Medication-related osteonecrosis of the lower jaw without osteolysis on computed tomography images.

INTRODUCTION: Surgery is the standard treatment for medication-related osteonecrosis of the jaw (MRONJ). This study reviewed patients with mandibular MRONJ who underwent surgical treatment, and in particular the characteristics of non-osteolytic MRONJ with no evidence of osteolysis on CT were described. MATERIALS AND METHODS: We conducted a retrospective study of patients with mandibular MRONJ who underwent surgery between January 2016 and September 2022. Various clinical and imaging factors regarding treatment outcomes were investigated and analyzed. Additionally, the disease course of non-osteolytic MRONJ was examined in detail. RESULTS: This study included 55 patients (66 surgeries) with a mean age of 74.7. The primary disease was osteoporosis (24 patients) and malignancy (31 patients); the type of antiresorptive agent was bisphosphonate (BP) in 21 patients and denosumab (DMB) in 26. BP was initially administered; however, it was changed to DMB in eight patients. Preoperatively, the cumulative cure rates for all 66 surgeries were 72.8% at 1 year and 77.3% at 2 years. Cure rates were significantly lower in patients with malignancy, those without osteolysis, and those who underwent sequestrum removal or marginal mandibulectomy than those with osteoporosis, osteolysis, and segmental mandibulectomy. Non-osteolytic MRONJ was observed in eight patients, all with malignancy and receiving high-dose DMB. Only two patients were cured after the initial surgery, and most patients ultimately underwent segmental mandibulectomy. CONCLUSIONS: Surgical treatment yielded good treatment outcomes in most patients with mandibular MRONJ; however, the cure rate was lower in patients with malignancy who showed no osteolysis on CT images.

Risk Factors for Infection Recurrence After Surgical Resection of Advanced Stage Osteonecrosis of the Mandible.

BACKGROUND: Advanced stage osteoradionecrosis (ORN) and medication-related osteonecrosis of the jaw (MRONJ) are challenging disease entities requiring multimodal therapy including surgical resection. However, risk factors associated with infection recurrence are poorly understood. PURPOSE: The purpose of this study was to identify risk factors associated with infection recurrence following resection of advanced stage ORN or MRONJ of the mandible. STUDY DESIGN, SETTING, SAMPLE: This was a retrospective cohort study including patients who underwent segmental mandibulectomy for management of ORN or MRONJ between 2016 and 2021 at the authors' institution. Subjects who did not have margin viability data were excluded. PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE: The primary predictor variable was viability of resection margins on histopathologic analysis (viable or nonviable). Secondarily, other risk factors categorized as demographic (age, sex, race), medical (comorbidities), and perioperative (reconstructive modality, antibiotic duration, microbiological growth) were evaluated. MAIN OUTCOME VARIABLE: The primary outcome variable was time to infection recurrence defined as time from surgical resection to clinical diagnosis of a fistula tract, abscess, or persistent inflammatory symptoms necessitating surgical intervention. COVARIATES: Not applicable. ANALYSES: Descriptive and bivariate statistics were used to identify associations between risk factors and time to infection recurrence. A significance level of P ≤ .05 was considered significant. RESULTS: The cohort consisted of 57 subjects with a mean age of 63.3 ± 10.0 years (71.9% Male, 75.4% White) treated for ORN (47.4%) or MRONJ (52.6%). A total of 19/57 (33%) subjects developed a recurrence of infection with 1 and 2 year survival of 75.8 and 66.2%, respectively. Nonviable resection margins were associated with earlier time to infection recurrence (P ≤ .001, hazard ratio (HR) = 11.9, 95% confidence interval (CI) = 3.84 to 36.7) as was younger age (P = .005, HR = 0.921, 95% CI = 0.869 to 0.976) and atypical pathogen growth on culture (P = .002, HR = 8.58, 95% CI = 2.24 to 32.8). CONCLUSIONS AND RELEVANCE: Histopathologic margin viability was associated with earlier time to infection recurrence following resection of advanced stage ORN or MRONJ of the mandible. Additional studies are needed to identify interventions that may improve outcomes in this demographic.

Can medication-related osteonecrosis of the jaw be attributed to specific microorganisms through oral microbiota analyses? A preliminary study.

BACKGROUND: Medication-related osteonecrosis of the jaw (MRONJ) can cause significant pain and loss of aesthetics and function if not treated properly. However, diagnosis still relies on detailed intraoral examinations and imaging. Prognosis varies even among patients with similar stages or conditions of MRONJ, emphasizing the need for a deeper understanding of its complex mechanisms. Thus, this study aimed to identify the oral microbiota of patients with MRONJ. METHODS: This single-center prospective cohort study included patients with confirmed MRONJ who visited the Department of Oral and Maxillofacial Surgery at Yonsei University Dental Hospital between 2021 and 2022. Oral swab samples were collected from the affected and unaffected sides of each patient. The composition and enumeration of the microbial communities were analyzed, and the diversity was compared to verify ecological changes in the groups using a next-generation sequencing-based 16S metagenomic analysis. A statistical analysis was performed using Wilcoxon signed-rank test with SPSS version 22, and values of P less than 0.05 were considered statistically significant. RESULTS: The final study sample included 12 patients. The mean age was 82.67 ± 5.73 (range, 72-90) years. Changes in microbial composition were observed at different taxonomic levels (phylum, genus, and species). The identified microorganisms were commonly associated with periodontitis, gingival disease, and endodontic infection, suggesting a multifactorial etiology of MRONJ. CONCLUSIONS: Although this study is based on a small number of cases, it shows that MRONJ is not caused by a specific microorganism but can rather be caused by a variety of factors. By addressing these findings in large-scale studies, the significance of oral microbiome in pathogenesis can be further elucidated and can facilitate the development of effective therapeutic interventions for patients with MRONJ.

[Application of double-layer soft tissue suture closure technique in the surgical treatment of patients with mandible medication-related osteonecrosis of the jaw of early and medium stages].

OBJECTIVE: To investigate the clinical application effect of double-layer soft tissue (DLST) suture closure technique in patients with mandible medication-related osteonecrosis of the jaw (MRONJ) of early and medium stages resulted in application of anti-bone-resorptive drugs. METHODS: Early to medium stage mandible MRONJ patients who underwent surgical treatment in the fourth ward of Peking University School and Hospital of Stomatology from October 2021 to September 2022 were included. Clinical information of the patients were collected, including primary disease, concomitant disease, medication regimen (drug type, duration of medication), MRONJ stage, clinical symptoms, imaging manifestations, etc. During surgery, after using marginal mandibulae resection to remove the necrotic bone, the wound was closed using DLST closure technique. Regular post-operative follow-up was performed to evaluate the therapeutic effect and complications of the DLST technique, the pain score and functional status of the patiens were evaluated. RESULTS: This study totally included 13 patients, 12 women and 1 man, aged (66.69±13.14) years. Seven patients had osteoporosis, 2 had lung cancer, 3 had breast cancer and 1 had prostate cancer among their primary diseases; 7 had no concomitant diseases, 2 had diabetes mellitus, 2 had cardiovascular disease and 1 had dry syndrome. Intravenous zoledronic acid were used in 9 patients, the average duration was (37.7±20.0) months, and other drugs, such as letrozole tablets were taken in 7 patients at the same time; Denosumab injection was used in 3 patients for an average of (10.3±11.9) months; Alendronate sodium tablets were taken in 5 patients for an average of (55.20±27.20) months, and prednisone acetate tablets or acarbose tablets were taken to varying degrees in 2 patients. The average post-operative follow-up was 11.9 months (9 to 17 months), and all the 13 patients were cured without complications, such as pus overflow and so forth. The pre-operative score of Karnofsky performance status (KPS) in the patients was 68.46±14.05, and the post-operative score was 82.31±15.36, and the difference was statistically significant (P < 0.05). The pre-operative score of visual analogue scale (VAS) in the patients was 5.77±0.73 and the post-operative score was 0.38±0.51, and the difference had statistical significance (P < 0.001). CONCLUSION: The double-layer soft tissue suture closure technique can achieve good clinical results in patients with MRONJ of the mandible using anti-bone-resorptive drugs alone, and can provide clinical treatment ideas for MRONJ patients with more complicated drug use.

Medication-related osteonecrosis of the jaw triggered by endodontic failure in oncologic patients.

OBJECTIVES: To describe the association between endodontic treatment failure and medication-related osteonecrosis of the jaw (MRONJ) in a cohort of oncologic patients in therapy with antiresorptive and antiangiogenic drugs. MATERIALS AND METHODS: Patients were selected as affected by MRONJ in absence of the common local risk factors (oral surgical procedures or ill-fitting dentures) but showing failure of previous endodontic treatment performed at least 6 months before the starting of antiresorptive/antiangiogenic therapies. Jaw lesions were all surgically treated and patients underwent a strict clinical and radiological follow-up. RESULTS: Among 18 patients, who developed 18 MRONJ, the only detectable local risk factor was the presence of teeth with failed endodontic treatment (more precisely, root canal underfilling in eight cases, root canal overfilling in two cases, root perforation in three cases, root fracture in five cases). All patients completely healed after surgical procedure and no recurrence was observed. CONCLUSIONS: Endodontic treatment failure should be considered a local risk factor for MRONJ development in oncologic patients. For such reason, it is mandatory to carefully evaluate them prior than the beginning of antiresorptive and antiangiogenic drugs administration.

Bone Morphogenetic Protein 2 Plus Leukocyte and Platelet-Rich Fibrin for the Treatment of MRONJ.

Leukocyte and platelet-rich fibrin is known to contain high concentrations of growth factors and when associated with rhBMP-2, it may increase bone remodeling due to its osteoinductive property. The aim of this case is to report the outcome of surgical treatment of medication-related osteonecrosis of the jaw with prototype plate installation and the use of leukocyte and platelet-rich fibrin in association with rhBMP-2 in a 78-year-old female patient under therapy with alendronate. The present Studies describes that the combination of this treatment presented complete healing of osteonecrosis and represents a promising treatment option to be used for medication-related osteonecrosis of the jaw.

Use of Leukocyte-rich and Platelet-rich Fibrin (L-PRF) Adjunct to Surgical Debridement in the Treatment of Stage 2 and 3 Medication-Related Osteonecrosis of the Jaw.

Medication-related osteonecrosis of the jaw (MRONJ) is characterized by exposed necrotic bone persisting for more than 8 weeks in the maxillofacial region in patients using antiresorptive or antiangiogenetic drugs for several treatment options like bone metastasis or osteoporosis. There are several treatment options studied in scientific literature, and one of them with promising results is using platelet concentrates adjunct to surgical therapy. The aim of this study is to examine the therapeutic effect of leukocyte and platelet-rich fibrin (L-PRF) on patients with MRONJ. This 2-centered study investigated patients referred to oral and maxillofacial surgery departments of 2 university clinics between the years 2014 and 2020 with the diagnosis of MRONJ. Demographic data, the indication of the drug usage, drug type, duration, administration route, and systemic comorbidities of the patients were recorded. L-PRF was applied to 20 osteonecrotic lesions of 19 patients following surgical debridement. The male/female ratio was 5/14. Except 1 of the patients, all of the indications of medication were neoplasia-related. The mean follow-up period of patients was 27.9±9.2 months. Most common antirezorptive drug was zoledronate (84.2%). Complete resolution was observed in 16 necrosis sites (80%). It could be concluded that the use of L-PRF may represent an important adjunct in the surgical management of MRONJ.

Successful New Dental Implant Installation in a Healed Site of Medication-Related Osteonecrosis of the Jaw: A Case Report.

The purpose of this case report was to present a rare clinical case of successful new dental implant installation in the site of previously healed medication-related osteonecrosis of the jaw (MRONJ). An 80-year-old female patient with history of oral bisphosphonate (BP) therapy presented with pain and swelling of gingiva in the right posterior mandible. One of the 3 implants placed 15 years ago in the right mandibular posterior area was removed 6 months before the visit to our hospital, which led to worsening of the symptoms. After clinical and radiographic examination, the patient was diagnosed with stage 2 MRONJ. Along with antibiotic therapy, the patient underwent surgical intervention via sequestrectomy and removal of the remaining 2 implants. Adequate soft and hard tissue healing without any complications and signs of recurrence was confirmed, and implant installation with simultaneous bone grafting and prosthesis fabrication were done in the explantation sites of MRONJ. By the 7-year follow-up, no implant failure has been observed, and installation of implants was successful in the previously healed MRONJ site. Dental implant installation is possible in a patient with history of failed implant due to MRONJ. However, a careful treatment planning is needed before implantation in a previously healed site of MRONJ to reduce the potential risks of MRONJ recurrence and implant failure.

The Use of Human Amniotic Membrane (hAM) as a Treatment Strategy of Medication-Related Osteonecrosis of the Jaw (MRONJ): A Systematic Review and Meta-Analysis of the Literature.

Background and objectives: Although it is very uncommon, medication-induced osteonecrosis of the jaw (also known as MRONJ) can have serious consequences. Traditionally, this adverse event has been recognised in patients who were treated with bisphosphonate (BP) drugs. Nevertheless, in recent years, it has been established that individuals having treatment with various types of medications, such as a receptor activator of nuclear factor kappa-Β ligand inhibitor (denosumab) and antiangiogenic agents, have had the same issue. The purpose of this research is to determine if the application of human amniotic membrane (hAM) may be used as a therapy for MRONJ. Material and Methods: A multi-source database (MEDLINE, EMBASE, AMED, and CENTRAL) systematic search was performed. The major objective of this study is to obtain an understanding of the efficacy of hAM when it is employed as a treatment modality for MRONJ. The protocol of this review was registered in the INPLASY register under the number NPLASY202330010. Results: The authors were able to include a total of five studies for the quality analysis, whereas for the quantity evaluation, only four studies were eligible. A total of 91 patients were considered for the investigation. After treatment with human amniotic membrane (hAM), a recurrence of osteonecrosis was observed in n = 6 cases (8.8%). The combined efficacy of surgical therapy and the use of hAM resulted in an overall success rate of 91.2%. Intraoperative complications were only documented in one article, and they were mostly caused by the positioning of the hAM, which led to wound breakdown at the surgical site. Conclusions: Based on the small amount of data and low-quality research included in this study, using human amniotic membranes to treat MRONJ might represent a feasible option. Nevertheless, further studies with a wider patient population are required to understand the long-term impacts.

[A Case of Anti-Resorptive Agents-Related Osteonecrosis of the Jaw and Extensive Loss of Maxillary Bone in a Patient of Breast Cancer].

A 74-year-old woman had a mastectomy for right breast cancer in 201X. Eight years later, the patient developed multiple bone metastases and was treated with denosumab by her previous doctor. A year after, she was diagnosed with anti-resorptive agents-related osteonecrosis of the jaw, and preservation treatment was performed. In 201X+11, the patient had difficulty walking and was admitted to our palliative care ward. A month later, her maxillary bone detached extensively and spontaneously. By applying infection preventive measures and in cooperation with the former doctor, dentist, and oral surgeon, as well as visiting the dental department in our hospital, the patient managed to continue eating what she liked. Jaw infection did not occur. The patient died of liver dysfunction due to liver metastasis 5 months following the extensive loss of the maxillary bone.

One changing and challenging scenario: the treatment of cancer patients with bone metastases by bisphosphonates and denosumab, the cost-benefit evaluation of different options, and the risk of medication-related osteonecrosis of the jaw (MRONJ).

Antiresorptive drugs (bisphosphonates and denosumab) have become the cornerstone of medical supportive treatment of bone metastases in solid cancer patients. In the beginning, the choice of available antiresorptive agents was limited to bisphosphonates and the treatment options restricted principally to monthly pamidronate and monthly zoledronic acid. Introduction of new antiresorptive therapies (monthly denosumab) and schedules (zoledronic acid every 3 months, upfront or after initial period of monthly infusion) in the last decade increased the range of available options, thus challenging treatment decision making. Direct and indirect costs of very different treatment options are difficult to interpret in a global cost-benefit analysis. In addition, awareness of the increased risk of medication-related osteonecrosis of the jaw (MRONJ) in bone metastatic cancer patients receiving long-term antiresorptive medications is likely to influence therapy choice in the real-life scenario. We discuss the possible threat of MRONJ risk underestimation and the need for long-term risk stratification of patients based on actuarial data, the role of bisphosphonates and denosumab in that scenario, and the emerging role of surgical therapy to successfully cure MRONJ, in the light of the improved quality of life and survival of patients with bone metastases from solid cancers.

Surgical Therapy in Patients With Medication-Related Osteonecrosis of the Jaw Is Associated With Disease Resolution and Improved Quality of Life: A Prospective Cohort Study.

PURPOSE: Although recent evidence has suggested the value of operative therapy for the management of medication-related osteonecrosis of the jaw (MRONJ), its effectiveness remains controversial. The purpose of this study was to measure and compare MRONJ disease resolution and changes to the quality of life (QoL) between operative and nonoperative management of MRONJ. METHODS: This is a prospective cohort study. Consecutive MRONJ patients presenting to Mount Sinai Hospital and Sunnybrook Health Sciences Center (September 2016 to August 2020) were recruited and divided by the treatments provided into operative and nonoperative groups. The primary and secondary outcome variables were disease resolution and QoL at 6 months, respectively. Disease resolution was defined as mucosal coverage with an absence of pain, and QoL was measured via the MRONJ-QoL questionnaire. The primary and secondary outcomes, after adjusting for potential confounders, were assessed via multivariate logistic regression and multivariate linear regression analyses, respectively, with significance set to P < .05. RESULTS: Sixty patients were included in this study. Of these, 40 patients received operative treatment, and 20 received nonoperative treatment. In the unadjusted analyses, operative therapy was found to be significantly associated with both disease resolution and improvement in QoL (relative risk 6.75, 95% confidence interval [CI] 1.78 to 25.6, P < .001; and MRONJ-QoL score improvement of 3.35, 95% CI 0.16 to 6.54, P = .04). When controlling for potential confounders, operative therapy was found to be significantly associated with disease resolution when compared with nonoperative therapy (adjusted odds ratio 46.2, 95% CI 5.57 to 383.9, P < .001). Linear regression analysis also showed operative therapy to be significantly associated with improved QoL compared with nonoperative therapy (adjusted MRONJ-QoL score improvement of 3.72, 95% CI 0.34 to 7.11, P = .03). CONCLUSIONS: Our study demonstrated operative therapy to be significantly associated with disease resolution and improvement in QoL.

American Association of Oral and Maxillofacial Surgeons' Position Paper on Medication-Related Osteonecrosis of the Jaws-2022 Update.

Strategies for management of patients with, or at risk for, medication-related osteonecrosis of the jaws (MRONJ) - formerly referred to as bisphosphonate-related osteonecrosis of the jaws (BRONJ)-were set forth in the American Association of Oral and Maxillofacial Surgeons (AAOMS) position papers in 2007, 2009 and 2014. The position papers were developed by a committee appointed by the AAOMS Board of Trustees and comprising clinicians with extensive experience in caring for these patients, as well as clinical and basic science researchers. The knowledge base and experience in addressing MRONJ continues to evolve and expand, necessitating modifications and refinements to the previous position papers. Three members of the AAOMS Committee on Oral, Head, and Neck Oncologic and Reconstructive Surgery (COHNORS) and three authors of the 2014 position paper were appointed to serve as a working group to analyze the current literature and revise the guidance as indicated to reflect current knowledge in this field. This update contains revisions to diagnosis and management strategies and highlights the current research status. AAOMS maintains that it is vitally important for this information to be disseminated to other relevant healthcare professionals and organizations.

Quality of life after segmental mandibulectomy and free flap for mandibular osteonecrosis: Systematic review.

OBJECTIVE: Review QOL outcomes among patients undergoing segmental mandibulectomy and bony free flap reconstruction for ONJ. DATA SOURCES: PubMed was searched for MeSH terms "Quality of life," "Osteonecrosis," "Osteoradionecrosis," "Bisphosphonate-associated osteonecrosis of the jaw," "Free tissue flaps," and "Mandibular reconstruction." REVIEW METHODS: English language studies with QOL outcomes data for patients undergoing free flap reconstruction for advanced ONJ were included. 197 records were initially screened; 18 full texts assessed; 10 full texts included. PRISMA guidelines were followed. RESULTS: Ten studies were included in this systematic review: six retrospective, three retrospective with comparison groups, and one prospective. In studies with comparison groups, ONJ patients have worse self-reported QOL than the general population as well as head and neck cancer patients without ONJ. Nearly all patients with QOL measurements (220/235 patients) had ONJ from prior radiation. Segmental mandibulectomy and bony free flap improved overall QOL in over half of patients, as well as pain associated with ONJ in 70-75 % of patients. Surgery did not improve long-term effects of radiation such as chewing, swallowing, and salivary production. Donor site morbidity rarely affects QOL. CONCLUSIONS: Osteonecrosis of the jaw (ONJ) worsens quality-of-life, and advanced disease often requires segmental mandibulectomy and bony free flap reconstruction. Patients and surgeons may expect improvement in some, but not all, domains of patient-reported QOL by the use of segmental mandibulectomy and reconstruction for advanced ONJ.

Treatment of Refractory Medicine Related Osteonecrosis of Jaw With Piezosurgical Debridement and Autologous Platelet Rich Fibrin: Feasibility Study.

ABSTRACT: Medicine related osteonecrosis of jaw (MRONJ) is incidental in patients receiving certain bone modifying agents in oncology. These lesions may not respond to conservative management and aggravate. Autologous platelet derivatives contain bone growth factors, which help in bone regeneration. The aim of this pilot study is to develop protocol for treatment of refractory MRONJ with pizosurgical debridement and advanced platelet rich fibrin.In this feasibility study, refractory MRONJ lesions were treated by piezosurgical debridement and insertion of autologous advanced platelet rich fibrin in 15 patients. One patient had 2 lesion sites, so in all 16 MRONJ sites were treated. These patients were evaluated at the end of 1 month and 4 months for healing of MRONJ lesion. Statistical analysis was done by using Fisher test for response assessment in relation to variable. Eight lesions (50%) showed complete healing at the end of 1 month. At the end of 4 months 13 lesions (81.50%) were completely healed, 2 lesions (12.5%) were downgrades, and 1 lesion (6.25%) did not respond to treatment. Number of doses of bone modifying agent was only factor found associated with nonhealing of MRONJ when treated with this protocol.In this pilot study, feasibility of use of piezosurgical debridement and platelet rich fibrin was evaluated. The results of the study suggest complete healing can be achieved with this treatment protocol. Further research with increased sample size is warranted to determine optimum use of autologous platelet concentrates in treatment of MRONJ.

Medication-Related Osteonecrosis of the Jaw Associated in a Patient Treated With Etanercept.

ABSTRACT: Medication-related osteonecrosis of the jaws (MRONJ) is defined as a pathologic condition affecting the maxillary and mandibular bones arising subsequently to pharmacological treatment with antiresorptive and antiangiogenic drugs.In this case report, the occurrence of MRONJ is described in a 66-year-old female patient affected by rheumatoid arthritis and treated with Etanercept, a Tumor Necrosis Factor (TNF)-a inhibitor. The patient developed a mandibular MRONJ following the extraction of teeth 3.4 and 3.5. The patient was then treated with conservative surgery of the necrotic bone. At 12-month follow-up complete resolution was observed. According to the data presented, the evaluation of the effects of new immunosuppressive biological therapies on the oral cavity appears of utmost importance in preventing the development of MRONJ. Although the risk related to TNF-a inhibitors has not been quantified yet, the clinician should be aware of the potential adverse effects on the oral cavity.

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.

[Analysis of pathological characteristics of medication-related osteonecrosis of the jaw and discussion of clinical treatment strategies based on the pathological analysis results].

OBJECTIVE: To summarize the pathological characteristics of medication-related osteonecrosis of the jaw (MRONJ) specimens after jaw curettage or jaw osteotomy treatment and to comprehensively analyze the relationship between the different pathological features, treatment methods, and treatment effects to provide new ideas for effective treatment of MRONJ in clinical work. METHODS: The clinical and pathological data were collected from 23 patients with MRONJ who were treated with curettage (18 patients) and jaw osteotomy (5 patients) at the Department of Oral and Maxillofacial Surgery of Peking University Hospital of Stomatology between June 2014 and December 2015. The pathological characteristics of MRONJ were summarized and analyzed with treatment effects based on various surgical treatment methods. The diagnostic criteria and disease staging of MRONJ were determined according to the 2014 American Association of Oral and Maxillofacial Surgeon's Position Paper. RESULTS: In this study, 5 patients have treated with jaw segmental osteotomy, and all of them were in stage Ⅲ; the other 18 patients were treated with jaw curettage, including 5 patients in stage Ⅱ and 13 patients in stage Ⅲ. The pathological features of MRONJ in five cases of jaw segmental osteotomy were divided into three adjacent regions from shallow to deep: inflammation region (IR), sclerosis region (SR), and bone remodeling layer (BRL). Moreover, three types of pathological features of specimens from traditional curettage were defined as type 1 (IR), type 2 (IR + SR), and type 3 (IR + SR + BRL). The pathological features of the patients treated with jaw curettage were: type Ⅰ, 38.9% (7/18); type Ⅱ, 44.4% (8/18); type Ⅲ, 16.7% (3/18). Complete healing was achieved in 5 patients treated with jaw segmental osteo-tomy. Moreover, 2 cases with type Ⅰ, 1 case with type Ⅱ, and 1 with type Ⅲ completely healed after jaw curettage, while 5 cases with type Ⅰ, 7 cases with type Ⅱ, and 2 cases with type Ⅲ experienced recurrence after surgery. CONCLUSION: Pathological features of continuous regions of inflammation, sclerosis, and bone remodeling layer were identified from shallow to deep, based on the microscopic observation of jaw segmental osteotomy samples. Insufficient removal of the sclerotic region during jaw curettage that blocks the required blood, nutritional factors, and mesenchymal stem cells seems to be a common cause for failed treatment of MRONJ after curettage surgery.

Spontaneous medication-related osteonecrosis of the jaw: a bimodal treatment approach.

While most incidences of medication-related osteonecrosis of the jaw (MRONJ) are associated with a history of oral trauma, tooth extraction, or prior oral surgical procedures, osteonecrosis and exposed bone can occur spontaneously in the oral cavity. This case report describes the successful treatment of spontaneous MRONJ in a patient who had a history of breast cancer, drug allergies, occasional respiratory insufficiency, heart murmur, untreated borderline hypertension, and gastroesophageal reflux disease. In addition, the patient was prescribed the antiresorptive drug denosumab for osteoporosis. A nonsurgical treatment regimen followed by a surgical approach was a safe and successful treatment method for this patient who had a complicated medical history and a number of medical considerations. The bimodal approach allowed the effects of the prescribed medication (denosumab) to dissipate and enhanced the local conditions for the surgical procedure to achieve optimal results. A careful and thorough oral evaluation combined with head and neck examination can uncover a previously undiagnosed necrotic condition. The patient is often unaware of the exposed bone, which is relatively painless. Patients with complicated medical histories, who often are treated by multiple medical practitioners and prescribed multiple medications for different conditions, may require a similar bimodal treatment approach.

Effect of periosteal reaction in medication-related osteonecrosis of the jaw on treatment outcome after surgery.

INTRODUCTION: Surgical treatment in patients with medication-related osteonecrosis of the jaw (MRONJ) is superior to conservative treatment. However, treatment outcome in patients with periosteal reaction (PR) was significantly poorer than that of those without PR. The purpose of this retrospective study was to analyze the pathophysiology and clinical significance of PR in MRONJ. MATERIALS AND METHODS: Out of 181 patients with MRONJ undergoing surgery, 38 patients with PR were enrolled in the study. CT examinations, histological examinations, and bacteriological examinations using real-time polymerase chain reaction were performed, and the relationship among the opted surgical method, CT findings, and treatment outcome was investigated. RESULTS: The pattern of PR was classified into three types: type 1, new bone is formed parallel to the mandible, and no gap was evident between the mandible and new bone; type 2, new bone is formed parallel to the mandible, and a gap was evident between them; type 3, an irregular shape. Histological examinations revealed inflammatory tissue in the area visualized as a gap on CT. Bacteriological examination showed the presence of bacteria in the type 2 or type 3 PR. Complete cure was observed in 21 of 38 (55.3%) patients, which was lower than the cure rate of 73.4% in 143 patients without PR. The cure rate was significantly lower in cases with type 3 PR or with persistent osteolysis. CONCLUSIONS: It seems that complete resection of both osteolytic area and type 3 PR is necessary to obtain complete healing in patients undergoing marginal mandibulectomy.