Prevention and management of drug‐induced osteonecrosis of the jaws using platelet‐rich fibrin: A clinical feasibility study

Abstract Objective Although a standard treatment guideline has not been established to date, various treatment modalities have been described in the literature based on the staging of medication‐related osteonecrosis of the jaw (MRONJ). The aim of this case series was to describe the outcomes of surgical intervention of MRONJ cases with the adjunctive use of platelet‐rich fibrin (PRF). Materials and Methods Thirteen patients under therapy with zoledronic acid, seven of them underwent surgical removal of necrotic bone with debridement, followed by placement of three to four PRF membranes and achieving primary closure. In six patients, PRF was used preventively to avoid MRONJ. Results The surgical treatment outcomes were successful in all patients, with a follow‐up range of 12–48 months. In the presented cases, the intraoral evaluation showed excellent soft tissue healing except for one patient secondary wound healing was reported. Additionally, there was no recurrence of bone exposure in all cases. PRF membranes were comparatively effective in postsurgical pain control. Conclusion The use of PRF could represent a valuable adjunct in the surgical management for advanced stages of MRONJ cases. Clinical Relevance This clinical case series describes the use of PRF membranes as a valuable adjunct in the surgical management of MRONJ patients, especially when treating advanced MRONJ cases. Moreover, PRF demonstrates usefulness in preventing such difficult complications from occurring.


| INTRODUCTION
Medication-related osteonecrosis of the jaw (MRONJ) was first described by Marx in 2003 as a complication among cancer or osteoporosis patients who had received bisphosphonate (BP) therapy with no previous history of radiation therapy of the jaw (Marx et al., 2005;Ruggiero et al., 2014).Ever since, the literature formerly describing this condition has constantly grown with regard to BPs and several other medication families such as denosumab (DMB) for which several treatment protocols have been proposed (ICD-10; Ruggiero et al., 2014Ruggiero et al., , 2022)).As the main effect of the BPs is on the osteoclasts, they interfere with the process of bone turnover by inhibiting the resorption of trabecular bone, hence increasing bone density, and impairing angiogenesis (Marx et al., 2005;Ruggiero et al., 2014;ICD-10).The main indication for BPs is to reduce the risk of fractures in patients with osteoporosis/osteopenia and to decrease the risk of metastasis in cancer patients, especially breast and prostate cancers (Ruggiero et al., 2014(Ruggiero et al., , 2022)).One of the consequences of impaired bone healing and turnover in the jaws, particularly following common oral surgical procedures such as tooth extraction or implant placement, is the exposure of the bone to the oral environment.This can lead to the development of infection, pain, and even jawbone fracture (Marx et al., 2005).Generally, the greatest initiator of MRONJ is a tooth extraction (Advisory Task Force on Bisphosphonate-Related Ostenonecrosis of the Jaws, American Association of Oral and Maxillofacial Surgeons, 2007).
Other classes of non-BP drugs (mainly antiresorptive or antiangiogenic medications) are associated with clinical features of bone exposure in the jaws (Advisory Task Force on Bisphosphonate-Related Ostenonecrosis of the Jaws, American Association of Oral and Maxillofacial Surgeons, 2007;Ruggiero et al., 2022;Sarkarat et al., 2022)."In the recent Position Paper of the American Association of Oral and Maxillofacial Surgeons (AAOMS) published in 2022 (Ruggiero et al., 2022), the term medication-related osteonecrosis of the jaw (MRONJ) remains unchanged," where the World Health Organization coined the term drug-induced osteonecrosis of the jaws (DIONJ) (ICD-10).In the last update of the same article in 2022, the lesions of MRONJ still staged into stages 0, 1, 2, and 3 (Ruggiero et al., 2022).In the first stage, the patient is asymptomatic with exposed and necrotic bone or fistula that probes to the bone without evidence of infection or inflammation.These patients also may present with radiographic findings mentioned for stage 0 that are localized to the alveolar bone region.The final stage, stage 3, is characterized by exposed necrotic bone in patients experiencing pain, infection, and complications such as pathologic fracture, extraoral fistula, and oral antral/oral nasal communication (Ruggiero et al., 2022).
Currently, there is no standardized protocol for treating MRONJ cases (Ruggiero et al., 2022).However, many treatment modalities have been described in the literature depending on the stage and degree of bone necrosis (Alrmali, 2018;Sarkarat et al., 2014).Over the years, a conservative approach has been the first choice of treatment including local debridement, removal of bone sequestrum, and a combination of systemic antibiotic treatment and/or antiseptic solutions (e.g., chlorhexidine) (Myneni Venkatasatya et al., 2017;Ruggiero et al., 2022).
These yield superior outcomes in the early stages of MRONJ (Ruggiero et al., 2022).In the majority of the cases, a reduction in the clinical signs and symptoms or complete healing can be achieved (Ruggiero et al., 2022).In recent years, some therapeutic protocols have been proposed to enhance the healing and the predictability of the surgical treatment, such as ozone therapy (Ripamonti et al., 2011), low-level laser therapy (Sarkarat et al., 2019;Scoletta et al., 2010), hyperbaric oxygen (Freiberger et al., 2012), autologous platelet concentrates (APCs) (Adornato et al., 2007;Del Fabbro et al., 2018;Miranda et al., 2021;Sarkarat et al., 2014) and combination therapies (Sarkarat et al., 2022).The combination of the surgical treatment and autologous membranes of platelet-rich fibrin (PRF) has the objective of adding bioactive factors to the surgical site to accelerate bone and soft tissue healing (Adornato et al., 2007;Mohammadi et al., 2022;Nørholt & Hartlev, 2016;Sabri et al., 2022).Recent systematic reviews on this topic have concluded that there is still insufficient evidence to prove the true benefits of platelet concentrates in the healing of ONJ lesions (Fabbro et al. 2015(Fabbro et al. , 2018;;Fortunato et al., 2020;Lopez-Jornet et al., 2016).Therefore, this study aimed to propose a protocol for the management and prevention of MRONJ using PRF and describe the treatment outcomes in a series of patients.

| Diagnosis
The diagnosis was made based on the diagnostic criteria of MRONJ, according to the position article published in 2022 (Ruggiero et al., 2022).This diagnosis was confirmed in all patients after clinical examination, which included a review of their past medical and dental history, as well as oral and radiographic examinations.

| General treatment protocol
Oral antibiotic treatment with a combination of amoxicillin and clavulanic acid were initiated the day before surgery (Clavulin BD1, 875/125 mg; GlaxoSmithKline) and continued for every 12 h for 9 more days.
All the patients had been receiving oral corticosteroids all of whom continued the use of their medication, according to the recommendation by their medical doctor.After proper surgical preparation, medical consultation was done.Standard surgical protocol was followed for all patients to eradicate the defects under aseptic technique and with the concept of applying PRF into the defected areas further followed by applying a chlorhexidine 0.2% + hyaluronic acid 1% gel (PerioKIN, Kin Laboratories, S. A.) (Figures 1a, 2e, and 3d,g).

| PRF preparation protocol
Before starting the surgery, blood samples were collected from each patient with a 21-gauge vein needle.Six to eight collection tubes of 10-mL were filled, without the addition of anticoagulants.After collection, the blood was immediately centrifuged with a force of approximately 400g (2700 rpm) for 12 min. 1After centrifugation, the tubes were placed vertically in a rack, allowing for the blood to clot for almost 15-20 min.At the end of the procedure, the clot (PRF) was removed from the collection tubes bluntly and placed into the PRF box, a light pressure was applied to the PRF clot with PRF-Box to form a membrane 2 (Figure 1a).

| Surgical intervention
Seven patients were treated under local anesthesia with 2% lidocaine containing 1:100,000 epinephrine.While two of them were admitted to the hospital for general anesthesia due to the severity of the necrosis that could not be treated under local anesthesia.To access the surgical site, a mucoperiosteal flap was extended from mesial to the distal of the lesion, and it was elevated and mobilized by performing deep split and superficial split to facilitate tension-free primary closure.Necrotic bone was removed with surgical bur and the bone surface underwent surgical debridement to remove all necrotic bones (Figure 1a-i).The extent of the resection was based on the preoperative cone beam computed tomography (CBCT) findings and intraoperative appearance of the bone vitality (bleeding) at the resected surface.The first key after removal of the necrotic bone is to identify the healthy bone by creating small holes using a small round bur under copious irrigation to improve the blood supply to the area and identify bone vitality.Any sharp edges were smoothened and the residual bone was perforated using a small round bur to enhance the blood supply.After this, flap release by periosteal scoring was done to achieve primary closure.The amount of PRF membranes to use was left to the surgeon's decision and it varied for each case depending on the extension of the surgical bone defect (Table 1).In all cases, PRF was placed in layers directly over the perforated bone.Finally, the flap was sutured with 5-0 polypropylene sutures, 3 and this would be the second key as primary closure is critical in such cases (Figure 2a-f).Postoperative instructions and medications were given, and careful follow-up was done.A soft diet was prescribed for 4 weeks, and topical 0.2% chlorhexidine (Periodex) was used for 2 weeks after the surgical procedure.This was continued with 0.012% for another 2 weeks.The patients were strictly followed every week for the first month until achieving soft tissue closure and elimination of any symptoms.Next, they were scheduled for follow-up visits (Figure 3a-i).

| Prevention protocol
To prevent the reoccurrence or occurrence of MRONJ in patients who are at risk, a protocol based on the experience of the authors using PRF is proposed as follows.Six preventive cases were included in the study, two of whom had a history of MRONJ and were treated among the aforementioned treatment group.Based on the evaluation, two patients were under therapy with oral alendronate for osteoporosis, and four were receiving IV zolendronic acid for the treatment of breast cancer metastasis.The patients did not report any previous treatment in the affected area.The same steps of clinical examination, including history, oral, and radiographical examinations, were performed for the tooth which was indicated for extraction.Overall, for the preventive cases, atraumatic extraction was carried out.Next, multiple PRF plugs were condensed in the socket with multiple cross sutures without achieving primary closure.

| DISCUSSION
MRONJ causes significant morbidity and adversely affects the patient's quality of life.Several strategies and treatment modalities for management of patients with or at risk of MRONJ have been proposed in previous clinical studies and consensus (Ruggiero et al., 2014(Ruggiero et al., , 2022)).The current paper presents the treatment and prevention of MRONJ in 13 patients, 12 females, and 1 male, using PRF.The higher incidence rate of MRONJ in females has been reported in previous studies.Furthermore, spontaneous MRONJ occurs four times more commonly in females than males (Urade et al., 2011).In addition, three patients had a history of taking the oral BP (alendronate) while 10 patients had been receiving IV BP (Zoledronic acid).Consistently, a 4-year prospective study by "Hallmer et al. (2018), showed that MRONJ occurs more frequently in patients taking IV bisphosphonates than oral bisphosphonates."While patients with IV BPs have increased risk of developing MRONJ following dental extraction (Khominsky & Lim, 2018), some clinical reports also suggest a spontaneous occurrence of MRONJ in this population of patients (Wysowski & Greene, 2013).Conversely, other studies reported more frequent incidence of MRONJ in patients taking oral BPs, attributed to the high prescription rates of oral BPs (Vandone et al., 2012).
Many clinical strategies addressing the treatment and prevention of MRONJ.These proposed strategies were tested and shown to enhance healing and reduce the risk of MRONJ in patients on BPs (Ferlito et al., 2011).BPs inhibit osteoclastic function by interfering with osteoclast recruitment, differentiation, and resorptive activity.
Considering albeit a drug holiday can reverse their systemic effect, it is unlikely to affect the activity of bone matrix-bound BPs (Ruggiero et al., 2022).However, the use of antibiotics before and/or after the surgical procedure (Schubert et al., 2012), the use of antimicrobial mouthwashes (Lodi et al., 2010), appropriate closure of the wound following tooth extraction (Francini et al., 2011), good oral hygiene (Weiss et al., 2008), the use of neodymium-doped yttrium aluminium garnet laser (Vescovi et al., 2007), and the use of growth factors are all prove helpful antibacterial properties and in minimizing the risks of MRONJ (Asaka et al., 2017;Fabbro et al., 2016;Feng et al., 2020;Fernando de Almeida Barros Mourão et al., 2020;Yüce et al., 2021).plasma as a therapeutic agent in the treatment of MRONJ was tested in a split-mouth animal study " Sarkarat et al. (2014), who showed that a significantly higher sound bone formation in the PRP group than the non-PRF treated groups in zoledronic acid induced MRONJ defects."This is because PRF induces the survival and proliferation of fibroblast and keratinocytes, and PRF also antagonizing the effects of BPs as well as possess antibacterial function.In addition, PRF was used by others to prevent MRONJ due to the high concentration of platelet-derived growth factors (PDGF), which plays a crucial role as an essential regulator for the migration, proliferation, and survival of mesenchymal cells.In addition, PRF contains transforming growth factor-β1, a growth factor that is released by autologous bone, which stimulates synthesis of type 1 collagen and fibronectin and vascular endothelial growth factor (VEGF), the most potent growth factor leading to tissue angiogenesis (Mohammadi et al., 2022).
When it comes to using autogenous platelet concentrates as preventive agents before extractions, the results of a systematic review by "Fortunato et al. (2020) indicated that there is still lack of sufficient evidence to conclude its efficacy."In addition, it was not mentioned in the last position paper updated protocol (Ruggiero et al., 2022).However, several other recent human studies queried the feasibility of the use of PRF as a preventive strategy for the patients taking BPs and reported promising results." Miranda et al. (2021), in a comparative study design, compared occurrence of MRONJ after the extraction and found the PRF group showed no occurrence while in the no PRF group an approximately 20% of the patients developed MRONJ."Based upon the findings from literature and the reported results, this case series strengthen and support the concept of using PRF in the management of MRONJ cases or the patients under high risk of developing it.
Readers should be borne in mind that due to the case-series nature of this study; the results should be interpretated with cautious.Future studies with larger sample sized and the longer follow-up are needed to validate the results of this clinical feasibility study.
T A B L E 1 Summarizes demographic data, treatment variables, and clinical outcomes for patients with different MRONJ stages treated using surgical intervention with PRF membranes.Abbreviations: AAOMS, American Association of Oral and Maxillofacial Surgeons; F, female; IV, intravenous; M, male; MRONJ, medication-related osteonecrosis of the jaw; PRF, platelet-rich fibrin.
Within its limitations, the results of this case series indicated that the use of PRF could a valuable adjunct in the treatment and prevention of MRONJ due to its biological action attributed to high concentrations of growth factors that increase angiogenesis to enhance bone repair and promote soft tissue healing to achieve primary wound closure.

|
Study design and subject recruitmentThis study was designed as a prospective clinical feasibility report.The procedures employed were in accordance with the ethical standards of the 1975 Declaration of Helsinki revised in 2013.All the patients underwent surgical treatment at a private practice setting (between 2016 and 2021) at Tripoli and Misurata cities, Libya.Ethical approval was obtained from the Ethics Committee, Ministry of health, registration number: 00002A/16.Signed informed consent was obtained from all patients.The surgical intervention was performed by one surgeon (A.A).The study was also conducted in conformance with strengthening the reporting of observational studies in epidemiology guidelines: http://www.strobe-statement.org(Vandenbroucke et al., 2007).The inclusion criteria were (1) diagnosis of MRONJ and need for surgical management either under local or general anesthesia or patients under the risk of developing MRONJ and requiring preventive intervention; (2) patients able to undergo surgical treatment (American Society of Anesthesiologists-2 [ASA-2] or ASA-3); and the exclusion criteria was reserved for: (1) any contraindications or conditions limiting the surgical intervention.The following information was collected: demographic data, medication (antiresorptive drug or antiangiogenic), duration of the therapy (time of BPs use), route of administration (oral or intravenous [IV]), location of the lesion, surgical site, MRONJ stage, number of PRF membranes utilized, and postoperative follow-up.

Intra
Overall, 13 patients (11 females and 2 males) were included to this study.The mean age of the subjects was 58 ± 12 years (range 43-74 years).The complete demographic data of the patients is depicted in 1 The number of affected mandibles and maxillae were almost equal among the four cases in maxilla versus three cases in mandible.MRONJ was triggered after a tooth extraction in four patients.While in three patients it had occurred spontaneously.Two of the patients (#2 and #13) had been taking 70 mg tablet of alendronate sodium orally per week.The mean duration of medication therapy before the onset of MRONJ was 3.14 ± 1.8 years (range 36-84 months).The outcome of the surgical treatment was successful in all patients (100%) except in one case patient #5 in which flap dehiscence occurred.This case kept under mouthwash use F I G U R E 1 (a) Platelet-rich fibrin (PRF) membranes prepared; (b) preoperative photos of idiopathic medication-related osteonecrosis of the jaw of the maxilla; (c) resection of the necrotic bone and decortication of the maxillary sinus floor; (d) removal of the necrotic bone; (e, f) application of buccal fat pad over the PRF and closure using a palatal pedicled flap; (g) primary closure achieved; (h) 2-week healing; (i) 8-week healing.F I G U R E 2 (a) Cone beam computed tomography image showing the boney sequestrum; (b) the necrotic bone was readily removal following flap elevation; (c) removal of the necrotic bone; (d) decortication of the underlying bone was performed following complete removal of the necrotic bone; (e) application of the platelet-rich fibrin into the defect area; (f) 12-week healing.until secondary wound granulation and disappearance of any symptoms.The mean follow-up period was 24.5 ± 14.11 months (range months).The clinical evaluation showed excellent soft tissue healing at any follow-up appointments, without bone exposure and signs of infections.In most cases, complete soft tissue closure was achieved by 2-4 weeks.Local pain disappeared within the first week postsurgery in all patients.No complications occurred throughout the follow-up period except for one case.No recurrence was reported among all the cases during follow-up period.

Furthermore
, our current study involved seven cases of MRONJ that were treated with debridement of necrotic bone and application of PRF.Whereas for the other six cases who had been taking BPs, PRF was used to prevent the occurrence of MRONJ.The average duration of BPs therapy for those patients was 3.14 ± 1.8 years.All cases healed properly with neither complications nor recurrence of MRONJ postsurgically.The concept of employing platelet-derived F I G U R E 3 (a) Periapical radiograph image showing changes in trabecular pattern; (b) the necrotic bone was involved inter radicular and buccal bones of the upper first molar socket; (c) removal of the necrotic bone and decortication of the maxillary sinus floor was performed; (d) application of the PRF into the defect area in layers; (e) primary closure achieved; (f) 2-week healing; (g) application of 1% hyaluronic acid over the wound; (h) 8-week healing; (i) 24-week healing.