Bisphosphonate associated osteomyelitis of the jaw in patients with bony exposure: prevention, a new way of thinking

Radiological manifestations and clinical findings of patients with oncologic and osteoporotic medication-related osteonecrosis of the jaw

Medication-related osteonecrosis of the jaw (MRONJ) poses a challenging form of osteomyelitis in patients undergoing antiresorptive therapies in contrast to conventional osteomyelitis. This study aimed to compare the clinical and radiological features of MRONJ between patients receiving low-dose medications for osteoporosis and those receiving high-dose medications for oncologic purposes. The clinical, panoramic radiographic, and computed tomography data of 159 patients with MRONJ (osteoporotic group, n = 120; oncologic group, n = 39) who developed the condition after using antiresorptive medications for the management of osteoporosis or bone malignancy were analyzed. The osteoporotic group was older (75.8 vs. 60.4 years, p < 0.01) and had a longer duration of medication usage than the oncologic group (58.1 vs. 28.0 months, p < 0.01). Pus discharge and swelling were more common in the osteoporotic group (p < 0.05), whereas bone exposure was more frequent in the oncologic group (p < 0.01). The mandibular cortical index (MCI) in panoramic radiographs was higher in the osteoporotic group (p < 0.01). The mean sequestra size was larger in the oncologic group than in the osteoporotic group (15.3 vs. 10.6 mm, p < 0.05). The cured rate was significantly higher in the osteoporotic group (66.3% vs. 33.3%, p < 0.01). Oncologic MRONJ exhibited distinct clinical findings including rapid disease onset, fewer purulent signs, and lower cure rates than osteoporotic MRONJ. Radiological features such as sequestrum size on CT scan, and MCI values on panoramic radiographs, may aid in differentiating MRONJ in osteoporotic and oncologic patients.

Borate bioactive glass prevents zoledronate-induced osteonecrosis of the jaw by restoring osteogenesis and angiogenesis

OBJECTIVES

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a severe complication of systemic nitrogen-containing bisphosphonate (N-BP) administration, which leads to osteonecrosis, pain, and infection. Despite much effort, effective remedies are yet to be established. This study aimed to investigate potential recovery effect of borate bioactive glass (BBG) in vitro and in vivo.

METHODS

The effect of BBG on zoledronate-treated bone marrow mesenchymal cells (BMSCs) and human umbilical vein endothelial cells (HUVECs) was explored by cell counting kit-8, EdU assay, flow cytometry, alkaline phosphatase staining, alizarin red staining, angiogenesis experiment, and real-time quantitative polymerase chain reaction. The preventive effect of BBG on zoledronate-induced osteonecrosis of the jaw in rat model was examined by micro-CT, HE staining, and immunohistochemistry.

RESULTS

Exposure of BBG to BMSCs and HUVECs increased cell proliferation and restored their osteogenesis and angiogenesis potential in vitro. The BRONJ lesions were satisfactorily repaired and bone mineral density, bone volume/tissue volume, trabecula number, OCN-positive cells, and CD31-positive cells were increased in the BBG-treated groups compared with saline-treated groups.

CONCLUSIONS

Exposure of BMSCs and HUVECs to BBG restores osteogenesis and angiogenesis inhibited by zoledronate. BBG successfully restores extraction socket healing of BRONJ in rat model.

Computed tomography imaging features of osteomyelitis of the jaw: comparison between antiresorptive medication-related conditions and medication-unrelated conditions

OBJECTIVES

The aim of this study was to analyze and compare the imaging features of osteomyelitis according to the presence or absence of antiresorptive medications by using computed tomography (CT).

STUDY DESIGN

We retrospectively reviewed the records of 270 patients with osteomyelitis (83 males and 187 females; average age 66.6 years). CT imaging features were analyzed, and imaging and demographic features were compared between the medication-related osteomyelitis (MROM) group and the medication-unrelated osteomyelitis (MUOM) group.

RESULTS

Trabecular defects, cortical defects, sclerosis, and sequestra were detected in the majority of patients, whereas periosteal new bone formation was less common. The MROM group exhibited sequestra and periosteal new bone formation more frequently on CT images, but the size and appearance of the sequestra and type of periosteal new bone were not significantly different between the 2 groups.

CONCLUSIONS

Sequestra and periosteal new bone formation were characteristic CT features of osteomyelitis more commonly found in the medication-related condition. These findings may be useful in the evaluation of osteomyelitis and medication-related osteonecrosis of the jaw.

Risk of Delayed Healing of Tooth Extraction Wounds and Osteonecrosis of the Jaw among Patients Treated with Potential Immunosuppressive Drugs: A Retrospective Cohort Study

Bone-modifying or antiresorptive agents that target osteoclasts, such as bisphosphonates, are known to cause delayed wound healing and osteonecrosis of the jaw (ONJ) following tooth extraction. However, there are no data on whether such adverse events are also caused by drugs that may suppress the immune system, including corticosteroids, immunosuppressants, biological agents, and disease-modifying anti-rheumatic drugs (DMARDs). The aim of this retrospective study was to examine the incidence of delayed post-extraction wound healing and identify risk factors among patients treated with potential immunosuppressive drugs undergoing tooth extraction. We performed a retrospective cohort study involving 101 patients by reviewing their medical records. The underlying diseases of the enrolled patients included dilated cardiomyopathy, hematological malignancy, sarcoidosis, rheumatoid arthritis, and systemic lupus erythematosus. The sample comprised 131 cases of tooth extraction among the 101 patients; delayed post-extraction wound healing occurred in 10 patients (12 cases, 9.2%), including ONJ in three patients (3 cases, 2.3%). The surgical tooth extraction performed for impacted teeth or a residual root (P = 0.009), the number of surgical tooth extraction (P = 0.012), decreased lymphocyte counts (P = 0.008), and decreased eosinophil counts (P = 0.009) were significantly related to delayed wound healing. Thus, among patients taking corticosteroids, immunosuppressants, biological agents, and/or DMARDs, there is a risk of delayed wound healing and ONJ. Moreover, the significant risk factors are low lymphocyte counts, low eosinophil counts, and surgical extraction. It is of particular importance to prevent surgical site infection, when the high-risk patients undergo tooth extraction.

Dental Implant Placement in Patients on Bisphosphonate Therapy: a Systematic Review

Objectives

The review aims to study dental implant placement purposefulness for patients who have been treated or are on treatment with bisphosphonate medication.

Material and Methods

Structured search strategy was applied on electronic databases: MEDLINE, PubMed, PubMed Central and ResearchGate. Scientific publications in English between 2006 and 2017 were identified in accordance with inclusion, exclusion criteria. Publication screening, data extraction, and quality assessment were performed. Outcome measures included implant failure or implant-related osteonecrosis of the jaw.

Results

In total, 32 literature sources were reviewed, and 9 of the most relevant articles that are suitable to the criteria were selected. Heterogeneity between the studies was found and no meta-analysis could be done. Five studies analysed intraoral bisphosphonate medication in relation with implant placement, three studies investigated intravenous bisphosphonate medication in relation with implant placement and one study evaluated both types of medication given in relation with implant placement. Patients with intraoral therapy appeared to have a better implant survival (5 implants failed out of 423) rate at 98.8% vs. patients treated intravenously (6 implants failed out of 68) at 91%; the control group compared with intraoral bisphosphonate group appeared with 97% success implant survival rate (27 implants failed out of 842), showing no significant difference in terms of success in implant placement.

Conclusions

Patients treated with intravenous bisphosphonates seemed to have a higher chance of developing implant-related osteonecrosis of the jaw. The intraorally treated patient group appeared to have more successful results. Implant placement in patients treated intraorally could be considered safe with precautions.

Clinical impact of bisphosphonates in root canal therapy

Bisphosphonates are stable structural analogs of pyrophosphate, which suppress the activity of osteoclasts, leading to decreased bone resorption. They are essential medications in the treatment of osteoporosis. Osteonecrosis of the jaw is a serious adverse effect of bisphosphonate therapy. The prevalence of bisphosphonate-related osteonecrosis of the jaw varies from 0% to 28%, and it can be triggered by dental extraction and trauma. Root canal therapy can delay, or even eliminate, the need for tooth extraction, and therefore, may reduce the risk of bisphosphonate-related osteonecrosis of the jaw. We suggest that this might be the best treatment for teeth with pulpal and/or periapical disease.

Clinical analysis of medication related osteonecrosis of the jaws: A growing severe complication in China

Background/purpose

Medication-related osteonecrosis of the jaws (MRONJ) is an unusual but quite serious complication. However, its mechanism remains unclear, and its treatment protocol is still controversial.

Materials and methods

Our study involved 201 osteonecrosis of the jaw (ONJ) patients from September 2006 to March 2017. We analyzed risk factors, clinical characteristics, treatment, etc., by comparing MRONJ with other ONJs.

Results

Among 201 patients, MRONJ accounted for 14.71% and it presented a consistent increase tendency. In comparison with other ONJs, we considered advanced age, maxilla lesion, diabetes mellitus, tooth extraction, especially multi-teeth extraction as risk factors (P < 0.0125). Our study demonstrated that maxillary lesion was associated with an advanced stage and it was inclined to worse prognoses. We also found MRONJ had little correlation to Actinomyces infection. Surgical treatment could improve patients' condition successfully (P > 0.05). 81.3% patients with advanced stage showed complete or partial healing lesions after surgery.

Conclusion

Advanced age, maxilla lesion, diabetes mellitus, tooth extraction seem to be important triggering factors for MRONJ. Clinicians and surgeons should pay attention to maxillary lesions as it is related to severe symptoms and unfavorable prognosis. Once diagnosed as MRONJ, surgery is an effective treatment for patients with advanced stage.

[Research progress on bisphosphonate-related osteonecrosis of the jaws]

Bisphosphonates (BPs), as potent drugs inhibiting bone resorption, have been widely used for treatment of several diseases. In recent years, dentists and oral and maxillofacial surgeons reported continuously increasing cases of bisphosphonate-related osteonecrosis of the jaws (BRONJ). This disease is clinically characterized by exposed bones, formation of sequestrum, pain, and halitosis. Provided that pathogenesis of BRONJ is unclear, effective treatments for this disease are currently unavailable. Thus, prevention plays an important role in the management of BRONJ. This review summarizes research progress on pathogenesis, risk factors, clinical characteristics, treatment, and prevention of this condition.

Skeletal Site-specific Effects of Zoledronate on in vivo Bone Remodeling and in vitro BMSCs Osteogenic Activity

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) has been associated with long-term oral or intravenous administration of nitrogen-containing bisphosphonates (BPs). However, the pathogenesis of BRONJ remains unknown, and definitively effective treatment has not yet been established. Bisphosphonate-related osteonecrosis (BRON) tends to occur in maxillofacial bones. Why this occurs is still unclear. Here we show that zoledronate (Zol) treatment suppresses alveolar bone remodeling after tooth typical clinical and radiographic hallmarks of the human BRONJ, whereas enhances peripheral bone quantity in bone remodeling following injury in the same individuals, shown as increased cortical bone thickness, increased trabecular bone formation and accelerated bone defect repair. We find that the RANKL/OPG ratio and Wnt-3a expression are suppressed at the extracted alveolar sites in Zol-treated rats compared with those at the injured sites of peripheral bones. We also show that Zol-treated bone marrow stromal cell (BMSCs) derived from jaw and peripheral bones exhibit differences in cell proliferation, alkaline phosphatase (ALP) activity, expression of osteogenic and chondrogenic related marker genes, and in vivo bone formation capacity. Hopefully, this study will help us better understand the pathogenesis of BRONJ, and deepen the theoretical research.