Spontaneous bone regeneration in resected non-continuous mandible due to medication-related osteonecrosis of the jaw

Abstract Background Bisphosphonates are frequently used for osteoporosis. Medication-related osteonecrosis of the jaw, a complication of bone-modifying agents, including bisphosphonates or angiogenic inhibitors, can be challenging to treat in elderly patients with numerous preexisting conditions. Achieving good treatment outcomes is especially difficult in patients with pathological fractures accompanied with extraoral fistulae. Case presentation We report an unusual case of prominent bone regeneration following palliative surgical treatment in a 72-year-old Japanese female patient undergoing hemodialysis. She previously had severe osteoporosis due to renal osteodystrophy and was receiving antiresorptive intravenous bisphosphonate. Computed tomography revealed a discontinuous left lower mandibular margin with a pathologic fracture and extensive, morphologically irregular sequestrum formation (80 × 35 × 20 mm). The patient was diagnosed with stage III medication-related osteonecrosis of the jaw and pathologic mandibular fracture. Immediately before the surgery, the anticoagulant used for dialysis was changed from heparin to nafamostat mesylate to reduce the risk of intraoperative bleeding. Sequestrectomy was performed under general anesthesia. Postoperative infection was not observed, the intraoral and submandibular fistula disappeared, and, surprisingly, prominent spontaneous bone regeneration was observed postoperatively at 6 months. Despite the severe systemic condition of the patient, the conservative surgical approach with sequestrectomy has yielded desirable results for more than 6 years since the surgery. Conclusions This rare report of spontaneous bone regeneration in a patient of advanced age and poor general condition is the oldest case of mandibular regeneration ever reported.

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Decellularized bone extracellular matrix in skeletal tissue engineering

Biochemical Society Transactions ◽

10.1042/bst20190079 ◽

2020 ◽

Vol 48 (3) ◽

pp. 755-764

Author(s):

Benjamin B. Rothrauff ◽

Rocky S. Tuan

Keyword(s):

Tissue Engineering ◽

Bone Regeneration ◽

Tissue Regeneration ◽

Animal Studies ◽

Tumor Resection ◽

Regenerative Capacity ◽

Skeletal Tissue ◽

Large Bone

Bone possesses an intrinsic regenerative capacity, which can be compromised by aging, disease, trauma, and iatrogenesis (e.g. tumor resection, pharmacological). At present, autografts and allografts are the principal biological treatments available to replace large bone segments, but both entail several limitations that reduce wider use and consistent success. The use of decellularized extracellular matrices (ECM), often derived from xenogeneic sources, has been shown to favorably influence the immune response to injury and promote site-appropriate tissue regeneration. Decellularized bone ECM (dbECM), utilized in several forms — whole organ, particles, hydrogels — has shown promise in both in vitro and in vivo animal studies to promote osteogenic differentiation of stem/progenitor cells and enhance bone regeneration. However, dbECM has yet to be investigated in clinical studies, which are needed to determine the relative efficacy of this emerging biomaterial as compared with established treatments. This mini-review highlights the recent exploration of dbECM as a biomaterial for skeletal tissue engineering and considers modifications on its future use to more consistently promote bone regeneration.

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