Relevant factors for treatment outcome and time to healing in medication-related osteonecrosis of the jaws - A retrospective cohort study

What Affects Healing Rates in Patients Treated for Medication-Related Osteonecrosis of the Jaw? The Role of Operative Therapy and Other Clinical Factors

BACKGROUND

In the therapy of medication-related osteonecrosis of the jaw (MRONJ), the healing rate, effectiveness of operative therapy, and factors associated with healing remain unclear.

PURPOSE

This study aimed to estimate MRONJ therapy healing rates and identify associated prognostic factors.

STUDY DESIGN, SETTING, SAMPLE

A 25-center prospective cohort study was conducted on 291 patients with MRONJ treated with a common therapeutic protocol during 2013-2016. Patients unable to continue examinations or treatment were excluded.

PREDICTOR VARIABLE

The primary predictor variable was MRONJ therapy grouped into two categories: operative and nonoperative. Secondarily, the prognostic factors categorized as demographic, medical, clinical, and perioperative were evaluated.

MAIN OUTCOME VARIABLES

The primary outcome variable was treatment duration, defined as the time (in months) between the initiation of therapy and when the site was healed or the date of the final visit or loss to follow-up.

COVARIATES

Not applicable.

ANALYSES

Descriptive statistics and 3-year cumulative healing rates were calculated. The association between clinical factors and time to healing was analyzed using bivariate and multivariate analyses and propensity score analysis. P < .05 was considered significant.

RESULTS

We analyzed data from 291 subjects with 76 (26.1%) and 215 (73.9%) subjects in the operative and nonoperative therapy groups, respectively. The healing rates for operative and nonoperative therapies were 95.8 and 70.7%, respectively (hazard ratio [HR] = 1.6, 95% confidence interval [CI] = 1.1-2.2, P value [P] < .01). The healing rates in patients for whom anti-resorptive agent (ARA) treatment was discontinued and continued were 87.2 and 37.4%, respectively (HR = 1.8, 95% CI = 1.1-3.0, P = .02). In a multiple regression analysis using ARA indication, the therapy method showed a significant association in the MRONJ malignancy group (HR = 2.75, 95% CI = 1.46-5.17, P < .01).

CONCLUSION AND RELEVANCE

Operative therapy and ARA discontinuation were associated with better healing rates in MRONJ therapy. However, the choice of therapy for MRONJ should be based on a comprehensive consideration of the patient's condition. ARA discontinuation should be considered an adjunctive measure because of the possibility of adverse events such as fragility fractures and skeletal related events.

Platelet-Rich Fibrin Treatment Evaluation in Patients with Medication-Related Osteonecrosis of the Jaw and Osteoradionecrosis

Background. Medication-related osteonecrosis of the jaw (MRONJ) and osteoradionecrosis (ORN) are associated with severe disability and continuous pain, both of which are very difficult to control. This study aims to evaluate the outcome of platelet-rich fibrin (PRF) treatment compared to iodoform gauze packing and the primary suture of oral mucosa in patients with both MRONJ and ORN. Methods. Patients suffering from MRONJ and ORN who were treated in the Oral and Maxillofacial Surgery Clinic of Cluj-Napoca in the last 10 years were selected for this study from the hospital database. Results. PRF treatment proved to be a reliable method to help heal the necrotic bone sites. High-ASA risk patients and immunosuppressed patients are more prone to recurrence and persistent signs and symptoms. Intravenous bisphosphonates produce more intense symptomatology compared to oral administration. The posterior mandible is more difficult to treat compared to other sites. Conclusions. The quality of life of MRONJ and ORN patients may be improved by a protocol that reduces pain and hospitalization.

Treatment outcomes and time to healing of medication-related osteonecrosis of the jaw based on image findings

OBJECTIVES

This study aimed to evaluate the prognostic treatment outcome of non-operative management of medication-related osteonecrosis of the jaw (MRONJ), particularly regarding the relationship between image findings and treatment outcomes.

METHODS

This single-center, retrospective observational study included patients with MRONJ who were conservatively treated between 2010 and 2020. All patients were evaluated in terms of MRONJ treatment outcomes, time to healing, and prognostic factors, including sex, age, underlying disease, antiresorptive drug type, discontinuation of antiresorptive treatment, chemotherapy, corticosteroid treatment, diabetes mellitus, location of MRONJ, clinical stage of MRONJ, and computed tomography image findings.

RESULTS

The complete healing rate among the patients was 68.5%. Cox proportional hazards regression analysis revealed that "Sequestrum formation" on the internal texture (hazard ratio = 3.66; 95% confidence interval, 1.30-10.29; P =.014) and chemotherapy (hazard ratio = 0.41; 95% confidence interval, 0.18-0.95; P =.037) were significantly associated with treatment outcome. The median time to healing in patients with "Sequestrum formation" on the internal texture (4.4 months) was significantly shorter than the median time to healing in those marked with "Sclerosis" or "Normal" (35.5 months; P <.001) and "Lytic changes with sclerosis" (14.5 months; P =.015).

CONCLUSIONS

The image findings on the internal texture of the lesions at the initial examination and chemotherapy were associated with the treatment outcomes of nonoperative management of MRONJ. The image findings of "Sequestrum formation" were associated with lesions taking a short time to heal and better outcomes, whereas "Sclerosis" and "Normal" were associated with lesions with longer healing times.

Osteonecrosis of the Jaw and Antiresorptive Agents in Benign and Malignant Diseases: A Critical Review Organized by the ECTS

CONTEXT

Antiresorptive therapy significantly reduces fracture risk in patients with benign bone disease and skeletal-related events (SREs) in patients with bone metastases (BM). Osteonecrosis of the jaw (ONJ) is a rare but severe condition manifested as necrotic bone lesion or lesions of the jaws. ONJ has been linked to the use of potent antiresorptive agents, termed medication-related ONJ (MRONJ).

OBJECTIVE

We aimed to identify the differences various aspects of MRONJ among distinct patient categories and provide recommendations on how to mitigate the risk and optimally manage MRONJ in each of them.

METHODS

A working group of the European Calcified Tissue Society (ECTS) and 2 experts performed an updated detailed review of existing literature on MRONJ incidence, characteristics, and treatment applied in bone diseases with variable severity of skeletal insult, ranging from osteoporosis to prevention of cancer treatment-induced bone loss and SREs in cancer patients with BM.

RESULTS

The risk for MRONJ is much higher in patients with advanced malignancies compared to those with benign bone diseases because of the higher doses and more frequent administration of antiresorptive agents in individuals with compromised general health, along with coadministration of other medications that predispose to MRONJ. The overall risk for MRONJ is considerably lower than the benefits in all categories of patients.

CONCLUSION

The risk for MRONJ largely depends on the underlying bone disease and the relevant antiresorptive regimen applied. Physicians and dentists should keep in mind that the benefits of antiresorptive therapy far outweigh the risk for MRONJ development.

Indigenous microbiota protects development of medication-related osteonecrosis induced by periapical disease in mice

Bacterial infection is a common finding in patients, who develop medication-related osteonecrosis of the jaw (MRONJ) by the long-term and/or high-dose use of anti-resorptive agents such as bisphosphonate (BPs). However, pathological role of bacteria in MRONJ development at the early stage remains controversial. Here, we demonstrated that commensal microbiota protects against MRONJ development in the pulp-exposed periapical periodontitis mouse model. C57/BL6 female mice were treated with intragastric broad-spectrum antibiotics for 1 week. Zoledronic acid (ZOL) through intravenous injection and antibiotics in drinking water were administered for throughout the experiment. Pulp was exposed on the left maxillary first molar, then the mice were left for 5 weeks after which bilateral maxillary first molar was extracted and mice were left for additional 3 weeks to heal. All mice were harvested, and cecum, maxilla, and femurs were collected. ONJ development was assessed using μCT and histologic analyses. When antibiotic was treated in mice, these mice had no weight changes, but developed significantly enlarged ceca compared to the control group (CTL mice). Periapical bone resorption prior to the tooth extraction was similarly prevented when treated with antibiotics, which was confirmed by decreased osteoclasts and inflammation. ZOL treatment with pulp exposure significantly increased bone necrosis as determined by empty lacunae and necrotic bone amount. Furthermore, antibiotics treatment could further exacerbate bone necrosis, with increased osteoclast number. Our findings suggest that the commensal microbiome may play protective role, rather than pathological role, in the early stages of MRONJ development.

Is teriparatide therapy effective for medication-related osteonecrosis of the jaw? A systematic review and meta-analysis

Considering the lack of studies determining the real TPTD efficacy in individuals who develop MRONJ, our objective was to combine the available data on MRONJ cases treated with TPTD. The findings demonstrated that TPTD in combination with another therapy, especially antibiotic therapy, can be considered an effective protocol for MRONJ.

PURPOSE

To integrate the data published on the effect of teriparatide (TPTD) therapy on cases of medication-related osteonecrosis of the jaws (MRONJ) into a comprehensive analysis of clinical features.

METHODS

An electronic search was undertaken in six databases. Descriptive analyses of clinicodemographic data of MRONJ were carried out. Poisson regression was also run to evaluate predictors of total resolution of MRONJ treated with TPTD.

RESULTS

Twenty-six publications comprising 111 cases were included. Most reported cases affected female individuals (82.0%) with a mean age of 76.54 years. Osteoporosis (76.5%) represented the main reason for using antiresorptive drugs, with bisphosphonates (98.1%) as the most frequently reported. Comorbidities were commonly present. The most related trigger factor of MRONJ was dental extraction (61.7%). Mandible (75.8%) was the most commonly affected site, with a mean evolution time of 5 months. MRONJ stage 2 (61.3%) was the most prevalent. Regarding TPTD treatment, in 45.1% cases, TPTD was used alone, with the total resolution being observed in 59.5% of the individuals. Associated therapy (54.9%) included surgery, antibiotic therapy, and laser therapy. Mean follow-up was 8.7 months. Poisson regression demonstrated that individuals with MRONJ stage 1 were 1.21 times more likely to present total resolution of osteonecrosis than individuals with MRONJ stage 3 (CI = 1.02-1.43; p < 0.023). Individuals who had undergone treatment with TPTD in association with another therapeutic modality were 1.21 times more likely to present total resolution of osteonecrosis than those who had undergone treatment with TPTD alone (CI = 1.40-1.39; p < 0.010).

CONCLUSION

TPTD in combination with another therapy, especially antibiotic therapy, should be considered an effective therapeutic modality for MRONJ.

CD34 and CD105 Microvessels in Resected Bone Specimen May Implicate Wound Healing in MRONJ

Clinical treatment outcome of MRONJ (medication-related osteonecrosis of the jaw) surgery despite radical osseous removal and primary closure healing still shows differences in terms of outcome and disease recurrence. The study aims to assess the rate of angiogenesis of MRONJ lesions in order to understand the impact of angiogenesis and neoangiogenesis status on MRONJ surgical treatment outcome. This is the first study correlating microvessel density with prognosis in MRONJ surgically-treated patients. The immunohistochemical expression of CD34 and CD105 in MRONJ specimens obtained from surgically-treated patients was evaluated. The most vascularized areas detected by CD34 and CD105 were selected and the microvessel density value of the samples was registered. Samples were retrospectively divided according to the clinical outcome of MRONJ surgical treatment, dividing patients into two groups, “healed” and “not healed”. Statistical analysis was performed to assess if neovessels could influence treatment outcome in patients undergoing radical surgery. In the examined cohort, this value was highly predictive of better treatment outcome after radical surgery of MRONJ. Understanding of angiogenesis-dependent factors deserves further attention as a future target for MRONJ prevention and therapies.

Analysis of Factors Associated with the Postoperative Healing of Medication-Related Osteonecrosis of the Jaw in Patients with Osteoporosis

BACKGROUND

Surgical treatment is considered the best approach by many researchers for medication-related osteonecrosis of the jaws (MRONJ). While postoperative outcomes are mainly favorable, wound healing still fails in some cases. This retrospective study aimed to evaluate the factors affecting the postoperative healing of MRONJ.

METHODS

This study involved 400 osteoporosis patients who received surgical treatment from January 2009 to January 2018 in Kyungpook National University Hospital. The patient, drug, and clinical factors were collected as investigation variables. The obtained data were statistically analyzed to identify relationships between the factors and healing aspect.

RESULTS

Univariate logistic regression analysis showed that the route of drug administration, bone exposure, types of surgical management, and wound management had a significant influence (p < 0.05) on the healing outcome. Sequestrectomy with primary closure had a more positive effect on favorable healing. In the multivariate logistic regression test, the effect of wound management alone was not statistically significant (p > 0.05).

CONCLUSION

In patients with osteoporosis, the factors such as intravenously administered drugs, fistulas that were probed to the bone, and surgical management with curettage were associated with a lower rate of postoperative complete healing of MRONJ, whereas primary closure of wounds led, possibly, to good healing outcomes. The strengths of the study include its relatively large sample size and that its results can hopefully aid in the clinical decisions for practitioners and future research studies for researchers.

Clinical considerations for medication-related osteonecrosis of the jaw: a comprehensive literature review

Background

Medication-related osteonecrosis of the jaw (MRONJ), which was first reported as bisphosphonate-related osteonecrosis of the jaw (BRONJ) in bisphosphonate users, is a rare but severe soft and hard tissue disease induced by several types of medications. There has been a deluge of information about MRONJ, such as epidemiology, risk factors, clinical recommendations for dental treatment to prevent it, and treatment strategies in medication-prescribed users. The aim of this study was to comprehensively review recent articles and provide the current scientific information about MRONJ, especially clinical considerations or recommendations for dental treatment to prevent its occurrence.

Materials and methods

The current literature review was mainly based on 14 systematic reviews with or without meta-analysis, 4 position papers, 1 consensus statement, 1 clinical guideline, and 2 clinical reviews regarding MRONJ after a PubMed database and manual searches according to inclusion and exclusion criteria. Moreover, 53 articles were selected by manual search in regard to all references from selected articles and other articles identified on the PubMed search, irrespective of publication date, and inclusion and exclusion criteria.

Results

The incidence and prevalence of MRONJ are relatively low, although they are clearly higher in cancer patients receiving high-dose antiresorptive agents or angiogenesis inhibitors rather than osteoporosis patients receiving oral bisphosphonates or denosumab. There are many types of local, systemic, and other risk factors for the development of MRONJ. Clinical recommendations are provided for each clinical situation of patients to prevent MRONJ. There are also treatment strategies for MRONJ in each stage.

Conclusions

General dentists should perform appropriate dental treatment to prevent MRONJ in the patients prior to or when receiving medications that could induce MRONJ. Moreover, there are treatment strategies for MRONJ in each stage that oral surgeons could follow. Adequate and updated clinical information regarding MRONJ based on scientific data is required whenever possible.

Various Therapeutic Methods for the Treatment of Medication-Related Osteonecrosis of the Jaw (MRONJ) and Their Limitations: A Narrative Review on New Molecular and Cellular Therapeutic Approaches

Medication-related osteonecrosis of the jaw (MRONJ) is one of the most interesting diseases in the field of maxillofacial surgery. In addition to bisphosphonates, the use of antiresorptive and antiangiogenic agents is known to be the leading cause. However, the exact pathogenesis of MRONJ has not been established, and various hypotheses have been proposed, such as oxidative stress-related theory. As a result, a definitive treatment protocol for MRONJ has not been identified, while various therapeutic approaches are applied to manage patients with MRONJ. Although the surgical approach to treat osteomyelitis of the jaw has been proven to be most effective, there are limitations, such as recurrence and delayed healing. Many studies and clinical trials are being conducted to develop another effective therapeutic modality. The use of some materials, including platelet concentrates and bone morphogenetic proteins, showed a positive effect on MRONJ. Among them, teriparatide is currently the most promising material, and it has shown encouraging results when applied to patients with MRONJ. Furthermore, cell therapy using mesenchymal stem cells showed promising results, and it can be the new therapeutic approach for the treatment of MRONJ. This review presents various treatment methods for MRONJ and their limitations while investigating newly developed and researched molecular and cellular therapeutic approaches along with a literature review.

Conservative Management of Medication-Related Osteonecrosis of the Jaws (MRONJ): A Retrospective Cohort Study

BACKGROUND

Medication-related osteonecrosis of the jaw (MRONJ) is a severe side effect of bisphosphonates and anti-resorptive drugs prescribed for treatment of severe osteoporosis, Paget's disease, and bone malignancies. The aim of this study was to evaluate the clinical outcome of a combined pharmacological and surgical management strategy on patients affected by MRONJ.

MATERIALS AND METHODS

Medical records of patients with MRONJ were retrospectively examined to collect clinical history data. Conservative management included an initial pharmacological phase with antibiotics and antiseptic agents, followed by surgical intervention to remove bone sequestrum. Primary outcomes were healing from MRONJ at short term (1 month after surgery) and at longer term (3 months after surgery). Secondary outcome was assessment of recurrences at longer-term follow-up.

RESULTS

Thirty-five patients were included in the study with mean follow-up of 23.86 ± 18.14 months. Seven cases showed spontaneous exfoliation of necrotic bone during pharmacological therapy, which in one case did not require any further intervention. At 1-month posttreatment, 31 out of 35 (88.5%) patients showed complete healing. The 25 patients who were followed for at least 3 months revealed a healing rate of 92% (23/25). Recurrences occurred in 7 patients out 23 who showed the long-term healing, after a mean period of 7.29 ± 3.45 months. The prognostic score (University of Connecticut Osteonecrosis Numerical Scale-UCONNS) was significantly higher (p = 0.01) in patients with poor healing as compared to complete healing, both at 1 and 3 months posttreatment.

CONCLUSIONS

A MRONJ treatment approach based on a combined pharmacological and surgical treatment strategy showed a high rate of healing and few recurrences.

Bisphosphonate application and volumetric effects on MRONJ lesions

The purpose of this investigation was to analyze the volume of medication-related osteonecrosis of the jaw (MRONJ) lesions by semi-automatic segmentation of cone-beam computed tomography images, and correlate the results with the underlying diseases and applied medication. MRONJ lesions detected in cone-beam computed tomography images were assessed. The open-source software ITK-Snap enabled volumetric measurements of MRONJ lesions based on semi-automatic segmentation. Results were analyzed according to necrosis volume, localization, and gender. In addition, the underlying disease and the type of application of antiresorptive medication were investigated. Cone-beam computed tomography images of 66 patients were studied. 34 male and 32 female patients were included, with ages ranging from 50 to 93 years at the time of diagnosis. The mean volume was 993.24 ± 620.94 mm³: 484.73 ± 230.97 mm³ for the upper jaw and 1084.04 ± 625.74 mm³ for the lower jaw. The results indicated statistically significant differences between lesions of the upper and lower jaw, regardless of gender (p = 0.003). The analysis of differences between males and females did not show any significant results (p = 0.464), although males presented slightly larger lesions than females. With regard to the underlying disease, patients with osteoporosis presented larger volumes, whereas patients with malignant tumors presented smaller volumes. Nevertheless, no statistically significant differences according to the underlying disease (p = 0.313) were detected. However, patients with intravenous (iv) application showed statistically significantly larger lesions than patients who underwent oral or subcutaneous (s.c.) applications (p = 0.004). It seems that the osteonecrosis volume correlates with the applied antiresorptive agents. Larger MRONJ lesions should be expected in patients who receive intravenous antiresorptive therapy.

Update and review of the gerodontology prospective for 2020's: Linking the interactions of oral (hypo)-functions to health vs. systemic diseases

New lines of evidence suggest that the oral-systemic medical links and oral hypo-function are progressively transcending beyond the traditional clinical signs and symptoms of oral diseases. Research into the dysbiotic microbiome, host immune/inflammatory regulations and patho-physiologic changes and subsequent adaptations through the oral-systemic measures under ageism points to pathways leading to mastication deficiency, dysphagia, signature brain activities for (neuro)-cognition circuitries, dementia and certain cancers of the digestive system as well. Therefore, the coming era of oral health-linked systemic disorders will likely reshape the future of diagnostics in oral geriatrics, treatment modalities and professional therapies in clinical disciplines. In parallel to these highlights, a recent international symposium was jointly held by the International Association of Gerontology and Geriatrics (IAGG), Japanese Society of Gerodontology (JSG), the representative of USA and Taiwan Academy of Geriatric Dentistry (TAGD) on Oct 25th, 2019. Herein, specific notes are briefly addressed and updated for a summative prospective from this symposium and the recent literature.

Antimicrobial photodynamic and photobiomodulation adjuvant therapies for prevention and treatment of medication-related osteonecrosis of the jaws: Case series and long-term follow-up

BACKGROUND

Medication-Related Osteonecrosis of the Jaws (MRONJ) incidence are increasing among elderly. Treatment can be challenging. Prevent or treatment protocols that control evolution of the lesion are warranted.

OBJECTIVE

To observe long-term outcomes of two protocols based on photonics [antimicrobial photodynamic therapy (aPDT) and photobiomodulation (PBM)] for prevention and treatment of MRONJ lesions.

METHODS

In a prospective study, patients who needed oral surgery and had been exposed to antiresorptive drugs were long-term followed-up. For MRONJ prevention, immediately after tooth extraction aPDT was applied. For aPDT a 0.01 % methylene blue solution was applied inside socket for 5 min followed by irradiation with a diode laser [660 nm, 0.028cm², 0.1 W, 3.57 W/cm², 90 s and 9 J per point, 321 J/cm², at least at in 3 points (laser probe was placed at central, and two equidistant points) and total energy of 27J]. Irradiation was repeated weekly until total tissue repair. MRONJ treatment included preoperative aPDT sessions until signs and symptoms of infection had reduced. Then, after necrotic bone removal, aPDT was applied inside surgical wounds and re-applied weekly until healing. Antibiotics were administered pre or postoperatively for no longer than 7 days. PBM therapy was applied with 808 nm diode laser, 0.028cm², 0.1 W, 3.57 W/cm², 30 s, 107 J/cm², 3 J and total energy of 12 J until evidence of remission.

RESULTS

Eighteen patients underwent preventive protocol, and none presented signs of MRONJ after a follow-up of at least 6 months. Seventeen patients presented with MRONJ underwent aPDT protocol and sixteen of them showed total regression of lesions.

PRACTICAL IMPLICATIONS

aPDT and PBM therapy protocols appear to be effective as adjuvant approach not only for preventing MRONJ development due to tooth extraction but for treating MRONJ lesions at early stages with no adverse effects.

Drug holiday clinical relevance verification for antiresorptive agents in medication-related osteonecrosis cases of the jaw

Treatment strategies of medication-related osteonecrosis of the jaw (MRONJ) are controversial. Recently, surgical treatment has been reported as superior to nonsurgical treatment, but the contribution discontinued antiresorptive agent use during MRONJ treatment remains unclear. This study aimed to evaluate the efficacy of drug holidays and treatment strategies in MRONJ cases. Four-hundred and twenty-seven patients with MRONJ treated at nine hospitals from 2009 to 2017 were included in this multicenter retrospective study. Multivariate Cox regression analysis showed that the primary disease (osteoporosis or malignant tumor), diabetes, serum albumin, and treatment method (surgical or nonsurgical) were significantly correlated with the cure rate. The cumulative 1-year cure rates in the surgical and nonsurgical treatment groups were 64.7% and 18.2%, respectively. However, discontinuing antiresorptive agents did not influence the treatment outcome in the cohort overall, or in 230 patients after performing propensity score matching among the discontinuation and continuation groups. When stratifying by treatment method, antiresorptive agent discontinuation significantly increased the cure rate in patients with osteoporosis who underwent nonsurgical treatment. In patients with malignant tumors undergoing nonsurgical therapy, discontinuing the antiresorptive agent was associated with a better treatment outcome, but not with statistical significance. In contrast, drug holidays showed no effect on improving outcomes in patients with both osteoporosis and malignant tumors who underwent surgical therapy. Thus, regardless of the primary disease, discontinuing antiresorptive agents during treatment for MRONJ may not be necessary and may be helpful in some cases. Future prospective trials should examine this question further.

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

PURPOSE

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

METHODS

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

RESULTS

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

RECOMMENDATIONS

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

Osteonecrosis of the jaws produced by sunitinib: a systematic review

Background

Tyrosine kinase receptor family is involved in tumor growth, pathological angiogenesis and the progression (metastasis) of cancer. Sunitinib (Sutent®) inhibits members of the tyrosine kinase receptor family affecting the induction of angiogenesis and tumor progression. It is not clear if sunitinib increases the risk of osteonecrosis of the jaws (ONJ). The aim of this study was to carry out a systematic review about ONJ related to sunitinib, describing existing cases and possible associated risk factors.

Material and Methods

The PubMed/MEDLINE and Cochrane Library databases were searched without date restriction up to September 2018. We included prospective and retrospective observational studies, cross-sectional studies, clinical cases and series of cases, involving only human subjects. The methodological quality of the studies was assessed using The Joanna Briggs Institute (JBI) and Newcastle-Ottawa tools.

Results

A total of 13 studies fulfilled our inclusion criteria of which 7 were clinical cases, 5 case series and a retrospective study. All the articles were published between 2009 and 2018. Of the 102 patients treated with sunitinib analyzed in this study, 58 developed ONJ, being or having been treated with sunitinib and bisphosphonates or exclusively with sunitinib.

Conclusions

In this systematic review, we found an increase of ONJ in patients who are medicated with other drugs different than bisphosphonates and denosumab. It is necessary that dentists, oral and maxillofacial surgeons as well as oncologists know the risk of ONJ that these antiresorptive drugs could have. There is a need to continue researching in this field with the aim of an increasing knowledge in this area and creating an adequate protocol of action for this population.

Key words:Medication-related osteonecrosis of the jaws, osteonecrosis of the jaws, sunitinib, systematic review.

Medication-Related Osteonecrosis of the Jaws: Two Center Retrospective Cohort Studies

This retrospective cohort study aims to describe characteristics of patients with MRONJ, to identify factors associated with MRONJ development, and to examine variables associated with favourable outcome. Totally 32 patients were followed and observed: 21 females and 11 males, in the age range 35-84 in the period from 2009 to 2018. Clinical, radiological examination (Orthopantomograph and CBCT) and biopsy were performed in order to achieve diagnosis. Demographic and clinical variables were taken into consideration: sex, age, primary disease, medication type, mode of delivery, anatomic location, drug treatment duration, timing of tooth extraction, chemotherapy, presence of bone metastasis, aetiology of MRONJ, disease stage, and treatment modality. MRONJ developed under osteoporosis and malignant disease in 11 and 21 patients, respectively. MRONJ development was triggered by tooth extraction or trauma in 30 out of 32 cases, whereas the two patients developed MRONJ spontaneously. Stages I, II, and III were confirmed in 5 (16%), 18 (58%), and 9 (28%) patients, respectively. Mandible was affected in 23 (72%) patients. MRONJ was treated in our department by conservative and surgical modality. In this study we found that 65% of all patients were classified in the cured/improvement group and 35% in the stable/progression group. The female gender, osteoporosis as primary disease, oral regime intake, shorter period on BPs, earlier stage of disease, and specific anatomic localisation (frontal and premolar maxilla) were factors associated with better response to therapy and favourable clinical outcome. Comprehensive treatment protocol and further randomized studies are necessary for further improvements.

A literature review of perioperative antibiotic administration in surgery for medication-related osteonecrosis of the jaw

PURPOSE

Few studies exist that focus on the details of perioperative antibiotic administration for surgery to treat medication-related osteonecrosis of the jaw (MRONJ). The regime and duration of perioperative antibiotics applied in published studies were reviewed to clarify appropriate perioperative antibiotic use in MRONJ surgery.

METHODS

A literature search was conducted using the MEDLINE database via PubMed.

RESULTS

The search resulted in 453 hits on PubMed. After reading the downloaded full-text articles, 17 articles met the inclusion and exclusion criteria. The most common perioperative antibiotic used for MRONJ surgery was a combination of penicillin-based antibiotics and β-lactamase inhibitor (52.9%), and the second most common regime was penicillin-based antibiotics with metronidazole (17.6%). The duration of administration was 2 weeks postoperatively in nine studies, whereas four studies applied long-term administration (2-6 weeks postoperatively).

CONCLUSIONS

Oral and maxillofacial surgeons mostly prefer penicillin-based antibiotics plus β-lactamase inhibitor or metronidazole for MRONJ surgery. The duration of administration of these medications may be based on empirical experience.

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.