Primary Wound Closure Using L-PRF in Patients with Mronj and Osteoradionecrosis - a Case Series

Primary Wound Closure Using L-PRF in Patients with MRONJ and Osteoradionecrosis - a Case Series

MRONJ and Osteoradionecrosis (ORN) are recognised pathological complications affecting both jaws. The 2014 Position Paper from AAOMS described MRONJ as established if the following criteria were met – Ôcurrent or previous treatment with antiresorptive or antiangiogenic agents; exposed bone or bone that can be probed through an intraoral or extraoral fistula(e) in the maxillofacial region that has persisted for more than eight weeks; and no history of radiation therapy to, or obvious metastatic disease in the jawbonesÕ.

ORN is the presence of exposed, devitalised bone in a previously irradiated field, without evidence of tumour recurrence. It can be spontaneous but is usually precipitated by trauma, e.g. tooth extraction or ill-fitting denture.

Both are debilitating complications and can present at a much later date, months or years down the line. Both are clinically challenging to manage, the overall problem lying with the exposed, drug-injured or irradiated bone. Treatment has been limited to conservative measures e.g. antiseptic mouthwash, monitoring and systemic antibiotics as required. The aim of conservative treatment is to prevent further episodes and avoid surgical intervention.

Platelet concentrates have been utilised for their adjuvant and regenerative properties across many medical fields. Four main subtypes exist, classified by their fibrin and cell properties; Pure Platelet-Rich Plasma (P-PRP); Leucocyte- and Platelet-Rich Plasma (L-PRP); Pure Platelet-Rich Fibrin (P-PRF); and Leucocyte- and Platelet-Rich Fibrin (L-PRF).  The general basis for their use is to stimulate, improve and accelerate healing. The most commonly used are L-PRP and L-PRF. They were first used in Oral and Maxillofacial Surgery by Whitman et al in 1997, and in Oral Surgery by Choukroun et al in 2001, both as healing adjuncts. More advanced use has harnessed growth factors present in these preparations and used them for tissue regeneration. Preparation is by separation of blood by centrifugation and discarding those parts not considered useful – namely the red cells.

Current postulated dental uses of L-PRP and L-PRF include placement in extraction sockets, mucogingival surgery, Guided Tissue Regeneration (GTR) for periodontal bony defects, and regeneration of alveolar ridges using Guided Bone Regeneration (GBR). Studies comparing L-PRP and L-PRF suggest the latter may provide better clinical results.

Given this huge healing potential, placement of L-PRF in areas of potentially poor healing such as in MRONJ or ORN could change our management strategy.

We identified 7 patients referred to our department diagnosed with MRONJ or ORN based on the aforementioned definitions, had undergone conservative management, were still symptomatic and had Stage I or II disease.

All patients had 24ml venous blood taken prior to the procedure, which was spun at 3,000 RPM for 10 minutes. They underwent Piezoelectric debridement to bone with evidence of vascular supply, placement of L-PRF and attempted primary wound closure without surgical flaps.

Three patients had been diagnosed with MRONJ and four with ORN. Patients were followed up initially at 2 weeks and 2-5 week intervals thereafter. Epithelial regeneration or full mucosal coverage was noted in 5 patients at 2, 8, 10, 13 and 15 weeks respectively. One patient had initial good mucosal healing but a later dehiscence, and one patient did not attend follow up appointments.

   

L-PRF has already shown promise in assisting intra-oral healing. We have shown that it can also be used successfully in an intra-oral environment compromised by irradiation therapy or medication-related necrosis to encourage this healing process.

References

1. Medication-Related Osteonecrosis of the Jaw – 2014 Update; AAOMS Position Paper
2. Platelet-Rich Fibrin Application in Dentistry: a literature review; E.Borie et al, International Journal of Clinical and Experimental Medicine 2015;8(5):7922-7929