Double-layer closure techniques after bone surgery of medication-related osteonecrosis of the jaw – A single center cohort study

Efficacy of submental island flap closing advanced mandibular MRONJ lesion in malignancy patients

OBJECTIVE

This study evaluated the effectiveness of a submental island flap in closing advanced mandibular medication-related osteonecrosis of the jaw (MRONJ) wounds in patients with malignant tumors.

SUBJECTS AND METHODS

A total of 85 patients with stage II and III MRONJ of mandible with malignant tumor as their primary disease were retrospectively analyzed. All patients underwent surgical treatment, and the soft tissue wound closure was performed either with a submental island flap (SIF) or mucoperiosteal flap (MF). Univariate and multifactorial models were applied to analyze the factors influencing patients' prognosis.

RESULTS

Univariate analysis (p = 0.004, OR 0.075-0.575, 95% CI) and binary logistic regression (p = 0.017, OR 0.032-0.713, 95% CI) suggested that the surgical prognosis of SIF wound closure was significantly better than that of MF.

CONCLUSION

Closure of wound after resection of mandibular MRONJ lesions in patients with malignant tumors using SIF had a better clinical prognosis compared with MF.

Skin and Muscle Closure Techniques Following Large-Scale Osteosarcoma Removal: A Comparative Analysis

Osteosarcoma (OS), the most prevalent form of bone cancer, typically arises in osteoblast cells responsible for generating new bone. The bone produced by these cancer cells is weaker compared to healthy bone. OS is an aggressive bone cancer that often requires extensive resection, leaving behind substantial soft tissue defects. Successful closure after tumor excision is critical for wound healing and postoperative recovery. However, the optimal approach varies depending on factors like defect size and location. After extensive resection of OS, restoring the integrity of the affected area demands careful closure of both the skin and underlying muscle. The appropriate closure technique depends on the size and location of the soft tissue defect. The main objective of this systematic review is to evaluate and compare different surgical techniques for closing skin and muscle layers following large-scale OS removal. Through a systematic review methodology, we conducted an extensive analysis of the existing body of literature on this topic, drawing from relevant research papers published over the past two decades. This allowed us to collectively evaluate and synthesize available data on the subject. This review found that negative pressure wound therapy (NPWT) and flap reconstruction are the main surgical approaches used to close skin and muscle following extensive OS resection, which commonly results in large soft tissue defects due to the nature of tumor removal. Furthermore, NPWT was the most widely used method for closing soft tissue defects after major OS removal, while flap reconstruction was also common when NPWT was not appropriate or the defect was too large. An integrated approach combining vacuum therapy, skin stretching, and occasional flaps seeks to primarily close large defects after OS resection through optimized healing and tension reduction to achieve the best postoperative results.

Antiresorptive agents enhance ossification of free flap reconstructions of the mandible: a radiological retrospective cohort study

Background

The aim of this study was to investigate the effect of antiresorptive agents on the ossification of reconstructed mandibles by free bone grafts for the first time.

Methods

A total of 38 reconstructions of the jaw were retrospectively evaluated for ossification between bone segments by two raters based on postoperative panoramic radiographs. The study group (n = 13) had segmental resection of the mandible and free bone flap reconstruction due to medication-related osteonecrosis of the jaw (MRONJ). The control group (noMRONJ, n = 25) comprised segmental mandibular resections and free bone flap reconstructions due to tumors, chronic osteomyelitis, or trauma without any radiation. Ossification time and influencing factors were evaluated.

Results

Both duration of surgery (346 ± 90 min. vs. 498 ± 124 min.; p < 0.001) and hospitalization (8.7 ± 2.8 days vs. 13.4 ± 5.3 days, p = 0.006) were shorter in the MRONJ group compared to the noMRONJ group. Ossification after mandibular reconstruction was significantly faster in the MRONJ study group [224 days, interquartile range (IQR) 175-287] compared to the control group (288 days, IQR 194-445; p < 0.001). Moreover, good initial contact between the segments resulted in faster ossification (p < 0.001) in the MRONJ group. Ossification rate between original and grafted bone or between grafted bone segments only did not differ in both the study and control groups (MRONJ, p = 0.705 vs. control, p = 0.292). The type of antiresorptive agent did not show any significance for ossification. The rate of wound healing disturbances did also not differ between the study and control groups (p = 0.69).

Conclusion

Advanced MRONJ (stage 3) can be resected and reconstructed safely with free microvascular bone flaps. Antiresorptive agents enhance the ossification of the bone segments. Optimal initial contact of the bone segments accelerates bone healing. Surgery and hospitalization are markedly shortened in this vulnerable group of MRONJ patients compared to oncologic patients.

Comparative clinical study of phosphorous necrosis and medical-related osteonecrosis of the jaws

BACKGROUND

Phosphorous necrosis of the jaw (PNJ) exhibits similar clinical and pathological features as medical-related osteonecrosis of the jaw (MRONJ). This study aims at comparing the similarities and differences between PNJ and MRONJ regarding pathological features and to provide a theoretical basis for the clinical diagnosis and management of PNJ.

MATERIAL AND METHODS

A retrospective analysis was conducted to assess clinical differences among 38 PNJ patients and 31 MRONJ patients, who were diagnosed and treated between January 2009 and October 2022. Pathological alterations in bone tissue were evaluated using EDS, H&E, Masson, and TRAP staining on five specimens from both MRONJ and PNJ cases; furthermore, immunohistochemistry was used to determine the expression levels of OPG, RANKL, and Runx2. The mandibular coronoid process was removed from individuals with temporomandibular joint ankylosis to serve as a control.

RESULTS

CBCT imaging demonstrated necrotic bone formation in block, strip, or plaque shapes. EDS analysis showed that the calcium/phosphorus ratio in the bone tissue of PNJ and MRONJ was significantly lower than that of the control group (P < 0.05). Additionally, staining indicated reduced osteoblast counts, disrupted bone trabecular structure, and decreased collagen fiber content in the bone tissues of PNJ and MRONJ. Immunohistochemistry demonstrated that RANKL expression was significantly lower in MRONJ compared to PNJ and control groups (P < 0.05). Conversely, Runx2 expression was significantly higher in PNJ than in MRONJ and control groups (P < 0.05), and there was no significant difference in OPG expression.

CONCLUSION

PNJ and MRONJ demonstrate comparable clinical manifestations and pathological traits, although disparities may exist in their underlying exhibit comparable clinical manifestations, pathological traits, and molecular mechanisms.

Diagnostic accuracy comparing OPT and CBCT in the detection of non-vital bone changes before tooth extractions in patients with antiresorptive intake

OBJECTIVES

To compare the diagnostic accuracy in detecting early non-vital bone changes between orthopantomography (OPT) and cone-beam computed tomography (CBCT) in correlation with histopathological findings before tooth extractions in patients with antiresorptive (AR) intake.

SUBJECTS

Patients with an indication tooth extraction who had received OPT and CBCT preoperatively while or after undergoing AR treatment were prospectively enrolled over a 24-month period in the progesterone in spontaneous miscarriage (PRISM) trial. Imaging studies were randomly analyzed by three examiners for early non-vital bone changes using specific predefined characteristics and a 5-level scale (1 definite absence of criteria to 5 definite presence of criteria). Sensitivity and specificity values were calculated in correlation with the histopathologically evaluated bone samples at the time point of tooth extraction.

RESULTS

One hundred thirty patients with 237 treated extraction sites met the inclusion criteria. For all images evaluated by all examiners, CBCT (430/492; 87.4%; receiver operating characteristic [ROC]: area under the curve [AUC] = 0.88; p < 0.001) was more likely to detect histopathologically confirmed non-vital bone than the OPT (132/492; 26.8%; ROC: AUC = 0.562; p = 0.115).

CONCLUSIONS

In the detection of non-vital bone changes, CBCT is superior to OPT in both sensitivity and specificity. Specific imaging characteristics allow for the prediction of early non-vital bone changes already at the time before tooth extractions.

A liquid chromatography-tandem mass spectrometry method for the quantification of ampicillin/sulbactam and clindamycin in jawbone, plasma, and platelet-rich fibrin: Application to patients with osteonecrosis of the jaw

Ampicillin in combination with sulbactam is a widely used drug choice for infection prophylaxis, especially in oral and maxillofacial surgery. Clindamycin serves as an alternative in patients with known allergy to β-lactam antibiotics. To ensure effective prophylaxis, it is important to achieve sufficiently high concentrations of active antibiotic substances in the tissues affected by the surgery. To this end, a LC-MS/MS method was developed and validated that allows the quantification of ampicillin, sulbactam and clindamycin in jawbone, plasma, and so-called platelet-rich fibrin (PRF). Validation was performed in accordance with the European Medicines Agency guidelines for bioanalytical method validation. For all matrices, sample processing was carried out by protein precipitation with acetonitrile or methanol 80%, containing the isotope labelled internal standards (IS) of the three drugs. Analytes were separated on a pentaflourophenyl column at 20 °C using gradient elution. Furthermore, detection was accomplished by electrospray ionisation in positive-ion mode (ampicillin, clindamycin and corresponding IS) and negative-ion mode (sulbactam and corresponding IS) in combination with multiple reaction monitoring. Depending on the analyte and the matrix under investigation, calibration curves ranged from 0.14 to 59.8 µg/g (jawbone - ampicillin), 2.0-1000 µg/mL (plasma - ampicillin), and 1.0-495 µg/mL (PRF - ampicillin). All analytes fulfilled the requirements of the guideline regarding sensitivity, linearity, selectivity, carryover, within-run and between run accuracy and precision, matrix effect and extraction recovery in all matrices. The method was successfully applied to measure concentrations of ampicillin, sulbactam and clindamycin in real-life samples obtained in routine clinical practice.

Comparing the Influence of Surgical and Conservative Therapy on Quality of Life in Patients with Early-Stage Medication-Related Osteonecrosis of the Jaw-A Prospective Longitudinal Study

Background and Objectives: The purpose of this study was to evaluate the impact of surgical and conservative, non-surgical treatment on general health-related (QoL) and oral health-related quality of life (OHRQoL) in patients suffering from AAOMS stage I MRONJ. Materials and Methods: In the course of this prospective clinical study, QoL and OHRQoL using QLQ-C30 and QHIP G14 questionnaire were longitudinally assessed in N = 174 prospectively enrolled patients with indication of treatment of MRONJ stage I over a period of 12 months. Patients received conservative or surgical treatment. The measurement time points were preoperatively (T0), 12 weeks (T1), 6 months (T2) and 1 year after operation (T3). Results: For OHRQoL, no significant (p > 0.05) differences were found between both treatment groups for all timepoints (T0-T3). In the surgical treatment group, OHIP scores of T1, T2 and T3 were significantly lower than baseline measures (T0) (T0-T1 (2.99, p = 0.024), T0-T2 (5.20, p < 0.001), T0-T3 (7.44, p < 0.001)). For conservative treatment group OHIP, scores of T2 and T3 were significantly lower than baseline measures (T0) (T0-T2 (9.09, p = 0.013), T0-T3 (12.79, p < 0.001)). There was no statistically significant effect of time on QLQ-C30 scores in both groups (surgical treatment: F(3, 174) = 1.542, p < 0.205, partial η² = 0.026; conservative treatment: F(3, 30) = 0.528, p = 0.667, partial η² = 0.050). QLQ-C30 scores turned out to be significantly lower in the non-surgical group at T1 (p = 0.036) and T3 (p = 0.047) compared to the surgical treatment group. Conclusions: Surgical and conservative treatment of MRONJ stage I significantly improves patients' OHRQoL. Surgical treatment is superior to conservative treatment of MRONJ stage I regarding general QoL. Therefore, surgical treatment of MRONJ stage I should not be omitted for QoL reasons.

Osteoradionecrosis of the Jaw-Comparison between Bone and Soft Tissue Injury and Their Influence on Surgical Outcomes-A Retrospective Cohort Study

Surgical therapy of osteoradionecrosis of the jaw (ORN) is challenging and requires treatment of the affected hard and soft tissue. To understand how tissue injury after irradiation influences surgical outcomes, the objective of this study was to find out whether (a) bone-related, (b) soft tissue-related, and (c) treatment-related parameters influence the surgical success of patients with ORN. A total of 175 patients (324 lesions) were included in this retrospective, single-center study. All patients were diagnosed with ORN and underwent surgical therapy. The primary outcome was complete soft tissue recovery (mucosa/skin) and the absence of symptoms 3 months after surgery. At the time of follow-up, 58% of patients (189 of 324 lesions) had intact intraoral or extraoral soft tissue. The extent of bone destruction had no effect on treatment success, whereas soft tissue injury due to fibrosis (OR: 0.344; CI 0.142-0.834; p = 0.01818) and xerostomia (OR: 0.163; CI 0.064-0.419; p = 0.00016) increased the probability of treatment failure. Soft tissue reconstruction with a microvascular graft improved therapeutic success compared to local wound closure (OR: 2.998; CI 1.371-6.555; p = 0.006). Thus, for the treatment of ORN, it is extremely important to pay attention not only to the extent of bone destruction but especially to soft tissue defects. Because the extent of soft tissue injury is a predictor for therapeutic success, it should influence the choice of surgical treatment.

Reporting Criteria for Clinical Trials on Medication-Related Osteonecrosis of the Jaw (MRONJ): A Review and Recommendations

Medication-related osteonecrosis of the jaw (MRONJ) is a complication caused by anti-resorptive agents and anti-angiogenesis drugs. Since we wanted to write a protocol for a randomized clinical trial (RCT), we reviewed the literature for the essential information needed to estimate the size of the active patient population and measure the effects of therapeutics. At the same time, we designed a questionnaire intended for clinicians to collect detailed information about their practices. Twelve essential criteria and seven additional items were identified and compiled from 43 selected articles. Some of these criteria were incorporated in the questionnaire coupled with data on clinical practices. Our review found extensive missing data and a lack of consensus. For example, the success rate often combined MRONJ stages, diseases, and drug treatments. The occurrence date and evaluation methods were not harmonized or quantitative enough. The primary and secondary endpoints, failure definition, and date coupled to bone measurements were not well established. This information is critical for writing a RCT protocol. With this review article, we aim to encourage authors to contribute all their findings in the field to bridge the current knowledge gap and provide a stronger database for the coming years.

Osteonecrosis of the jaw in primary dental care: Recognition and referral

Osteoradionecrosis (ORN) and medication-related osteonecrosis of the jaw (MRONJ) are uncommon conditions, however when present they have a significant impact on a patient's quality of life and are notoriously difficult to treat. With medical advances resulting in improved survival rates and increased life expectancy, it is likely that general dental practitioners (GDPs) will more frequently be involved in the oral health management of patients at risk of both ORN and MRONJ. Though management of both diseases is beyond the scope of primary care dentistry, the GDP still has a key role in the patient's overall care. It is therefore important to have a good understanding of these conditions and their consequences for dental treatment in order to provide adequate patient support. Management requires a multidisciplinary approach to treatment and as part of this GDPs are integral in prevention, early recognition and maintenance of oral health following diagnosis. This article aims to refresh the reader's knowledge regarding MRONJ and ORN and support the GDP in managing this patient group.

Evaluation of advanced platelet-rich fibrin (PRF) as a bio-carrier for ampicillin/sulbactam

OBJECTIVES

Mechanisms of wound healing are often impaired in patients with osteonecrosis of the jaw (ONJ). According to the guidelines for the treatment of this disease, early surgical intervention is indicated. However, surgery often faces complications such as wound healing disorders. The application of platelet-rich fibrin (PRF) after necrosectomy between bone and mucosa may constitute a promising approach to improve surgical results. An aspect that was not investigated until now is that PRF acts as a "bio-carrier" for antibiotics previously applied intravenously.

MATERIALS AND METHODS

We investigated the antimicrobial properties of PRF in 24 patients presenting ONJ undergoing systemic antibiosis with ampicillin/sulbactam. We measured the concentration of ampicillin/sulbactam in plasma and PRF and performed agar diffusion tests. Ampicillin/sulbactam was applied intravenously to the patient 10 minutes for blood sampling for PRF. No further incorporation of patients' blood or PRF product with antibiotic drugs was obtained. Four healthy patients served as controls.

RESULTS

Our results revealed that PRF is highly enriched with ampicillin/sulbactam that is released to the environment. The antibiotic concentration in PRF was comparable to the plasma concentration of ampicillin/sulbactam. The inhibition zone (IZ) of PRF was comparable to the standard ampicillin/sulbactam discs used in sensitivity testing.

CONCLUSIONS

The results of our study demonstrated that PRF is a reliable bio-carrier for systemic applied antibiotics and exhibits a large antimicrobial effect.

CLINICAL RELEVANCE

We describe a clinically useful feature of PRF as a bio-carrier for antibiotics. Especially when applied to poorly perfused tissues and bone such as in ONJ, the local release of antibiotics can reduce wound healing disorders like infections.

A comparative study of the clinical characteristics of patients with medication-related osteonecrosis of the jaw and osteoporosis or malignancy

OBJECTIVE

This study aimed to compare the clinical characteristics of patients with medication-related osteonecrosis of the jaw (MRONJ) and osteoporosis vs malignancy.

STUDY DESIGN

The study included patients hospitalized with MRONJ between July 2013 and April 2021. These patients were assigned to the osteoporosis or malignancy groups according to their primary disease. Characteristics and clinical variables were recorded and compared.

RESULTS

Nighty-one patients (107 MRONJ lesions) were included, with 12 (14 lesions) in the osteoporosis group and 79 (93 lesions) in the malignancy group. The osteoporosis and malignancy groups differed in their respective incubation periods (57.0 ± 42.8 vs 29.3 ± 19.8 months, respectively; P = .048), bisphosphonates cumulative dose (16,487.4 ± 14,268.8 mg alendronate vs 104.0 ± 79.9 mg zoledronic; P = .014), and rate of patients receiving antiangiogenic agents (0/12, 0.0% vs 48/79, 60.8%; P = .001). The groups were similar in their treatment outcomes, measured as successful surgeries (11/12, 91.7% vs 59/79, 74.7%; P = .351).

CONCLUSIONS

For stage 2 or 3 MRONJ, patients with osteoporosis (exposed to oral bisphosphonates) developed MRONJ over a longer incubation period than patients with malignancy. The groups had similar responses to surgery.

Surgical treatment of 61 consecutive patients with maxillary stage 3 medication-related osteonecrosis of the jaws using a pedicled buccal fat pad

PURPOSE

Buccal fat pad (BFP) is used for the closure of large oroantral defects caused by surgical removal of the necrotic bone in patients with medication-related osteonecrosis of the jaw (MRONJ). This study aimed to evaluate the use of BFP for the closure of maxillary sinus defects in stage 3 MRONJ patients.

METHODS

This study recruited 61patients with large oroantral defects caused by MRONJ, including 49 patients with cancer and 12 patients with osteoporosis. Lesions were evaluated clinically and radiographically.

RESULTS

Among the 61 patients, 51 (83.6%) healed uneventfully, and 5 patients (8.2%) had local dehiscence and exposed bone; these 56 patients (91.8%) all healed after first or second operation. The Eastern Cooperative Oncology Group Performance Status was associated with being non-cured and might be an indicator for the healing process. All patients experienced a significant increase in body weight postoperatively.

CONCLUSIONS

This study suggest that block resection with removal of the necrotic bone combined with radical sinusotomy and closure of the defect with BFP is a reliable method to cure MRONJ lesions with a high success rate, and successful operation and prosthetic rehabilitation may improve body weight and the quality of life. The study was approved by the appropriate ethical approval for the Copenhagen ONJ Cohort (protocol no. H-6-2013-010) November 20, 2013.

Non-Interventional Prospective Observational Study of Platelet Rich Fibrin as a Therapy Adjunctive in Patients with Medication-Related Osteonecrosis of the Jaw

BACKGROUND

Medication-related osteonecrosis (MRONJ) of the jaw is a severe and feared side effect of antiresorptive therapy in the oncological setting. With growing evidence that impaired angiogenesis may represent a key factor in pathogenesis, the aim of this study was to evaluate an autologous platelet concentrate as a possible additive in surgical therapy to optimize vascularization and, subsequently, resolution rates.

MATERIAL AND METHODS

A non-interventional, prospective, multicenter study was conducted, and all patients with stage I-III MRONJ, undergoing antiresorptive therapy for an oncological indication, were included. The necrosis was treated surgically without (study arm A) or with (arm B) the addition of an autologous platelet concentrate (platelet-rich fibrin, PRF).

RESULTS

After 5, 14, and 42 days postoperative, wound healing (primary outcome: mucosal integrity) as well as downstaging, pain perception, and oral health-related quality of life (secondary outcome) were assessed via clinical evaluation. Among the 52 patients included, primarily with MRONJ stage I and II, the use of PRF as an additive in surgical therapy did not display a significant advantage for wound healing (p = 0.302), downstaging (p = 0.9), pain reduction (p = 0.169), or quality of life (p = 0.9).

SUMMARY

In conclusion, PRF as an adjunct did not significantly optimize wound healing. Further, no significant changes in terms of downstaging, pain sensation, and oral health-related quality of life were found.

The efficacy of mylohyoid muscle flap use in surgical treatment of 'krokodil' drug-related osteonecrosis of the mandible

The aim of this study is to show the effectiveness of the use of mylohyoid muscle flap in surgical treatment of stage 1 and 2 Krokodil drug-related ON of mandible. Retrospective study of patients with stage 2 Krokodil drug-related ON of distal mandible was performed. Regarding to the used surgical technique the patients were divided into two groups (groups 1 and 2). In group 1(control group) the wound was closed only by the local mucoperiosteal flaps, while in group 2 (experimental group) the wound was closed by combining mylohyoid muscle flap and local mucoperiosteal flaps. 24 patients were included in this study (15 patients in the group 1 and 9 patients in the group 2). In all patients of experimental group the postoperative period was uneventful and no recurrence occurred. In group 1 recurrence was found in 7 patients, which is significantly higher than in group 2 (χ²=5.9, p=0.015). Disease recurrence occurred as wound dehiscence during 4-10 postoperative days. Within the limitations of the study it seems that the adoption of the mylohyoid muscle flap as double-layer closure technique is an effective and predictable method for the treatment of such patients and, therefore, should be chosen whenever deemed appropriate.

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.

Surgical management of stage-2 medication-related osteonecrosis of the jaw with transplantation of human amniotic membrane: Preliminary results

Medication-related osteonecrosis of the jaw (MRONJ) is a drug adverse reaction. Seven osteonecrosis areas in 5 cases were treated with stage-2 MRONJ using human amniotic membrane (HAM) transplantation after sequestrectomy. Patients were evaluated in terms of infection (pain, erythema, and pus), mucosal coverage, and pain at 1, 2, 4, 8, and 12 weeks. Patients who showed improvement (total mucosal coverage, no sign of infection and pain) at the end of 12 weeks were followed up every 8 weeks. Also, radiographic examinations (panoramic radiography at every 8 weeks, cone-beam computed tomography at every 6 months) were performed to evaluate bone destruction. Complete mucosal closure was achieved in 6 necrosis sites. In only 1 patient, mucosal coverage was not achieved. No pain and infection relapse were observed during the follow-ups. HAM might be an effective material in terms of soft tissue healing and elimination of pain and infection for stage-2 MRONJ. Clinical Trials Registration Number: NCT04967963.

Characterization of Mesenchymal Stem Cells Derived from Bisphosphonate-Related Osteonecrosis of the Jaw Patients' Gingiva

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a clinical condition that specifically occurs in the oral cavity, characterized by retarded wound healing in oral mucosa accelerating the exposure of bone. Moreover, the pathological mechanism remains poorly understood. Gingival mesenchymal stem cells (GMSCs) play a critical role in gingival healing and soft tissue regeneration. Although previous studies have showed that bisphosphonates (BPs) are highly toxic to healthy GMSC, there is overall lack of direct evidence demonstrating the characterization of GMSCs derived from BRONJ patients. In present study, we isolated GMSCs for the first time from the central area of BRONJ patients' gingiva (center-BRONJ GMSCs) and the peripheral area (peri-BRONJ GMSCs), and found that they exhibited decreased proliferation, adhesion, migration capacities and underwent early apoptosis in vitro compared control GMSCs. Notably, the central and peripheral BRONJ GMSCs transplantation in a mice excisional skin model also displayed lower cell survival rate and poor healing effects than that of controls. Mechanistically, TGF-β1 signaling pathway was suppressed not only in BRONJ patients' gingival lesions but also in BRONJ GMSCs transplantation animal model. The results above suggested that under the microenvironment of BRONJ patients, the dysfunction of GMSCs and the suppressed TGF-β1 signaling pathway may be the vital factors in impaired gingival healing, thus contributing to persistent exposure of underlying bone and development of BRONJ. This study provides new insights into the prevention for BRONJ by improving the functions of GMSCs and upregulating TGF-β1 in accelerating gingival wound healing. Schematic illustration of the dysfunction of BRONJ GMSCs in vitro and BRONJ GMSCs transplantation in a mice skin model delaying cutaneous wound healing mainly via suppressing TGF-β1 signaling pathway.

Recurrence-Related Factors of Medication-Related Osteonecrosis of the Jaw: A Five-Year Experience

PURPOSE

The treatment of medication-related osteonecrosis of the jaw (MRONJ) is greatly challenging for surgeons. In this study, we reviewed patients with MRONJ treated in our hospital in the past 5 years and explored the risk factors of recurrence.

METHODS

A retrospective cohort study was conducted to review the patients with MRONJ from January 1, 2016 to December 31, 2020. All patients received a monthly intravenous application of zoledronic acid. The primary outcome variable was the treatment outcome during follow-up. The predictor variables were local and systemic factors related to the treatment outcome. Multivariate logistic regression analysis was performed to identify the risk factors of recurrence after MRONJ treatment.

RESULTS

A total of 58 patients (62 sites) were included in this study. In multivariate regression analysis, the risk factor associated with recurrence after MRONJ treatment was the duration of medication of more than 18 months (odds ratio = 7.346; 95% confidence interval: 1.461-36.946; P = .016).

CONCLUSIONS

Using zoledronic acid over 18 months may increase the risk of recurrence in MRONJ patients.

Combined approach to treatment of advanced stages of medication-related osteonecrosis of the jaw patients

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Removal of necrotic bone is important in the treatment of medication- related osteonecrosis of the jaw.

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Surgical treatment is more successful than conservative treatment in advanced stages (stage 2–3) of the medication- related osteonecrosis of the jaw.

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Relatively less invasive and supportive treatments are recommended in patients with advanced medication- related osteonecrosis of the jaw.

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Patient follow-up, good oral hygiene and patient motivation increase the success rate of the treatment.

Introduction

Increased incidence of localized osteonecrosis in the jaw bones caused by bisphosphanate use and reduced quality of life of the patients led researchers to diagnose the disease in the early period and to investigate the effective treatment modality.

Objective

Treatment of medication-related osteonecrosis of the jaw patients is based on individual protocols from clinical experience, as there are no definitive treatment guidelines. In view of the lack of consensus on the effectiveness of medication-related osteonecrosis of the jaw treatments in the literature, the aim of this study was to evaluate the surgical technique described in the treatment of advanced stages of medication-related osteonecrosis of the jaw patients.

Methods

Twenty-one patients affected by Stage 2–3 medication-related osteonecrosis of the jaw were treated with ultrasonic piezoelectric bone surgery for necrotic bone removing, leukocyte and platelet-rich fibrin concentrate obtained from the patient’s peripheral blood and Nd:YAG laser for biostimulation. Success was assessed as the maintenance of full mucosal coverage without signs of residual infection at 1-month (T1), 3-months (T2), 6-months (T3) and 1-year (T4) after surgery. Logistic regressions were used to evaluate the association between the different independent variables and treatment outcomes.

Results

Two Stage 3 patients had delayed healing at 1 month after the operation. Complete mucosal healing was achieved in all patients at the third month. Multivariate analysis demonstrated that different variables were not significantly correlated with delayed healing (p > 0.05).

Conclusion

The surgical protocol presented in this study shows promising results for surgical management of advanced stages of medication-related osteonecrosis of the jaw patients.

A critical assessment of the medication-related osteonecrosis of the jaw classification in stage I patients: a retrospective analysis

Objectives

It is unclear whether the extent of intraoral mucosa defects in patients with medication-related osteonecrosis of the jaw indicates disease severity. Therefore, this study investigated whether mucosal lesions correlate with the true extent of osseous defects in stage I patients.

Materials and Methods

Retrospectively, all patients with stage I medication-related osteonecrosis of the jaw who underwent surgical treatment between April 2018 and April 2019 were enrolled. Preoperatively, the extent of their mucosal lesions was measured in clinical evaluations, and patients were assigned to either the visible or the probeable bone group. Intraoperatively, the extent of necrosis was measured manually and with fluorescence.

Results

Fifty-five patients (36 female, 19 male) with 86 lesions (46 visible bone, 40 probeable bone) were enrolled. Intraoperatively, the necrotic lesions were significantly larger (P<0.001) than the preoperative mucosal lesions in both groups. A significant (P<0.05) but very weak (R2<0.2) relationship was noted between the extent of the mucosal lesions and the necrotic bone area.

Conclusion

Preoperative mucosal defects (visible or probeable) in patients with medication-related osteonecrosis of the jaw do not indicate the extent of bone necrosis or disease severity.

New Perspective for Soft Tissue Closure in Medication-Related Osteonecrosis of the Jaw (MRONJ) Using Barbed Sutures

The aim of this study was to compare the effectiveness of barbed versus smooth sutures for soft tissue closure of exposed jawbone sites in medication-related osteonecrosis of the jaw (MRONJ) patients. Exposed necrotic jawbone sites surgically managed by intraoral soft tissue closure were evaluated. Either barbed sutures (Stratafix™ or V-Loc™) together with Prolene^® or Vicryl^® sutures were used. We estimated the effect of barbed sutures (BS) with Prolene^® compared to smooth sutures (Vicryl^®) on the hazard rate of intraoral soft tissue dehiscence using a multivariate Cox regression model within a target trial framework, adjusting for relevant confounders. In total, 306 operations were performed in 188 sites. In the primary analysis 182 sites without prior surgery were included. Of these, 113 sites developed a dehiscence during follow-up. 84 sites were operated using BS and Prolene^®. A total of 222 sites were operated with Vicryl^® (control group). In the BS group, the median time to event (i.e., dehiscence) was 148 days (interquartile range (IQR), 42–449 days) compared to 15 days (IQR, 12–52 days) in the control group. The hazard rate of developing intraoral dehiscence was 0.03 times (95%-confidence interval (CI): 0.01; 0.14, p < 0.001) lower for BS patients compared to the control group. Within the limits of a retrospective study, BS showed a high success rate and are therefore recommended for soft tissue closure of exposed jawbone sites in MRONJ patients. Additional studies are warranted to further evaluate this novel application of BS.

Clinical outcomes of open and closed management after surgical treatments in patients with medication-related osteonecrosis of the jaw

CONTEXT AND PURPOSE

To achieve success following surgical treatment of MRONJ, complete wound closure has been considered necessary; open wound management has not been generally recommended. Therefore, various closure techniques using local flaps have been reported. However, these techniques often increase surgical invasiveness, and there is minimal evidence regarding whether complete wound closure is preferable to open wound management following surgical treatment of MRONJ. The aim of this study was to clarify whether complete wound closure is necessary for successful healing following surgical treatment of MRONJ.

PROCEDURES

This retrospective study included 52 patients with stage 2 and 3 MRONJ who underwent surgical treatment. Twenty-seven of the 52 patients received open wound management, while the remaining 25 received complete wound closure management. The outcomes of both groups were evaluated at the 6-month follow-up visit; 'success' was defined as complete mucosal covering without symptoms and 'failure' was defined as the presence of residual bone exposure or progression of disease.

MAIN FINDINGS

In the open wound group, 23 patients (85.1%) exhibited 'success' and four patients (14.8%) exhibited 'failure'; in the closed wound group, 21 patients (84.0%) exhibited 'success' and four patients (16.0%) exhibited 'failure'. These outcomes were not significantly different between groups.

PRINCIPAL CONCLUSIONS

Although complete wound closure has many advantages with respect to the healing process, open wound management is also acceptable for patients with difficulty achieving complete wound closure, as well as for surgeons who wish to reduce surgical invasiveness.

Factors Influencing Severity of Medication-Related Osteonecrosis of the Jaw: A Retrospective Study

PURPOSE

The progression of medication-related osteonecrosis of the jaw (MRONJ) is influenced by many factors. This study aimed to identify the clinical risk factors associated with severe MRONJ (stage 3).

PATIENTS AND METHODS

The data of patients with MRONJ who were hospitalized between July 2013 and December 2019 were retrospectively analyzed. Demographic and clinical factors were the independent variables, and the clinical stage of MRONJ lesions was the dependent variable. Multivariate logistic regression analysis was performed to identify the risk factors for advanced stage disease (MRONJ stage 3).

RESULTS

A total of 79 patients (with 93 MRONJ lesions) were included. In multivariate regression analysis, the risk factors associated with stage 3 MRONJ were age ≤65 years (odds ratio [OR] = 3.968, 95% confidence interval [CI]: 1.280-12.301; P = .017); chemotherapy (OR = 3.687, 95% CI: 1.048-12.972; P = .042); preoperative MRONJ duration ≥12 months (OR = 7.616, 95% CI: 1.865-31.110; P = .005); lesion location in maxilla (OR = 1.150, 95% CI: 1.006-1.315; P = .041); lesion location in posterior jaw, that is, in molar area (OR = 1.384, 95% CI; 1.118-1.715; P = .003); and serum albumin <40 g/L (OR = 6.257, 95% CI: 1.313-29.815; P = .021).

CONCLUSIONS

Age ≤65 years, chemotherapy, preoperative MRONJ duration ≥12 months, lesion location in maxilla, lesion location in the molar area, and serum albumin <40 g/L may increase the risk for severe MRONJ.

The Type of Antiresorptive Treatment Influences the Time to Onset and the Surgical Outcome of Medication-Related Osteonecrosis of the Jaw

PURPOSE

Few data exist focusing on differences in the time to disease onset and the success rates in patients suffering from medication-related osteonecrosis of the jaw (MRONJ) dependent on their different antiresorptive treatment. The purpose of this study was to analyze and compare these variables for patients treated with bisphosphonate (BP) or denosumab (DNO) and for patients who switched the antiresorptive drug (BP/DNO).

PATIENTS AND METHODSS

A retrospective single-center cohort study with patients suffering from MRONJ was conducted. The predictor variable was the antiresorptive treatment, the outcome variables were 1) time to onset of MRONJ (time of antiresorptive treatment to MRONJ diagnosis) and 2) treatment success (mucosal integrity 12 months postoperatively). The other variables include data on demographic, underlying disease, MRONJ stage, and trigger events. Cox and logistic regression, Phi-coefficient, Cramer's V, and Kruskal-Wallis tests were applied.

RESULTS

One hundred thirty-two patients were included and divided into 3 groups: group I (BP) n = 45 patients, n = 59 lesions; group II (BP/DNO) n = 42 patients, n = 71 lesions; and group III (DNO) n = 45 patients, n = 62 MRONJ lesions. Treatment success and time to onset differed significantly between the groups: success rates in group I BP (84.7%) were significantly lower (P = .04) than in group II BP/DNO (91.5%, P = .12) and group III DNO (90.3%, P = .35). The onset was significantly earlier in group III DNO (median 2.0 years, Q_0.25: 1.49, Q_0.75: 2.98; confidence interval 95%: 1.93 to 2.83) than in group II BP/DNO (median 4.07 years, Q_0.25: 1.64, Q_0.75: 6.70; confidence interval 95%: 3.55 to 5.68) and group I BP (median 3.86 years, Q_0.25: 1.69, Q_0.75: 6.46; confidence interval 95%: 3.43 to 5.87).

CONCLUSIONS

The different antiresorptive drugs show distinctive characteristics of time to onset and treatment success with the lowest success rates in the BP group and the earliest onset in the DNO group. The switch of the antiresorptive therapy (BP to DNO) did not influence the outcome variables negatively.

Autofluorescence-guided surgery for the treatment of medication-related osteonecrosis of the jaw (MRONJ): a retrospective single-center study

OBJECTIVE

Medication-related osteonecrosis of the jaw (MRONJ) has become a serious concern for patients under antiresorptive treatment, especially in the oncological setting. Different approaches have been described in the management of MRONJ, including innovative autofluorescence-guided surgery. However, until now, there has been a lack of data regarding the outcome. In this study, we evaluated the efficacy of minimally invasive autofluorescence-guided resection in MRONJ.

STUDY DESIGN

Seventy-five patients with 82 lesions were included in this retrospective, single-center study. All included patients were diagnosed with MRONJ according to the American Association of Oral and Maxillofacial Surgeons guidelines and underwent autofluorescence-guided surgery with a minimum follow-up of 3 months. The primary outcome was complete integrity of the mucosa and absence of bone exposure.

RESULTS

The MRONJ stages were stage 0 (3.7%), stage 1 (3.7%), stage 2 (75.6%), and stage 3 (17%). Overall, complete mucosal healing of all lesions after the first surgery was 81.7% (67 of 82), whereas it was 90.2% (74 of 82) after revision surgery.

CONCLUSIONS

The study showed that autofluorescence-guided surgery is a safe and successful treatment option that can be considered for all stages of MRONJ.

Wound closure and alveoplasty after preventive tooth extractions in patients with antiresorptive intake-A randomized pilot trial

OBJECTIVES

To compare success rates between the sub-periosteal prepared (SPP) muco-periosteal flap and the epi-periosteal prepared (EPP) mucosa flap and the feasibility of alveoplasty after surgical tooth extractions in patients undergoing/after antiresorptive treatment.

SUBJECTS

Patients with an indication for preventive tooth extraction undergoing/after antiresorptive treatment were enrolled over a 24-month period in a parallel-group randomized clinical pilot trial and randomly assigned for primary wound closure to either the SPP or the EPP group. The primary outcome was treatment failure 8 weeks after surgery. To assess the feasibility of alveoplasty, necrotic bone changes at the time point of tooth extraction were evaluated.

RESULTS

One hundred and sixty patients were randomized to the SSP (n = 82) or the EPP (n = 78) group. One hundred and fifty-seven patients met the primary endpoint 8 weeks after surgery with five treatment failures for the SPP group (6.3%) and 18 (23.4%) for the EPP group (p = .004). A significant relationship (p < .0001) was observed between symptomatic teeth and non-vital bone found in 54.8% of all biopsies.

CONCLUSIONS

The strong superiority of the muco-periosteal flap as primary wound closure revealed the feasibility and effectiveness of the study. The large number of necrotic biopsies emphasizes the importance of alveoplasty as a preventive measure.

Surgical treatment of advanced medication-related osteonecrosis of the jaws: Comparison of soft tissue closure techniques and evaluation of side effects

The aim of the study was to evaluate the surgical outcome of patients with advanced medication-related osteonecrosis of the jaw (MRONJ) treated with different flaps for soft tissue closure. Only MRONJ stage III patients with a minimum follow-up of 6 months were included in our prospective study. The soft tissue closure techniques were: Mylohyoid Muscle Flap, Buccal Fat Flap and mucoperiosteal flap alone. Potential risk factors and surgical side effects were analyzed. Relapses occurred in 12 of 44 included cases and 38 reached mucosal integrity within the follow-up. Cases treated with the muscle or fat flap showed better results regarding the recurrence rate (p < 0.001) and soft tissue healing (p = 0.002): only 3 of 33 developed a relapse, and 31 of 33 reached mucosal integrity. The outcome was worse if MRONJ occurred at the front areas of the jaw (p = 0.025). Postoperative, the pain level was reduced significantly (p < 0.001). Partial hypoesthesia of the lip arose in 18 cases. An impairment of the long-term prosthetic rehabilitation has not been seen.Patients with MRONJ stage III undergoing surgery benefit from extensive soft tissue closure.

Oral Surgical Management of Bone and Soft Tissues in MRONJ Treatment: A Decisional Tree

Background: The aim of the present work was to analyze a 10-year retrospective series of surgically treated medication-related osteonecrosis of the jaws (MRONJ) cases, reporting the clinical outcome and success rate for each adopted procedure in order to draw a treatment algorithm that is able to standardize clinical decision making and maximize the success of oral surgical treatment of MRONJ. Methods: Different surgical approaches were categorized taking into consideration two variables (a) hard tissue management (defined as debridement, saucerization or marginal resective surgery of maxillary necrotic bone) and (b) soft tissue management (defined as type of flap design and related modality of wound-healing). Results: For the retrospective cohort study, 103 MRONJ patients were enrolled and a total of 128 surgical procedures were performed. The role of radical-intended surgery using local flaps in MRONJ treatment was investigated, as well as palliative treatments. All stage I–II patients completely healed when a combination of radical necrotic bone surgery associated with a first intention healing of soft tissues was obtained. In stage III, when a patient was not eligible for maxillo-facial surgery, the use of palliative surgical strategies was effective in symptom relief in order to maintain a better quality of life for the duration of the patient’s life. Conclusions: Oral surgery with radical intent associated with a flap design able to ensure first intention healing might represent a valid option for the majority of MRONJ patients. The designed decision tree allows clinicians to assess individual surgical approaches for MRONJ treatment in accordance with patient-centered outcomes and surgical skills.

Replacing one evil with another: Is the fibula really a dispensable spare part available for transfer in patients with medication-related osteonecrosis of the jaws?

Because of the long-term and consecutive use of different causative agents, clinicians are increasingly encountering patients needing restoration of the stomatognathic system after surgical resection of highly advanced necroses of the jaw. For plastic restoration in these cases, microvascular reconstruction seems to represent the most viable option. According to the limited data available, the risks of this operation are considered comparable with those faced by other patient cohorts. We report here the case of a patient who suffered 2 successive pathologic fractures of the tibia after microsurgical reconstruction of the mandible with a free fibula flap. This exemplifies a general problem, especially because the patient also suffered from a treatment-refractory infection of the transplanted bone. Although the present literature indicates otherwise, fibula transplants might not be the gold standard in these cases. Therefore, alternatives to transplants from the weight-bearing parts of the body need to be considered until more data are available.

Adipose-derived stem cells prevent the onset of bisphosphonate-related osteonecrosis of the jaw through transforming growth factor β-1-mediated gingival wound healing

Background

Due to its complex pathogenesis and low clinical cure rate, bisphosphonate-related osteonecrosis of the jaw (BRONJ) poses a substantial challenge for oral and maxillofacial surgeons. Therefore, the treatment of BRONJ should focus on prevention. In clinical studies, primary wound closure can significantly reduce the incidence of BRONJ. Whether local stem cell transplantation can promote primary gingival healing in patients with a medication history and prevent BRONJ has not been reported.

Methods

In this study, animals were divided into a healthy group (non-drug treatment), a BP group, a hydroxyapatite (HA) group, and an adipose-derived stem cell (ADSC) group. All groups except the healthy group were treated with BPs and immunosuppressive drugs once per week for 8 weeks, simulating clinical use for the treatment of cancer patients with bone metastasis, to induce BRONJ-like animals. After the sixth drug treatment, the bilateral premolars were extracted in all groups. In contrast to the healthy and BP groups, the extraction sockets in the HA and ADSC groups were filled with HA or HA + ADSCs simultaneously post extraction to observe the preventive effect of ADSCs on the occurrence of BRONJ. At 2 and 8 weeks post extraction, animals from all groups were sacrificed.

Results

At 8 weeks post transplantation, ADSCs prevented the occurrence of BRONJ, mainly through accelerating healing of the gingival epithelium at 2 weeks post extraction. We also found that ADSCs could upregulate the expression of transforming growth factor β1 (TGF-β1) and fibronectin in tissue from animals with a medication history by accelerating gingival healing of the extraction socket. A rescue assay further demonstrated that TGF-β1 and fibronectin expression decreased in TGF-β1-deficient ADSC-treated animals, which partially abolished the preventive effect of ADSCs on the onset of BRONJ.

Conclusion

ADSCs prevent the onset of BRONJ, mainly by upregulating the expression of TGF-β1 and fibronectin to promote primary gingival healing, ultimately leading to bone regeneration in the tooth extraction socket. Our new findings provide a novel stem cell treatment for the prevention of BRONJ.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1277-y) contains supplementary material, which is available to authorized users.

Is the conservative non-surgical management of medication-related osteonecrosis of the jaw an appropriate treatment option for early stages? A long-term single-center cohort study

PURPOSE

No consensus has been reached regarding the best treatment option for early-stage lesions in medication-related osteonecrosis of the jaw (MRONJ). The purpose of the present study was to evaluate the long-time outcomes of conservative non-surgical management in stage I patients with underlying malignant disease.

MATERIALS AND METHODS

We designed and implemented a retrospective cohort study and enrolled, between 2008 and 2018, a sample of patients with the indication for non-surgical conservative treatment stage I lesions. The primary outcome variable was treatment success defined as mucosal integrity without signs of infection. Secondary outcomes were: (i) worsening stage, (ii) necessity for surgical intervention over time, and (iii) discontinuation of antiresorptive therapy.

RESULTS

The sample included 75 patients with 92 lesions. Eight lesions showed full mucosal coverage, whereas 84 continued with exposed jaw bone (91.3%). Of the treatment-resistent 84 lesions, 67 presented a worsening stage shift over time. Indication for surgical intervention was set in 57 lesions. Of all lesions, 28 developed highly advanced necrotic bone destruction. Antiresorptive medication was paused in all evaluated patients after the first diagnosis of MRONJ.

CONCLUSION

Conservative non-surgical therapy in MRONJ stage I leads to a healing in rare cases. Conservative management might be a good option to preserve symptoms in patients either unwilling to undergo surgery or in those whose reduced general condition does not allow surgery. Early and consequent surgical advances should be performed throughout all stages of the disease to prevent the possibility of silent disease progression with the risk of large-scale bone loss.

Surgical treatment of medication-related osteonecrosis of the upper jaw: Case series

PURPOSE

The management of maxillary medication-related osteonecrosis of the jaw (MRONJ) is challenging. Therefore, identifying the proper treatment is important. This study aimed to evaluate the surgical treatment of maxillary MRONJ using single-layer closure with mucoperiosteal flap and double-layer closure with buccal fat pad flap (BFPF) and mucoperiosteal flap and to find the outcomes after rehabilitation with obturators.

METHODS

A retrospective analysis was conducted and included all surgically treated and followed-up maxillary MRONJ cases in a single center. Demographics and clinical data, stage of MRONJ, surgical treatment, and treatment outcome were collected.

RESULTS

Seventy-nine lesions were included. Removal of necrotic bone was followed by coverage with mucoperiosteal flap in 60 lesions and BFPF in 14 lesions. Seven lesions (five primarily and two following unsuccessful treatment with BFPF) underwent necrectomy and were reconstructed with obturators. Complete mucosal healing was achieved in 76.7% of the lesions covered with mucoperiosteal flap. BFPF led to complete mucosal healing in 85.7% of the lesions. No complications were observed in the defects rehabilitated with obturators.

CONCLUSION

Removal of necrotic bone followed by closure with mucoperiosteal flap is reliable for MRONJ treatment. BFPF is effective for closure of MRONJ-related oroantral communications (OACs).