Microsurgical Reconstruction of the Jaws Using Vascularised Free Flap Technique in Patients with Medication-Related Osteonecrosis: A Systematic Review

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.

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.

Volumetric analysis of spontaneous bone formation after segmental mandibulectomy in patients with MRONJ

OBJECTIVE

The purpose of this study was to quantify the spontaneous new bone formation and bony bridge formation by 3-dimensional analysis of cone-beam computed tomography (CBCT) after segmental mandibulectomy reconstruction using an R-plate without any graft material in patients with medication-related osteonecrosis of the jaw (MRONJ).

STUDY DESIGN

15 MRONJ patients (13 females and 2 males) were selected based on the inclusion criteria. Data on new bone formation, bony bridge formation, R-plate fracture, patient age, and type and duration of medication were collected. Panoramic and CBCT scans were obtained at 1 day, 6, 12, and 24 months postoperatively. CBCT images of each period were transferred to a personal computer using MIMICS 21.0 for volumetric analysis. After quantifying the volume of new bone formation, we calculated the percentage of the volume of new bone to the segmentally resected necrotic bone volume (%NB).

RESULTS

All patients showed spontaneous new bone formation with the average of 20.69% within a year and 28.52% within 2 years, and 80.0% showed bony bridge formation within a year.

CONCLUSIONS

The R-plate reconstruction in patients with MRONJ showed significant amount of spontaneous new bone formation within 2 years after segmental mandibulectomy.

Medication-related osteonecrosis of the jaw (MRONJ): a review of pathogenesis hypothesis and therapy strategies

Medication-related osteonecrosis of the jaw (MRONJ), a severe side effect caused by antiresorptive antiangiogenic medication, particularly bisphosphonates (BPs), has become a challenging disease with serious and profound effects on the physical and mental health of patients. Although it occurs with high frequency and is harmful, the exact mechanism of MRONJ remains unknown, and systematic and targeted approaches are still lacking. Maxillofacial surgeons focus on the etiology of osteonecrosis in the mandible and maxilla as well as the appropriate oral interventions for high-risk patients. Adequate nursing care and pharmacotherapy management are also crucial. This review provides a current overview of the clinicopathologic feature and research of MRONJ caused by BPs, with an emphasis on the potential mechanisms and current therapy and prevention strategies of the disease. We are of the opinion that an in-depth comprehension of the mechanisms underlying MRONJ will facilitate the development of more precise and efficacious therapeutic approaches, resulting in enhanced clinical outcomes for patients.

Alloplastic reconstruction of the mandible after subtotal mandibulectomy for medication-related osteonecrosis of the jaw: An update of the method

BACKGROUND

Reconstruction of continuity defects following osteonecrosis in multimorbid patients is challenging. In all cases of the predescribed palliative treatment method for alloplastic mandible reconstruction, plate fractures were detected in follow-up. We hypothesized that a modification could avoid these fractures, leading to stable long-term results.

METHODS

This retrospective study compares the original method with a modification using single, laser-sintered CAD-CAM plates instead of manually bent miniplates. The predescribed shuttering technique was used to reconstruct the mandible in its original shape with bone cement.

RESULTS

Uneventful wound healing was observed in 86% of the cases after modification of the method. No implant or plate fracture occurred.

CONCLUSIONS

The presented method should be considered as a treatment option for mandible reconstruction in elderly, multimorbid patients in palliative situations. The results of this study suggest that the modification of the method leads to significantly improved long-term stability. Donor site morbidity is avoided with this method of palliative surgery.

Medication-Related Osteonecrosis of the Jaws: A Comparison of SICMF-SIPMO and AAOMS Guidelines

(1) Background: Medication-related osteonecrosis of the jaws (MRONJ) is an adverse drug reaction characterized by progressive bone disruption and necrosis in the mandibular and/or maxillary bones. It occurs in individuals who have received antiresorptive drugs without prior radiotherapy. Since its first reported cases in the USA in 2003, extensive literature has emerged worldwide, leading to significant advancements in understanding MRONJ's pathogenesis and management. (2) Results: This article aims to compare the current national recommendations provided by the Italian Society of Maxillofacial Surgery (SICMF)/Italian Society of Oral Pathology and Medicine (SIPMO) and the American Association of Oral and Maxillofacial Surgeons (AAOMS). (3) Conclusions: Historically, the AAOMS advocated for a more conservative approach compared to the Italian guidelines. However, in their 2022 update, the AAOMS adopted a different perspective based on reported evidence, highlighting the advantages of early surgical treatment. Despite resolving some initial controversies, differences still exist between the two sets of recommendations, particularly regarding diagnosis and staging.

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

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

Uncovering the unique characteristics of the mandible to improve clinical approaches to mandibular regeneration

The mandible (lower jaw) bone is aesthetically responsible for shaping the lower face, physiologically in charge of the masticatory movements, and phonetically accountable for the articulation of different phonemes. Thus, pathologies that result in great damage to the mandible severely impact the lives of patients. Mandibular reconstruction techniques are mainly based on the use of flaps, most notably free vascularized fibula flaps. However, the mandible is a craniofacial bone with unique characteristics. Its morphogenesis, morphology, physiology, biomechanics, genetic profile, and osteoimmune environment are different from any other non-craniofacial bone. This fact is especially important to consider during mandibular reconstruction, as all these differences result in unique clinical traits of the mandible that can impact the results of jaw reconstructions. Furthermore, overall changes in the mandible and the flap post-reconstruction may be dissimilar, and the replacement process of the bone graft tissue during healing can take years, which in some cases can result in postsurgical complications. Therefore, the present review highlights the uniqueness of the jaw and how this factor can influence the outcome of its reconstruction while using an exemplary clinical case of pseudoarthrosis in a free vascularized fibula flap.

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

OBJECTIVE

To summarize the pathological characteristics of medication-related osteonecrosis of the jaw (MRONJ) specimens after jaw curettage or jaw osteotomy treatment and to comprehensively analyze the relationship between the different pathological features, treatment methods, and treatment effects to provide new ideas for effective treatment of MRONJ in clinical work.

METHODS

The clinical and pathological data were collected from 23 patients with MRONJ who were treated with curettage (18 patients) and jaw osteotomy (5 patients) at the Department of Oral and Maxillofacial Surgery of Peking University Hospital of Stomatology between June 2014 and December 2015. The pathological characteristics of MRONJ were summarized and analyzed with treatment effects based on various surgical treatment methods. The diagnostic criteria and disease staging of MRONJ were determined according to the 2014 American Association of Oral and Maxillofacial Surgeon's Position Paper.

RESULTS

In this study, 5 patients have treated with jaw segmental osteotomy, and all of them were in stage Ⅲ; the other 18 patients were treated with jaw curettage, including 5 patients in stage Ⅱ and 13 patients in stage Ⅲ. The pathological features of MRONJ in five cases of jaw segmental osteotomy were divided into three adjacent regions from shallow to deep: inflammation region (IR), sclerosis region (SR), and bone remodeling layer (BRL). Moreover, three types of pathological features of specimens from traditional curettage were defined as type 1 (IR), type 2 (IR + SR), and type 3 (IR + SR + BRL). The pathological features of the patients treated with jaw curettage were: type Ⅰ, 38.9% (7/18); type Ⅱ, 44.4% (8/18); type Ⅲ, 16.7% (3/18). Complete healing was achieved in 5 patients treated with jaw segmental osteo-tomy. Moreover, 2 cases with type Ⅰ, 1 case with type Ⅱ, and 1 with type Ⅲ completely healed after jaw curettage, while 5 cases with type Ⅰ, 7 cases with type Ⅱ, and 2 cases with type Ⅲ experienced recurrence after surgery.

CONCLUSION

Pathological features of continuous regions of inflammation, sclerosis, and bone remodeling layer were identified from shallow to deep, based on the microscopic observation of jaw segmental osteotomy samples. Insufficient removal of the sclerotic region during jaw curettage that blocks the required blood, nutritional factors, and mesenchymal stem cells seems to be a common cause for failed treatment of MRONJ after curettage surgery.

A Review Into the Effects of Pamidronic Acid and Zoledronic Acid on the Oral Mucosa in Medication-Related Osteonecrosis of the Jaw

Medication-related osteonecrosis of the jaw (MRONJ) is a growing problem without an effective treatment, presenting as necrotic bone sections exposed via lesions in the overlying soft tissue. There is currently a lack of clarity on how the factors involved in MRONJ development and progression contribute to disease prognosis and outcomes. Bisphosphonates (BPs), the most common cause of MRONJ, affect bone remodeling, angiogenesis, infection, inflammation and soft tissue toxicity, all of which contribute to MRONJ development. This article reviews the cellular mechanisms through which BPs contribute to MRONJ pathology, with a focus on the effects on cells of the oral mucosa. BPs have been shown to reduce cell viability, reduce proliferation, and increase apoptosis in oral keratinocytes and fibroblasts. BPs have also been demonstrated to reduce epithelial thickness and prevent epithelial formation in three-dimensional tissue engineered models of the oral mucosa. This combination of factors demonstrates how BPs lead to the reduced wound healing seen in MRONJ and begins to uncover the mechanisms through which these effects occur. The evidence presented here supports identification of targets which can be used to develop novel treatment strategies to promote soft tissue wound healing and restore mucosal coverage of exposed bone in MRONJ.

Medication-Related Osteonecrosis of the Jaw—A Continuing Issue

Introduction: Medication-related osteonecrosis of the jaw (MRONJ) is a condition that is becoming more common in the everyday practice of both dental and maxillofacial surgeons. Materials and methods: This paper aims to provide a comprehensive and easy to read by clinicians presentation of comprehensive, accessible, and up-to-date data on MRONJ. The individual chapters focus on the etiology, epidemiology, diagnosis, prevention, treatment, and recurrence of MRONJ. Results and discussion: It has been observed over the years that among drugs that increase the risk of the disease, apart from bisphosphonates, angiogenesis inhibitors and anti-RANKL monoclonal antibodies should also be included. A thorough physical and subjective examination, periodic correction of dental prostheses, and an adequate preparation for even the simplest of procedures in the oral cavity area can prevent or minimize the risk of MRONJ. Conclusions: It is extremely difficult to treat once it occurs and oftentimes is a recurring problem that leads to a multitude of symptoms that gradually decrease the quality of a patient’s life.

Mandibulectomy Reconstruction with Pectoralis Major Island Flap Associated with Primary Reconstruction Plate for Mandibular Medication-Related Osteonecrosis

A bimaxillary edentulous male patient, aged 67 years, diagnosed with prostate cancer who underwent intravenous bisphosphonates treatment (zoledronic acid) for about one year presented with pain in the anterior mandibular arch, with exposed necrotic bone, and was diagnosed with stage 2 medication-related osteonecrosis of the jaw (MRONJ). MRONJ is the development of bone necrosis in the oral cavity as an adverse reaction in patients treated with antiresorptive and antiangiogenic medication, without radiation therapy to the head and neck. This persistent bone necrosis does not always respond to standard treatments. The reconstruction technique with pectoralis major flap, at a distance, associated with the primary reconstruction plate, was an effective treatment modality for the treatment of large osteonecrosis noncompliant with conservatory treatments. Through this technique, the morpho-functionality of the jaw can be restored almost completely.

Evaluation of segmental mandibular resection without microvascular reconstruction in patients affected by medication-related osteonecrosis of the jaw: a systematic review

Medication-related osteonecrosis of the jaw (MRONJ) is a severe condition that affects the jaw in patients exposed to specific drugs. More often it has been described in association with bisphosphonates (BP), but nowadays it has been observed with the use of other medications, such as denosumab (a RANK ligand inhibitor and monoclonal antibody agent) and antiangiogenic drugs. Managing the condition has unfortunately proven difficult and still remains a major challenge for clinicians and surgeons. The aim of this systematic review was to identify and analyse the evidence on mandibular segmental resection in patients with advanced MRONJ. A multi-database (PubMed, MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials) systematic search was performed. Any type of study on human patients treated with antiresorptive and antiangiogenic drugs was considered. The primary aim was to understand the success of mandibular segmental resection in the short, medium, and long term, and to understand its effects before, during, and after the operation. The search yielded 11 studies that were eligible for analysis with a total of 67 patients. Of the 11 studies, seven reported no complications, and overall, postoperative complications were seen in 16 cases. Recurrence of osteonecrosis was reported in one study. The most common postoperative complication was removal of hardware (n = 11). The mean (SD) follow-up time for eight studies was 35.57 (17.73) months. According to the limited data available in the literature, mandibular segmental resection is a viable treatment that has been used successfully in patients with various stages of MRONJ. The data show a relatively high percentage of recurrence. Additional data based on a larger cohort of patients or case-control studies are necessary to justify routine use of this type of intervention in patients affected by the condition.

Multidisciplinary approaches to odontogenic lesions

PURPOSE OF REVIEW

To give an overview of technical considerations and relevant literature in the management odontogenic pathology with involvement of the maxillary sinus.

RECENT FINDINGS

Infections, cysts, benign neoplasms (odontogenic and nonodontogenic), and inflammatory conditions impact the maxillary sinus in various ways, could result in significant expansion within the maxillary sinus and significant infections.

SUMMARY

This manuscript provides an overview of common pathologic entities of the oral cavity proper that impacts the maxillary sinus health, with discussion of the role of the otorhinolaryngologist and the dental specialist.

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.

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

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