Medication-Related Osteonecrosis of the Jaw: A Systematic Review of Case Reports and Case Series

Medication-related osteonecrosis of the jaw (MRONJ) is a rare condition, typically seen in patients receiving antiresorptive or antiangiogenic drugs. This study aims to synthesize reports and case series of MRONJ regarding sociodemographic and clinical characteristics and to evaluate the effectiveness of the treatments applied. Following PRISMA guidelines, a search for case reports and case series was carried out in the PubMed-Medline database until March 2024. A total of 88 articles were included in this review, in a total of 151 cases. The key findings reveal that females were the most affected individuals (71% of the cases) with the average age at diagnosis being 66.27 years with a standard deviation of ±13.03. Stage 2 was the most observed stage, in 43% of cases, and zoledronic acid was the most commonly used drug (32% of cases). The oral route was the most common route of administration, in 26% of cases, with an average administration duration of 60.88 months (standard deviation ± 50.92). The mandible was the most commonly affected anatomical location (in 60% of cases). Amoxicillin + clavulanic acid (875 mg + 125 mg) and chlorhexidine (0.12%) were the most used antibiotics and mouthwash, with 16% and 26% of the cases, respectively. Surgical debridement was the most common surgical procedure, in 32% of cases, while the use of an L-PRF membrane was the most prevalent unconventional treatment, in 21% of cases. This study identified a statistically significant relationship between unconventional treatments and the cure of MRONJ (p < 0.001), indicating the need for further research to confirm these results.

Jaw osteonecrosis in patients treated with denosumab 120 mg with regular dental monitoring: 4-year retrospective study

Background: Medication-related osteonecrosis of the jaw (MRONJ) is an expected, but rare adverse effect of denosumab. There are few data denosumab 120 mg related MRONJ occurrence when regular dental monitoring is planned. International and French recommendations do not detail the schedule of the follow-up visits, allowing local interpretations. Methods: The aim of this retrospective study was to describe our local experience of regular dental monitoring in patients receiving denosumab 120 mg. We included all ≥18-year-old patients exposed to denosumab 120 mg, bisphosphonate- and denosumab-naive, and with regular dental monitoring (pre-treatment and every 4 months after denosumab initiation) at the University Hospital Center, France, from 2015 to 2019. The crude incidence of denosumab-related osteonecrosis of the jaw was estimated per 100 person-years (95% confidence interval). Results: During the study period, 251 patients were included, of whom 77 did not attend the 1st follow-up visit at 4 months. Almost all patients had osteonecrosis of the jaw risk factors. Ten MRONJ cases were reported (four stage 0 and six stage 1). The crude incidence rate was 5.1 per 100 person-years (95% CI: 1.9–8.2). Denosumab was stopped in all patients who developed MRONJ, with favorable outcome for 3 cases and stabilization in 4 cases after osteonecrosis of the jaw management. Conclusion: This study suggested that a regular dental follow-up every 4 months may be a suitable option for prevention and early detection/treatment of MRONJ. A randomized study should be performed to determine the best dental monitoring schedule.

Dynamic polarization shifting from M1 to M2 macrophages in reduced osteonecrosis of the jaw-like lesions by cessation of anti-RANKL antibody in mice

Denosumab-related osteonecrosis of the jaw (DRONJ), which mainly occurs in cancer patients receiving anti-receptor activator NF-kappaB ligand (RANKL) antibody, reduces oral health-related quality of life. However, the exact mechanisms of and definitive treatment strategies for DRONJ remain unknown. We hypothesized that cessation of denosumab heals and/or ameliorates DRONJ, since it is a protein-based antibody agent, although stopping denosumab should be avoided in clinical situations. Therefore, the aims of this study were: 1) to create a healing and/or amelioration murine model of DRONJ-like lesions induced by chemotherapy/anti-RANKL antibody (mAb) combination therapy and tooth extraction; and 2) to investigate histopathology and immunopathology in the extraction sockets by comparing the murine model of DRONJ-like lesions with the amelioration/healing model of DRONJ-like lesions. Eight-week-old, female C57B/6J mice received chemotherapeutic drug (cyclophosphamide: CY) and mAb combination therapy (CY/mAb) with tooth extraction. Open wounds were sustained in CY/mAb-treated mice at 2 and 4 weeks post-extraction. Impaired socket healing was diagnosed as CY/mAb-related ONJ-like lesions at 3 weeks post-extraction in this study. Next, mAb was discontinued for 2 and 4 weeks after diagnosis of CY/mAb-related ONJ-like lesions. mAb cessation for 2 weeks induced partial osseous wound healing and significantly improved soft tissue wound healing of the extraction sockets. Anti-angiogenesis and normal lymphangiogenesis with CY/mAb combination therapy was not changed by mAb discontinuation. However, mAb cessation for 2 weeks significantly increased the number of CD38⁺F4/80⁺ M1 and CD163⁺F4/80⁺ M2 macrophages, which significantly increased the M2/M1 ratio in the connective tissue of extraction sockets. No direct effects of mAb on macrophages were noted both in vivo and in vitro. Therefore, the developed healing and/or amelioration murine model of CY/mAb-related ONJ-like lesions is a useful tool to investigate the histopathology and immunopathology of DRONJ in humans. Dynamic polarization shifting from M1 to M2 macrophages induced by mAb cessation may play an important role in wound healing, rather than angiogenesis and lymphangiogenesis, in DRONJ.

Can Surgical Management Improve Resolution of Medication-Related Osteonecrosis of the Jaw at Early Stages? A Prospective Cohort Study

PURPOSE

There is no clarity on which protocol is proper to use in the management of medication-related osteonecrosis of the jaw (MRONJ) at early stages (ie, stages 1 and 2) to halt disease progression. The aim of this study was to evaluate the success of surgical treatment in terms of time to mucosal integrity and downstaging in patients with MRONJ at early stages.

MATERIALS AND METHODS

The study was implemented as a prospective, single-center cohort study. The sample included patients who presented at Magna Graecia University of Catanzaro with a clinical diagnosis of MRONJ and underwent surgical treatment. The primary predictor variables were gender, age, medical history, drug administration, MRONJ localization, trigger factors, and stage. The outcome variables were 1) time to mucosal integrity after surgery with time-to-event analysis and 2) time to downstaging of MRONJ lesions. Descriptive, bivariate, and regression statistics were performed.

RESULTS

The study sample included 129 MRONJ patients (90 women and 39 men; mean age, 71.2 ± 12.7 years), of whom 57 had stage 1 and 72 had stage 2. The mean time to achieve mucosal integrity was 71.6 ± 67.7 days, considering the survival probability always to be 93% or greater. The mean time to achieve downstaging of the lesion was 43.6 ± 38.4 days. Patients older than 70 years, those affected by osteometabolic disorders, and those treated with oral antiresorptive therapy showed a significantly shorter time to mucosal healing and downstaging (P < .05). In patients with stage 2 MRONJ, we recorded a significantly longer time to mucosal integrity (56.4 ± 54.5 days) but shorter time to lesion downstaging (33.6 ± 9.9 days) than in patients with stage 1 MRONJ (P < .05).

CONCLUSIONS

Surgical treatment of patients in the early stages of MRONJ guarantees benefits in outcomes such as mucosal integrity and lesion downstaging, improvement in quality of life, and faster reuptake of medication therapy, especially for oncologic patients.