Skin and Bone Regeneration of Solid Bone Marrow Aspirate Concentrate Versus Platelet-Rich Fibrin.

Solid bone marrow aspirate concentrate (sBMAC) is harvested from bone marrow aspirate without anticoagulants by a centrifugation protocol similar to that for platelet-rich fibrin (PRF) prepared from peripheral blood. It was hypothesized that sBMAC could accelerate not only wound healing but also bone regeneration because of the abundant growth factor (GF) releases from enriched bone marrow cells. The purpose of the present study was to investigate skin wound healing and bone regenerative potential of sBMAC compared with arterial blood-derived PRF (Ar-PRF) and venous blood-derived PRF (Ve-PRF) in a skin defect and calvarial bone defect model in rabbits. GF release assays revealed significantly higher release of transforming growth factor-ß (TGF-ß), alkaline phosphatase (ALP), and osteocalcin (OCN) from sBMAC compared with PRFs for 24 h. In the skin defect animal model, sBMAC and PRFs promoted wound bed angiogenesis and re-epithelization in skin defect sites with higher collagen 1 synthesis, cytokeratin AE1/AE3, vascular endothelial growth factor (VEGF) expressions on week 1. Furthermore, a calvarial defect assay revealed that sBMAC promoted new bone formation with a sufficient bone marrow structure similar to that of intact bone in the bone defects. Ar-PRF achieved the second highest bone closure and new bone volume but yielded new bone that was thinner than the intact bone. In conclusion, sBMAC treatment might be a good option instead of PRF as an adjuvant therapy for both skin and bone tissue regeneration therapies in certain clinical situations. Impact statement Solid bone marrow aspirate concentrate (sBMAC) is new type of clot material prepared from bone marrow aspirate. The present study for the first time showed that sBMAC significantly accelerated both skin wound healing and bone formation in the defects, compared with conventional platelet-rich fibrin in rabbit experiment models.

Regenerative Potential of Solid Bone Marrow Aspirate Concentrate Compared with Platelet-Rich Fibrin.

Platelet-rich fibrin (PRF) prepared from venous blood is used in the clinic to improve soft tissue wound healing. Nevertheless, arterial blood or bone marrow aspirate might also be a candidate for the source of PRF-like concentrates. The purpose of the present study was to investigate blood/bone marrow aspirate concentrates obtained from arterial blood, venous blood, and bone marrow aspirate to determine its respective regenerative potential in vitro. Arterial blood-derived PRF (Ar-PRF), venous blood-derived PRF (Ve-PRF), and solid-type bone marrow aspirate concentrate (sBMAC) were prepared from New Zealand white rabbits. Each clot was evaluated for its cytocompatibility and regenerative potential on primary rabbit gingival fibroblasts and osteoblasts. Both gingival fibroblasts and osteoblasts treated with each concentrate showed excellent viability. Interestingly, the sBMAC-treated cells demonstrated a significantly greater migratory potential than the other treatment groups. Furthermore, higher mRNA levels of transforming growth factor-beta, vascular endothelial growth factor, and collagen 1 (COL1) in gingival fibroblasts were observed in the sBMAC group compared with the Ar-PRF and Ve-PRF groups. Greater osteoblast differentiation potential, including higher osteocalcin (OCN) expression and mineralization potential, was found in osteoblasts treated with sBMAC. However, minor differences between the behaviors of cells treated with Ar-PRF and Ve-PRF were observed. In conclusion, sBMAC might be a new candidate for promoting wound healing and bone regeneration. Further preclinical and clinical experiments are necessary to prove the regenerative potential of sBMAC in the body. Impact Statement Blood concentrate material such as platelet-rich plasma or platelet-rich fibrin (PRF) is used in clinical practice to promote tissue regeneration in the field of dentistry, orthopedic surgery, and plastic surgery. The present study introduces a new type of solid bone marrow aspirate concentrate material and, for the first time, shows its excellent regenerative potential in both gingival fibroblasts and osteoblasts in vitro compared with that of conventional PRF.

The Usefulness of Saturated Salt Solution Embalming Method for Oral Surgical Skills Training: A New Cadaveric Training Model for Bone Harvesting.

The purpose of this study was to assess the usefulness of saturated salt solution-embalmed cadavers for oral surgical skills training related to bone graft harvesting. Two half-day surgical skills training workshops were held at the Tokyo Medical University utilizing eight cadavers embalmed with the saturated salt solution. A total of 22 participants including oral surgeons, residents, and dentists attended the workshop. Surgical training consisted of six procedures related to intraoral and extraoral bone harvesting. The participants were surveyed to assess self-confidence levels for each surgical procedure before and after completion of each workshop. The Wilcoxon signed-rank test was used to compare the differences between each median score before and after the workshop. There were statistically significant increases in the self-assessed confidence scores in bone harvesting procedures for the zygomatic bone (P = 0.003), maxillary tuberosity (P = 0.002), and other sites (P < 0.001). The anatomical features of saturated salt solution-embalmed cadavers were also examined. The textures of the oral mucosa and skin were similar to those of living individuals. The structure of bone tissues was well-preserved and the hardness was realistic. Consequently, all procedures were performed with sufficient realism. The saturated salt solution method has a relatively low cost of preparation and storage, and almost no odor. The authors suggest that saturated salt solution-embalmed cadavers could provide a new model for oral surgical skills training in bone harvesting.

Follicular lymphoid hyperplasia of the posterior maxillary site presenting as uncommon entity: a case report and review of the literature.

BACKGROUND: Follicular lymphoid hyperplasia (FLH) is characterized by an increased number and size of lymphoid follicles. In some cases, the etiology of FLH is unclear. FLH in the oral and maxillofacial region is an uncommon benign entity which may resemble malignant lymphoma clinically and histologically. CASE PRESENTATION: We report the case of a 51-year-old woman who presented with an asymptomatic firm mass in the left posterior maxillary site. Computed tomography scan of her head and neck showed a clear circumscribed solid mass measuring 28 × 23 mm in size. There was no evidence of bone involvement. Incisional biopsy demonstrated benign lymphoid tissue. The patient underwent complete surgical resection. Histologically, the resected specimen showed scattered lymphoid follicles with germinal centers and predominant small lymphocytes in the interfollicular areas. Immunohistochemically, the lymphoid follicles were positive for CD20, CD79a, CD10, CD21, and Bcl6. The germinal centers were negative for Bcl2. Based on these findings, a diagnosis of benign FLH was made. There was no recurrence at 1 year postoperatively. CONCLUSIONS: We diagnosed an extremely rare case of FLH arising from an unusual site and whose onset of entity is unknown. Careful clinical and histopathological evaluations are essential in making a differential diagnosis from a neoplastic lymphoid proliferation with a nodular growth pattern.