Objective: The aim of this study was to test the effects of rhBMP-2 and FGF-2 on osteoblast mineralization, and ENPP1, ANK and TNAP  gene expression on osteoblast-like cell line MC3T3-E1 Subclone 14 in vitro. Methods: The MC3T3-E1 Subclone 14 cells were divided into 3 groups. Group 1, osteoblast-like cells were cultured only with  osteogenic medium  as control group. Group 2, cells were cultured with rhBMP-2 + osteogenic medium.  Group3, cells were cultured with FGF-2+ osteogenic medium.  Alkaline phosphatase activities were determined and specific mineralization detection was performed with  Alizarin red staining. Osteoblast mineralization-related gene expression of  ENPP1, ANK and TNAP were evaluated by real -time PCR. Analysis of variance was performed by SPSS 13.0 software. Data were expressed as the x+s of  triplicate measurements.  P<0.05 was accepted as significant. Ｒesults: In rhBMP-2 intervention group, ALP  activities, calcium deposition and the mineralization-related genes expression  were markedly higher than those of control group. In FGF-2 intervention group, ALP activities and calcium deposition were markedly lower than those of control group, the mRNA of ENPP1 and ANK was highly expressed, the mRNA of TNAP was marked lowly expressed than those  of control group. Conclusion: rhBMP-2 and FGF-2 may  regulate ENPP1, ANK and TNAP gene expression on osteoblast mineralization.

Objective: This study aimed to design and synthesize small interfering RNA( siRNA) targeting glucose transporter-1(GLUT1), and further screen the siRNA which can specifically and effectively suppresses GLUT1 expression. Methods: Four GLUT1 specific double stranded siRNAs were designed and electroporated into Cal-27 cells by LipofectamineTM 2000 in 293T cells. The transcription level of GLUT1 were analyzed by Real-time fluorescence quantitative polymerase chain reaction (Real-time PCR), GLUT1 protein was tested by western blotting and glucose uptake inhibition rates were tested by 18F-FDG after GLUT1-siRNA. Results: Two of the four customized siRNA manifested effective inhibition on the expression of GLUT1. Conclusion: siRNA targeting GLUT1 can be successfully designed and synthesized, which can specifically and effectively suppresses the expression of GLUT1 gene and glucose uptake. The results may be beneficial to further study on gene therapy of tumors by RNA interfere (RNAi).

Targeting therapy using the drugs selected by genetic detection is to block specific gene target and signaling pathway in tumor cells. The therapy can kill the tumor cells and does not affect normal cells, and has good curative effect and less side effects, so it is considered to be a treatment option of combined therapy for oral and maxillofacial-head and neck cancer. Targeting therapy combined by radiation therapy improves radiosensitivity. For advanced patients with tumor recurrence, or with distant metastasis, who can't tolerate with concurrent radiation and chemotherapy, targeted therapy can be used alone. Targeting therapy can decline risks of recurrence or worsening, and has the very big advantage in clinical application, and is becoming one of the indispensable important means of the combined therapy in the patients with oral and maxillofacial-head and neck cancer.

Objective: To summarize the diagnostic significance of digital radiography(DR) in mid-facial fracture patients. Methods: 135 patients suffered from middle facial complex fractures with DR examination were retrospectively analyzed.Projections of radiographic examinations included plain film of the skull, Water’s position, lateral projection of the nasal bone, Caldwell position, Towne position, and modified submentovertical view. Results: In 91 cases, positive frature lines were determined by DR imagines. 31 cases showed indirect signs, while in 13 fracture cases showed negative findings on fractures. Conclusion：Digital radiography may be effective in diagnosis of middle facial combined injuries. Meticulous analysis of the  radiographs and optimization of radiographic projections are helpful.

Objective：To evaluate the clinical effects of bleomycin, dexamethasone, and sodium morrhuate combined injection on the treatment of oral and facial cavernomas. Methods: 92 infant  patients were divided randomly into two groups. Group A (n=46) was injected with bleomycin, dexamethasone, and sodium morrhuate into the lesion, while group B (n=46) was only injected with bleomycin and dexamethasone. Results: A perfect cure was obtained in all 92 patients. In group A, injection frequency was repeated （3.20±0.13） times and treatment lasted for 20 days.  In group B, the injection frequency was repeated（4.90±0.15） times and lasted for  28 days.  Conclusion： Combination of these three drugs can  shorten the treatment course and reduce the injection frequency. It may be a safe, valid and feasible method and be worthy to widely applying.

Objective: The current paper was aimed to detect the expression of stem cell factor (SCF) during the repair process of rats′ mandibular defects.  Methods: 36 SD rats were used in this study. In one side of the mandible , critical size bone defect (CSD) in 5 mm dimension was established. A self-healing bone defect in 2 mm dimension was created in the contralateral side of the mandible. Animals were randomly divided into 6 groups and sacrificed on 1, 3, 5, 7, 14, 21 d after surgery respectively. Expression of SCF during the regeneration process were determined by immunohistochemistry and Western blot. Data were expressed as x+s by SPSS 13.0 software. We used Student′s t test to determine the significance of difference between groups.  Significance was set at P<0.05. Results: The expression of SCF genes was detected in both groups at all times, and expression of SCF in CSD group was weaker  than those in self-healing bone defect group at the same time(P<0.05). The results of western blot also confirmed the results by immunohistochemistry. Conclusion: SCF plays an important role in bone defect repair.

Objective: To evaluate the efficacy of grinding residue surface combined with curettage or osteotomy to prevent recurrence of jaw bone lesions. Methods: 142 patients of 97 cysts, 28 benign tumors, 3 malignant tumors, and 14 osteomyelitis of the jaws were retrospectively reviewed.  After operative treatment of the lesions, dental burs were used to trim and grind the bone wounds surface for 0.2-0.5 cm depth. The grinding speed was 40 000 r/s. Follow-up period lasted for one year.   Results: There were no recurrence of cyst and tumor of the jaws.  However, there were 2 cases recurrence of osteomyelitis. Conclusion: Grinding residue surface combined with curettage or osteotomy may improve the therapeutic results.

Objective: The study was designed to construct Lenti-HIF-1α, and detect HIF-1α expression and location in bone marrow mesenchymal stem cells (BMSCs) transduced by Lenti-HIF-1α. Methods: According to human HIF-1α gene sequence (NM_001530), its primer was designed and was amplified through PCR. The eukaryotic expression vector (pEGFP-N1-HIF-1α) was constructed by connecting the PCR products of the target gene to the vector pEGFP-N1. To identify the plasmid, target gene PCR product and the purpose vector were digested by NheI and BamHI. Lenti-HIF-1α (control group, Lenti-LacZ) was constructed using the LR recombination system (the lentiviral vector plenti6.3V5-DEST). After lentiviral titer was detected, BMSCs was transduced by Lenti-HIF-1α. The analysis of target gene expression was done with qPCR. Besides, the immunohistochemistry examination was also completed to observe the location of HIF-1α in BMSCs. Results: The results of plasmid sequencing and digestion confirmed that the eukaryotic expression vector pEGFP-N1-HIF-1α was successfully constructed. After Lenti-HIF-1α was transduced to BMSCs at 0 d, 1 d, 4 d, 7 d, 14 d and 21 d, the results of qPCR showed that the over-expression of HIF-1α was detected on 4 d, and continued until the 21 d. Immunohistochemical results showed that the target gene was located in the nucleus of BMSCs. Conclusion: We successfully constructed the Lenti-HIF-1α, and target gene located in the nucleus of BMSCs. This study will lay the foundation for experimental studies of bone defect repair using HIF-1α-mediated BMSCs in the future.

Objective: This study was designed to investigate whether the interaction of periodontal ligament cells (PDLCs) and bone marrow stromal cells (BMSCs) is related to better periodontal tissue regeneration. Methods: PDLCs and BMSCs were co-cultured by Transwell chambers. The co-cultured PDLCs and BMSCs were examined by MTT applying 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide and Real-time PCR  assays. Results: PDLCs and BMSCs manifested multilineage differentiation potential. When co-cultured, proliferation rates of PDLCs and BMSCs raised. Gene expressions of COLI, ALP, BSP, OCN, RUNX2 were upregulated. Conclusion: It may be better to use PDLCs and BMSCs together for periodontal tissue regeneration.

Objective: To assess the effect of transfusion tube irrigation and drainage  in the management  of dentigerous cysts in the period of mixed dentition. Method: 22 children patients whose pathological diagnoses were dentigerous cysts were retrospectively reviewed.  Patients′ average age was 11 years old and diameters of cysts were from 3 to 5 centimeters, 9 patients had supernumerary teeth. All patients were operated by cyst fenestration through tooth extraction wounds. At the same time some baby teeth and supernumerary teeth were extracted. Cystic fluids were suctioned completely. The transfusion tube with 0.4cm in diameters and 1.0 to 1.5 cm in length were placed into cystic cavity, fixed and sutured with adjoining teeth or gum. Normal saline irrigation and drainage of cystic cavity through transfusion tube 3-4 times per day. The patients were followed-up and took panoramic radiography after 3 months, 6 months and 1-year respectively. Results: All patients had a little pain and local edema in the early period of post-operation but without infection. Cystic cavities reduced significantly after 3 months and the lamella of bone surrounding the cyst   disappeared after 6-7 months. The capsular spaces disappeared by X-ray examination after 10-11 months. 13 patients′ permanent teeth erupted, 4 patients′ permanent teeth erupted on malposition but 5 patients′ permanent teeth did not erupt. Conclusion: The transfusion tube used in the irrigation and drainage of fenestrated dentigerous cyst in the period of mixed dentition has advantages: easy operation, less trauma and pain, fewer referral, unobstructed drainage, low-cost, easy to spread and so on. Therefore, it is an ideal method of choice.

To culture and educate a new type of applied personnel in oral medical sciences who will adapt to this era, that the existing teaching mode on stomatology must be renewed and modified. The integrated problem-based learning (PBL) program introduced in 2007 involves the study of basic biomedical sciences and social and behavioural sciences, alongside the study of clinical dental sciences and professional practice. In this respect , the teaching content and teaching methods, examination evaluation, the paper review level were concerned. The integrated PBL curriculum also emphasizes early clinical exposure, and the development of psychomotor and clinical skills increases progressively. The school mailed a questionnaire in 2007 covering an area of dental practice in oral surgery.  Great significances have been improved to the undergraduates in their overall quality. They were well prepared to adapt  to the needs of economic development and social progress in this era.

Objective：To analyze whether the expression of high mobility group box 1 protein (HMGB-1) in gingival crevicular fluid (GCF) are associated with the severity of peri-implantitis.   Methods：GCF was sampled from 79 implantation patients including 39 normal peri-implant tissue and 40 peri-implantitis tissues.  HMGB-1，IL-1β，IL-8，and TNF-α levels were analyzed using ABC-ELISA. Clinical parameters were measured to investigate their relationships. Statistical analyses were performed with SPSS 13.0 software. Results：Significant difference of HMGB-1 expression was observed between healthy implant sites and peri-implantitis sites (P<0.01). The expression levels of HMGB-1 showed positive correlation  with those of IL-1β，IL-8, and TNF-α. Conclusion: HMGB-1 cytokine in GCF may be of value as a parameter in diagnosis and prognosis for peri-implantitis.

 The treatment of advanced oral and maxillofacial-head and neck squamous cell carcinoma(SCCHN) is still a challenge in the section of oncology in oral and maxillofacial surgery. Although the traditional treatments like radical surgical operation combined with radiotherapy or chemotherapy has progressed a lot recently, the prognosis of the advanced SCCHN is still poor. However, the progress of target drugs brings hope for it. Two primary strategies have emerged that account for most of the success of current targeted therapies: one is epidermal growth factor receptor (EGFR), and the other is vascular endothelial growth factor (VEGF) receptor. The typical drugs to block EGFR are cetuximab and nimotuzumab, both of them have demonstrated survival benefits across whatever monotherapy, or multitherapy with radiotherapy or chemotherapy. The typical drug to block VEGF is bevacizumab, which is now proceeding through  Phase III clinical trial.  The targeted therapy is a new choice for the advanced SCCHN.

The damage to the inferior alveolar nerve (IAN) is the most common complication of the sagittal split ramus osteotomy (SSRO). It is affected by many factors and can be tested by a variety of methods. There are different versions on the incidence of the IAN damage and its recovery process after surgery. Certain preventive measures and treatments can help to reduce the incidence of the IAN damage and accelerate the IAN recovery process. In this review, we discuss on the risk factors, incidence, evaluate methods of IAN postoperative paresthesia,  and provide a summary of the key findings on preventive measures and treatment of the IAN damage after SSRO.

Objective: The objective of this study was to observe the changes of rat submandibular gland morphology and salivary flow rate after radiation. Methods: Forty SD rats were randomly divided into experiment group and control group. In experiment group, a one-time 18 Gy irradiation was applied locally on the submandibular glands. In the control group, only celiac anesthesia was administered. 8 weeks later, saliva from both groups was collected with polyethylene tube, their volume weighed, and salivary flow rate calculated. After death, submandibular glands were draw out and weighed.Morphology examination was assessed by  HE staining. Results: Water and food consumption in radiated rats decreased, with less activity. But drinking frequency was higher than that of control group. Salivary flow rate was (18.64 ±8.23) μL/min in control group, and (10.70 ±2.22) μL/min in experiment group, with an equivalent to 57.42% in control group (P<0.05). Morphological changes of the radiated submandibular gland cells showed edema, and interstitial vascular congestion. The number of vacuoles in the acinar cells increased significantly. Conclusion: Effects of  radiation on rat submandibular gland include obvious salivary flow rate reduction, and degenerative changes of acinar cells. Long-term effects of radiation on the morphology of rat submandibular gland and saliva secretory function still need further observation and research.

Objective: To investigate the expression and synthesis of  proteoglycans in the bell stage of odontogenesis in cultured mouse molars. Methods: Mouse molar tooth germs were obtained from 30 pregnant ICR mouse and to establish culture model in vitro  by  Trowell culture system  at early bell stage. Enamel organs and dental papilla were separated. and  metabolically labeled with [³⁵S]Na2SO4 as precursors. The culture suspension was analyzed by gel chromatography,  enzymatic digestion, and alkaline treatment. Results: Three eluted peaks were obtained in all samples. A major peak eluted at Vo (Vo peak) which was completely susceptible to digestion with chondroitinase ABC. The other two were susceptible to digestion with chondroitinase ABC and Heparitinase respectively. After alkaline borohydride reaction, the eluted three peaks disappeared and a large peak was observed at effective distribution coefficient Kd=0.47.  However, all [³⁵S]-labeled samples were not susceptible to digestion with keratanase. Conclusion: At the bell stage of odontogenesis, a macromolecule chondroitin sulfate proteoglycan, micromolecule  chondroitin sulfate proteoglycans, and  heparan sulphate proteoglycans were identified. No kerantin sulfate was detected.

Objective: To evaluate the clinical significance on  the expression of S100A4 and MMP-2 in oral squanous cell carcinoma (OSCC). Methods: In 40 pathological diagnosed OSCC cases, S100A4 and MMP-2 were  detected by immunohistochemical SP method. Normal oral mucosa was used as control. Result: ①Expression intensity of S100A4 in OSCC was  not obviously related with the age， gender， tumor size，TNM clinical stage and pathological grade（P>0.05）. But expression rate of S100A4 in OSCC was positively correlated with lymph node metastasis(P＜0.05)．② Expression of MMP-2 was not obviously related with the age， gender， tumor size and pathological grade（P>0.05）. The expression rate of MMP-2 in OSCC was positively correlated with lymph node metastasis(P＜0.05)． In OSCC, protein expression of S100A4 and MMP-2 were positively coreelated. Conclusion: These genes and protein  products may be served as a potential diagnostic targets in tumor metastasis.

Objective: To evaluate the clinical results of submental island flap in the restoration of soft tissue defects in orofacial region. Methods: 26 oral and maxillofacial defect patients were retrospectively reviewed. The ages of the patients ranged from 35 to 80 years, 18 were male, 8 were female. Malignant tumors were 21 cases while benign lesions were 3 case and trauma deformity in 2 cases. The sizes of submental island flap varied from 3.5 cm×8.0 cm to 4.0 cm×10.0 cm. Result: Flaps healed with first intension in 25 cases. One case showed wound dehiscence and then a delayed healing. Functions and appearances of the defects were well restored in all patients. Conclusions: Submental flap is reliable for reconstruction of small and mid-sized defects in oral and maxillofacial region.

Objective: This study was designed to evaluate the osteogenic capacity of rabbit mesenchymal stem cells both isolated from bone marrow (BMSCs) and adipose tissue (ADSCs) in vitro.  Methods: BMSCS and ADSCS were obtained from iliac bone marrow and inguinal fat tissue respectively of the same animal.  BMSCs and ADSCs were cultured in the medium and their third-passage cells were used for experiments. We compared their multi-differentiation potential, and cell surface antigen markers. Alkaline phosphatase (ALP) activity was assayed as well as to assess gene expression by RT-PCR. Results: BMSCs and ADSCs both have multilineage differentiation potentials. BMSCs expressed  highest ALP activity and more calcium nodule formation after osteogenic differentiation. RT-PCR results showed that BMSCs also express higher osteogenic genes like BMP-2, OCN and OPN. Conclusion: BMSCs and ADSCs both have multilineage differentiation potentials; but compared to the ADSCs which expressed more adipogenic differentiation capacity, the BMSCs osteogenic differentiation capacity is more better. Both of them can be used as seed cells for tissue engineering.

Objective: This study was aimed to evaluate the regenerative potential of concentrate growth factors(CGF) complex with bone substitute material in osteoinduction. Method: Twelve health hybrid dogs were used. Bilateral first mandibular premolars were extracted and BLB implants were installed immediately into the sockets. Bone defect (measured 2mm ×4mm) was created in the distal aspect of each socket. Bone defect in both sides of the mandible were randomly divided into experiment or control groups. In experimental group, bone defects were filled with CGF complex and bone substitute material, in control group only bone substitute material were used. Every 4 dogs were killed  at the end of 4、8 and 12 weeks respectively. Specimens were obtained and checked by X ray examination, scanning electric microscope observation, histological examination and survey the bone contact ratio(BCR）. SPSS 11.5 was used. Results were statistically analyzed via one-way analysis of variance (ANOVA), with a significance level of P<0.05. Results: The experimental group manifested osseointegration process earlier  than the control group,  the healing time of bone defect is also earlier than the control group. The BCR of experimental group was also higher than control group. Conclusion: CGF has the ability of promote the peri-implant bone regeneration, facilitate the osseointegration between implant and bone, and at the same time shorten the time needed for the process.

Objective：To evaluate the peri-implant marginal bone loss and gingiva condition of immediate flapless implants within 6 months after implantation. Methods: 18 cases were performed flapless operations of immediate implantation for 22 dental implants. Alveolar bone height  and the gingival attachment level mesial and distal to implants were surveyed and recorded during operations. Immediate restorations without teeth contact were given when the patient was light overbite and overjet. All cases were given final restorations after 6 months. Bone level and gingival attachment were also recorded in the 3rd and 6th months after operations. Results: X-ray radiographs showed that all implants were well osseointegrated. Radiographic examination yielded (0.47±0.03) mm medial and (0.56±0.06) mm distal bone level loss respectively in 3 months after implantation. The medial and distal papilla shrinkage were (0.41±0.05) mm and (0.53±0.03) mm respectively. 6 months after operation, medial and distal bone level loss were (1.60±0.05) mm and (1.73±0.04) mm, while papilla shrinkage were (0.51±0.03) mm and (0.62±0.04) mm. Conclusions: The immediate flapless implantation may lead to less bone loss and papilla shrinkage than delayed implantation.

Objective: To review and summarize the clinical characteristics and treatment outcomes of odontogenic descending necrotizing mediastinitis (ODNM). Methods: Five ODNM patients were retrospectively analyzed. 2 males and 3 females with a median age of 54.6 years. 3 patients had mandibular wisdom teeth pericoronitis and 2 patients had periapical abcess of molars. The diagnosis measures included clinical examination, CT scan, and bacteriological culture. Treatments consisted of antibiotic administration and aggressive transcervial(3 cases) and/or transthoracic surgical mediastinal drainage (2 cases) . Patients hospitalized from 23 to 51 days, and the average stay was 29.2 days.  Results:  All patients achieved satisfactory recovery. Conclusion: Diagnosis without delay and aggressive surgical mediastinal drainage are significant in control of ODNM.

Objective: The purpose of this study was to examine whether  cyclopamine is related to  apoptosis and growth inhibition of human salivary pleomorphic adenoma (HSPA) cells.  Methods: HSPA cells were treated  with cyclopamine.Observed the cells quantity change and morphology after 48 h. Cells cultured with DMSO 0.08% or void were used as control. Gli-2 and Bcl-2 mRNA expression was examined by Real-time PCR after 48 h. Flow cytometry was used to analyze cell apoptosis after 24 h. Experiment results are presented as x±s. Statistical analysis was undertaken with SAS 9.13. The differences among the groups were identified by one-way ANOVA. Significance was accepted at P<0.01. Result: The number of cyclopamine treated  HSPA cells was significantly decreased. Cyclopamine treated (10 μmol/L) HSPA cells showed  nuclear psychosis or fragmentation, chromatospherite disfiguration with apoptoticmorphology.  The expression levels of Gli-2 and Bcl-2 mRNA in 10 μmol∕L cyclopamine treated group was down-regulated significantly compare with blank and DMSO control groups (P<0.01). Apoptosis rate of 10 μmol∕L cyclopamine treatment group was significantly higher than blank and DMSO control group (P<0.01). Conclusion: Cyclopamine appears to induce growth inhibition and apoptosis in human salivary pleomorphic adenoma cells. The mechanism may be related to down-regulation of  Gli-2 and Bcl-2 mRNA, which activates the mitochondrial apoptotic pathways.

Objective: The present study was designed to examine the expression levels of Rad50 in the salivary gland of Wistar rats after irradiation． Methods: 60 Wistar rats were randomly distributed into 6 groups: five groups  were irradiated for 3，6，9，12，and 15 Gy doses of 60Co γ-ray respectively,  and a sham irradiation group as control. The rats were sacrificed at 2-hour after irradiation. Histopathological changes in the parotid and submandibular glands  were observed by  transmission electron microscopy (TEM)． Rad50 mRNA levels were evaluated by RT-PCR. Rad50 protein levels were evaluated by immunohistochemistry method． Statistical analysis were performed by means of SPSS 13.0 software. The experimental data were expressed as x±s; comparisons were made by factorial ANOVA. P<0.05 were considered significant. Results： Expressions of Rad50 mRNA and protein level in  parotid glands and submandibular glands after irradiation were significantly higher than those in normal control salivary glands (P<0.05). The expression level of Rad50 in each irradiated groups appeared differently but did not reach statistical significance (P>0.05). Ultra structures of those irradiated salivary gland cells showed injured variations at some degree in a dose-dependent manner as demonstrated by the transmission electron microscope. Conclusion： γ-ray  radiation may affect expression of Rad50 mRNA and protein levels  in the parotid and submandibular glands, but the expression intensity does not manifested in a radiation dose-dependent manner. Our study demonstrate that the limitation of expression potential of Rad50 in the salivary glands, may be  related to the radiation unsensitivities of the salivary glands.

Objective: This study was designed to assess the regeneration outcome of fibrin glue with chitosan-collagen conduit in peripheral nerve repair. Methods: Thirty Chinese rabbits were used in this study and their right facial nerves were traumatized. Rabbits were randomly divided into 3 groups: group Ⅰ, nerve repaired by  autografts,  group Ⅱ, nerve repaired by fibrin glue , and group Ⅲ, fibrin glue with chitosan-collagen conduit were applied. At the end of 16 weeks after operation, gross examination of the animals, electrophysiological studies, histological studies ,  and image analysis were performed. Database and calculations were analyzed using analysis of variance (one-way ANOVA) with the SPSS 17.0. Results: The nerve regenerated uneventful  at 16 weeks after postoperation. Chitosan-collagen conduit was seemingly degraded and restrained the formation of fibrosis. Adherence of repaired nerve with surrounding soft tissue were found more severe in group Ⅰ than other two groups. The potential motor nerve action and the compound muscle action potential (CMAP) of regenerated nerve  showed  no significant difference between three groups (P>0.05). Histological study revealed various degree  of fibrous hyperplasia and inflammatory reaction in the regenerative site. Fibrin glue and chitosan - collagen conduit induced effective regeneration manifested not only in low magnification of HE sections but also in high magnification of Gomori silver stain. The cross rate of myelinated fiber cross section diameter of the three groups showed differences (P<0.05), which was higher in group Ⅱ and group Ⅲ than in group Ⅰ (P<0.05). There was also significant difference between group Ⅱ and  group Ⅰ(P<0.01). The recovery rate of myelinated fiber cross section diameter of the three groups showed no significant difference（P>0.05）. Conclusion: Chitosan-collagen conduit possesses excellent biocompatibility,   fibrin glue may effectively regenerate peripheral nerve.

With the advent of population aging in our country, the implant-supported overdenture has a broad prospect of clinical application in treating edentulous patients. Implant-supported overdenture mainly includes bar-clip attachment, ball attachment, telescopic coping attachment, magnetic attachment, locator and other attachments. And it is paid high attention by implant dentists with advantages of being easy to clean and effective in facial contour restoration with strong retention force and low price. This paper, aimed to provide useful information for choosing the optimal type of implant-supported overdenture in reconstruction of patients' oral function and facial aesthetics, by comparing the patients' satisfaction, the retention and stability and the condition of the hard and soft tissues around the implant after using the five attachment systems.

Objective: This study was designed to observe the effects of liquid nitrogen cryotherapy combined with Nd:YAG laser radiation on veins in rabbit ears, so as to assess its feasibility in the treatment of venous malformations. Methods: Sixty-five rabbits were randomly divided into 4 groups：Group A, Group B and Group C were experimental groups (n=20), Group D was a blank control group (n=5). The central postauricolar veins of rabbits were taken as the models. Group A, veins were frozen with liquid nitrogen and immediately irradiated by Nd:YAG laser; Group B, veins were frozen by liquid nitrogen only; Group C, veins were irradiated by Nd:YAG laser only. Group D, veins retained in blank control. After 1, 3, 7, 14 and 21 days of disposal, the veins were examined under gross observation, light microscopy, and transmission electron microscopy (SEM). Results: In Group A, damages to endothelial cells, vascular smooth muscles and the architecture of structures of veins were obvious, thrombosis appeared and finally resulted in venous obstruction. Group B and Group C, vascular endothelial cell injuries and thrombosis could be found, but thrombosis was gradually dissolved and veins were repaired. Conclusion: Liquid nitrogen cryotherapy combined with Nd:YAG laser radiation could result in major injury to the auricular veins of rabbits and may be applied for venous malformation treatment.

Objective: The present study was designed to explore vascular distribution characteristics in mucoperiosteum  of the oral zone  in order to provide vascular anatomical basis for the incision design. Methods: Three healthy mini-pigs aged 9 months were used in the study. The vascular supply sources, ramifications and distributions were investigated through latex perfusion and micro-dissection. Microvasculature was investigated through ink perfusion and histological  technique. Results: Vascular supplies of the gingival mucoperiosteam came from the arteries going through the muscle layer beneath the alveolar mucosa of the oral vestibular sulcus, which issued branches toward and into the lamina propria of the gingiva vertically to the mucogingival junction. The microvascular of the lamina propria run vertically toward the surface of  epithelia. The vascular supply of the hard palate mucoperiosteam was provided by major palatine artery. Double vascular network could be seen in the submucosa layer. The vasculature of the palatine plica had a dendritic structure. Conclusion: The incision design of oral mucoperiosteum flap should follow  vasculature directions and anatomic features. The gingival mucoperiosteam should not be split separately  into two layers when elevating the flap, while the hard palate mucoperiosteam flap could be designed flexibly.

The use of endosseous implants for complete dental restoration has gained popularity in the past few decades, with reliable long-term stability. Although most studies of the outcomes of prosthodontic rehabilitation with implant-supported dentures have focused on the evaluation of clinical and technical aspects, still several factors involving the design of restoration and surgery are remained debatable. This article will focus on these doubtful points and try to find out an accepted  solution  based on previous researches.

 Objective: To evaluate the osteogenic activities of Bio-Oss after combining with fibrin glue（FG） and ADM in reconstruction of canine mandibular defects． Methods: The second and fourth premolar teeth and the second molar teeth were extracted bilaterally，in 9 hibrid canines，resulting in 6 bone defects(1 cm × 1 cm)in each canine． Bio-Oss ， Bio-Oss+FG ，Bio-Oss+FG+ADM were implanted into the bone defects randomly． Three Canines in every group were executed after 4，8，and 12 weeks to observe the healing of soft and hard tissues．The property of Bio-Oss and ADM were observed via gross specimen，the morphology of the newly-formed bone and ADM was observed by tissue sections．The proportion of newly-formed bone was obtained by computer image analysis(SAS software，analysis of variance)．Results: The soft tissue all coalesced. The patch was existed after 12 weeks. The rate of new bone in ADM group was higher than that in Bio-Oss group.  Conclusion:  The tissue patch can guide the bone regeneration, and thick the soft tissue. It can improve the osteogenic activities of Bio-Oss after combining with fibrin glue.