Principles of oral surgery for prevention of bisphosphonate-related osteonecrosis of the jaw

Effect of osteopenia and osteoporosis on failure of first and second dental implants: a retrospective observational study

PURPOSE

The present study evaluated osteopenia (OPN) and osteoporosis (OP) as risk factors for dental implant failure and repeat failure.

METHODS

We performed a retrospective study on over 100 randomly selected patients per analysis to determine the effect of health status, smoking status, sex, implant location and operative conditions on first and second (re-implantation) implant survival. Analyses were conducted first using chi-squared test, followed by multiple logistic regression for significant variables.

RESULTS

In the cohort examining the effect of myriad risk factors on second implant survival, it was found that OPN and OP greatly impacted implant survival, wherein patients with osteoporosis or osteopenia had significantly more implant failures (p = 0.0353). Sex and operative conditions had no effect on implant survival, while implant location showed a notable effect wherein significantly more failures occurred in the maxilla vs mandible (p = 0.0299). Upon finding that OPN and OP have a significant effect on second implant survival, we conducted an additional study focusing on the impact of health status. Based on the multiple logistical regression analysis, we found that OPN and OP are the most significant factor in first implant survival (p = 0.0065), followed by diabetes (p = 0.0297). Importantly, it was observed that early implant failure is also significantly correlated with osteoporosis (p = 0.0044).

CONCLUSION

We show here a marked relationship in which the risk of first and second implant failure are significantly higher in patients with osteoporosis and osteopenia.

Italian position paper (SIPMO-SICMF) on medication-related osteonecrosis of the jaw (MRONJ)

OBJECTIVE

This paper aims to describe the 2023 update position paper on MRONJ developed by the Italian Societies of Oral Pathology and Medicine (SIPMO) and of Maxillofacial Surgery (SICMF).

METHODS

This is the second update following the 2013 and 2020 Italian position papers by the Expert panel, which is a representation of the two scientific societies (SIPMO and SICMF). The paper is based on an extensive analysis of the available literature from January 2003 to February 2020, and the subsequent review of literature conducted between March 2020 and December 2022 to include all new relevant published papers to confirm or modify the previous set of recommendations.

RESULTS

This position paper highlights the main issues of MRONJ on risk estimates, disease definition, diagnostic pathway, individual risk assessment, and the fundamental role of imaging in the diagnosis, classification, and management of MRONJ.

CONCLUSION

The Expert Panel confirmed the MRONJ definition, the diagnostic work-up, the clinical-radiological staging system and the prophylactic drug holiday, as recognized by SIPMO-SICMF; while, it presented novel indications regarding the categories at risk of MRONJ, the prevention strategies, and the treatment strategies associated with the therapeutic drug holiday.

The role of leukocyte and platelet-rich fibrin in the prevention of medication-related osteonecrosis of the jaw, in patients requiring dental extractions: an observational study

PURPOSE

Medication-related osteonecrosis of the jaw (MRONJ) is a significant complication which can present following a dental extraction in patients receiving anti-resorptive and anti-angiogenic medications. The purpose of this study was to investigate the possible beneficial effect of L-PRF in the prevention of MRONJ in patients receiving these medications and requiring dental extractions.

METHODS

Thirty-nine patients were included and divided into two groups, depending on whether L-PRF was used after the required dental extraction or not. Subsequently, the patients were categorised into low and high-risk for developing MRONJ, as recommended by the SDCEP guidance.

RESULTS

None of the patients in the L-PRF group returned with established MRONJ. Five high-risk patients in the control group presented with established MRONJ in the follow-up appointment. A significant statistical difference (p = 0.04) was observed following a comparison of the high-risk patients of the two groups.

CONCLUSION

These encouraging results suggest that L-PRF may be useful in the prevention of MRONJ following a dental extraction especially in patients of the higher risk category. A protocol for the management of this type of patients is also introduced.

Management of Medication-Related Osteonecrosis of the Jaw with Photobiomodulation and Minimal Surgical Intervention

Medication-related osteonecrosis of the jaw (MRONJ) is a relatively common pathology occurring in around 5% of patients taking bisphosphate and other antiresorptive or anti-angiogenic medications. Despite the efforts, as of today there is still no consensus on its management. In this case report, the successful management of stage II MRONJ was performed for an eighty-three-year-old female patient suffering from pain and alteration in her normal oral functions (swallowing and phonation). The treatment consisted of three sessions of photobiomodulation therapy (PBM), followed by minimal surgical intervention and three other sessions of PBM. PBM was applied on the sites of osteonecrosis with the follow parameters: 4 J/cm²; a power of 50 mW; 8 mm applicator diameter; a continuous contact mode. Irradiation was performed on three points, including the vestibular, occlusal and lingual parts of each of the bone exposure areas. Each point was irradiated for 40 s, and, in total, nine points were made per session, and nine sessions were conducted. To assess the pain, a visual analogue scale was used in which zero represented no pain at all and ten represented the greatest pain. At the first session and before any intervention, the patient stated that her pain was 8 out of 10. At the end of the treatment, a significant reduction in VAS was noted (2/10) and, clinically, a healing of the soft tissue in the previously exposed bone was observed. This case report suggests that the combination of PBM with surgical intervention is promising in the management of MRONJ.

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.

MRONJ of the Mandible—From Decortication to a Complex Jaw Reconstruction Using a CAD/CAM-Guided Bilateral Scapula Flap

Medication-related osteonecrosis of the jaw (MRONJ) has been an integral part of the maxillofacial patient population for some time. The therapeutic concept ranges from conservative approaches over less extended decortications to major jaw resections, which can result in a considerable loss of quality of life. Based on three case reports, this paper presents the long-term history of patients with MRONJ of the mandible, whose disease ultimately resulted in partial or total mandibular resection and subsequent multisegmental reconstruction using a microvascular anastomosed bone flap. Furthermore, a suitable alternative for complex mandibular reconstruction is demonstrated when using a free fibula flap is not possible. The options are limited, particularly when multisegmental restoration of mandibular continuity is required. One case presents a mandible reconstruction using a CAD/CAM-guided bilateral scapular free flap (CAD/CAM = Computer-Aided Design and Manufacturing), which has not been described for this purpose before. Due to the complexity, computer-assisted surgery and patient-specific implants seem reasonable, which is why a special focus was applied to this topic.

Outcome of healing after dental implant placement in patients with cancer on high-dose antiresorptive medications: a prospective feasibility study

PURPOSE

Implant placement in patients with cancer receiving high-dose antiresorptive medication (HDAR) is considered contraindicated. This prospective, feasibility study tested the hypothesis that dental implants can be placed in such patients by applying a staged implant placement protocol with submerged healing.

METHODS

Three groups of patients on HDAR were included as follows: group 1: patients who underwent tooth extraction, without the development of medication-related osteonecrosis of the jaws (MRONJ); group 2: patients with surgically treated MRONJ who had demonstrated clinical healing for at least 3 months; group 3: patients with established MRONJ who was planned for surgical resection and simultaneous implant placement.

RESULTS

A total of 49 implants were placed in 27 patients (group 1: 12, group 2: 7 and group 3: 8). HDAR included bisphosphonates and denosumab. The mean HDAR time was 25 months (SD: ± 18.4, range 3-68 months). An abutment operation was performed 4 months following the implant placement (SD: ± 1.9, range 3-14 months). All patients healed uneventfully.

CONCLUSIONS

This study demonstrated that it is feasible to insert dental implants and perform an abutment surgery in patients with cancer on HDAR, without the development of MRONJ.

CLINICALTRIALS

gov Identifier: NCT04741906.

Incidence and risk factors for medication-related osteonecrosis after tooth extraction in cancer patients-A systematic review

OBJECTIVES

Antiresorptive medication has been reported to be associated with medication-related osteonecrosis of the jaw (MRONJ). This systematic review aims at investigating the incidence of and risk factors for MRONJ after tooth extractions in cancer patients treated with high-dose bisphosphonate and denosumab (BP and DS). MATERIAL AND METHODS: The protocol followed the PRISMA statement list and was registered in PROSPERO. Searches were performed for literature published up to April 2021 in the electronic databases PubMed, Embase, Web of Science, and CINAHL and then supplemented by manual research.

RESULTS

The search process resulted in 771 identified articles, of which seven studies fitted the population, intervention, comparison, and outcome framework. All were observational studies and four had control groups. A total of 550 patients treated with BP and DS were identified of whom 271 had received tooth extractions after medication onset. Due to significant heterogenicity in the collected data, only a qualitative analysis was performed. The MRONJ incidence after tooth extractions varied between 11% and 50% at the patient level. MRONJ occurred up to 3 years after the tooth extraction. Teeth affected by inflammation before the extraction and additional osteotomy during the surgical procedure were identified as risk factors.

CONCLUSIONS

Reliable methods of diagnosing MRONJ and adequate follow-up periods are important factors in obtaining the actual incidence of MRONJ after tooth extractions in patients treated with high-dose BP and DS.

Customized Titanium Mesh for Guided Bone Regeneration in the Posterior Mandible in a Patient Previously Treated with Bisphosphonates

We describe the restorative treatment of an 86-year-old female patient who was referred to our specialist prosthodontics clinic. Due to secondary osteoporosis, she underwent oral antiresorptive therapy with ibandronic acid for 10 years. Although she was classified as a patient at increased risk of drug-induced osteonecrosis of the jaw, she eventually signed a consent form for fixed implant-supported prosthetic rehabilitation in her 4th sextant. However, after tooth extraction, the bone ridge was too small at the intended implant positions. Therefore, guided bone regeneration was performed with a computer-aided design/computer-aided manufacturing three-dimensional printed titanium mesh. Finally, a continuous augmented hard tissue ridge above 7 mm was found, and three implants were inserted. Eventually, after four months of submerged healing, the implants were loaded with single crowns. Now, the patient is seen regularly for supportive peri-implant therapy.

Evaluation of Preventive Treatment Protocols for Patients under Antiresorptive Therapy Undergoing Tooth Extraction at a Swiss University Clinic

Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is a dreaded complication in patients with compromised bone metabolism. The purpose of the present study was to examine the occurrence of ARONJ and its related factors among patients with a history of antiresorptive therapy undergoing tooth extraction using preventive protocols at a Swiss university clinic. Data were retrospectively pooled from health records of patients having received a surgical tooth extraction between January 2015 and April 2020 in the Clinic of Cranio-Maxillofacial and Oral surgery, University of Zurich. A total of 970 patients received an extraction with flap elevation or wound closure during this period. A total of 104 patients could be included in the study. Furthermore, variables including age, gender, smoking, risk profile, choice, indication and duration of antiresorptive therapy, number of extractions, extraction site, surgical technique, choice and duration of antibiotics as well as the presence of postoperative inflammatory complications were assessed. Overall, 4 patients developed ARONJ (incidence of 3.8%) after tooth extraction at the same location, without previous signs of osteonecrosis. Preventive methods included predominantly primary wound closure using a full thickness mucoperiosteal flap and prolonged perioperative antibiotic prophylaxis. In accordance with current literature, the applied protocol showed a reliable outcome in preventing ARONJ when a tooth extraction is required.

Lack of evidence in reducing risk of MRONJ after teeth extractions with systemic antibiotics

A systematic review was carried out to identify if periprocedural administration of systemic antibiotics could decrease risk of medication-related osteonecrosis of the jaws (MRONJ) in patients under antiresorptive and/or biologic agents for teeth extraction. PubMed/MEDLINE and Scopus were systematically searched for case-series with more than 10 patients, retrospective/prospective studies, and trials concerning this issue. Manual searching of references from previous reviews was also carried out. Of 1,512 results, 17 studies were included, focusing on antibiotics for extraction in patients under intravenous bisphosphonates (8 studies), oral bisphosphonates (2 studies), oral and intravenous bisphosphonates (6 studies), and denosumab (1 study), of which 12 performed dental extraction with surgical flap. With no trials found, "quality in prognosis studies" (QUIPS) tool was used to evaluate risk of bias. First-line treatment was 2-3 grams of oral amoxicillin in 76.4% of studies; 300-600 mg of clindamycin was the alternative treatment in 23.5% of studies. Treatment ranged from 3 to 20 days, consisting of 6-7 days in 47% of studies. No microbiologic insight was provided. A significantly higher risk of MRONJ for patients unexposed to antibiotics was provided in one retrospective study. QUIPS tool revealed moderate-high risk of bias. With empirical data from bias-carrying, heterogeneous observational studies, the validity of antibiotics is yet to be established.

The role of antiresorptive drugs and medication-related osteonecrosis of the jaw in nononcologic immunosuppressed patients: A systematic review

Medication related osteonecrosis of the jaw (MRONJ) is a severe condition affecting the jaws of patients exposed to specific drugs, and is primarily described in patients receiving bisphosphonate (BP) therapy. However, more recently it has been observed in patients taking other medications, such as the RANK ligand inhibitor (denosumab) and antiangiogenic drugs. It has been proposed that the existence of other concomitant medical conditions may increase the incidence of MRONJ. The primary aim of this research was to analyze all available evidence and evaluate the reported outcomes of osteonecrosis of the jaws (ONJ) due to antiresorptive drugs in immunosuppressed patients. A multi-database (PubMed, MEDLINE, EMBASE and CINAHL) systematic search was performed. The search generated twenty-seven studies eligible for the analysis. The total number of patients included in the analysis was two hundred and six. All patients were deemed to have some form of immunosuppression, with some patients having more than one disorder contributing to their immunosuppression. Within this cohort the commonest trigger for MRONJ was a dental extraction (n=197). MRONJ complications and recurrence after treatment was sparsely reported in the literature, however a total of fourteen cases were observed. The data reviewed have confirmed that an invasive procedure is the commonest trigger of MRONJ with relatively high frequency of post-operative complications or recurrence following management. However, due to low-quality research available in the literature it is difficult to draw a definitive conclusion on the outcomes analysed in this systematic review.

Antiresorptive medication in oncology: the clinical and dental profile of patients in a reference center

Objectives

: The aim of this study was to evaluate the profile of patients on antiresorptive therapies for cancer treatment and assess presence of oral lesions, oral hygiene status, and knowledge regarding medication-related osteonecrosis of the jaw (MRONJ).

Materials and Methods

This was an observational cross-sectional study that evaluated patients treated with antiresorptive medication at a single cancer hospital. Clinical data were collected and oral examination was performed to assess patient oral health.

Results

From July 2017 to December 2018, 90 patients were assessed; 64 were female and 26 were male, and the mean age was 61 years. The most common drug was an intravenous bisphosphonate, zoledronic acid. Among the 90 patients, 47 presented with some type of oral disease, isolated or associated. Among these 47 patients, 9 patients (10%) developed osteonecrosis. Oral hygiene was evaluated, and most patients, with or without MRONJ, presented with regular to poor condition. Regarding patient knowledge of the risks of MRONJ and the risks associated with dental surgery, 60% stated that they were not aware of the risks.

Conclusion

Identifying the profile of patients and their needs facilitates not only the preventive process, but also the emergence of new therapeutic options. Our study shows that most patients are weakened both by metastatic disease and antineoplastic treatment as well as by issues associated with aging because most were over 60 years of age. Collectively, this information should be considered for management of preventive and therapeutic measures.

The risk of osteonecrosis of the jaw and adverse outcomes in patients using antiresorptive drugs undergoing orthodontic treatment: A systematic review

Objectives

Medication-related osteonecrosis of the jaw (MRONJ) is rare. It is a serious adverse effect of certain drugs, of which bisphosphonates (BPs) are the most widely known. The aim of this systematic review was to analyze all published evidence for the reported adverse outcomes as a result of orthodontic treatment in patients undergoing antiresorptive therapy.

Data

All types of studies involving patients undergoing orthodontic treatment and treated with antiresorptive drugs were considered. A meta-analysis was not conducted due to the high amount of variability and heterogeneity in the reporting and presentation of data among the studies meeting the inclusion criteria.

Sources

A systematic search was performed using 4 databases (PubMed, MEDLINE, EMBASE and CINAHL).

Study selection

Seven studies matched the inclusion criteria for this review, reporting a total of 29 patients. MRONJ was only reported in 1 patient. The adverse outcomes following orthodontic treatment included difficulty achieving root parallelism (n = 4), difficulty achieving complete space closure (n = 3), exaggerated tooth mobility post-debond (n = 2), increased duration of orthodontic treatment beyond expected completion (n = 1), sclerotic alveolar bone changes seen on post-op radiographic images (n = 2), and an increased amount of root resorption (n = 1).

Conclusions

The high amount of heterogeneity and limited evidence precluded a valid interpretation and analysis of the results through pooling of data. Additional data with sufficient quality, a reduction of bias, and a greater prospective cohort of patients is crucial to assess adverse effects, mechanisms of action, and associated risk factors in at-risk patients.

Clinical significance

Based on the limited evidence available in the literature, it is unclear whether orthodontic treatment alone can precipitate MRONJ. However, antiresorptive drug therapy may be associated with a sub-optimal treatment outcome.

A systematic review of metastatic cancer presenting in osteonecrosis of the jaws (MC-ONJ) in patients undergoing antiresorptive and/or antiangiogenic therapy for skeletal-related adverse events

INTRODUCTION

Osteonecrosis of the jaw (ONJ) is reported to be primarily associated with patients receiving bisphosphonate therapies but has been found in patients taking a number of other medications. A number of recent reports have noted the presence of metastatic cancers in the histologic analysis of osteonecrotic lesions from the jaw. The aim of the present review is to estimate the frequency and the type of metastatic cancer most commonly found in ONJ specimens in patients undergoing antiresorptive and/or antiangiogenic drug therapy.

MATERIAL AND METHODS

A multidatabase (PubMed, MEDLINE, EMBASE, and CINAHL) systematic search was performed. Any studies involving human participants treated with antiresorptive and antiangiogenic drugs were considered. Where study patients presented with malignant cells within osteonecrotic specimens, further data were collected. Data are presented using descriptive statistics.

RESULTS

A total of 13 studies met the inclusion criteria for this systematic review. Thirty-seven study patients had histologic evidence of malignant cells within medication-related osteonecrosis of the jaw (MRONJ) specimens. The most frequent phenotype of malignant cells found within MRONJ specimens were breast cancer variants (n = 15). The frequency of malignant tumor cells found within the MRONJ specimens was calculated using 4 studies. Out of 604 patients, the frequency was 4.64% (n = 28).

CONCLUSIONS

Based on the limited data available in the literature, it is plausible that not histologically analyzing all ONJ specimens could result in a small number of undiagnosed and untreated malignant diseases. Additional data based on a larger cohort of study patients is necessary to understand the role of MRONJ in metastatic spread and the influence of surgical treatment and reoccurrence.

A Drug Holiday Reduces the Frequency and Severity of Medication-Related Osteonecrosis of the Jaw in a Minipig Model

Treatment of medication-related osteonecrosis of the jaw (MRONJ) is challenging and no clear consensus has been achieved. This study investigated preventive measures recommended for tooth extractions under antiresorptive (AR) treatment and the role of discontinuation of AR therapy to avoid the onset of MRONJ in a minipig model. Thirty-six Göttingen minipigs were divided into four groups. Group 1 (negative control): tooth extractions but no zoledronate (ZOL). Group 2 (positive control): weekly ZOL infusions for 12 weeks followed by tooth extractions without wound management followed by 8 weeks of ZOL treatment. Group 3: weekly ZOL infusions for 12 weeks followed by tooth extractions; surgical wound management (resection of sharp bone edges, mucoperiosteal coverage); and continuation of ZOL infusions for 8 weeks plus antibiotic treatment. Group 4: 12 weeks of ZOL infusions followed by a drug holiday for 6 weeks. Tooth extractions with preventive wound management followed by antibiotic treatment for 8 weeks but no ZOL infusions. Jawbones were subjected to macroscopic, radiological (CT and micro-CT) and histopathological investigations. No clinical cases of MRONJ were observed in the negative group, in the positive control all animals developed MRONJ. Group 3 developed MRONJ in 83% of cases. With a drug holiday, 40% developed MRONJ in areas of tooth extraction. This is the first large animal model that reduces the occurrence of MRONJ following tooth extraction by the implementation of a drug holiday combined with antibiotic prophylaxis and smoothening of sharp bony edges. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research..

Apical surgery in cancer patients receiving high-dose antiresorptive medication-a retrospective clinical study with a mean follow-up of 13 months

PURPOSE

The aim of the study is to evaluate the results of apical surgery (AS) in patients receiving high-dose antiresorptive medication (HDAR).

METHODS

Retrospective descriptive quality control study conducted in an Oral and Maxillofacial Department at a University Hospital. Fourteen patients on HDAR met the inclusion criteria. Only descriptive statistics were applied.

RESULTS

Fourteen patients had operation on seventeen teeth. Mean HDAR treatment period before apical surgery: 25 months (SD, ± 24.27; range, 1-78 months). Drug holiday during surgery and initial healing: mean, 8 months (SD, ± 5.96; range, 0.4-22 months). Sixteen out of seventeen teeth healed clinically and showed complete or ongoing radiographic healing. All patients except one became free of symptoms. Mean follow-up: 13 months (SD, ± 9.05; range, 2-31 months). Radiographic healing according to Molven and Rud: 7, complete; 6, uncertain; 1, unsatisfactory. Three patients died during follow-up and were considered drop-outs.

CONCLUSIONS

The present case series suggest that apical surgery is a valid treatment option for apical periodontitis in patients on HDAR, where orthograde endodontic retreatment is not possible. None of the patients developed medication-related osteonecrosis of the jaw. Further studies in larger study groups and with longer follow-up periods are needed. The regional scientific ethical committee provided a document exemption, registration date 20 November 2013, and the local data protection agency approved handling of the recorded data (No. 2012-41-0045), registration date 11 January 2012.

Preventing, identifying, and managing medication-related osteonecrosis of the jaw: a practical guide for nurses and other allied healthcare professionals

BACKGROUND

Medication-related osteonecrosis of the jaw (MRONJ) is an infrequent, but potentially serious, adverse event that can occur after exposure to bone-modifying agents (BMAs; e.g., bisphosphonates, denosumab, and antiangiogenic therapies). BMAs are typically used at higher doses to prevent skeletal-related events in cancer patients and at lower doses for osteoporosis/bone loss. MRONJ can cause significant pain, reduce quality of life, and can be difficult to treat, requiring a multiprofessional approach to care.

METHODS

We reviewed the literature and guidelines to summarize a practical guide on MRONJ for nurses and other allied healthcare professionals.

RESULTS

While there is a risk of MRONJ with BMAs, this should be considered in relation to the benefits of treatment. Nurses and other allied healthcare professionals can play a key role alongside physicians and dentists in assessing MRONJ risk, identifying MRONJ, counseling the patient on the benefit-risk of BMA treatment, preventing MRONJ, and managing the care pathway of these patients. Assessing patients for MRONJ risk factors before starting BMA treatment can guide preventative measures to reduce the risk of MRONJ. Nurses can play a pivotal role in facilitating multiprofessional management of MRONJ by communicating with patients to ensure compliance with preventative measures, and with patients' physicians and dentists to ensure early detection and referral for prompt treatment of MRONJ.

CONCLUSIONS

This review summarizes current evidence on MRONJ and provides practical guidance for nurses, from before BMA treatment is started through to approaches that can be taken to prevent and manage MRONJ in patients receiving BMAs.

Standardized Arrabidaea chica Extract Shows Cytoprotective Effects in Zoledronic Acid-Treated Fibroblasts and Osteoblasts

INTRODUCTION

Osteonecrosis of the jaw is a condition associated with intraoral ulceration and bone necrosis induced by antiresorptive medications, such as zoledronic acid, a bisphosphonate. Previous data on Arrabidaea chica (H&B.) Verlot wound healing activity prompted the study reported herein on A. chica standardized hydro alcoholic extract in vitro cytoprotective activity data on epithelial and osteoblastic cells exposed to zoledronic acid (ZA).

METHODS

Primary human gingival fibroblasts and murine pre-osteoblasts were treated with ZA 10 µM together with 5 or 10 µg.mL-1 A. chica extract for 24h and 48 h. At both times, cells were submitted to viability assay and caspase 3/7 activation evaluation. Statistical analysis used one-way ANOVA and p=0.05.

RESULTS

In cell viability assay, a drastic damage effect of ZA appeared after 48 h in both epithelial (55.8%) and pre-osteoblastic cells (39.7%). When treated with ZA in combination with A. chica extract, cells showed higher viability values: 74.1%-82.3% for fibroblasts and 66% for pre-osteoblasts. Furthermore, the combined treatment presented lower caspase 3/7 activation in fibroblasts and pre-osteoblasts.

CONCLUSION

At low concentrations, A. chica extract showed promising cytoprotective effects against ZA-induced damage actions; however, further in vitro and in vivo studies are required to establish the mechanism of action.

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.

Alendronate or Zoledronic acid do not impair wound healing after tooth extraction in postmenopausal women with osteoporosis

BACKGROUND

Bisphosphonates (BPs) are widely used for the prevention or treatment of osteoporosis. One of the most serious complications associated with BPs is medication-related osteonecrosis of the jaw (MRONJ) but its incidence in patients with osteoporosis is very low ranging from 0.001-0.15%. A major predisposing factor for MRONJ is tooth extraction (TE). Controversies persist about the influence of current BP therapy regarding socket healing after TE. The aims of this study were to investigate prospectively, (i) alveolar bone healing, i.e., filling of the bony socket by new bone and (ii) mucosal healing, i.e., closure of the overlying mucosa, after TE in women receiving current BP therapy for the prevention or the treatment of postmenopausal osteoporosis.

METHODS

Women with osteoporosis under current treatment with BPs (BP+ group) or other anti-osteoporotic medications (BP- group) undergoing single TE were included in this study. No antibiotic prophylaxis was prescribed solely for the BP therapy, but antibiotic treatment may have been required for local infectious conditions. Chlorohexidine mouthwashes were systematically prescribed in all study patients for one week after TE. New bone height (NBH) and rate of socket filling (RSF) were recorded using intraoral standardized radiographs one month and 3 months after TE (T30 and T90 respectively). The closure of the overlying mucosa was assessed by measuring the wound extent with an electronic caliper at 1 week and at 1 month after TE (T7 and T30 respectively).

RESULTS

At T30, NBH was not statistically different between the BP+ and BP- groups (p = .76). At T90, more than a two-fold in NBH increase was recorded for both groups with no statistically significant difference between them (p = .76). At T30 and T90, RSF was similar in both groups (p = .58 and p = .32 respectively). More than a two-fold RSF increase was founded between T30 and T90 in both groups. No demographic or BPs-related factors were correlated with the RSF at T90. At T7, the mucosa wound extent was reduced by more than two-fold with no statistically significant difference between both groups (p = .80). At this time, mucosa healing was achieved in 11.9% of the BP+ group and 10% of the BP- group (p = .99). At T30, mucosal healing was achieved in all patients but two, and at T90 it was achieved in all patients.

CONCLUSION

This study provides new insights into bone and mucosal healing in patients with osteoporosis taking BPs after TE. In this population, TE can be managed successfully with an appropriate surgical protocol and without discontinuation of BP treatment.

Prevention of medication related osteonecrosis of the jaw after dentoalveolar surgery: An institution's experience

Background

Dentoalveolar surgery is a predisposing factor for medication related osteonecrosis of the jaw (MRONJ). The aim of our study was to evaluate the described surgical procedures to prevent the development of MRONJ after dentoalveolar surgery in patients receiving bisphosphonates.

Material and Methods

In this retrospective study, sixty-three dentoalveolar surgeries were performed on 44 patients taking bisphosphonate in accordance with the treatment procedures we described. The following procedures were applied to patients 1) use of antibiotics 2) performed dentoalveolar surgical procedures 3) fill the socket with leukocyte- and platelet-rich fibrin (L-PRF) 4) post-operative application of low level laser therapy through Nd: YAG laser 5) sutures were removed on post-op 14th day 6) long-term results were evaluated.

Results

Healing of all patients was uneventful. Complete mucosal healing was achieved in all patients at 1 month. There is no failure was observed in long-term follow-up.

Conclusions

Because of the pathophysiology of MRONJ is not fully understood and has many risk factors, definitive protocols on prevention and treatment have not been established yet. Personal risk assessment is required for the prevention and treatment of MRONJ. The described surgical protocol may be considered to reduce the risk of developing MRONJ after dentoalveolar surgery due to its high success rate.

Key words:Tooth extraction, medication related osteonecrosis of the jaw, preventive dentistry, L-PRF, low level laser therapy.

Platelet-Rich Plasma (PRP) in Dental Extraction of Patients at Risk of Bisphosphonate-Related Osteonecrosis of the Jaws: A Two-Year Longitudinal Study

Dental extraction has often been described as the main trigger event of osteonecrosis of the jaws (ONJ). This longitudinal hospital-based study aimed to evaluate the outcome at 2 years of a standardized medical-surgical protocol for dental extraction, combined with platelet rich-plasma (PRP) application, compared with conventional protocol not combined with PRP or any other autologous platelet concentrate in cancer (ONC) and osteometabolic (OST) patients, at risk of bisphosphonate (BP)-related ONJ. Twenty patients were consecutively recruited: six received BPs for cancer skeletal-related events (34.17 ± 19.97 months), while fourteen received BPs for metabolic bone disease (74.5 ± 34.73 months). These patients underwent a standardized protocol for dental extraction, combined with autologous PRP application in the post-extraction socket. A total of 63 dental extractions were performed (24 and 39 in ONC and OST groups, respectively). As controls, historical cases, derived from the literature and including 171 ONC and 734 OST patients, were considered. The outcome of the surgical treatment was successful in all patients treated with PRP: two years after extraction, no patient had clinical or radiological signs of ONJ. When this datum was compared with historical controls, no statistically significant differences were found (p > 0.1). The combination of a standardized medical-surgical protocol with PRP application may contribute to limit the occurrence of BP-related ONJ, in both ONC and OST patients. Additional prospective studies with a larger patient sample are necessary to confirm this datum.

Bisphosphonate-related osteonecrosis. Application of adipose-derived stem cells in an experimental murine model

Background

Bisphosphonate-related osteonecrosis of the jaw is a pathological condition without effective established treatment and preventive strategies. The aim of this study was to analyse the effect of adipose-derived stem cells (ASC) in an experimental murine model of osteonecrosis.

Material and Methods

38 Wistar rats were injected intraperitoneally with zoledronic acid. After treatment, upper jaw molars were extracted. The animals were randomly assigned to one of two groups. In the control group, saline solution was applied over the alveolar sockets after the tooth extractions. In the treatment group, ASCs were applied instead of saline solution. The control and treatment groups were subdivided based on the time of euthanasia. A clinical and histological analysis was performed.

Results

The presence of osteonecrosis in alveolar bone was observed in a similar distribution in both groups. In the ASC-treated group, new bone formation was greater than in controls.

Conclusions

In this study, application of ASCs showed greater new bone formation in an osteonecrosis-like murine model. Previous inhibited post-extraction bone remodelling could be reactivated, and these findings appeared to be secondary to implantation of ASCs.

Key words:Osteonecrosis; bisphosphonates, Mesenchymal stem cells (MSC), adipose-derived stem cells (ASCs), zoledronic acid.

A Systematic Review of Oxygen Therapy for the Management of Medication-Related Osteonecrosis of the Jaw (MRONJ)

Background: Medication-related osteonecrosis of the jaw (MRONJ) can be a life changing iatrogenic complication of antiresorptive and antiangiogenic drug therapy. It is most often associated with high doses of these medications that are used to prevent skeletal-related events in patients with cancer and bone pathologies. Unfortunately, managing MRONJ lesions has proven difficult and remains a major challenge for clinicians. Due to the lack of efficacy in treating MRONJ by surgical modalities (local debridement and free flap reconstruction), the nonsurgical management of MRONJ is still advocated to aid healing or avoid disease progression. The aim of this systematic review is to identify, analyse and understand the published evidence related to the success of oxygen therapies such as ozone (OT) and hyperbaric oxygen (HBO) in treating MRONJ. Material and methods: A multi-database (PubMed, MEDLINE, EMBASE, CINAHL and Cochrane CENTRAL) systematic search was performed by three authors. The identified articles were independently assessed for their risk of bias. Any type of study evaluating humans treated with antiresorptive and antiangiogenic drugs were considered. The aim is primarily to evaluate the success of OT and HBO in resolving MRONJ and secondarily to identify any improvements in quality of life (QoL), rate of complications, time-to-event and severity of side effects related to these treatments. Results: In total, just 13 studies were eligible for analysis. A pooled total of 313 patients (HBO group n = 82; OT group n = 231) described in these studies have shown good tolerance for oxygen therapies. Complete resolution of MRONJ was reported in 44.58% of OT patients but only 5.17% of the HBO group. Progression of MRONJ was reported only in the HBO studies in 10.34% of cases (6 patients). The quality of evidence was low or very low in all studies. This was due to limitations in how the studies were designed, run and reported. Conclusions: Based on the limited data available, it is difficult to suggest OT is better or worse than HBO or whether it is better than a placebo. As the level of evidence available is low, this necessitates larger well-designed trials to justify these interventions for patients affected by MRONJ.

Medication-related osteonecrosis of the jaw after tooth extraction in cancer patients: a multicenter retrospective study

Root amputation, immunosuppressive therapy, mandibular tooth extraction, pre-existing inflammation, and longer duration of treatment with bone-modifying agents were significantly associated with an increased risk of medication-related osteonecrosis of the jaw. Hopeless teeth should be extracted without drug holiday before the development of inflammation in cancer patients receiving high-dose bone-modifying agents.

INTRODUCTION

No studies have comprehensively analyzed the influence of pre-existing inflammation, surgical procedure-related factors such as primary wound closure, demographic factors, and drug holiday on the incidence of medication-related osteonecrosis of the jaw (MRONJ). The purpose of this study was to retrospectively investigate the relationships between these various factors and the development of MRONJ after tooth extraction in cancer patients receiving high-dose bone-modifying agents (BMAs) such as bisphosphonates or denosumab.

METHODS

Risk factors for MRONJ after tooth extraction were evaluated with univariate and multivariate analyses. The following parameters were investigated in all patients: demographics, type and duration of BMA use, whether BMA use was discontinued before tooth extraction (drug holiday), the duration of such discontinuation, the presence of pre-existing inflammation, and whether additional surgical procedures (e.g., incision, removal of bone edges, root amputation) were performed.

RESULTS

We found that root amputation (OR = 22.62), immunosuppressive therapy (OR = 16.61), extraction of mandibular teeth (OR = 12.14), extraction of teeth with pre-existing inflammation, and longer duration (≥ 8 months) of high-dose BMA (OR = 7.85) were all significantly associated with MRONJ.

CONCLUSIONS

Tooth extraction should not necessarily be postponed in cancer patients receiving high-dose BMA. The effectiveness of a short-term drug holiday was not confirmed, as drug holidays had no significant impact on MRONJ incidence. Tooth extraction may be acceptable during high-dose BMA therapy until 8 months after initiation.

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.

The Prevention of Medication-related Osteonecrosis of the Jaw

BACKGROUND

Medication-related osteonecrosis of the jaw (MRONJ) is a preventable complication of antiresorptive treatment. It arises in 1-20% of patients with bone metastases of solid tumors and hematologic malignancies and in 0.1-2% of patients being treated for osteoporosis with bisphosphonates. Depending on the underlying disease and medication dosage, the risk of MRONJ can be elevated even in the first year of antiresorptive treatment. The treatment of MRONJ is difficult and often involves surgery of the jaw.

METHODS

We systematically reviewed publications retrieved by a selective search for literature on the prevention of MRONJ in the PubMed and Cochrane Library databases and with the aid of the Google Scholar search engine.

RESULTS

15 of 559 retrieved publications were included in the analysis. The quality of the evidence in the studies was generally moderate to low, with most of them being case series. In one case series of over 1200 patients with multiple myeloma, the incidence of MRONJ was lowered from 4.6% to 0.8% through regular dental checkups and improved oral hygiene. Tooth extraction, in particular, is associated with a high risk of MRONJ. In a retrospective study, 57% of patients who underwent tooth extraction without antibiotic prophylaxis developed MRONJ, compared to 0% with antibiotic prophylaxis.

CONCLUSION

Before antiresorptive medication is begun, oral hygiene should be improved. Moreover, it seems that perioperative antibiotic prophylaxis and adequate plastic wound closure can often prevent MRONJ. In view of the fact that bisphosphonates can persist in bone for more than 15 years, patients should be thoroughly informed of the risk that antiresorptive treatment can cause MRONJ, and the measures discussed should be initiated.

Long-term oral bisphosphonates delay healing after tooth extraction: a single institutional prospective study

Tooth extraction in patients receiving bisphosphonates is thought to be a risk factor for osteonecrosis of the jaw (ONJ); however, ONJ did not develop, even when tooth extraction was performed with continued oral bisphosphonate therapy. A drug holiday from bisphosphonates before tooth extraction may not be necessary.

INTRODUCTION

It is controversial whether bisphosphonate withdrawal is necessary prior to invasive procedures such as tooth extraction in order to prevent bisphosphonate-related osteonecrosis of the jaw (BRONJ). This study aimed to evaluate the clinical safety of continuing oral bisphosphonate therapy in patients undergoing tooth extraction.

METHODS

We prospectively enrolled 132 patients (20 men, 112 women) who were receiving oral bisphosphonates for the prevention or treatment of osteoporosis and required tooth extraction. All patients were managed using an identical protocol, which included preoperative antibiotic prophylaxis and did not necessarily require complete wound closure. The patients were classified into groups according to the duration of bisphosphonate administration: < 2 years (n = 51), 2-5 years (n = 41), 5-10 years (n = 28), and > 10 years (n = 12). The groups were compared regarding the time taken for the extraction socket to heal, and the occurrence of BRONJ. Follow-up duration was at least 3 months.

RESULTS

A total of 274 teeth were removed. Long-term oral bisphosphonate therapy for > 5 years significantly delayed the healing of the extraction socket in comparison with administration for < 5 years; however, BRONJ did not develop in any group. There was no prolongation of wound healing due to systemic risk factors such as glucocorticoid administration and diabetes mellitus. There were no adverse skeletal events such as bone fracture.

CONCLUSIONS

Patients who underwent tooth extraction with continued oral bisphosphonate therapy showed delayed healing of the extraction socket as the cumulative administration period prolonged, but BRONJ did not develop.

The Dental Management of Patients at Risk of Medication-Related Osteonecrosis of the Jaw: New Paradigm of Primary Prevention

Medication-related osteonecrosis of the jaw (MRONJ) is a serious adverse reaction of antiresorptive and antiangiogenic agents; it is a potentially painful and debilitating condition that can considerably affect the quality of life of patients. Furthermore, even if its epidemiology and pathogenesis have still not been fully clarified, several risk factors related to MRONJ have been recognized in prevention protocols. Three main risk factors are as follows: (i) the type of ONJ-related medications: antiresorptive (e.g., Bisphosphonates, Denosumab) and antiangiogenic drugs (e.g., Bevacizumab, Sunitinib); (ii) the category of patient at MRONJ risk: cancer versus non-cancer patient; (iii) the typologies and timing of dental treatments (e.g., before, during, or after the drug administration). The aim of this paper is to describe the new paradigm by the Italian Society of Oral Pathology and Medicine (SIPMO) on preventive dental management in patients at risk of MRONJ, prior to and during/after the administration of the aforementioned ONJ-related drugs. In reducing the risk of MRONJ, dentists and oral hygienists are key figures in applying a correct protocol of primary prevention for pre-treatment and in-treatment patients. However, the necessity of a multidisciplinary standardized approach, with a sustained dialogue among specialists involved, should be always adopted in order to improve the efficacy of preventive strategies and to ameliorate the patient's quality of life.

Risk-reductive dental strategies for medication related osteonecrosis of the jaw among cancer patients: A systematic review with meta-analyses

The purpose of this systematic review with meta-analysis was to assess the effectiveness of dental interventions in preventing or reducing the incidence of medication-related osteonecrosis of the jaw (MRONJ) in cancer patients receiving antiresorptive therapy, compared to similar control groups receiving no intervention. Randomized controlled trials (RCT), case-controls and cohorts on cancer patients with primary outcome being the prevalence of MRONJ were included. Four electronic databases were searched (Cochrane Library, PubMed, EMBASE and Web of Science) up to February 12, 2018. A total of 409 abstracts were assessed and one case-control, one RCT and four cohort studies with 2332 cancer patients met our inclusion criteria. Risk of bias analysis followed Cochrane's handbook. Risk of bias was unclear for the case-control study and high risk for the RCT and all cohort studies. Five studies utilized preventive measures consisting of an initial examination and performing all necessary dental treatment before patients initiated antiresorptive therapy; one study used specialized post-extraction protocols utilizing plasma-rich in growth factors (PRGF) on cancer patients receiving antiresorptive therapy. Though dental preventive measures decreased MRONJ incidence by 77.3% in six studies with 2332 cancer patients (95% CI = 47.4-90.2%; p = .001) compared to control groups, quality of the evidence was low due to high or unclear risk of bias and the observational nature of five of the included studies. In conclusion, high-quality long-term prospective large sample size studies are needed to confirm these results due to high risk of bias and heterogeneous interventions. No funding.

Medication-related osteonecrosis of the jaw: Prevention, diagnosis and management in patients with cancer and bone metastases

Medication-related osteonecrosis of the jaw (MRONJ) is primarily an adverse side effect of denosumab or bisphosphonates (particularly when used at high doses to prevent skeletal-related events [SREs] in patients with cancer and bone metastases) or possibly anti-angiogenic cancer treatment. While the implementation of preventive measures over recent years has reduced the risk of MRONJ in patients with bone metastases due to cancer, it is imperative to balance the risk of MRONJ against the beneficial effects of treatment with denosumab or bisphosphonates on the skeletal health of patients. Despite growing awareness of MRONJ within the medical community, there is a lack of large-scale, prospective clinical studies in this rapidly evolving field. Discussing preventive measures with patients and implementing them, both before and during treatment with bisphosphonates or denosumab, is the best option to reduce the risk of MRONJ. In particular, avoiding bone trauma and preventing and treating dental infections before and during denosumab or bisphosphonate therapy is crucial to minimize the risk of MRONJ. If MRONJ develops, conservative (non-surgical) treatment can provide symptom relief, but achieving mucosal closure remains challenging. When management of symptoms and mucosal healing are the ultimate goals of therapy, or after failure of conservative treatment, a surgical approach may be beneficial. This critical review, based on a best-evidence review of currently available literature, provides clear practical guidelines to help to prevent, manage and treat MRONJ. Overall, a multidisciplinary, pragmatic approach to MRONJ should be adopted, prioritizing patient's quality of life and management of their skeletal malignant disease.

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

Background

Osteonecrosis of the jaw (ONJ) has been reported to be associated with patients receiving primarily bisphosphonate (BP) therapies. However, lately it has been documented that other medications, such as RANK ligand inhibitor (denosumab) and antiangiogenic drug, can cause ONJ. Micro-osseous-vascular reconstruction of the jaws in patients affected by medication-related osteonecrosis of the jaw represents a viable option of treatment for patients affected by stage III of the disease. However, there are still considerable doubts about the success of this procedure in the short, medium, and long term.

Material and Methods

A multidatabase (PubMed/MEDLINE, EMBASE, and CENTRAL) systematic search was performed. Any type of studies considering human patients treated with antiresorptive and antiangiogenic drugs was considered. The aim of the research is to primarily understand the success rate of micro-osseous-vascular reconstruction in the short, medium, and long period of time. This review has also the goal of better understanding any perioperative and postoperative complications resulting from the use of the reconstruction techniques.

Results

Eighteen studies resulted eligible for the study. Fibula free flap is the most commonly utilised vascularised free flap reconstruction technique (80.76%). Ten out of eighteen studies reported no complications. Recurrence of osteonecrosis was registered in five cases (6.41%) after free flap reconstruction. The overall free flap success rate was 96.16%.

Conclusions

Based on the limited data available in literature (Level 4 of the Oxford Evidence-based medicine scale), micro-osseous-vascular reconstruction of the jaws represents a valid treatment in patients with bisphosphonate-related osteonecrosis at stage III of the disease. However, additional data based on a larger cohort of patients are necessary to justify this type of intervention in patient affected by MRONJ.

A multicenter retrospective study of the risk factors associated with medication-related osteonecrosis of the jaw after tooth extraction in patients receiving oral bisphosphonate therapy: can primary wound closure and a drug holiday really prevent MRONJ?

Root amputation, extraction of a single tooth, bone loss or severe tooth mobility, and an unclosed wound were significantly associated with increased risk of developing medication-related osteonecrosis of the jaw (MRONJ). We recommend a minimally traumatic extraction technique, removal of any bone edges, and mucosal wound closure as standard procedures in patients receiving bisphosphonates.

INTRODUCTION

Osteonecrosis of the jaws can occur following tooth extraction in patients receiving bisphosphonate drugs. Various strategies for minimizing the risk of MRONJ have been advanced, but no studies have comprehensively analyzed the efficacy of factors such as primary wound closure, demographics, and drug holidays in reducing its incidence. The purpose of this study was to retrospectively investigate the relationships between these various risk factors after tooth extraction in patients receiving oral bisphosphonate therapy.

METHODS

Risk factors for MRONJ after tooth extraction were evaluated using univariate and multivariate analysis. All patients were investigated with regard to demographics; type and duration of oral bisphosphonate use; whether they underwent a discontinuation of oral bisphosphonates before tooth extraction (drug holiday), and the duration of such discontinuation; and whether any additional surgical procedures (e.g., incision, removal of bone edges, root amputation) were performed.

RESULTS

We found that root amputation (OR = 6.64), extraction of a single tooth (OR = 3.70), bone loss or severe tooth mobility (OR = 3.60), and an unclosed wound (OR = 2.51) were significantly associated with increased risk of developing MRONJ.

CONCLUSIONS

We recommend a minimally traumatic extraction technique, removal of any bone edges, and mucosal wound closure as standard procedures in patients receiving bisphosphonates. We find no evidence supporting the efficacy of a pre-extraction short-term drug holiday from oral bisphosphonates in reducing the risk of MRONJ.

The effect of chronic dental inflammation on development of Stage 0 medication-related osteonecrosis of the jaw

OBJECTIVE

The pathogenesis of medication-related osteonecrosis of jaw (MRONJ) is poorly understood. The aim of this prospective study was to determine the effect of chronic dental inflammation on the development of Stage 0 MRONJ based on histopathological findings.

METHODS

The study involved patients with a history of bisphosphonate use and an indication for tooth extraction. Before surgery, C-terminal telopeptide test (CTX) values were collected from all patients. All tooth extractions were performed according to a determined protocol. To detect whether any medication-related osteonecrotic changes were present in the non-exposed bone, biopsy samples were taken from the alveolar bone.

RESULTS

A total of 50 patients were included in the study (39 women and 11 men). The patients were mean age of 57.4 ± 12.1 years. In total, 74 teeth were extracted (29 maxillary and 45 mandibular). Histologic examination of three patients (6%) revealed Stage 0 MRONJ. Postoperatively, the complete mucosal healing success rate was 96%. MRONJ risk was not significantly correlated with low CTX value (p = 0.285).

CONCLUSIONS

Chronic inflammation may contribute to Stage 0 MRONJ; however, its role may not be sufficient alone for its development. Application of a predetermined protocol for dentoalveolar processes will help to prevent MRONJ development.

Applying orthodontic tooth extrusion in a patient treated with bisphosphonate and irradiation: a case report

Bisphosphonates and irradiation are useful medical treatments, but can often cause oral complications such as medication-related oral necrosis of the jaw (MRONJ) and osteoradionecrosis (ORN) during oral surgery, including tooth extraction. Therefore, we should take all risks into consideration carefully before choosing dental treatment for patients with a medical history of such therapies. A 55-year-old woman who underwent cord blood transplantation to treat extranodal natural killer T (NK/T) cell lymphoma (nasal type IVB) had a medical history of bisphosphonate and irradiation treatments. We treated her residual tooth root by applying orthodontic extrusion to avoid extraction and successfully restored the tooth. Application of an orthodontic tooth extrusion technique for conservative treatment of a residual tooth is a useful means of avoiding MRONJ or ORN in patients who have a medical history of bisphosphonate and irradiation treatments.

Primary wound closure after tooth extraction for prevention of medication-related osteonecrosis of the jaw in patients under denosumab

OBJECTIVES

Some recent reports have indicated that local infection causes osteonecrosis of the jaw and described that tooth extraction may not be a direct cause of developing medication-related osteonecrosis of the jaw (MRONJ) in patients receiving antiresorptive medications. Tooth extraction and elimination of the source of infection are expected to reduce the risk of developing MRONJ. However, there is no data regarding prevention for developing osteonecrosis of the jaw in patients receiving denosumab. Therefore, the aim of this study was to investigate the outcome of tooth extractions with proper wound closure in patients receiving denosumab.

PATIENTS AND METHODS

Forty teeth in 19 patients treated with denosumab therapy were extracted under preoperative intravenous antibiotics. Patients who had already developed MRONJ in the extraction sites or who had a history of radiation therapy were excluded. During surgery, bone edges were smoothed and all wounds were closed using the double-layered technique.

RESULTS

Thirty-seven extraction sites (92.5 %) in 17 out of 19 patients (89.5 %) were healed. However, three extraction sites in two patients had complications; one patient had exposed bone and developed MRONJ (stage 1) and the other developed a mucosa fistula. Additional surgical procedures were performed and all wounds were completely healed.

CONCLUSIONS

Tooth extractions in patients receiving denosumab can be performed in an appropriate manner and result in good outcomes.

CLINICAL RELEVANCE

This study indicated that tooth extraction with proper wound closure to avoid secondary infection may be effective for the prevention of MRONJ even in high-risk patients.

Preventive Strategies for Patients at Risk of Medication-related Osteonecrosis of the Jaw

For patients at risk of osteonecrosis of the jaw (ONJ), information can be provided by the pharmaceutical manufacturer, pharmacist, prescribing physician, dentist, and oral and maxillofacial surgeon. Prevention strategies to reduce the incidence of osteonecrosis should be applied as soon as it is determined that a patient will be placed on antiresorptive medication. Proper screening involves a comprehensive oral examination with radiographs followed by oral hygiene instruction and necessary dental treatment; surgical techniques and adjunctive therapies that favor optimum healing of bone and soft tissue decrease the risk of ONJ. No dental procedures are absolutely contraindicated.

The effect of laser therapy on the expression of osteocalcin and osteopontin after tooth extraction in rats treated with zoledronate and dexamethasone

PURPOSE

Laser therapy has been used for the prevention and management of medication-related ostenecrosis of the jaw (MRONJ). The aim of this paper was to investigate the action of laser therapy on extraction socket healing in rats in conditions at risk for MRONJ, evaluating the expression of markers of bone metabolism.

METHODS

Thirty male Sprague-Dawley rats were divided in four groups: control group (C, n = 5), laser group (L, n = 5), treatment group (T, n = 10), and treatment plus laser group (T + L, n = 10). Rats of group T and T + L received zoledronate 0.1 mg/kg and dexamethasone 1 mg/kg every 2 days for 10 weeks. Rats of group C and L were infused with vehicle. After 9 weeks, the left maxillary molars were extracted in all rats. Rats of groups L and T + L received laser therapy (Nd:YAG, 1064 nm, 1.25 W, 15 Hz, 5 min, 14.37 J/cm(2)) in the socket area at days 0, 2, 4, and 6 after surgery. Western blot analysis was performed to evaluate the alveolar expression of osteopontin (OPN) and osteocalcin (OCN) 8 days after extraction.

RESULTS

Rats of groups L and T + L showed a significant higher expression of OCN compared to rats of groups C and T (+348 and +400 %, respectively; P = 0.013 and P = 0.002, respectively). The expression of OPN did not show significant differences among the different groups.

CONCLUSIONS

Our findings suggest that laser irradiation after tooth extraction can promote osteoblast differentiation, as demonstrated by the higher expression of OCN. Thus, laser irradiation could be considered a way to improve socket healing in conditions at risk for MRONJ development.

Zoledronate induces bisphosphonate-related osteonecrosis of the jaw in osteopenic sheep

OBJECTIVES

Bisphosphonate-related osteonecrosis of the jaw (BP-ONJ) occurs in 1 % of patients with medication-induced osteoporosis treated with bisphosphonates. Sheep are an established large animal model for investigating osteoporotic skeletal changes. Zoledronate significantly reduces tissue mineral variability in ovariectomized sheep. The aim of this study was to analyze bone healing after tooth extraction in sheep with induced osteopenia and zoledronate administration.

MATERIALS AND METHODS

Eight adult ewes were randomly divided into two groups of four animals. All sheep underwent ovariectomy and a low-calcium diet. Dexamethasone was administered weekly for 16 weeks. Zoledronate was then given every third week for a further 16 weeks in four sheep; these infusions were repeated after extraction of two lower premolars. Four sheep without zoledronate administrations served as controls.

RESULTS

Due to general health conditions, two sheep of the zoledronate group had to be excluded before surgery. The remaining two sheep of this group developed BP-ONJ lesions at the extraction site and various other sites in both jaws. Control group animals showed uneventful wound healing. Histology of the alveolar processes as well as lumbar spine revealed larger portions of old bone and smaller portions of new bone in the zoledronate group.

CONCLUSIONS

This animal study showed uneventful wound healing after tooth extraction in osteopenic sheep whereas zoledronate treatment leads to development of BP-ONJ-like lesions.

CLINICAL RELEVANCE

As bisphosphonate administration is a standard treatment for glucocorticoid-induced osteoporosis, this model can be used for further research in pathogenesis and management of bisphosphonate-related adverse events.

An unusual case of atrophic mandible fracture in a patient with osteogenesis imperfecta and on oral bisphosphonate therapy: Case report

Fractures of severely atrophic (height < 10 mm) edentulous mandibles are infrequent and challenging to manage. Factors such as sclerotic bone and decreased vascularity combined with systemic diseases complicate the management of such fractures. Osteogenesis imperfecta (OI) is a heterogeneous group of inherited disorders of type I collagen metabolism. Patients with OI characteristically present with histories of long bone fractures, deformities, blue sclerae, and opalescent dentin. However, fractures of the facial skeleton are rare. Bisphosphonate therapy has been proven to effectively reduce the fracture risk in patients with OI. The purpose of this clinical report is to present an unusual case of spontaneous fracture of the atrophic mandible in a patient with OI. Despite open reduction and internal fixation (ORIF) with miniplate osteosynthesis, the patient developed a second fracture at a screw placement site distal to the first fracture. The patient was successfully treated with ORIF using locking reconstruction plates fixed in the symphyseal and angle regions. Bone healing following ORIF was normal, and no clinical sign of osteonecrosis as a result of bisphosphonate therapy was observed. Patients with OI can present with spontaneous fractures of already weakened mandibles. Although such fractures can be managed with care using established protocols, further research is required to examine the effects of concomitant medication, such as bisphosphonates.