Ultrasonic Piezoelectric Bone Surgery Combined With Leukocyte and Platelet-Rich Fibrin and Pedicled Buccal Fat Pad Flap in Denosumab-Related Osteonecrosis of the Jaw:

Use of buccal fat pad-derived stem cells cultured on bioceramics for repair of critical-sized mandibular defects in healthy and osteoporotic rats

OBJECTIVE

To compare new bone formation in mandibular symphysis critical-sized bone defects (CSBDs) in healthy and osteoporotic rats filled with bioceramics (BCs) with or without buccal fat pad mesenchymal stem cells (BFPSCs).

MATERIALS AND METHODS

Thirty-two adult female Sprague-Dawley rats were randomized to two groups (n = 16 per group): group 1 healthy and group 2 osteoporotic (with bilateral ovariectomy). The central portion of the rat mandibular symphysis was used as a physiological CSBD. In each group, eight defects were filled with BC (hydroxyapatite 60% and β-tricalcium phosphate 40%) alone and eight with BFPSCs cultured on BC. The animals were sacrificed at 4 and 8 weeks, and the mandibles were processed for micro-computed tomography to analyze radiological union and bone mineral density (BMD); histological analysis of the bone union; and immunohistochemical analysis, which included immunoreactivity of vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2).

RESULTS

In both groups, CSBDs filled with BC + BFPSCs showed greater radiological bone union, BMD and histological bone union, and more VEGF and BMP-2 positivity, compared with CSBDs treated with BC alone at 4 and 8 weeks.

CONCLUSIONS

The application of BFPSCs cultured on BCs improves bone regeneration in CSBDs compared with BCs alone in healthy and osteoporotic rats.

CLINICAL RELEVANCE

Our results may aid bone regeneration of maxillofacial CSBDs of both healthy and osteoporotic patients, but further studies are necessary.

Surgical treatment of 61 consecutive patients with maxillary stage 3 medication-related osteonecrosis of the jaws using a pedicled buccal fat pad

PURPOSE

Buccal fat pad (BFP) is used for the closure of large oroantral defects caused by surgical removal of the necrotic bone in patients with medication-related osteonecrosis of the jaw (MRONJ). This study aimed to evaluate the use of BFP for the closure of maxillary sinus defects in stage 3 MRONJ patients.

METHODS

This study recruited 61patients with large oroantral defects caused by MRONJ, including 49 patients with cancer and 12 patients with osteoporosis. Lesions were evaluated clinically and radiographically.

RESULTS

Among the 61 patients, 51 (83.6%) healed uneventfully, and 5 patients (8.2%) had local dehiscence and exposed bone; these 56 patients (91.8%) all healed after first or second operation. The Eastern Cooperative Oncology Group Performance Status was associated with being non-cured and might be an indicator for the healing process. All patients experienced a significant increase in body weight postoperatively.

CONCLUSIONS

This study suggest that block resection with removal of the necrotic bone combined with radical sinusotomy and closure of the defect with BFP is a reliable method to cure MRONJ lesions with a high success rate, and successful operation and prosthetic rehabilitation may improve body weight and the quality of life. The study was approved by the appropriate ethical approval for the Copenhagen ONJ Cohort (protocol no. H-6-2013-010) November 20, 2013.

Application of the Buccal Fat Pad in Oral Reconstruction: Covered With Collagen Membrane or Not?

OBJECTIVE

To evaluate the clinical effectiveness of collagen membrane as biological dressing in protecting the covered buccal fat pad (BFP) from physical damage during postoperative healing phase in the reconstruction of oral soft tissue defect.

METHODS

A retrospective cohort study was performed in patients undergoing oral defects reconstruction using BFP. The predictor variable was the application of collagen membrane or not. The primary outcome variable was the wound healing. Other variables considered included age, gender, pain score, time taken for epithelialization, defect size and site. Postoperative follow-up was done at 1 week, 3 weeks, 6 months, and 1 year.

RESULTS

Thirty patients in Zhuhai People's Hospital were selected and randomly divided in 2 groups. Group I patients were reconstructed using BFP alone, whereas collagen membrane was used as a covering over BFP in group II patients. In group I, 4 patients developed dehiscence 1-week postoperative, and underwent Infection with food lodgment along with another 1 patient at 3-week follow-up, whereas none of the group II patients developed dehiscence or infection. Pain score was lesser in group II patients as compared to group I. Time taken for epithelialization was about 3 weeks in both groups.

CONCLUSIONS

Combined application of collagen membrane protects the covered BFP from masticatory physical damage and food lodgment, which reduces infection and graft loss. It is worthy of consideration as an effective method for the reconstruction of selected moderate-sized oral defects, especially in larger size or at distant location.

Comparing the Surgical Response of Bisphosphonate-Related Versus Denosumab-Related Osteonecrosis of the Jaws

PURPOSE

The pathophysiology and treatment of medication-related osteonecrosis of the jaws (MRONJ) remain unclear after nearly two decades of recorded observation and discussion. The purpose of this study was to assess outcomes of surgical resection of MRONJ in patients exposed to denosumab.

MATERIALS AND METHODS

A literature review was performed in conjunction with experts at the University of Illinois at Chicago Library. The primary outcome of interest was surgical success defined by maintenance of complete mucosal closure without bone exposure and infection after surgical resection. Secondary interests included demographics, MRONJ stage, location of the focus of osteonecrosis, and the primary underlying disease necessitating antiresorptive treatment. Statistical analysis was performed by χ², analysis of variance, or t test (P < .05 and b = 0.2 or a power of 0.8).

RESULTS

A total of 70 articles were identified and 14 met inclusion criteria. Twenty patients were included (13 women; 7 men); age 61.8 years ± 12.9 (range 19 to 77); and MRONJ stage I (40.0%), II (35.0%), and III (25.0%). Most cases occurred in the mandible (65.0%), followed by the maxilla (30.0%). The success rate of surgical intervention for MRONJ secondary to denosumab was in 16 of 20 (80.0%) patients. Stage I MRONJ lesions achieved mucosal closure in 100% of patients, stage II in 71.4%, and stage III in 60.0%. The surgical success rate was 83.3% in the maxilla and 76.9% in the mandible.

CONCLUSIONS

The surgical success rate for MRONJ secondary to denosumab was 80.0%, similar to that reported in bisphosphonates of 85 to 95%; however, more evidence must be reported and analyzed.

The Case of Medication-Related Osteonecrosis of the Jaw Addressed from a Pathogenic Point of View. Innovative Therapeutic Strategies: Focus on the Most Recent Discoveries on Oral Mesenchymal Stem Cell-Derived Exosomes

Bisphosphonates-related osteonecrosis of the jaw (BRONJ) was firstly reported by Marx in 2003. Since 2014, the term medication-related osteonecrosis of the jaw (MRONJ) is recommended by the American Association of Oral and Maxillofacial Surgeons (AAOMS). Development of MRONJ has been associated to the assumption of bisphosphonates but many MRONJ-promoting factors have been identified. A strong involvement of immunity components has been suggested. Therapeutic intervention includes surgical and non-surgical treatments, as well as regenerative medicine procedures for the replacement of the lost tissues. The literature confirms that the combination of mesenchymal stem cells (MSCs), biomaterials and local biomolecules can support the regeneration/repair of different structures. In this review, we report the major open topics in the pathogenesis of MRONJ. Then, we introduce the oral tissues recognized as sources of MSCs, summing up in functional terms what is known about the exosomes release in physiological and pathological conditions.

Medication-Related Osteonecrosis of the Jaw with Spontaneous Hemimaxilla Exfoliation: Report of a Case in Metastatic Renal Cancer Patient under Multidrug Therapy

Medication-related osteonecrosis of the jaw (MRONJ) is a well-recognized complication of drug therapies for bone metabolic disorders or cancer related to administration of antiresorptive (bisphosphonates and denosumab) and antiangiogenic drugs. This report describes an advanced and unusual case of stage III peri-implantitis-induced MRONJ involving the right upper jaw which was attempting to self-exfoliate. A 61-year-old male patient, rehabilitated with the placement of two implants when he was still healthy, was suffering from metastatic renal cancer previously treated with bevacizumab, interleukin-2, zoledronic acid, denosumab, cabozantinib and nivolumab. He had been under treatment of nonsurgical therapy over a year, based on antibiotic and antiseptic mouth rinse, without improvement of oral conditions. Surgical treatment consisted of massive sequestrectomy and complete surgical debridement of necrotic bone tissues. The specimen was sent for histopathologic analysis, which confirmed bone tissue necrosis with no evidence of metastatic disease. Two-month follow-up revealed a considerable life quality improvement. Although this complication is well known, the uniqueness of this case is given by its severity, related to the administration of multiple antiresorptive and antiangiogenic drugs, by the natural response of the oral cavity with the almost complete self-exfoliation of the massive necrotic zone. This case is emblematic in highlighting the controversies in the management of MRONJ, which certainly require effective collaboration of the multidisciplinary health care team that could improve patient safety and reduce the risk of developing MRONJ.

Is the application of platelet concentrates effective in the prevention and treatment of medication-related osteonecrosis of the jaw? A systematic review

The aim of this systematic review was to answer the question: Is the application of autologous platelet concentrates (APCs) effective in the prevention and treatment of medication-related osteonecrosis of the jaw (MRONJ)? A literature search of PubMed, Scopus, and Web of Science databases (articles published until June 30, 2019) was conducted, in accordance with the PRISMA statement, using search terms related to "platelet concentrate" and "osteonecrosis". The Jadad scale was used to assess the quality of the articles. Fisher's exact test was used to evaluate eventual differences between groups. Of 594 articles, 43 were included in the review (8 for MRONJ prevention and 35 for MRONJ treatment). Out of a total of 1219 dental extractions recorded (786 with APCs), only 12 cases of MRONJ have been reported (1%), all in patients with a history of high-dose antiresorptive treatment, and regardless of the use of APCs (p = 0.7634). Regarding MRONJ treatment, there were no statistically significant differences in terms of improvement between APC application and surgical treatment alone (p = 0.0788). Results are not sufficient to establish the effectiveness of APCs in the prevention and treatment of MRONJ. Randomized controlled trials with large sample size are needed.