

Rebound Vertebral Fractures in a Patient With Lung Cancer After Oncology-Dose Denosumab Discontinuation: A Cautionary Tale

We describe a 55-year-old woman with lung cancer complicated by bone metastases. Treatment with denosumab (120 mg monthly) was interrupted after 9 doses because of concern for potential osteonecrosis of the jaw during upcoming dental work. Fifteen months after receiving the last dose of denosumab, the patient presented with 7 atraumatic spinal compression fractures requiring kyphoplasty for symptom relief. No malignancy was found in pathology specimens. Evaluation for secondary causes of osteoporosis was negative. This phenomenon of rebound fractures after discontinuing the use of denosumab, an inhibitor of RANK ligand, has been well described in patients with osteoporosis, who receive much lower doses than do patients with cancer. However, this has not been previously reported in oncology patients, likely because most succumb to their disease before denosumab therapy is stopped.

Genetic predisposition for medication-related osteonecrosis of the jaws: a systematic review

The purpose of this study was to assess whether genetic variation is a predictor for the development of medication-related osteonecrosis of the jaws (MRONJ) in patients receiving bisphosphonate therapy for various conditions. A systematic review based on the PRISMA guidelines was performed. A search strategy was developed. Comprehensive searches of major databases were conducted for studies published January 2003 through July 2018. The PICOS strategy was used to develop the inclusion criteria. The analysis in each study was performed primarily using single nucleotide polymorphism (SNP) frequency mean values and odds ratios between cases and controls. A total of 3301 patients were enrolled in the 15 included studies (two genome-wide association studies, n = 1877; 10 candidate gene studies, n = 1195; three whole genome/whole exome studies, n = 229). Multiple myeloma was the most prevalent primary disease (54.8%). Zoledronate was prescribed in 68.8% of patients. No one SNP was definitively identified as a risk factor for the development of MRONJ. To date, studies have failed to show a single gene as a risk factor for MRONJ. Heterogeneity of case and control populations may be contributory. Next generation sequencing studies may help elucidate the role and interplay of genetic events in the development of MRONJ.

Uncommon presentation of medication-related osteonecrosis of the mandible in a patient with metastatic prostate cancer

An 82-year-old man with a background of prostate carcinoma and bony metastases presented with bilateral discharging neck fistulae. Two years prior to presentation, the patient had been treated with intravenous zoledronic acid for 1 year as part of chemotherapy. Intraoral examination revealed extensive bilateral medication-related osteonecrosis, with orocutaneous fistulae within the neck. Treatment comprised removal of loose necrotic bone sequestrae, debridement of the fistulae and long-term administration of antibiotics, vitamin E and pentoxifylline. Four weeks later, the orocutaneous fistulae had healed.