This paper focuses on the diagnosis and treatment of upper impacted canines.Radiograph diagnosis is the most important tool in-cluding panoramic,CT and CBCT.Preventive and interceptive treatment,tooth extraction,self tooth transplantation and orthodontic traction can be used in the treatment.

The paper is to explore the goals and models of Orthodontic teaching in eight-year medical students. It tries to design some teaching goals, teaching models and standards of examination to train medical students according to the eight-year program characteristics, and discuss the problems of eight-year program orthodontic teaching.

Objective: To investigate the expression of CSF-1 and TGF-?1 in periodontal tissue of third premolar germ during second primary molar orthodontic movement in dog. Methods: Orthodontic appliance with the force of 0.784 N for the mesial movement of mandible second primary molar was used in 4 dogs for 14 d.Then the samples including mandibular second and third molars and surrounding tissues were prepared for CSF-1 and TGF-?1 detection by immunohistochemical staining technique. Results: Strong CSF-1, TGF-?1 expression was found in the dental follicle and alveolar bone of mesial part of third premolar germ, and weak in the dental follicle and alveolar bone of distal part of third premolar germ in the treated side of the dogs. Conclusion: CSF-1 and TGF-?1 may play roles in the bone remodeling for orthodontic primary tooth movement.

Objective:To investigate the third molar horizontal and vertical drift automatically after the second molar extraction.Methods: 26 patients,aged 11～18 years old, with the indications of second morlar extraction were divided into two groups:15 cases in experimental group with the extraction of the second molar and 11 in control group without the extraction. A cephalometric radiograph of each patient was traced on before and 9 months after treatment. Vertical and horizontal drift and mesio- angulation of the third molar were measured.Results:The third molar vertical mesio-movement (mm)in experimental and control groups was 7.08?2.04 and 2.09?0.47(P

Objective:To study the effects of treatment of Angle Ⅱ division 2 malocclusion with upper/lower arch expansion and Class Ⅱ elastics in adults. Methods:Expanding upper/lower arch and Class Ⅱ elastic were used to treat Angle Class Ⅱ division 2 malocclusion in 15 adults. Study models and cephalograms were analyzed before and after treatment. Results:Before and after treatment the maxillary variables of cephalograms showed no significant differences, the mandibular variables showed significant differences in sagittal and vertical direction. U1-NA, U1-PP, L1-NB, L1-MP, U1-L1 and L6-Ptm were significantly increased after treatment(P

Objective To study the effect of different concentration of tumor necrosis factor-? (TNF-?) on expression of the receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG) mRNA on human dental follicle cells in vitro, and investigate the role of TNF-? in osteoclast formation during tooth eruption. Methods The 5th passage of primary cultured human dental follicle cells were treated with 0 (control group), 5, 10, 25, 50 and 100ng/ml TNF-?, respectively, for 6 hours. Total RNA was then isolated from human dental follicle cells and subjected to RANKL and OPG mRNA assay by reverse transcription-polymerase chain reaction (RT-PCR) technique. The relative expression levels of RANKL and OPG mRNA were normalized to ?-actin gene expression. Results The mRNA expression of OPG in human dental follicle cells with 5ng/ml TNF-? treatment was down regulated significantly compared with that in control group (P

Objective:To study the effects of colony-stimulating factor-1 (CSF-1) on the expression of osteoprotegerin (OPG ) in human dental follicle cells.Methods:Human dental follicle cells culture was established and cell crawling slides were stained by OPG antibody. The third to sixth passage cells were incubated with 25 ng/ml CSF-1 for 0.5,1,3 and 6 h respectively,then the conditioned medium and cells were collected for ELISA and RT-PCR assay respectively.Results:OPG was expressed in the cytoplasm of human dental follicle cells.GSF-1 at 25 ng/ml and 1 h-exposure down-regulated OPG expression in the cells(P

Objective:To compare shear bond strength(SBS)of bonded and rebonded orthodontic brackets and influence of rebonded orthodontic brackets using different treatment methods on SBS.Methods:60 extracted premolars were evenly divided into three groups.Brackets were debonded with conventional techniques and then removed of residual adhesives from the base mesh using three different treatments.In groupⅠ,rebond a new bracket at the second,third bonding times.In group Ⅱ,remove residual adhesives from the base mesh with fire at the second,third times,then rebond the same bracket.In group Ⅲ,remove that using a tungsten carbide bur at the second,third times,then rebond the same bracket.Shear test was performed to compare the SBS and adhesive remnant indexes(ARI)among different groups.Results:The SBS of three groups at the first bonding sequence were(10.00?2.95)MPa,(9.57?2.45)MPa and(9.09?2.58)MPa.The SBS at the second,third debonding sequence in group I,group II,and group III were(9.55?2.84)MPa and(10.32?2.59)MPa,(7.30?2.15)MPa and(7.14?1.93)MPa,(12.13?2.93)MPa and(12.86?3.08)MPa,respectively.In group Ⅱ,the SBS was significantly lower,however,in group Ⅲ,the SBS was significantly higher,and the results showed significant differences(P

Objective:To study the morphologic standard values of craniofacial hard-tissue of the youths in Xi'an.Methods:CBCT scanned cephalometric data of 100 selected volunteers (50 males and 50 females)with individual normal occlusion were collected.31 landmarks and 31 measurements were compared between sexes and between 3D and 2D data with software InvivoDental 5.2,WinCeph 8.0.and SPSS 19.0.Results:1.In the 3D measurements,vertical growth of mandible in the females was more than that in the males. The values of torque of lower incisor,basis length,height of rumi mandibulae and length of corpora mandibulae in the males were bigger than those in the females.2.Compared with 2D measurements,there existed statistically significant differences in most parameters except U1-NA(mm).Conclusion:3D analysis with CBCT may provide more accurite morphologic data for craniofacial hard tissues.

Objective:To study 3-dimensional facial soft tissue reference values of Chinese Han nationality adults with normal occlusion and explore the facial morphology differences between men and women.Methods:3dMD images from 30 men and 32 women of Han nationality,aged 18-35 years,with normal occlusion were analyzed and compared between the men and women on 19 linear distances,8 angular measurements and 10 linear distance ratios.Results:Linear distances concerning the width and height of facial and organic contours were larger in men(P<0.05),while the ratio of facial height to width were larger in women(P<0.05);the nasofrontal angle and nasal prominence angle were both smaller(P<0.05) but nasofacial angle were larger(P<0.05) in men than in women.Conclusion:The facial and organic contours are larger in men than in women.Men have wide-elliptical face while women have thin-elliptical one.The nose of men is more prominent than women.