【Abstract】 Objective To investigate the effectiveness of the medical calcium sulfate—OsteoSet bone graft substitute in the treatment of defect after excision of jaw cyst. Methods Between December 2009 and May 2010, 15 cases of jaw cystic lesion were treated，including 9 males and 6 females with an average age of 36.6 years (range, 15-75 years). Orthopantomography (OPT) method was used to measure the cyst size before operation, and the size ranged from 1.5 cm × 1.5 cm to 8.0 cm × 3.0 cm. The range of bone defect was from 1.5 cm × 1.5 cm × 1.5 cm to 8.0 cm × 3.0 cm × 3.0 cm after cyst excision intraoperatively. The patients underwent cyst curettage and OsteoSet bone graft substitutes implantation (2-15 mL). Radiological method was used to evaluate the repair effect of OsteoSet pellets. Results The pathology biopsy was periapical cyst in 7 cases, odontogenic keratocyst in 5 cases, and dentigerous cyst in 3 cases. Fifteen patients were followed up 6-12 months. Thirteen patients achieved wound healing by first intention; 2 cases had longer drainage time (5 and 7 days, respectively), the incision healed after the pressure bandage. Swelling occurred in 1 case after 1 month with no symptom of infection. No postoperative infection and rejection was found. The X-ray examination showed that the materials filled the bone defect well after 1 day of operation. OsteoSet bone graft substitutes were absorbed by one-half after 1 month of operation and totally after 3 months by OPT. The low density area was smaller in the original cysts cavity, and high density in the cysts increased significantly with fuzzy boundaries of cysts. At 6 months after operation， there was no obvious difference in image density between the original cavity and normal bone, and the capsule cavity boundary disappeared, and defect area was full of new bone. Conclusion The medical calcium sulfate—OsteoSet bone graft substitute is an ideal filling material for bone defect.
Objective To compare the effect between vascularization osteogenesis and membrane guided osteogenesis in the bone repair by the tissue engineered bone with pedicled fascial flap packing autologous red bone marrow (ARBM), so as to provide a reference for the bone defect repair in cl inic. Methods The tissue engineered bone was constructed with ARBM and the osteoinductive absorbing recombinant human materials with recombinant human bone morphogenetic protein 2. Sixty New Zealand rabbits (aged 4-5 months, weighing 2.0-2.5 kg) were randomly divided into group A (n=16), group B (n=22), and group C (n=22). The complete periosteum defect model of 1.5 cm in length was prepared in right ulnar bone, then the tissue engineered bone was implanted in the bone defect area in group A, the tissue engineered bonewith free fascial flap in group B, and the tissue engineered bone with pedicled fascial flap in group C. At 4, 8, 12, and 16 weeks, the tissue of bone defect area was harvested from 4 rabbits of each group for the general, histological, and immunohistochemical staining observations; at 8, 12, and 16 weeks, 2 rabbits of groups B and C, respectively were selected to perform ink perfusion experiment by axillary artery. Results The general observation showed that the periosteum-l ike tissues formed in the fascial flap of groups B and C, chondroid tissues formed in group B, new bone formed in group C, and the fibrous and connective tissues in group A at 4 and 8 weeks; a few porosis was seen in group A, more new bone in group B, and bone stump formation in group C at 12 and 16 weeks. Histological observation showed that there were few new blood vessels and new bone trabeculae in groups A and B, while there were large amounts of new blood vessels and mature bone trabeculae in group C at 4 and 8 weeks. There were a few new blood vessels and new bone trabeculae in group A; more blood vessels, significantly increased mature trabeculae, and the medullary cavity formation in group B; and gradually decreased blood vessels, the mature bone structure formation, and the re-opened medullary cavity in group C at 12 and 16 weeks. The immunohistochemical staining observation showed that the levels of CD105, CD34, and factor VIII were higher in group C than in groups A and B at different time points.The bone morphometry analysis showed that the trabecular volume increased gradually with time in 3 groups after operation; the trabecular volume in group C was significantly more than those in groups A and B at different time points (P lt; 0.05); and there was significant difference between groups A and B (P lt; 0.05) except the volume at 4 weeks (P gt; 0.05). The vascular image analysis showed that the vascular regenerative area ratio in group C was significantly higher than those in groups A and B at different time points (P lt; 0.05). The ink perfusion experiment showed that the osteogenic zone had sparse ink area with no obvious change in group B, while the osteogenic zone had more intensive ink area and reached the peak at 8 weeks, then decreased in group C. Conclusion The tissue engineered bone with pedicled fascial flap packing ARBM has the vascularization osteogenesis effect at early stage, but the effect disappears at late stage gradually when the membrane guided osteogenesis is main.
Objective To investigate the effect of simvastatin on inducing endothel ial progenitor cells (EPCs) homing and promoting bone defect repair, and to explore the mechanism of local implanting simvastatin in promoting bone formation. Methods Simvastatin (50 mg) compounded with polylactic acid (PLA, 200 mg) or only PLA (200 mg) was dissolved in acetone (1 mL) to prepare implanted materials (Simvastatin-PLA material, PLA material). EPCs were harvested from bone marrow of 2 male rabbits and cultured with M199; after identified by immunohistochemistry, the cell suspension of EPCs at the 3rd generation (2 × 106 cells/mL) was prepared and transplanted into 12 female rabbits through auricular veins(2 mL). After 3 days, the models of cranial defect with 15 cm diameter were made in the 12 female rabbits. And the defects were repaired with Simvastatin-PLA materials (experimental group, n=6) and PLA materials (control group, n=6), respectively. The bone repair was observed after 8 weeks of operation by gross appearance, X-ray film, and histology; gelatin-ink perfusion and HE staining were used to show the new vessels formation in the defect. Fluorescence in situ hybridization (FISH) was performed to show the EPCs homing at the defect site. Results All experimental animals of 2 groups survived to the end of the experiment. After 8 weeks in experimental group, new bone formation was observed in the bone defect by gross and histology, and an irregular, hyperdense shadow by X-ray film; no similar changes were observed in control group. FISH showed that the male EPC containing Y chromosome was found in the wall of new vessels in the defect of experimental group, while no male EPC containing Y chromosome was found in control group. The percentage of new bone formation in defect area was 91.63% ± 4.07% in experimental group and 59.45% ± 5.43% in control group, showing significant difference (P lt; 0.05). Conclusion Simvastatin can promote bone defect repair, and its mechanism is probably associated with inducing EPCs homing and enhancing vasculogenesis.
ObjectiveTo investigate the feasibility of tissue engineered periosteum (TEP) constructed by porcine small intestinal submucosa (SIS) and bone marrow mesenchymal stem cells (BMSCs) of rabbit to repair the large irregular bone defects in allogenic rabbits. MethodsThe BMSCs were cultivated from the bone marrow of New Zealand white rabbits (aged, 2 weeks-1 month). SIS was fabricated by porcine proximal jejunum. The TEP constructed by SIS scaffold and BMSCs was prepared in vitro. Eighteen 6-month-old New Zealand white rabbits whose scapula was incompletely resected to establish one side large irregular bone defects (3 cm×3 cm) model. The bone defects were repaired with TEP (experimental group,n=9) and SIS (control group,n=9), respectively. At 8 weeks after operation, the rabbits were sacrificed, and the implants were harvested. The general condition of the rabbits was observed; X-ray radiography and score according to Lane-Sandhu criteria, and histological examination (HE staining and Masson staining) were performed. ResultsAfter operation, all animals had normal behavior and diet; the incision healed normally. The X-ray results showed new bone formation with normal bone density in the defect area of experimental group; but no bone formation was observed in control group. The X-ray score was 6.67±0.32 in experimental group and was 0.32±0.04 in control group, showing significant difference (t=19.871,P=0.001). The general observation of the specimens showed bone healing at both ends of the defect, and the defect was filled by new bone in experimental group; no new bone formed in the control group. The histological staining showed new bone tissue where there were a lot of new vessels and medullary cavity, and no macrophages or lymphocytes infiltration was observed in the defect area of experimental group; only some connective tissue was found in the control group. ConclusionTEP constructed by porcine SIS and BMSCs of rabbit can form new bone in allogenic rabbit and has the feasibility to repair the large irregular bone defects.
ObjectiveTo investigate the application of three-dimensional (3-D) printing technique combining with 3-D CT and computer aided-design technique in customized artificial bone fabrication, correcting mandibular asymmetry deformity after mandibular angle ostectomy. MethodsBetween April 2011 and June 2013, 23 female patients with mandibular asymmetry deformity after mandibular angle ostectomy were treated. The mean age was 27 years (range, 22-34 years). The disease duration of mandibular asymmetry deformity was 6-16 months (mean, 12 months). According to the CT data and individualized mandibular angle was simulated based on mirror theory, 3-D printed implants were fabricated as the standard reference for manufacturers to fabricated artificial bone graft, and then mandible repair operation was performed utilizing the customized artificial bone to improve mandibular asymmetry. ResultsThe operation time varied from 40 to 60 minutes (mean, 50 minutes). Primary healing of incisions was obtained in all patients; no infection, hematoma, and difficulty in opening mouth occurred. All 23 patients were followed up 3-10 months (mean, 6.7 months). After operation, all patients obtained satisfactory facial and mandibular symmetry. 3-D CT reconstructive examination results after 3 months of operation showed good integration of the artificial bone. Conclusion3-D printing technique combined with 3-D CT and computer aided design technique can be a viable alternative to the approach of maxillofacial defects repair after mandibular angle ostectomy, which provides a accurate and easy way.