The occlusion contact, which is engaged in many dental clinical scopes, is the primary subject in the field of dental occlusion. Prosthodontics is one of the fields that are involved in with this subject, including the static relation（the occlusal contacts in intercuspal occlusion） and the dynamic relation（such as that in chewing movement）. Not only the restorations, but also the abutments, that have to be properly managed to obtain a harmony occlusal contact relationship.

Objective To detect antisense-micro ribonucleic acid-21 oligonucleotide（AS-miR-21）’s inhibiting effect to tongue squamous cell carcinoma. Methods Living image and TUNEL experiments were performed, based upon the xenograft animal models set up by introduction of Tca8113-luc cells which were stably transfected with pGL6 luciferase report gene plasmid into nude mice, while the tumors were injected with AS-miR-21. Results Tca8113-luc cell line which steadily expressed luciferase activity was constructed by transfecting pGL6 report gene plasmid. The subcutaneous tumor formation rate was much higher in nude mice introduced with the cells, and the tumors grew well. After injection of AS-miR-21 into mice tumors, it was obviously viewed that tumors grew slower, the volume of the tumors
was smaller, the photon number in live body imaging was getting less, the necrosis in the tumor specimens was rare, cell nuclei was getting smaller, dyeing color was lighter, heteromorphism and new vessels were decreased, micro ribonucleic acid-21 expression in tumor cells was considerably lower, and apoptotic index was increased. Conclusion All the results indicate that the injection of AS-miR-21 can inhibit growth of tongue squamous cell carcinoma in nude mice model, and effectively promote cell apoptosis of tongue squamous cell carcinoma.

Objective To investigate the in situ visualization imaging and the in vivo distribution of the nearinfrared fluorescent quantum dots（QDs） epidermal growth factor receptor（EGFR） monoclonal antibody（mAb） probe in head and neck squamous cell carcinoma（HNSCC）. Methods QDs with an emission wavelength of 800 nm（QD800） was conjugated with EGFR mAb to produce QD800-EGFR mAb. QD800-EGFR mAb was co-cultured with BcaCD885 squamous cancer cell line for 30 min and observed with laser scanning confocal microscope（LSCM）. QD800-EGFR mAb was injected into HNSCC animal model through the tail vein, and the in situ visualization imaging and the in vivo distribution of QD800-EGFR mAb was analyzed at different time points. Results BcaCD885 squamous cell carcinoma in the head and neck can be imaged clearly and visually after intravenous injection of QD800-EGFR mAb probe, these fluorescence signals lasted for 24 h. The most complete tumor images with maximal signal-to-noise ratio were observed from 30 min to 6 h after injection of the probe. In vivo tissue distribution studies demonstrated that QD800 aggregated mostly in liver. QD800 aggregation decreased with time in tumors, and QD800 didn’t aggregate in heart, brain, intestine, lung and stomach. Conclusion The QD800-EGFR mAb probe can clearly produce visual images in head and neck cancer. It has promising prospects in visualization in vivo imaging and individual treatment of head and neck cancer.

Objective To investigate the effect of cyclic stretch on p38 mitogen-activated protein kinase（p38MAPK） signaling pathway during stretch -induced differentiation process of C2C12 myoblasts. Methods C2C12 cells were seeded on Bio Flex 6-well plates, and cells were subsequently subjected to cyclic stretch at an optimal magnitude （10%） and frequency（0.5 Hz）. The effects of cyclic stretch were examined at 2, 6, 12, 24 h. Antibodies specific to p38MAPK phosphorylated forms and the total protein levels of the p38MAPK were examined using Western blot analysis. Results These results indicated that p38MAPK was activated during stretch-induced C2C12 cell differentiation. The level of phosphorylated protein was higher in the p38MAPK signaling pathway. The expression of total protein was maintained at baseline level. There were no significant differences between groups. Treatment of cells with specific p38MAPK inhibitor SB203580 could decrease the expression of myogenin, but not completely abolish the myogenin expression after stretch. Conclusion p38MAPK signaling pathway plays an important role during stretch-induced differentiation process of C2C12 myoblasts, but is not activated exclusively in this process.

Objective To observe the differential ability of dental pulp stem cell（DPSC） and ectoblast mesenchyme stem cell（EMSC） that were cultured with tooth germ cell（TGC） as the tooth germ microenvironment. Methods The TGC of 4-day old rat was used as the tooth germ microenvironment. The BrdU marked and determined DPSC and EMSC were cultured with the TGC respectively. The expression of cell surface antigen dentin sialoprotein（DSP） and alkaline phosphatase（ALP） activity were determined with double marker immunofluorescence. The differential ability of DPSC and EMSC were determined by the immunohistochemistry and image analysis in the tooth germ microenvironment. Results The transformation efficiency of DSP positive cell in the EMSC co-culture group was higher than that in the DPSC co-culture group（P<0.05）. The transformation efficiency in the co-culture groups was higher than that in the non co-culture group after 7 days by the image analysis of immunohistochemistry（P<0.05）. The ALP activity in the co-culture groups increased after 3 and 7 days. The ALP activity in the EMSC co-culture group was higher than that in the DPSC co-culture group. Conclusion DPSC and EMSC cultured with TGC as the tooth germ microenvironment can be induced to differentiate into odontoblast. The ability of EMSC is higher than that of DPSC.

Objective To evaluate the effectiveness and feasibility of compound bone morphogenetic protein(BMP) with chitosan and cyanoacrylate on preventive absorption of rat’S alveolar ridge．Methods Fifry-four Wistar rats were divided randomly into three groups：Experimental group(compound BMP with chitosan and cyanoacrylate group)，control group(chitosan composite group)and blank group．After rat lower incisors were extracted，compound BMP with chitosan and cyanoacrylate were implanted into experimental group rat’S residual alveolar fossa，control group implanted with chitosan。blank group left empty．Animals were sacrificed after 3，6，9 weeks．X-ray examination，Image-Pro Plus analysis and pathologic observation were evaluated，Results The relative length Values of residual alveolar ridge and optical density test in experimental group were all greater than those of control group and blank group at 3，6，9 weeks after operation(P<0．05)．Light microscopy showed that new bone formations in experimental group were better than those in control group and blank group at 3，6，9 weeks after implantation．Conclusion Compound BMP with chitosan and cyanoacrylate can be used to prevent the absorption of residual alveolar ridge and have more clinical predications．

Objective To study the effect of high glucose and mannitol（osmotic control） on receptor activator of nuclear factor kappa B ligand（RANKL）-induced osteoclastogenesis and Notch2 expression using bone marrow macrophages（BMMs） from mice. Furthermore, the effect of Notch2 activation on RANKL-induced osteoclastogenesis with high glucose concentration was explored. Methods Preosteoclasts were cultured and exposed to sustained high glucose
（0, 5, 10, 20, 40 mmol·L-1） levels to mimic diabetic conditions. Osteoclast formation was analyzed using tartrate resistant acid phosphatase（TRAP） assay. Expression of Notch2 gene was analyzed using real-time polymerase chain reaction. Constitutively over-expressed active Notch2, via stable transfection of exogenous ICN2（intracellular fragment of Notch2） in preosteoclasts and the effect of Notch2 over expression on osteoclastogenesis was analyzed using Western blotting and TRAP staining. Results The osteoclast number with 20 mmol·L-1 glucose（110.3±6.8） and 40 mmol·L-1 glucose（72.0±8.0） was significantly less than the group with 20 mmol·L-1 mannitol（152.7±7.0） and 40 mmol·L-1 mannitol （157.0±12.5）. The relative gene expression of Notch2 with 20 mmol·L-1 glucose（1.65±0.23） and 40 mmol·L-1 glucose （1.10±0.11） was significantly less than the group with 20 mmol·L-1 mannitol（2.82±0.28） and 40 mmol·L-1 mannitol （2.42±0.27）（P<0.05）. The osteoclast number after Notch2 activation（ICN2-OE） with 20 mmol·L-1 glucose（206.7±7.8）
and 40 mmol·L-1 glucose（178.3±11.5） was significantly more than the control group（EMPTY）（102.3±8.7 and 76.0±10.1 respectively）（P<0.05）. Conclusion Notch2 signaling activation may promote osteoclastogenesis under high glucose concentration.

Objective To investigate the antibacterial activity of glycyrrhizic acid（GA） against Streptococcus mutans （S. mutans） under acidic environment in vitro. Methods Working culture were prepared by inoculation of S. mutans into TPY broth followed by static incubation under anaerobic condition at 37 ℃ for 24 h. TPY broth was supplemented with three kinds density of GA（0.78, 1.57, 3.13 mg·mL-1）, whose acidity was regulated to pH 7.0, pH 5.5 and pH 4.0. And the group of pH 7.0 was used as negative control. The growth of S. mutans was measured by A600 of bacteria suspension and counting colony forming unit（CFU）. In addition, the survival rate of S. mutans was calculated. Results In pH 5.5 groups, the survival rates of 0.78, 1.57 and 3.13 mg·mL-1 GA groups were 60.96%, 60.27% and 45.58%, respectively, and in pH 4.0 groups, the survival rates were 68.75%, 53.12% and 45.83%. In 0.78, 1.57 and 3.13 mg·mL-1 GA groups, the survival rates of pH 5.5 and pH 4.0 were 52.25% and 39.05%, 74.39% and 43.11%, 86.38% and 55.30%, respectively. Conclusion GA could inhibit the gro wth of S.mutans under acidic environment, which the effect is improved as the acidity increased.

Objective To investigate the expression of protein tyrosine phosphatase non-receptor type 2（PTPN2） and nuclear factor-κB（NF-κB）, as well as the relationship between their expression and periodontal destruction in mice with diabetic periodontitis. Methods Four weeks old healthy C57BL/6J mice were randomly divided into normal control group（Group N）, periodontitis group（Group P） and diabetic periodontitis group（Group DP）, and each group
had six mice. Mice in Group P were inoculated Porphyromonas gingivalis orally to induce periodontitis. Mice in Group DP had high sugary and fatty food, streptozotocin intraperitoneal injection and Porphyromonas gingivalis oral inoculation to induce diabetic periodontitis. All mice were sacrificed 4 weeks after the last bacterium inoculation of Groups P and DP. Stereo microscope was chosen to detect morphological changes and bone loss areas of the alveolar bone. Hematoxylin-eosin（HE） staining was selected to observe loss heights of periodontal attachment. Immunohistochemical staining was used to detect PTPN2 and NF-κB expression in periodontal tissues. Results Group P and Group DP had significantly more attachment loss heights and areas than Group N（P<0.05）, and showed less PTPN2 expression（P<0.05） and higher NF-κB levels（P<0.01）. Conclusion PTPN2 may negatively regulate the development of diabetic periodontitis, while NF-κB may have opposite effects. PTPN2 down-regulation might contribute to NF-κB over -expression leading to exacerbated periodontal
destruction.

Objective To evaluate the accuracy and repeatability of alveolar bone height measurement in vitro by cone beam computed tomography（CBCT）, and to provide theoretical application of CBCT in periodontal clinic. Methods Eight dry mandibles with 236 selected markers were scanned by CBCT scanner, and the distance from alveolar ridge crest to cemento-enamel junction were measured on every marker by the images of CBCT. Meanwhile the distances on the dry mandibles were measured directly by vernier caliper. All the data were analyzed by SPSS 13.0 statistics software. Results There was no significant difference between the two repeated measurements by the CBCT images （P>0.05）, and no significant difference were found between the measurement by the CBCT images and by vernier caliperas well（P>0.05）. Conclusion The CBCT images could demonstrate the three-dimensional relationships between tooth and alveolar bone accurately. As far as the height of alveolar bone measurement was concerned, CBCT show good accuracy and repeatability in vitro.

Hospital of Stomatology, Nanjing University Medical School, Nanjing 210008, China） [Abstract] Objective To evaluate the effect of Oravive gel and fluor protectors on remineralization and the capacity of resisting sugar drink erosion. Methods The changes of surface microhardness（SMH） of young permanent teeth treated by Oravive gel or fluor protectors which were immersed in sugar drink in advance were measured. The morphological changes of surface were observed by scanning electron microscope（SEM）. Results The SMH values of the young permanent teeth immersed in sugar drink and then treated with Oravive gel or fluor protectors increased significantly, and the Oravive group was stronger than fluor protectors group（P＜0.05）. For the young permanent teeth treated with Oravive gel or fluor protectors and then immersed in sugar drink, the SHM value of Oravive group was significantly higher than fluor protectors group（P＜0.05）. Under SEM, the enamel surface appeared solvation and remineralization after Oravive gel or fluor protectors treatment. Conclusion Oravive gel may enhance the resistance of young permanent teeth enamel to sugar drink erosion, and promote the remineralization effects of demineralized enamel.

Objective To investigate the relationship between occlusal plane and sagittal position of the mandible by examining dental and skeletal morphologies of average angle patients for better understanding of etiologies and definitive clinical guidelines of mandibular malpositions. Methods The lateral cephalograms of 114 female average angle patients with neutral maxillary positions were selected and divided into three groups according to sagittal mandibular positions（ANB angle）. Twenty-five skeletal and dental measurements were compared. The correlations between skeletal and dental measurements were analyzed by rectilinear correlation. Results Cant of posterior occlusal plane（OP-P） and height of the upper second molar were significantly related to sagittal position of the mandible（P<0.05）. Height of the upper second molar was relatively inadequate and OP-P was sloped when the mandible was positioned posteriorly; conversely, height of the upper second molar was excessive and OP-P tended to be flat when the mandible was positioned anteriorly. Tooth axial inclinations were affected by sagittal position of the mandible. Maxillary teeth proclined distally and mandibular ones mesially for patients with retrognathia. On the other hand, maxillary teeth proclined mesially while mandibular ones distally for patients with prognathia. Conclusion There was a definite relationship between cant of posterior occlusal plane and sagittal position of the mandible in average angle patients, consistent with the dental morphologies of different skeletal configurations. In treating malocclusions of sagittal discrepancy of mandible, the height of posterior teeth and cant of OP-P might be a primary concern.

Objective To assess the efficacy and safety of drainage for the control of the complications following impacted mandibular third molar extraction. Methods To retrieve randomized controlled trials assessing the efficacy and safety of drainage for the control of the complications following impacted mandibular third molar extraction, bibliographic databases including MEDLINE, Cochrane Controlled Trials Register, EMBASE, OPEN SIGLE and China Biology Medicine Database（CBM） were searched on August 23th 2011. References of the included studies and Chinese dental journals were hand-searched. The risk of bias were used by Cochrane Collaboration’s tool and the data were extracted. Meta-analysis was done with Revman 5.1. Results Nine articles met the eligibility criteria and were included, seven randomized controlled trials and 2 quasi-randomized controlled trials. Seven of these studies had unclear risk of bias and 2 had high risk of bias. Drainage could significantly increase 4.44 mm of the post-operative maximal mouth opening （P=0.003）, relief facial swelling（P<0.05） and reduce post-operative complications（P=0.008）. But no evidence showed that drainage had a positive effects on post-operative pain（P=0.09）. Conclusion Drainage could probably control the complications following impacted mandibular third molar extraction; but more randomized controlled trials are needed to reinforce the conclusion.

Objective To investigate the relationship between the stages of calcification of various teeth and cervical vertebral bone ages among children and adolescents in Chengdu. Methods The study subjects consist of 256 children and adolescents in Chengdu with age ranging from 10 to 16 years. All panoramic radiographs and cephalometric radiographs were obtained. The relationship with the stages of chronological ages, calcification of various teeth and cervical vertebral bone ages were analyzed. Results The Spearman rank correlation coefficient revealed highly significant relationships between cervical vertebral bone ages and chronological ages（r=0.726, P＜0.01）. Dental ages and chronological ages had medium relationship（r=0.629, P＜0.01）, also dental ages and cervical vertebral bone ages medium relationship（ r=0.668, P＜0.01）. Conclusion Cervical vertebral bone ages, chronological ages and dental calcification stages have correlation among children and adolescents in Chengdu. The cervical vertebral bone ages have high connection with chronological ages. Cervical vertebral bone age might be a better indicator in judging growth and development of children and adolescents during orthodontic treatment.

Objective To obtain an evidence-based treatment for an adolescent patient with temporomandibular osteoarthritis. Methods The detailed history of an adolescent patient with temporomandibular osteoarthritis was analysed. Clinical Evidence（to Dec 2010）, National Guideline Clearinghouse（2000-Dec 2010）, Cochrane Library（Issue 4, 2010）, MEDLINE（OVID, 1950-Dec 2010） and China Biology Medicine Database（1978-Dec 2010） were searched to obtain evidence such as clinical guidelines, systematic reviews and randomized controlled trials related to surgery or conservative treatment to temporomandibular osteoarthritis to find a personal treatment strategy for the patient. Results Five articles were finally included, i.e. 1 clinical guideline, 3 systematic reviews and 1 randomized controlled trials. These evidence showed that: Conservative treatment like intra-articular injection instead of surgery should be adopted for adolescent patient; hyaluronate is the drug with sufficient evidence in supporting its use in treating temporomandibular disorders; inferior temporomandibular joint cavity injection or both upper and lower cavity injection has better effect than that of superior cavity injection only; and there was some evidence to support the use of glucosamine to treat temporomandibular disorders. Considering the situation of the case and the clinical evidence, an individual treatment plan of hyaluronate injection into the upper and lower cavity and glucosamine take orally was established. A long-term follow-up of 6 months showed a good treatment outcome. Conclusion Through the evidence-based methods and the use of clinical evidence, an individual treatment plan could be established for each patient with temporomandibular disorders, and this will provide strong supporting to the treatment of temporomandibular disorders.Up to now, it is clear that hyaluronate injection into the upper and lower cavity with glucosamine administration is effective in treating temporomandibular osteoarthritis.

Objective To study the relationship between endothelial nitric oxide synthase（eNOS） Glu298Asp gene polymorphism and chronic periodontitis（CP） with type 2 diabetes mellitus（T2DM）. Methods DNA from patients’buccal swabs of CP, CP with T2DM, T2DM and health was isolated and extracted. The eNOS Glu298Asp gene polymorphism were assessed by polymerase chain reaction-restriction fragment length polymorphism（PCR-RFLP） respectively. Results The distribution of eNOS Glu298Asp genotype in CP group, T2DM group, CP with T2DM group and health group showed statistical differences（掊2＝18.503, P＝0.005）, and the gene frequency showed statistical differences（掊2= 8.243, P=0.041）. Compared health group to CP with T2DM group, OR value of the genetype T was 0.962, 95% confidence interval lay in between 0.737 to 1.256, which showed T maybe a protective factor. While OR value of the genetype G was 1.043, 95% confidence interval lay in between 0.781 to 1.391, which showed G maybe a risk factor. However, neither T nor G was statistically significant. Conclusion Based on these findings, there are some association between eNOS Glu298Asp polymorphism and the risk of CP group, T2DM group, CP with T2DM group.

Objective To assess the diagnostic value of high-resolution ultrasonography for detecting of anterior disc displacement without reduction（ADDWR） of temporomandibular joint（TMJ）. Methods Thirty-five participants with 40 TMJs which were initially diagnosed as ADDWR were included. All the participants got both high-resolution ultrasonography and MRI examination. The results of MRI in diagnosis of ADDWR were considered as gold standard. Sensitivity, specificity, accuracy, positive predict value, negative predict value, positive likelihood ratio and negative likelihood ratio were calculated. Results In 40 TMJs, MRI revealed that there were 23 TMJs with ADDWR, and 17 disease-free. The sensitivity, specificity, accuracy, positive predict value, negative predict value, positive likelihood ratio and negative likelihood ratio of high-resolution ultrasonography were 82.6%, 94.1%, 92.5%, 0.95, 0.80, 14.04, 0.19, respectively. Conclusion The high -resolution ultrasonography has a relatively high diagnostic value in detecting ADDWR of TMJ.

Objective In order to find out the cause of molar intrusion and how to avoid molar intrusion, we analyze the movement tendency of tooth by changing the angles of upper accentuated-curve and the height of free traction hook. Methods Spiral CT scanning and Mimics 10.0 software were employed in this study to construct the three dimensional finite element model of maxillary teeth, periodontal ligaments and alveolar bone as well as the inch stainless steel upper accentuated-curve archwires with different angles（5°, 10°, 15°, 20°, 25°） and the free traction hook with different height（2.1, 4.0, 5.5 mm）. By exerting 1.5 N backward force to analysis the displacement trend of maxillary tooth. Results Upper accentuated-curve archwires made the incisors labially tip, intruse, distally upright and mesilabially torsion; made the canines labially tip, prolong, mesial-tipped and mesi-labially torsion; made the second premolars and the first molars buccal tip, intruse, distal upright and mesi-labially torsion. With the angle of upper accentuated- curve archwires increased, all tooth movement tendency increased; while with the height of free traction hook increased, all tooth movement tendency decreased. Conclusion When the angle of upper accentuated-curve archwires increased, the extent of molar intrusion increased, but when the height of free traction hook increased, the degree of molar intrusion decreased. The degree of molar intrusion was minimum using 5° upper accentuated-curve archwires cooperated with 5.5 mm free traction hook.

Objective To compare the releasing of growth factors between platelet-rich fibrin（PRF） and plateletrich plasma（PRP） as well as their effects on the proliferation and differentiation of adipose tissue-derived stem cells （ADSCs） in vitro. Methods Blood was taken from central artery of rabbits, acquiring PRF was acquired through one time centrifuge and PRP through two times centrifuge. Five milliliters of fresh α-MEM was added to PRF and PRP and incubated at 37 ℃. The time points to collect exudates was in day 1, 7, 14, 21, 28 and the mass concentrations of transforming growth factor-β1（TGF-β1） and platelet derived growth factor-AB（PDGF-AB） were quantified in PRF and PRP. Then the exudates of PRF and PRP were used to culture ADSCs and evaluate the effects of PRF and PRP on proliferation and differentiation of ADSCs. Results 1）Growth factor release: In the PRF exudates at different time points, the mass concentration of TGF-β1 was the highest at day 14 and the highest mass concentration of PDGF-AB at day 7, the mass concentration of both TGF-β1 and PDGF-AB was the highest at the first day and then gradually declined. 2）The effect on proliferation and differentiation: PRF exudates of day 14 expressed the maximum proliferation and alkaline phosphatase（ALP） activity. PRF exudates of day 1 demonstrat the maximum proliferation and ALP activity. Conclusion Comparing to PRP, PRF releases growth factors gradually and expressed stronger and more durable effect on proliferation and differentiation of ADSCs in vitro.

Objective Experimental study on the survival rate of random flap using vascular endothelial growth factor（VEGF） and bone marrow mesenchymal stem cell（MSC）. Methods MSC was isolated through the combined utilization of density gradient centrifugation and adherence screening methods. MSC was cultured and its purity and biological properties were identified. Forty Wistar rat models were established and divided into control group, VEGF group, MSC group and MSC+VEGF group. Designed 2 cm×5 cm pedicle flap on each rat’s back. The flaps were observed for 14 d after operation. On the 14th day, the rats were killed. The survival rates of random flap in each group were counted, and the histological sections were stained at the flap which was 4 cm far from the pedicle, and the number of microvascular was observed. Results 1）MSC was detected by flow cytometry, adipogenic and osteogenic induction detection. The results showed that MSC could differentiate to fat and cartilage by induction and certified that the MSC had multi-differentiation potential. 2）Immune rejection did not appear on each animal. The survival rate of random flap in control group, VEGF group, MSC group and MSC+VEGF group were 55.4%±4.4%, 70.7%±6.3%, 65.1%±7.1%, and 93.4%±9.4%, respectively. The survival rate of each experimental group was higher than control group（P<0.05）. The survival rate of MSC+VEGF group was the highest（P<0.05）. 3）The histological examination showed that the granulation tissue, fibroblast and neovascularity was most abundant in MSC+VEGF group. Conclusion 1）The purified and multi-differentiated MSC can be obtained by density gradient centrifugation and adherence screening methods. 2）The human MSC has no immunogens or minimal immunogenicity, immunological rejection would not be caused when it is transmitted in cross-species. 3）VEGF and MSC have synergetic effect when they are used together, it can rebuild the blood circulation of the ischemic region in a short time, solve ischemia of the flap far from the pedicle, improve survival rate of the flap and enhance the repair quality of the wound.

Objective To observe changes in tongue and hyoid position, and pharyngeal airway in patients with skeletal class Ⅲ malocclusion after the combined orthodontic and orthognathic treatment. Methods Twenty patients were involved in this study. Cone beam CT（CBCT） was performed on patients one week before and six months after treatment. Raw data were reconstructed into three-dimensional model. To set up a three-dimensional reference frame, which was based by point “S”, the sagittal and transversal measurements, cross sectional areas, partial and total volumes were computed. The three-dimensional position changes of chin, hyoid bone and tongue were measured in order to analyze the amount of mandibular setback relationship with the changes of pharyngeal airway, hyoid bone and tongue positions. Results After treatment, the pharyngeal airway was constricted significantly. The hyoid significantly moved inferoposteriorly by 5.72 mm（backward） and 2.76 mm（downward） and the tongue moved posteriorly by 4.04 mm after surgery（P<0.05）. Among the 19 correlated indexes between the amount of mandibular setback and other measurements, 14 of which were significantly correlated（P<0.05）. The strongest correlation was found between the amount of mandibular setback and total volumes of pharyngeal airway（r=0.834, P<0.01）. Conclusion Following combination therapy, the pharyngeal airway space decreased, the hyoid moved inferoposteriorly and tongue moved posteriorly. There were great correlations between the amount of mandibular setback and the changes.

Objective To investigate the shear bond strength between veneering ceramic and zirconia core in different all-ceramic systems. Methods Twenty disk-shaped specimens with 8 mm in diameter and 3 mm in height for each zirconia system（Lava, Cercon, IPS e.max ZirCAD, Procera） were fabricated respectively and divided into four groups： Lava group, Cercon group, IPS e.max ZirCAD group, Procera group. For each group, 10 specimens were sintered with 1 mm corresponding veneering ceramic, while the other were sintered with 2 mm corresponding veneering ceramic respectively. The shear bond strength and fracture mode of specimens were observed and determined. Results The values of shear bond strength for Lava, Cercon, IPS e.max ZirCAD and Procera were （13.82±3.71）,（13.24±2.09）,（6.37±4.15）, （5.19±5.31）MPa in the group of 1 mm thicked veneering ceramics, respectively, while the values in the group of 2 mm thicked veneering ceramics were （38.77±1.69）, （21.67±3.34）, （12.70±4.24）, （9.94±6.67）MPa. The values of Lava and Cercon groups were significantly higher than that of IPS e.max ZirCAD and Procera groups（P<0.05）. And the values of 2 mm thicked veneering ceramic group were significantly higher than that in 1 mm thicked groups（P<0.05）. Adhesive fracture between core and veneering ceramics were observed in the fracture modes of most specimens. Conclusion The shear bond strength of veneering ceramic to the zirconia framework are different from the zirconia system we chose, and the thickness of veneering ceramic has a great impact on its shear bond strength.

Acute pulmonary embolism after surgery of multiple maxillofacial fractures is rare. This paper reported a case of multiple maxillofacial fractures who experienced acute pulmonary embolism after operation and died.

A patient with defective dentition in the upper jaW was placed with implant in left upper jaW．Telescopic ovententure wasfabricated and supported by the implant and canine tooth in right upper jaw．The patient felt very comfortable，and this type of restoration could provide sufficient stability and maintain tooth and peri-implant tissues healthy．The preliminary elincal results of this restoration show that isolated canine tooth and single implant supported telescopic overdenture are feasible．