Association between CDK4/6 inhibitors and drug-related osteonecrosis of the jaw: A pharmacoepidemiological study using the FDA Adverse Events Reporting System.

The most common toxicities associated with cyclin-dependent kinase (CDK) 4/6 inhibitor therapy include decreased leukopenia and neutropenia due to the inhibition of CDK6 of leukocyte and neutrophil precursors in bone marrow. These hematological toxicities are more commonly observed with palbociclib administration than with abemaciclib administration, which is approximately 13 times more selective against CDK4 than CDK6. Thus, even though both successfully inhibit CDK4/6, the side effects of palbociclib and abemaciclib differ due to differences in selectivity. Recent reports have suggested an association between palbociclib and medication-related osteonecrosis of the jaw; however, reports on this association are inconsistent. This study investigated the potential association of palbociclib and abemaciclib with MRONJ using the FAERS. Signals of "Osteonecrosis of jaw" were detected only in females using palbociclib (cROR025: 2.08). Other signals detected included stomatitis-related adverse events with abemaciclib and intraoral soft tissue damage and infection with palbociclib. As previous exploratory studies have reported MRONJ signals for bisphosphonates and denosumab, we calculated the aROR for palbociclib-induced osteonecrosis of the jaw using concomitant bisphosphonates and denosumab as covariates. A signal was detected even after adjusting for sex, age, and concomitant medications as covariates (aROR0025: 5.74). A proper understanding of the differences in CDK selectivity is necessary for the appropriate use of CDK4/6 inhibitors. To the best of our knowledge, this is the first report on CDK4/6 inhibitors and drug-related osteonecrosis of the jaw. We believe that these results will offer new insights into adverse events related to the use of CDK4/6 inhibitors, and may aid in the proper use of CDK4/6 inhibitors.

Osteonecrosis of the jaw after radiation followed by bevacizumab.

Osteonecrosis of the jaw is a recognized complication associated with bevacizumab. Here, we present a patient with squamous cell carcinoma of the tonsil who experienced minimal skin fibrosis following intensity-modulated radiation therapy. Subsequently, the patient developed rectal adenocarcinoma and encountered osteonecrosis of the jaw after receiving two cycles of bevacizumab. Close monitoring, accompanied by thorough examination to detect early signs of osteonecrosis of the jaw, should be considered for patients who have undergone radiation therapy in the head and neck region and are receiving bevacizumab or other medications known to be associated with osteonecrosis of the jaw.

[Medication-related osteonecrosis of the jaws associated with the use of bone-modifying agents]. / Medikamentoznyi osteonekroz chelyustei, svyazannyi s priemom osteomodifitsiruyushchikh preparatov.

The relevance of the study is associated with the widespread use of osteomodifying agents in patients with bone metastases and osteoporosis. Bisphosphonates and other osteo-modifying agents are widely used in oncology and prevention of age-related changes in the human bone system. The use, therapeutic effects and complications of therapy with osteo modifying agents are being investigated all over the world. However, the etiology and pathogenesis of drug-induced osteonecrosis of the jaws (MONCH) have not been fully studied, in this regard, the study of risk factors and mechanisms of its development remains relevant. New data on the etiology and pathogenesis of drug-induced osteonecrosis are presented. The literature review is carried out on the electronic resource PubMed.

Osteonecrosis of the jaw: a rare but possible side effect in thyroid cancer patients treated with tyrosine-kinase inhibitors and bisphosphonates.

Osteonecrosis of the jaw (ONJ) is a rare but very serious disease that can affect both jaws. It is defined as exposed bone in the maxillofacial region that does not heal within 8 weeks after a health care provider identification. ONJ can occur spontaneously or can be due to drugs like bisphosphonates (BPS) and anti-RANK agents, in patients with no history of external radiation therapy in the craniofacial region. Although in phase 3 trials of tyrosine kinase inhibitors (TKIs) used in thyroid cancer (TC) the ONJ was not reported among the most common side effects, several papers reported the association between ONJ and TKIs, both when they are used alone and in combination with a bisphosphonate. The appearance of an ONJ in a patient with metastatic radio-iodine refractory differentiated TC, treated with zoledronic acid and sorafenib, has put us in front of an important clinical challenge: when a ONJ occurred during TKIs treatment, it really worsens the patients' quality of life. We should consider that in the case of ONJ a TKI discontinuation becomes necessary, and this could lead to a progression of neoplastic disease. The most important aim of this review is to aware the endocrinologists/oncologists dealing with TC to pay attention to this possible side effect of BPS and TKIs, especially when they are used in association. To significantly reduced the risk of ONJ, both preventive measures before initiating not only antiresorptive therapy but also antiangiogenic agents, and regular dental examinations during the treatment should always be proposed.

[Osteonecrosis of the jaws]. / Osteonecrosis de los maxilares asociada a medicamentos: revisión de la literatura y propuesta para la prevención y manejo.

Medication-related osteonecrosis of the jaw is a disease where there is necrotic bone exposed or that can be explored by means of a fistula in the maxillofacial region. It has been associated with the use Biphosphonates and denosumab for osteoporosis. Although its etiology is unclear, it may be related to a decrease in bone turnover produced by these drugs, rendering the bone more prone to generate cell necrosis during invasive dental procedures, especially in the posterior region of the jaw. There is no consensus about the prevention and treatment of this condition. The aim of this paper is to present a review of the literature with the main characteristics of osteonecrosis of the jaws associated with drugs, together with a proposal for prevention and treatment for these patients.

Removal of Pre-Existing Periodontal Inflammatory Condition before Tooth Extraction Ameliorates Medication-Related Osteonecrosis of the Jaw-Like Lesion in Mice.

Medication-related osteonecrosis of the jaw (MRONJ) is a rare but detrimental intraoral lesion that predominantly occurs in patients with long-term use of antiresorptive agents, such as bisphosphonate and denosumab, a human anti-receptor activator of NF-κB ligand (RANKL) monoclonal antibody (Ab). Surgical intervention, such as tooth extraction, is a known risk factor for MRONJ, which is often performed to eliminate preexiting pathologic inflammatory conditions, such as periodontal diseases. Nonetheless, it remains unknown whether pre-existing periodontal disease condition exacerbates, or removal of such condition ameliorates, MRONJ development after tooth extraction. In this study, we combined the ligature-induced periodontitis and the tooth extraction mouse models under the administration of zoledronic acid (ZOL) or anti-RANKL Ab, and provide experimental evidence that a pre-existing pathologic inflammatory condition exacerbates MRONJ development after tooth extraction in mice. Under ZOL administration, tooth extraction alone induced ONJ lesions; however, extraction of a ligature-placed tooth further exacerbated ONJ development. When the ligature was removed and the inflammatory condition was deescalated, ONJ development was ameliorated. Anti-RANKL Ab administration resulted in similar outcomes. Interestingly, unlike ZOL-administered mice, anti-RANKL Ab-administered mice exhibited complete absence of osteoclasts, suggesting that physical presence of osteoclasts is not directly involved in ONJ development. Collectively, our study demonstrated that periodontal disease is a functionally linked risk factor that predisposes ONJ development after tooth extraction in the presence of bisphosphonate and denosumab.

Interventions for preventing osteoradionecrosis of the jaws in adults receiving head and neck radiotherapy.

BACKGROUND: Osteoradionecrosis (ORN) of the jaws is among the most serious oral complications of head and neck cancer radiotherapy, arising from radiation-induced fibro-atrophic tissue injury, manifested by necrosis of osseous tissues and failure to heal, often secondary to operative interventions in the oral cavity. It is associated with considerable morbidity and has important quality of life ramifications. Since ORN is very difficult to treat effectively, preventive measures to limit the onset of this disease are needed; however, the effects of various preventive interventions has not been adequately quantified. OBJECTIVES: To assess the effects of interventions for preventing ORN of the jaws in adult patients with head and neck cancer undergoing curative or adjuvant (i.e. non-palliative) radiotherapy. SEARCH METHODS: Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 5 November 2019), the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 10) in the Cochrane Library (searched 5 November 2019), MEDLINE Ovid (1946 to 5 November 2019), Embase Ovid (1980 to 5 November 2019), Allied and Complementary Medicine (AMED) Ovid (1985 to 5 November 2019), Scopus (1966 to 5 November 2019), Proquest Dissertations and Theses International (1861 to 5 November 2019) and Web of Science Conference Proceedings (1990 to 5 November 2019). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: We selected randomised controlled trials (RCTs) or quasi-RCTs of adult patients 18 years or older with head and neck cancer who had undergone curative or adjuvant radiotherapy to the head and neck, who had received an intervention to prevent the onset of ORN. Eligible patients were those subjected to pre- or post-irradiation dental evaluation. Management of these patients was to be with interventions independent of their cancer therapy, including but not limited to local, systemic, or behavioural interventions. DATA COLLECTION AND ANALYSIS: Two review authors independently selected trials from search results, assessed risk of bias, and extracted relevant data for inclusion in the review. Authors of included studies were contacted to request missing data. We used standard methodological procedures expected by Cochrane. MAIN RESULTS: Four studies were identified that met pre-determined eligibility criteria, evaluating a total of 342 adults. From the four studies, all assessed as at high risk of bias, three broad interventions were identified that may potentially reduce the risk of ORN development: one study showed no reduction in ORN when using platelet-rich plasma placed in the extraction sockets of prophylactically removed healthy mandibular molar teeth prior to radiotherapy (odds ratio (OR) 3.32, 95% confidence interval (CI) 0.58 to 19.09; one trial, 44 participants; very low-certainty evidence). Another study involved comparing fluoride gel and high-content fluoride toothpaste (1350 parts per million (ppm)) in prevention of post-radiation caries, and found no difference between their use as no cases of ORN were reported (one trial, 220 participants; very low-certainty evidence). The other two studies involved the use of perioperative hyperbaric oxygen (HBO) therapy and antibiotics. One study showed that treatment with HBO caused a reduction in the development of ORN in comparison to patients treated with antibiotics following dental extractions (risk ratio (RR) 0.18, 95% CI 0.43 to 0.76; one trial, 74 participants; very low-certainty evidence). Another study found no difference between combined HBO and antibiotics compared to antibiotics alone prior to dental implant placement (RR 3.00, 95% CI 0.14 to 65.16; one trial, 26 participants; very low-certainty evidence). Adverse effects of the different interventions were not reported clearly or were not important. AUTHORS' CONCLUSIONS: Given the suboptimal reporting and inadequate sample sizes of the included studies, evidence regarding the interventions evaluated by the trials included in this review is uncertain. More well-designed RCTs with larger samples are required to make conclusive statements regarding the efficacy of these interventions.

[Diagnostic value of chromato-mass-spectrometry in patients with drug-induced jaws osteonecrosis]. / Kliniko-diagnosticheskoe znachenie khromato-mass-spektrometrii pri medikamentoznom osteonekroze cheliustei.

In patients with drag-induced jaw osteonecrosis which developed in cancer patients due to administration of bisphosphonates for metastases, the microflora of the oral cavity was examined by chromatography-mass spectrometry (HMS). The method of HMS can be used as an additional method of diagnostics in complex clinical cases with ineffective treatment.

Current Understanding of the Pathophysiology of Osteonecrosis of the Jaw.

PURPOSE OF REVIEW: Osteonecrosis of the jaw (ONJ) is a rare and severe necrotic bone disease reflecting a compromise in the body's osseous healing mechanisms and unique to the craniofacial region. Antiresorptive and antiangiogenic medications have been suggested to be associated with the occurrence of ONJ; yet, the pathophysiology of this disease has not been fully elucidated. This article raises the current theories underlying the pathophysiology of ONJ. RECENT FINDINGS: The proposed mechanisms highlight the unique localization of ONJ. The evidence-based mechanisms of ONJ pathogenesis include disturbed bone remodeling, inflammation or infection, altered immunity, soft tissue toxicity, and angiogenesis inhibition. The role of dental infections and the oral microbiome is central to ONJ, and systemic conditions such as rheumatoid arthritis and diabetes mellitus contribute through their impact on immune resiliency. Current experimental studies on mechanisms of ONJ are summarized. The definitive pathophysiology is as yet unclear. Recent studies are beginning to clarify the relative importance of the proposed mechanisms. A better understanding of osteoimmunology and the relationship of angiogenesis to the development of ONJ is needed along with detailed studies of the impact of drug holidays on the clinical condition of ONJ.

Changes in dimension of neurovascular canals in the mandible and maxilla: A radiographic finding in patients diagnosed with MRONJ.

BACKGROUND: The aim of this retrospective study was to compare the morphological features of neurovascular canals and foramina of patients with medication-related osteonecrosis of the jaws (MRONJ) and healthy individuals by using cone beam computed tomography (CBCT). MATERIAL AND METHODS: The CBCT images of 58 patients under bisphosphonate therapy diagnosed with MRONJ and age gender- matched controls were retrospectively evaluated. The diameter of mandibular and nasopalatine canal and mandibular, mental and lingual foramina were measured on several sections of CBCT. The value of mental index (MI) and panoramic mandibular index (PMI) were also assessed. RESULTS: The mean value of diametric measurements for all neurovascular canals and foramina in MRONJ patients were narrower than controls. Left mandibular foramen was the most affected area (p<0.001). There were significantly difference in all measurements of mental foramen, lingual foramen and mandibular incisive canal between two groups (p<0.05). PMI of MRONJ subjects were also significantly differences in both sides (p<0.05). CONCLUSION: In MRONJ patient, neurovascular canals and foramina are affected due to the alterations in bone remodeling. Therefore, the diametric measurement of neurovascular canals and assessment of MI and PMI on CBCT, is a potentially useful method for detection of early changes associated with bisphosphonate therapy and for predict areas where new necrosis may occur.

Influence of Japanese Regulatory Action on Denosumab-Related Hypocalcemia Using Japanese Adverse Drug Event Report Database.

The anti-receptor activator of nuclear factor kappa-B ligand (RANKL) antibody, Denosumab (DEN), was approved in April 2012 in Japan, but a Dear Healthcare Professional Letter of Rapid Safety Communication was released in September, 2012 by the regulatory authority because of the severe hypocalcemia risks. Currently, the effectiveness of this regulatory action has not been evaluated and, therefore, this study aimed to assess its impact on DEN-induced hypocalcemia using the Japanese Adverse Drug Event Report database (JADER). The case reports from April 2012 to September 2014 were collected from the JADER, which included 151642 adverse events for the primary suspected drugs. The reporting odds ratio (ROR) of hypocalcemia as a signal of the target adverse event was analyzed for DEN and zoledronic acid (ZOL, a reference drug). Changes in RORs were compared between the pre- (Pre, April 2012 to September 2012) and post- (Post 1, October 2012 to September 2013 and Post 2, October 2013 to September 2014) periods of the regulatory action. A decrease in the hypocalcemia ROR was observed for DEN in the post-periods, especially Post 2. Multivariate logistic regression analysis showed a significant decrease in hypocalcemia signal in Post 1 (p=0.0306 vs. Pre) and Post 2 (p=0.0054 vs. Pre). ZOL caused no significant changes in ROR of hypocalcemia, and none of the drugs caused ROR changes in jaw osteonecrosis (a reference adverse event). This study suggests that the regulatory action against hypocalcemia in DEN effectively decreased hypocalcemia signal. Further studies using medical information databases are needed to confirm this result.

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, the occurrence of this adverse drug reaction may be rare (e.g. following the oral administration of bisphosphonate or denosumab treatments for osteoporosis, or antiangiogenic agent-targeted cancer treatment) or common (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. 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 the following databases: Cochrane Oral Health's Trials Register (to 23 November 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2016, Issue 10), MEDLINE Ovid (1946 to 23 November 2016), and Embase Ovid (23 May 2016 to 23 November 2016). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on language or publication status when searching the electronic databases; however, the search of Embase was restricted to the last six months due to the Cochrane Embase Project to identify all clinical trials and add them to CENTRAL. 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 (CI). MAIN RESULTS: We included five RCTs (1218 participants) in the review. Three trials focused on the prophylaxis of MRONJ. Two trials investigated options for the treatment of established MRONJ. The RCTs included only participants treated with bisphosphonates and, thus, did not cover the entire spectrum of medications associated with MRONJ. Prophylaxis of MRONJOne trial compared standard care with regular dental examinations in 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; low-quality evidence). Secondary outcomes were not evaluated.As dentoalveolar surgery is considered a common predisposing event for developing MRONJ, one trial investigated the effect of plasma rich in growth factors (PRGF) for preventing MRONJ in people with cancer undergoing dental extractions. There was insufficient evidence to support or refute a benefit of PRGF on MRONJ incidence when compared with standard treatment (RR 0.08, 95% CI 0.00 to 1.51; 176 participants; very low-quality evidence). Secondary outcomes were not reported. In another trial comparing wound closure by primary intention with wound closure by secondary intention after dental extractions in people treated with oral bisphosphonates (700 participants), no cases of intraoperative complications or postoperative MRONJ were observed. QoL was not investigated. Treatment of MRONJOne trial analysed hyperbaric oxygen (HBO) treatment used in addition to standard care (antiseptic rinses, antibiotics, and surgery) compared with standard care alone. HBO in addition to standard care did not significantly improve healing from MRONJ compared with standard care alone (at last follow-up: RR 1.56; 95% CI 0.77 to 3.18; 46 participants included in the analysis; very low-quality evidence). QoL data were presented qualitatively as intragroup comparisons; hence, an effect estimate of treatment on QoL was not possible. Other secondary outcomes were not reported.The other RCT found no significant difference between autofluorescence- and tetracycline fluorescence-guided sequestrectomy for the surgical treatment of MRONJ at any timepoint (at one-year follow-up: RR 1.05; 95% CI 0.86 to 1.30; 34 participants included in the analysis; very low-quality evidence). Secondary outcomes were not reported. AUTHORS' CONCLUSIONS: Prophylaxis of MRONJOne open-label RCT provided some evidence that dental examinations in three-month intervals and preventive treatments may be more effective than standard care for reducing the incidence of MRONJ in individuals taking intravenous bisphosphonates for advanced cancer. We assessed the certainty of the evidence to be low.There is insufficient evidence to either claim or refute a benefit of either of the interventions tested for prophylaxis of MRONJ (i.e. PRGF inserted into the postextraction alveolus during dental extractions, and wound closure by primary or secondary intention after dental extractions). Treatment of MRONJAvailable evidence is insufficient to either claim or refute a benefit for hyperbaric oxygen therapy as an adjunct to conventional therapy. There is also insufficient evidence to draw conclusions about autofluorescence-guided versus tetracycline fluorescence-guided bone surgery.

Preventive Effect of Phosphodiesterase Inhibitor Pentoxifylline Against Medication-Related Osteonecrosis of the Jaw: An Animal Study.

PURPOSE: The aim of this experimental study was to investigate the prophylactic effect of pentoxifylline (PTX) on medication-related osteonecrosis of the jaw (MRONJ). MATERIALS AND METHODS: Female Sprague-Dawley rats (n = 33) received zoledronic acid (ZA) for 8 weeks to create an osteonecrosis model. The left mandibular second molars were extracted and the recovery period lasted 8 weeks before sacrifice. PTX was intraperitoneally administered to prevent MRONJ. The specimens were histopathologically and histomorphometrically evaluated. RESULTS: Histomorphometrically, between the control and ZA groups, there was no statistically significant difference in total bone volume (P = .999), but there was a statistically significant difference in bone ratio in the extraction sockets (P < .001). A comparison of the bone ratio of the ZA group with the ZA/PTX group (PTX administered after extraction) showed no statistically significant difference (P = .69), but there was a statistically significant difference with the ZA/PTX/PTX group (PTX administered before and after extraction; P = .008). Histopathologically, between the control and ZA groups, there were statistically significant differences for inflammation (P = .013), vascularization (P = .022), hemorrhage (P = .025), and regeneration (P = .008). Between the ZA and ZA/PTX groups, there were no statistically significant differences for inflammation (P = .536), vascularization (P = .642), hemorrhage (P = .765), and regeneration (P = .127). Between the ZA and ZA/PTX/PTX groups, there were statistically significant differences for inflammation (P = .017), vascularization (P = .04), hemorrhage (P = .044), and regeneration (P = .04). CONCLUSION: In this experimental model of MRONJ, it might be concluded that although PTX, given after tooth extraction, improves new bone formation that positively affects bone healing, it is not prophylactic. However, PTX given before tooth extraction is prophylactic. Therefore, PTX might affect healing in a positive way by optimizing the inflammatory response.

Osteonecrosis of the Jaw in a Patient Presenting With Post-Transplantation Lymphoproliferative Disorder Treated With Rituximab: A Case Report.

Osteonecrosis of the jaw (ONJ) is a rare but potentially severe condition that can be induced by specific treatments. We report the case of a 69-year-old male kidney transplant recipient who presented with ONJ 5 years after transplantation. The patient presented with ulcerations of the oral mucosa related to post-transplantation lymphoproliferative disorder, which was treated with rituximab. Subsequently, ONJ developed. Although rituximab treatment cannot be firmly established as the cause of this condition, similar cases of ONJ have been reported after treatment with this monoclonal antibody. This case raises a potential link between rituximab treatment and ONJ and prompts further studies to investigate the potential impact of rituximab on bone angiogenesis.

The assessment of surgical and non-surgical treatment of stage II medication-related osteonecrosis of the jaw.

BACKGROUND: Non-surgical treatment has generally been recommended for stage II medication-related osteonecrosis of the jaw (MRONJ) in preference to surgery. However, non-surgical treatment is not empirically effective. The aim of this study was to evaluate whether surgical or non-surgical treatment leads to better outcomes for stage II MRONJ. MATERIAL AND METHODS: In this retrospective study, surgery was performed in a total of 28 patients while 24 patients underwent non-surgical treatment. The outcomes of both treatment approaches after 6 months were evaluated and statistically compared. In addition, risk factors for surgical and non-surgical treatments were assessed for each. RESULTS: Surgical treatment in 25 patients (89.3%) resulted in success, with failure in 3 patients (10.7%). Non-surgical treatment was successful for 8 patients (33.3%) and failed in 16 patients (66.7%). There was therefore a significant difference between surgical and non-surgical treatment outcomes (P<0.01). Regarding risk factors, in non-surgical treatment primary diseases, medications, and drug holiday had a significant effect on outcomes (P<0.01). Risk factors for surgical treatment could not be clarified. CONCLUSIONS: Surgical treatment is more effective than non-surgical treatment for stage II MRONJ, and drug holiday, primary disease, and medication constitute risk factors in non-surgical treatment.

[Drug-induced osteonecrosis of the jaw - not just bisphosphonates].

Metastatic bone disease and osteoporosis have a large impact on quality of life and are associated with the development of skeletal-related events (SREs), such as fractures and spinal cord compression. Pharmacologic managing of metastatic bone disease and osteoporosis typically involves antiresorptive agents such as bisphosphonates and RANKL inhibitors. Undesired adverse effects resulting from the use of these drugs include osteonecrosis of the jaw (ONJ). Dentoalveolar surgery, particularly tooth extraction, appears to increase the risk of ONJ. However, spontaneous events were also documented. Therefore, it is of upmost importance for the general practitioner to have updated knowledge in order to prevent and early diagnose ONJ. We present a case of a metastatic breast cancer patient who spontaneously developed ONJ following the use of Denosumab, a monoclonal RANKL antibody.

Modified protocol including topical minocycline in orabase to manage medication-related osteonecrosis of the jaw cases.

OBJECTIVE: Management of medication-related osteone-crosis of the jaw (MRONJ) with active infection can be a serious challenge for clinicians. Based on Association of Oral and Maxillofacial Surgeons (AAOMS) recommendations, we have tested a modified treatment protocol using topical minocycline. STUDY DESIGN: Five patients diagnosed with stage II or III MRONJ lesions were willing to consent to our protocol. In addition to conventional treatment as suggested by the AAOMS, such as, surgical debridement, chlorhexidine irrigation, and systemic antibiotics, we applied 10% minocycline to the lesions once a week for sustained local antibiotic delivery. RESULTS: All five patients reported pain relief after the first minocycline application. Complete healing occurred in three patients; case three healed completely after the third application, one case continues to improve toward resolution and one withdraws due to other non-relevant medical problem. CONCLUSIONS: In this study, we are reporting favorable results using a modified protocol with topical minocycline to treat MRONJ lesions.

Bisphosphonate and Medication-Related Osteonecrosis of the Jaw: A Review.

For patients with malignant disease taking bisphosphonates and denosumab, the incidence of medication-related osteonecrosis of the jaw (MRONJ) is up to 15% in contrast to 0.01% in patients with osteoporosis. Clinical presentation of MRONJ extends from asymptomatic exposure of bone in 94% of patients to severe cases of mandibular fractures in a minority of 4.5%. The strongest risk factors for MRONJ are invasive dental procedures and dental infections. Advances in imaging provide more preoperation information compared with panoramic radiograph. Prevention strategies are the elimination of potential risk factors leading to invasive dental procedures and maintenance of good oral hygiene prior to the administration of antiresorptive agents. Management of MRONJ depends on the underlying disease, extent of the necrosis, and the presence of contributing therapy. Conservative therapies include topical anti-infective rinses and systemic antibiotic therapy. The most important part of surgical therapy is to remove the exposed and necrotic bone. Several options for defect closure are possible from local tissue flaps to microvascular free flap procedures. The development of MRONJ in conjunction with dental implants is a severe side effect and should be avoided if potentially harmful medication has already been administered.

Role of microcracks in the pathogenesis of bisphosphonate-related osteonecrosis of the jaw.

OBJECTIVES: The aim of this study was to investigate the potential role of microcrack accumulation in the pathogenesis of bisphosphonate-related osteonecrosis of the jaw (ONJ) through an animal model. MATERIALS AND METHODS: Twenty-four ovariectomized rats were randomly divided into a bisphosphonate group (n = 19) and control group (n = 5) and weekly injected with zoledronic acid and normal saline, respectively. After 6 weeks, surgical intervention was performed, and the injections were continued for eight additional weeks. Then, the animals were sacrificed, and ONJ lesions were inspected for the presence of microcracks using scanning electron microscopy. Measurements included bone dimension, number of cracks, crack length, and normalized indices; crack density (Cr.Dn) and crack surface density (Cr.S.Dn) were used for group comparison. RESULTS: Both number of cracks and crack length in the bisphosphonate group were greater than those in the control group (P < 0.05). Of the 19 rats injected with bisphosphonates, 13 rats (68.4 %) were classified into the ONJ group. Cr.Dn and Cr.S.Dn were significantly greater in the ONJ group than in the non-ONJ group, indicating accumulation of unrepaired microcracks (P < 0.05). Seventy-two percent of microcracks in the ONJ group conformed to the defined length that was considered significant according to a previous literature (30-80 µm); whereas 12 % of microcracks in the non-ONJ group were considered significant (P < 0.05). CONCLUSION: Accumulation of unrepaired microcracks was significantly associated with the development of bisphosphonate-related ONJ. Further research is required to determine the role of microcracks in the pathogenesis of bisphosphonate-related ONJ. CLINICAL RELEVANCE: Long-term bisphosphonates use may deteriorate the biomechanical and physiological bone integrity, contributing to the pathogenesis of bisphosphonate-related ONJ.

Prevention of medication-related osteonecrosis of the jaws secondary to tooth extractions. A systematic review.

BACKGROUND: A study was made to identify the most effective protocol for reducing the risk of osteonecrosis of the jaws (ONJ) following tooth extraction in patients subjected to treatment with antiresorptive or antiangiogenic drugs. MATERIAL AND METHODS: A MEDLINE and SCOPUS search (January 2003 - March 2015) was made with the purpose of conducting a systematic literature review based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. All articles contributing information on tooth extractions in patients treated with oral or intravenous antiresorptive or antiangiogenic drugs were included. RESULTS: Only 13 of the 380 selected articles were finally included in the review: 11 and 5 of them offered data on patients treated with intravenous and oral bisphosphonates, respectively. No randomized controlled trials were found - all publications corresponding to case series or cohort studies. The prevalence of ONJ in the patients treated with intravenous and oral bisphosphonates was 6,9% (range 0-34.7%) and 0.47% (range 0-2.5%), respectively. The main preventive measures comprised local and systemic infection control. CONCLUSIONS: No conclusive scientific evidence is available to date on the efficacy of ONJ prevention protocols in patients treated with antiresorptive or antiangiogenic drugs subjected to tooth extraction.