The role of mylohyoid flap in the treatment of bisphosphonate-related osteonecrosis of the jaws

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.

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.

Drug holiday of high-dose denosumab and recovery from osteoclast inhibition using immunohistochemical investigation of 7 patients with medication-related osteonecrosis of the jaw undergoing segmental mandibulectomy

Background/purpose

Denosumab is used to treat bone metastases from malignant tumors. Unlike bisphosphonates, denosumab is not deposited in the bone; thus, withdrawal for a relatively short period would help recovery from osteoclast suppression. This study investigated the relationship between drug holidays and recovery from osteoclast suppression.

Materials and methods

Seven patients who received high-dose denosumab and underwent segmental mandibulectomy for medication-related osteonecrosis of the jaw were enrolled in this study. Osteoclast suppression (+) was defined as the absence of cathepsin K-positive cells or cathepsin K-positive mononuclear or small multinucleated cells observed on the bone surface of both mesial and distal specimens. When normal osteoclasts were found, osteoclast suppression was defined as (-); when both suppressed cathepsin K-positive cells and normal morphological osteoclasts were found, it was defined as (±).

Results

Osteoclast suppression was: (+) in four patients, three without a drug holiday and one with a 9-month drug holiday; (±) in one patient with an 8-month drug holiday, and (-) in two patients with drug holidays for 13 and 20 months.

Conclusion

These findings suggest that a long-term drug holiday, such as 12 months, is required for recovery from osteoclast suppression in patients with cancer receiving high-dose denosumab.

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.

Relationship between drug holiday of the antiresorptive agents and surgical outcome of medication-related osteonecrosis of the jaw in osteoporosis patients

A drug holiday of 3 months does not promote separation of sequestra and is not correlated with treatment outcomes after surgical therapy in osteoporosis patients who receive antiresorptive agents and who have medication-related osteonecrosis of the jaw. Medication-related osteonecrosis of the jaw (MRONJ) is a serious adverse effect of antiresorptive agents alone or in combination with immune modulators or antiangiogenic medications, in the absence of radiation exposure to the head and neck region. The effectiveness of surgical treatment for MRONJ has been reported, but the timing of the operation remains controversial. The purpose of this study was to clarify whether preoperative drug holidays of antiresorptive agents promote sequestrum separation and improve treatment outcomes in patients who receive low doses of antiresorptive agents. This retrospective study included 173 patients who received low-dose antiresorptive agents and underwent surgical therapy. The effects of a drug holiday on the separation of sequestra and treatment outcomes were analyzed using logistic and Cox regression analyses. Multivariate analysis revealed that administration of an antiresorptive agent for more than 4 years, a high number of lymphocytes, and an extensive osteolytic area were significantly correlated with separation of sequestra, but drug holiday did not promote sequestrum separation. Furthermore, a drug holiday of 90, 120 or 180 days did not show any improvement in treatment outcomes. The drug holiday of the antiresorptive agents for the treatment of MRONJ is unnecessary, and surgical therapy should be performed early.

Retrospective Analysis of Treatment Outcomes of Maxillary Sinusitis Associated with Medication-Related Osteonecrosis of the Jaw

Although maxillary sinusitis often occurs in patients with medication-related osteonecrosis of the jaw (MRONJ) of the upper jaw, there have been few reports on the treatment and outcomes for maxillary sinusitis associated with maxillary MRONJ. This study aimed to retrospectively investigate the treatment outcomes of maxillary sinusitis in patients with MRONJ of the upper jaw. There were 34 patients diagnosed with maxillary MRONJ and sinusitis by preoperative computed tomography who underwent surgery in our institution between January 2011 and December 2019. Age, sex, primary disease, stage of MRONJ, class and administration period of an antiresorptive agent, corticosteroid administration, preoperative leukocyte count and serum albumin level, periosteal reaction, sinusitis grade, maxillary sinus surgical procedure, and treatment outcomes of MRONJ and sinusitis were examined. There were 7 male and 27 female patients (average age, 74.7 years). Complete healing of MRONJ was obtained in 29 of 34 patients (85.3%). Maxillary sinusitis resolved or improved in 21 patients (61.8%) but did not change or worsen in 13 patients (38.2%). We found that complete resection of necrotic bone with intraoperative irrigation of the maxillary sinus may provide good treatment outcomes for maxillary sinusitis associated with MRONJ, although our findings were not statistically significant owing to the small number of patients.

Vascularised periosteal free flap reconstruction for medication-related osteonecrosis of the jaw: a case series

Introduction: The standard of care for medication-related osteonecrosis of the jaw (MRONJ) involves anti-biotics and local debridement to promote tissue healing over exposed bone. We compare outcomes for patients with advanced MRONJ managed with vascularised periosteal radial forearm free flap (RFFF) ver-sus local nasolabial flap and conservative dental measures. Methods: A retrospective case series of patients presenting to the Alfred Hospital for evaluation and man-agement of stage II or above MRONJ between 1 January 2014 and 30 June 2018. The hospital database was searched And a medical record review performed. Results of pre- and post-treatment imaging were ana-lysed bya single senior radiologist blinded to treatment modality . Asymptomatic wound closure, radio-logical evidence of disease cessation and patient satisfaction at six months post-treatment according to treatment type were assessed. Results: Of the ten patients included in the study, four received dental measures, three received local na-solabial flap and three received RFFF flap. All flap reconstruction (6/6) showed asymptomatic wound clo-sure and patient satisfaction at six months follow-up compared to patients managed with dental measures (1/4). All RFFF patients (3/3) showed increased bone deposition radiologically at six months compared to the dental group who showed a mixed (3/4) picture or worsened (1/4) picture. Nasolabial flap patients showed a mixed (2/3) or improved radiological picture (1/3). Conclusion: MRONJ is a relapsing disease. Preliminary evidence suggests that radical debridement with local nasolabial flap or RFFF reconstruction for advanced MRONJ is more effective at halting the disease and alleviating morbidity than conservative dental measures alone.

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.

Bosutinib-induced osteonecrosis of the jaw in a patient with chronic myeloid leukemia: a case report

Medication-related osteonecrosis of the jaw (MRONJ) is an uncommon adverse drug reaction that can be induced by certain therapeutic drugs, including antiresorptive and antiangiogenic agents. Here, we describe the first case of ONJ induced by bosutinib, a tyrosine kinase inhibitor, in a patient with chronic myeloid leukemia (CML) who was not taking an antiresorptive agent. A 65-year-old male with no history of either antiresorptive treatment or dental surgery but diagnosed with CML had been undergoing treatment with bosutinib for 2 years. He developed right mandibular stage 2 osteonecrosis. The patient eventually underwent extensive surgery consisting of removal of the necrotic bone and infected soft tissue in combination with nasolabial flap reconstruction. He obtained complete resolution of MRONJ at 12 months postoperatively. As new cancer therapies become available, it is important that clinicians are aware of this novel case of bosutinib-induced ONJ in a patient undergoing CML treatment.

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.

Sublingual Gland and Mylohyoid Muscle Advancement: A Novel Combined Local Soft Tissue Reconstruction

ABSTRACT

Here the authors present the surgical management of a 78-year-old female with a superficial squamous cell carcinoma of the mucosa overlying her edentulous mandibular alveolus with no evidence of bony invasion.Combining the superficial nature of the lesion, patient age and substantial medical comorbidities, a limited intra-oral resection was planned, to avoid the need for free flap reconstruction. The operation required a wide local excision with clear clinical margins and a mandibular rim resection.All of the currently available reconstructions would result in prolonged surgical time, donor site morbidity, and possible secondary procedures. To overcome these pitfalls, a sublingual gland and mylohyoid muscle advancement flap was designed and executed. By combining the mylohyoid muscle and sublingual gland tissue as an advancement flap in a tension-free manner, secured to the remaining circumferential mucosa, a watertight closure was achieved.After an uneventful recovery without complication the patient was discharged the following day. Complete epithelialization was observed on day 25. Adjuvant radiotherapy was offered to reduce the risk of recurrence and progression. To date, no bony exposure and no pathological fractures have occurred.In conclusion, the entire procedure is simple and innovative. There is minimal donor site morbidity, with an immediate return to oral diet and tolerable surgical risks. It requires a small amount of surgical time compared to other reconstructive options and an overall reduced inpatient stay.

Application of a collagen scaffold saturated with platelet-rich plasma in prevention of bisphosphonate-related osteonecrosis of the jaw in the rat animal model

BACKGROUND

Among the myriad adverse events of drugs in the oral cavity, Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is one of the most detrimental drug reactions that have ever been known.

OBJECTIVE

This study was aimed to investigate the success of applying collagen scaffold alone and platelet-rich plasma (PRP)+collagen scaffold in prevention of zoledronic acid-induced BRONJ in the rat.

METHODS

A total of 17 male Wistar-rats were treated with 4 weekly doses of zoledronic acid. All rats were undergone bilateral tooth extraction of mandibular first molars and divided into three groups of scaffold + PRP + suture, scaffold + suture, and suture only. All rats were scarified and clinical, radiological, histological and histomorphomerical evaluations were made on week 8 post-treatment. The soft tissue healing, bone mineralized density (BMD), number of osteoclasts and osteoblasts, necrotic bone (NB), intensity of inflammation and new bone formation (NBF) were analyzed.

RESULTS

BMD, number of osteoblasts and NBF variables proved to be statistically were higher in the treatment groups than the control group. In addition, the PRP + scaffold group showed the better results in terms of BMD, number of osteoblasts and NBF than that of the scaffold alone group. Number of osteoclasts, inflammation intensity and osteonecrosis were also significantly different in the PRP + scaffold group compared to the scaffold alone and the control groups.

CONCLUSION

Application of a PRP-enriched collagen scaffold appeared to be a successful preventive treatment for BRONJ by effecting of the number of osteoblasts and osteoclasts, BMD, NBF, inflammation, and osteonecrosis.

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.

Adjuvant therapies for MRONJ: A systematic review

OBJECTIVE

Medication-related osteonecrosis of the jaw (MRONJ) is a severe adverse reaction caused by the use of antiresorptive antiangiogenic medication. Treating MRONJ is difficult and besides standard treatments, which are conservative medical and surgical approaches, there are some adjuvant therapies that might further stimulate healing. The aim of this systematic review is to compare outcome and effectiveness of currently available adjuvant therapies for MRONJ.

METHODS

This systematic review was conducted following the PRISMA guidelines. Articles focusing on mucosal healing in patients treated with an adjuvant therapy for MRONJ were selected and analysed. Inclusion was not limited to randomized controlled trials to present a complete review of the current literature.

RESULTS

A search was performed in Pubmed, Embase, Web of Science and Cochrane Central Register of Controlled Trials. Thirty articles out of 3297 were included. Laser ablation had a success of 60-95% for complete healing. The controlled trials of leukocyte- and platelet-rich-fibrine (LPRF) showed 60-100% success for the same outcome. Fluorescence guided surgery had a complete healing percentage of 85-90%.

CONCLUSIONS

The results suggest that laser ablation, LPRF and fluorescence guided surgery might have a potential in improving the healing process. Interpreting the results should however be done with great care and a critical point of view, as most articles had a medium to high risk of bias. More randomized controlled trials are necessary to define the most beneficial therapy protocols.

CLINICAL RELEVANCE

It seems that adjuvant surgical therapies for treating MRONJ are beneficial for mucosal healing, but there is only low scientific evidence.

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.

The effect of bisphosphonate discontinuation on the incidence of postoperative medication-related osteonecrosis of the jaw after tooth extraction

Objectives

The discontinuation of bisphosphonate (BP) treatment before tooth extraction may induce medication-related osteonecrosis of the jaw (MRONJ). Whether the long-term discontinuation of BP treatment before tooth extraction affects the risk of developing MRONJ after tooth extraction or whether extended drug holidays induce systemic side effects remains unclear. The present study assessed the incidence of MRONJ among patients who underwent tooth extraction and did not discontinue BP therapy prior to the procedure.

Materials and Methods

Patients were classified according to whether or not they discontinued BP therapy before tooth extraction. Differences in the incidence of MRONJ after tooth extraction were compared between the two groups using the chi-squared test.

Results

The BP-continuation (BPC) and BP-discontinuation (BPDC) groups included 179 and 286 patients, respectively. One patient in the BPC group and no patients in the BPDC group developed MRONJ (P=0.385). The patients in the BPDC group stopped receiving BP therapy at a mean of 39.0±35.5 months prior to tooth extraction.

Conclusion

The possibility of pre-existing MRONJ in the extraction area must be considered during the extraction procedure. Routine discontinuation of BP medications for several months before the extraction procedure should be carefully considered, as evidence of its efficacy in reducing the development of post-extraction MRONJ is limited.

Surgical Management of Medication-Related Osteonecrosis of the Jaw Is Associated With Improved Disease Resolution: A Retrospective Cohort Study

PURPOSE

Optimal management approaches for medication-related osteonecrosis of the jaw (MRONJ) using either surgical or nonsurgical approaches remain inconclusive. Our objective was to compare the effects of surgical versus nonsurgical therapy on the resolution of MRONJ.

METHODS

We conducted a retrospective review of eligible patients with a diagnosis of MRONJ at Mount Sinai Hospital, Toronto, Ontario, Canada, who either were seen in the outpatient clinic from January 2014 to December 2016 or received major surgical intervention from January 2011 to December 2016. A multivariate logistic regression was conducted to evaluate the effects of surgical therapy on disease resolution.

RESULTS

A total of 78 patients were included in this study. Of these, 56 (72%) received surgical therapy. Antiresorptive agents were being taken for the treatment of osteoporosis by 46 patients (82%) in the surgical group compared with 20 nonsurgical patients (91%) (P = .28). The median follow-up period was 15.5 months (interquartile range, 8.0 to 34.3 months) in the surgical group compared with 11.0 months (interquartile range, 8.0 to 20.5 months) in the nonsurgical group (P = .75). Disease resolution occurred in 39 surgical patients (70%) compared with 8 nonsurgical patients (36%). Surgical therapy was associated with disease resolution compared with nonsurgical therapy alone, after adjustment for age, duration of antiresorptive or antiangiogenic therapy, whether the antiresorptive or antiangiogenic agents were used for oncologic purposes, and the stage of MRONJ at initial presentation (adjusted odds ratio, 4.33; 95% confidence interval, 1.28 to 14.60).

CONCLUSIONS

Surgical therapy compared with nonsurgical therapy was associated with disease resolution in patients with MRONJ. High-quality evidence of the superiority of any specific surgical approach in the treatment of MRONJ is needed.

Should we pay attention to the aberrant nerve communication between the lingual and mylohyoid nerves?

An unusual communication between the lingual and mylohyoid nerves has been identified as one reason for incomplete mandibular anaesthesia, and for neuropathy. However, its anatomical features and function are poorly understood and its relations with neighbouring structures, which are valuable in reducing the side effects of surgical operations, have not been sufficiently described. The aim of this study, therefore, was to describe the communication between the nerves and to assess the implications for oral and maxillofacial surgery. We explored the communication between the mylohyoid nerves of 62 embalmed, and 16 fresh, hemifaces. The diameter, length of the communication, and other variables were measured, and the junctions with the two nerves microdissected. The nervous communications of fresh specimens and relative nerves were stained histochemically for acetylcholinesterase. Of the 62 embalmed specimens, 19 had a communication that pierced the mylohyoid muscle, and staining showed that this was a sensory nerve. Our results suggest that the sensory communication between the lingual and mylohyoid nerves pierces the mylohyoid muscle and connects these otherwise unrelated nerves, thereby contributing to the likelihood of operative side effects.

Nasolabial Flap Improves Healing in Medication-Related Osteonecrosis of the Jaw

PURPOSE

Medication-related osteonecrosis of the jaw (MRONJ) is an adverse side effect of antiresorptive and antiangiogenic therapeutic agents that is difficult to treat owing to its high relapse rate. The aim of the present study was to determine whether patients with MRONJ treated using decortication and a nasolabial flap compared with those who underwent decortication with mucoperiosteal flaps have better outcomes regarding stable wound closure.

MATERIALS AND METHODS

Two groups of patients with MRONJ and intraoral exposed bone were evaluated in a cohort clinical study retrospectively. The primary predictor variable was the treatment group. The experimental group used the nasolabial flap for wound closure, and the control group used the mucoperiosteal flap for closure. The outcome variable was successful wound closure defined as a symptomless and closed wound after at least 12 months. Other study variables included factors such as perioperative drug holiday, duration of postoperative oral antibiotic administration, and postoperative use of nasogastric feeding tubes. Cox proportional hazard regression analysis and Kaplan-Meier curves were used to determine the factors independently associated with the dependent variable. The Mann-Whitney U test and χ² test were used for analyses regarding group-related data.

RESULTS

Both groups showed similar demographics. The 16 study patients receiving nasolabial flaps had a mean age of 69.9 years, and the 16 control patients receiving mucoperiosteal flaps had a mean age of 71.8 years. Both groups included 10 women and 6 men. Of the 16 patients in each group, 15 had received a bisphosphonate and 1, monoclonal antibody therapy. All evaluated patients underwent combined treatment, including decortication and intravenous antibiotics. Of the 16 patients receiving nasolabial flaps, symptomless intact wound closure was achieved in 68.8%. Of the 16 patients with mucoperiosteal closure, 18.7% achieved wound closure, with 81.2% developing a relapse of MRONJ, a statistically significant difference (P < .001). No statistically significant differences were found between the 2 groups in the demographic variables. The mean interval to relapse for the experimental and control groups was 13.6 ± 7.8 and 8.2 ± 7.9 months, respectively (P = .017).

CONCLUSIONS

MRONJ is a complication of antiosteoclastic treatment of mostly oncologic, palliative patients, which requires a very methodical approach to surgical treatment. A variety of different methods have been reported. The use of nasolabial flaps can be considered as a highly reliable option for coverage the bone wound with less morbidity than microvascular free flaps and better long-term results compared with mucoperiosteal flaps.

Surgical treatment of stage 2 medication-related osteonecrosis of the jaw compared to osteomyelitis

OBJECTIVE

To compare the characteristics and outcomes of patients who underwent surgical treatment for stage 2 medication-related osteonecrosis of the jaw (MRONJ) versus osteomyelitis.

METHODS

This retrospective study compared the following variables in 73 patients with stage 2 MRONJ versus 89 patients with osteomyelitis: impaired wound healing after surgery, sex, age, the presence of actinomycosis, location of the jaw lesion, and involvement of the inferior alveolar nerve (IAN).

RESULTS

There were significant differences between the groups in age, sex, rates of impaired wound healing, actinomycosis, and the location (anterior/posterior) of the lesion. Impaired wound healing after surgical treatment in the stage 2 MRONJ group was associated with patient age. All patients with impaired wound healing after the initial surgery recovered fully after reoperation.

CONCLUSIONS

These findings for surgical treatment of stage 2 MRONJ may help clinicians plan surgical treatment of MRONJ.

Effectiveness of treatments for medication-related osteonecrosis of the jaw: A systematic review and meta-analysis

BACKGROUND

The effectiveness of management strategies used for the treatment of medication-related osteonecrosis of the jaw (MRONJ) remains poorly understood. The authors evaluated systematically the effectiveness of the various treatment modalities used for MRONJ.

TYPES OF STUDIES REVIEWED

The authors conducted a comprehensive search of MEDLINE, Embase, the Cochrane Library, and Scopus to identify randomized controlled trials, nonrandomized controlled trials, and prospective cohort studies to evaluate comparatively the effectiveness of management strategies for the treatment of MRONJ. The authors conducted the identification of eligible studies in duplicate and synthesized the extracted data by means of a meta-analysis, when feasible.

RESULTS

The authors found 13 studies with a medium-to-high risk of bias that met the inclusion criteria of this review. The authors found that, compared with medical treatment of local antimicrobials with or without systemic antimicrobials, the study investigators associated surgical treatment with higher odds of complete resolution of the condition (2 studies; 76 participants; unadjusted odds ratio, 3.55; 95% confidence interval, 1.12 to 11.19). The effectiveness of other therapies, such as bisphosphonate drug holidays, teriparatide, and hyperbaric oxygen, was uncertain.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

On the basis of the results of an unadjusted analysis, the results of the studies that were deemed to be medium to low quality and to have medium-to-low statistical power suggested that there are higher odds of resolving MRONJ with surgical treatment compared with medical treatment. High-quality research is required for conclusive statements to be made regarding treatment strategies for management of MRONJ.

Impact of Soft Tissue Pathophysiology in the Development and Maintenance of Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ)

Since the first description of bisphosphonate-related osteonecrosis of the jaw (BRONJ), numerous research groups have focused on possible pathological mechanisms including the suppression of the bone turnover of the jaw, antiangiogenic effects and soft tissue toxicity. In our review we focused on summarizing the role of the soft tissues in the development and progression of BRONJ. The biological behavior of fibroblasts can be significantly influenced by bisphosphonates (BP) such as a concentration dependent reduction of cell viability. High concentrations of BP can induce apoptosis and necrosis of the cells. Comparable effects could be detected for keratinocytes. Compared to non-nitrogen containing bisphosphonates, nitrogen-containing BP have worse effects on cell biology by blocking the mevalonate pathway. Further, the cell architecture and expression levels of several genes and proteins are significantly disturbed by BP. These inhibitory effects of BP are in accordance with BP-related reduced angiogenesis and neovascularization and could underline the hypothesis that inhibition of fibroblasts and keratinocytes results in delayed wound healing and can induce and trigger BRONJ.