A retrospective study on mandibular coracoid fractures / 华西口腔医学杂志

OBJECTIVE@#This study aimed to analyze the treatment for mandibular coracoid fractures retrospectively.@*METHODS@#A retrospective study on 37 patients with mandibular coracoid fractures treated at Department of Traumatic and Plastic Surgery, West China Hospital of Stomatology, Sichuan University from January 2010 to December 2015 was conducted. Eleven patients were treated conservatively, and 26 patients underwent surgical restoration and internal fixation. Mouth opening and pain degree were used as indicators to analyze treatment results.@*RESULTS@#The 37 cases of coracoid fractures accounted for 3.18% of the total mandibular fractures. The average age of patients was 38.05 years. Satisfactory results were obtained in both treatments. A considerable change in the degree of mouth opening before and after 6 months was found in the two groups. The pain degree before treatment and 1 day after operation, 1 day and 4 weeks after operation, and 4 weeks and 6 months after operation indicated that the two groups did not significantly differ. However, substantial changes between the two groups were found before treatment and 6 months after operation.@*CONCLUSIONS@#Conservative treatment is recommended for patients with linear, temporalis muscle-located, and non-displaced coracoid fractures. Surgical treatment is recommended for patients with large fractures and those with accompanying zygomatic arch and mandible fractures.

In vitro degradation rate of concentrated growth factors in simulated body fluid and simulated saliva fluid / 中国组织工程研究

BACKGROUND: Bioabsorbable biomaterials are of crucial importance in tissue engineering applications, and various factors affect their degradation. OBJECTIVE: To compare the degradation characteristics of concentrated growth factor (CGF) clot and CGF membrane in simulated body fluid (SBF) and simulated saliva fluid (SSF). METHODS: Fifteen volunteers were selected, and human blood samples were collected for the preparation of CGF clot or CGF membrane. All specimens from each subject were averagely divided into four groups: group A, CGF clot in SBF; group B, CGF clot in SSF; group C, CGF membrane in SBF; group D, CGF membrane in SSF. The specimens were subjected to the immersion test. The average daily rate of degradation of each group was calculated after the samples were thoroughly degraded, and weight loss ratio per unit time was also determined. RESULTS AND CONCLUSION: (1) The mean degradation time in groups A-D were (14.0±0.7), (9.7±0.9), (9.9±1.2) and (7.2±0.7) days, respectively. (2) By comparing CGF membrane with CGF clot in the same simulated fluid, the average daily degradation rate of CGF clot (groups A, B) was statistically significantly lower than counterparts of CGF membrane (groups C, D) (P < 0.05). By comparison between SBF and SSF, the average daily degradation rate in the SBF (groups A, B) was significantly lower than counterparts in the SSF (groups C, D) (P <0.05). Overall, the degradation rate of CGF membrane is higher than that of CGF clot under the same degradation environment; for CGF membrane or CGF clot, the degradation rate in SSF is higher than that in SBF.

A study on repairing mandibular defect by means of tissue-engineering and human bone morphogenetic protein-2 gene transfection in osteoporotic rats / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the feasibility of repairing bone defect with methods of tissue-engineering and human bone morphogenetic protein-2 (hBMP-2) gene transfection in osteoporotic rats.</p><p><b>METHODS</b>Twenty-four 6-month-old female Sprague-Dawley rats underwent ovariectomy, while 8 rats received sham-operations. Three months later, bone mesenchymal stem cells (BMSC) harvested from osteoporotic rats were divided into two groups randomly. Experimental group were transfected by recombinant plasmid carrying hBMP-2 gene, and control group left untreated. All BMSC were seeded into coralhydroxyapatite scaffolds. Then the cell/scaffold constructs were implanted into the defect site created in the ramus of mandible of osteoporotic rats respectively.</p><p><b>RESULTS</b>Positive results were confirmed by immunohistochemistry and in situ hybridization in experimental group. New bone formation was found at the margin of the defect treated with the BMSC modified by hBMP-2 gene transfer at 4 weeks after implantation and appeared mature 8 weeks after the treatment. However, the amount of newly formed bone was much less and there was some adipose tissue at defect margins 8 weeks after implantation in control group.</p><p><b>CONCLUSIONS</b>The results of this experiment indicate that BMSC-mediated rhBMP-2 gene therapy in conjunction with bone tissue engineering may allow for successful treatment of large bone defects in osteoporosis rats.</p>

Cultivation and induced differentiation of bone marrow stromal cells of SD rats with type I osteoporosis in vitro / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the biological features and osteoblast/adipocyte phenotypes of bone marrow stromal cells (BMSCs) of Sprague-Dawley (SD) rats with Type I osteoporosis by induced culture.</p><p><b>METHODS</b>Six-month-old SD rats were used in this study. 16 female rats were randomly divided into two groups. Eight rats were ovariectomied as experimental group to establish the modle of Type I osteoporosis, while other rats received sham-operation. Three month later BMSCs of 16 rats were isolated by discontinueous gradient centrifugation and then plated in alpha-MEM medium as primary culture. Secondary harvested cells were cultured for 14 days in alpha-MEM medium supplemented with dexamethasone, ascorbic acid, vitamin D3, beta-glycerophosphate or dexamethasone, 3-isobutyl-1-methylxanthine, insuline, and indomethine. The cells were screened by inverted microscope each day and cell growth was studied with cell counting. The osteoblast and adipocyte phenotypes were verified by cytochemistry staining, counted the percentage of positive stained cells.</p><p><b>RESULTS</b>The weight and bone mineral density of rats were statistically different between experimental group and control group. Gomori and Von Kossa's staining demonstrated positive osteoblast phenotypes of alkaline phosphatase and mineralized nods by osteogenic inducer, while Oil Red O staining identified BMSCs treated with adipogenic medium resulted in adipocyte formation and there was no significant difference in the percentage of positive stained cells between two groups.</p><p><b>CONCLUSION</b>The model of Type I osteoporosis has been established successfully. BMSCs from SD rats with osteoporosis maintain their differentiation potential.</p>

A study on myogenic differentiation of human adipose tissue-derived stromal cells / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To isolate human adipose tissue-derived stromal cells and study the potential of osteogenic differentiation after inductive culture.</p><p><b>METHODS</b>Liposuction human adipose tissues were minced and digested with collagenase type I. The obtained stromal cells were plated in BGJb medium as primary culture for ten days. The second passage cells were harvested and plated in DMEM/F12 medium supplemented with 10% FBS, 5% horse serum and 50 micromol/L hydrocortisone for myogenic induction culture. The cell-anchored slips were removed and fixed in 4% formaldehydam polymerisatum. Toluidine blue, Mallory's phosphotungstic hematoxylin staining and monoclonal antibody to human skeletal muscle myosin heavy chain immunocytochemical methods were used to assay the differentiation of cells.</p><p><b>RESULTS</b>It was observed that the size and shape of induced cells were much different from those of non-induced cells. Toluidine blue, Mallory's phosphotungstic hematoxylin staining demonstrated there were many basophilic striations within cytoplasm and multinucleated myotubes were formed. Immunocytochemical stain indicated that characterastic skeletal myosin heavy chain was positive in myogenic induced cells.</p><p><b>CONCLUSION</b>It seems that human adipose tissue represents an abundant reservoir of adult stem cells that have multi-germline potential to differentiate into myoblasts. Adipose tissue derived stromal cells will be another alternative source for cell-based tissue engineering in skeletal muscle reconstruction.</p>