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Lipopolysaccharide Stimulation Induces DNA Double-strand Breaks in Dental Pulp Cells. HUANG Ye-quan, MENG Liu-yan, QIAO Wei-wei, BIAN Zhuan 2017, 33(3): 235-239.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.001 Abstract ( 283 )   PDF (2035KB) ( 267 )   Objective: To investigate whether low dose of lipopolysaccharide (LPS) induces DNA damage in dental pulp cells, and to provide an experimental model for studying the DNA double-strand breaks and DNA repair. Methods: Ten μg/L LPS was added to dental pulp cells constantly once, three times, and six times, respectively. Cell proliferation was detected by MTT assay. Cell apoptosis was detected by TUNEL assay. The mRNA and protein expression levels of γ-H2A.X were investigated by q-PCR and Western blot. The expressions of γ-H2A. X in vivo or vitro were detected by immunofluorescence and immunohistochemistry. Results: Compared with the control group, the repeated stimulation of 10μg/L LPS had no significantinfluence on cell proliferation or on cell apoptosis. After repeated stimulation of 10μg/L LPS for six times,immunofluorescence revealed the positive expression of γ-H2A.X in cell nucleus. Moreover, compared with control groups, the mRNA and protein expression levels of γ-H2A.X increased significantly (P<0.05). Immunohistochemistry showed γ-H2A.X expression level increased remarkably after being induced by LPS for 4, 6 and 8days, respectively (P<0.05). Conclusion: The repeated stimulation of low dose of LPS may induce the occurrence of DNA double-strand breaks in dental pulp cells. References | Related Articles | Metrics

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Expression of RB1CC1 in the Occurrence and Development of Oral Squamous Cell Carcinoma of Human and Mouse. CHEN Lei, YU Da-hai, BI Shi-chang, QING Hai-yun, SHI Qiang, SUN Ying. 2017, 33(3): 240-243.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.002 Abstract ( 224 )   PDF (1322KB) ( 226 )   Objective: To compare the expression of RB1-inducible coiled-coil 1 (RB1CC1) in normal oral mucosa, dysplasia and oral squamous cell carcinoma (OSCC) of human and mouse model, and explore the role of RB1CC1 in the occurrence and development of OSCC. Methods: Immunohistochemical and reverse transcription-polymerase chain reaction method were used to detect the expression of RB1CC1 in 10 cases of human normal oral mucosa, 20 cases of dysplasia and 20 cases of well differentiated OSCC as well as 7 cases of mouse normal oral mucosa, 13 cases of dysplasia and 13 cases of OSCC, respectively. Results: In human, the positive expression rates of RB1CC1 in dysplasia and well differentiated squamous cell carcinoma group were higher than that in normal oral mucosa group (P<0.05). In mouse, the positive expression rate of RB1CC1 gradually increased from normal to carcinoma group (P<0.05). By contrast, in human, the gene expression of RB1CC1 in normal oral mucosa was higher than dysplasia and OSCC group (P<0.05), but not significantly different in dysplasia and well differentiated OSCC group. Conclusion: The expression of RB1CC1 was similar in the same pathological stages of between human and mouse, and may play an important role in early carcinogenesis of OSCC. References | Related Articles | Metrics

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Effect of Early Life Stress on the Progression of Experimental Periodontitis in Rats. LIU Fei, ZHANG Lin, XIAO Gang, GUO Qing-yu. 2017, 33(3): 244-248.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.003 Abstract ( 265 )   PDF (1571KB) ( 156 )   Objective: To explore the effect of early life stress on the progression of experimental periodontitis in rats. Methods: Twenty male SD rats of 3 weeks old were divided into two groups randomly. One group was suffered the unpredictable chronic mild stress (UCMS) procedure and the other was the control group. After five weeks' UCMS procedure, all rats received the operation of experimental periodontitis (EP). Then the behavioral tests, sucrose preference test, serum corticosterone (CORT) and inflammatory cytokines by ELISA, and HE staining were performed. Results: The UCMS rats showed the depression-like behaviors, including enhanced immobility time in forced swimming test (P<0.01) and lower sucrose preference test (P<0.001). Serum corticosterone, IL-1β and TNF-α was also elevated (P<0.05). In HE staining, rats with EP showed an obvious alveolar bone loss compared with that in the contra-lateral left side. The alveolar bone loss in the UCMS rats was significantly more severe compared with control group (P<0.001). The same tendency was found in the osteoclast numbers (P<0.001). Positive correlation was found between serum corticosterone and severity of EP (P<0.05). Conclusion: Early life stress could aggravate the progression of EP, which might be regulated by HPA axis and humoral immunity. References | Related Articles | Metrics

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Effects of Doxorubicin-loaded Mesoporous Silica Nanoparticles on Proliferation and Apoptosis of Human Tongue Cancer Tca-8113 Cells. LI Hai-qin, FAN Zeng-jie, LIU Bin, YU Zhan-hai. 2017, 33(3): 249-253.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.004 Abstract ( 245 )   PDF (2757KB) ( 298 )   Objective: To establish a drug delivery system based on mesoporous silica nanoparticles (MSNs) for its potential role in promoting the anticancer efficacy of doxorubicin (DOX) on Tca-8113 cells. Methods: MSNs were characterized by transmission electron microscope (TEM) and N2 adsorption/desorption method. The drug release profiles of DOX from MSNs were monitored by UV-Vis. The anticancer effect of MSNs@DOX was demonstrated by MTT assay, Hoechst 33342 staining, and flow cytometry. The related mechanism was explored by Western blot. Results: The particle size of MSNs was about 30 nm and its average pore size, surface area and pore volume were 19.59682 nm, 193.4296 m2/g and 0.947625 cm3/g, respectively. MSNs displayed good cytocompatibility. MSNs@DOX inhibited the proliferation of Tca-8113 cells, induced apoptosis remarkably and arrested cell cycle at G0/G1 checkpoints. Western blot revealed remarkable up-regulated expression of Bax, p53 and caspase-3 and down-regulated expression of Bcl-2. Conclusion: Such a doxorubicin delivery strategy might be promising in tongue cancer therapy. References | Related Articles | Metrics

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Temporal and Spatial Expression of Pik3cb at Different Developmental Stages of Mouse Mandibular First Molar. ZHANG Yang, CHAI Ji-hua, REN Ming-xin, WANG Ge 2017, 33(3): 254-257.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.005 Abstract ( 256 )   PDF (1364KB) ( 292 )   Objective: To detect the expression pattern and variation of Pik3cb at different developmental stages of mouse mandibular first molar. Methods: The probe for in situ hybridization was prepared. Mouse embryos at different times were obtained to get cryostat serial sections of tooth germ for ISH. Results: In bud period, Pik3cb obviously expressed in dental lamina epithelium. In bonnet period, the Pik3cb began to express in the enamel epithelium and dental papilla. In bell stage, the expression of Pik3cb was especially within the enamel epithelium and subsequently in the new formation of hard tissues surrounding the columnar cells into glaze. Conclusion: Pik3cb expresses in dental epithelial cells and ameloblasts and it is likely to associate with ameloblastoma through PI3K/PTEN/AKT/mTOR signaling pathway. References | Related Articles | Metrics

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Effects of Daidzein on Bone Rebuiling of Alveolar Fossa after Tooth Extraction in Osteoporotic-model Rats. ZHANG Yu, LIN JIU, GAO Wei, HU Yi, GAO Yi, XIONG Wen-bi, PAN Jian. 2017, 33(3): 258-261.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.006 Abstract ( 249 )   PDF (1107KB) ( 261 )   Objective: To explore the effect of Daidzein (Da) on the alveolar bone rebuilding after tooth extraction in osteoporotic-model rats. Methods: Twenty-four 3-months-old female SD rats were randomly divided into four groups: sham group (Sham), estrogen group (EG), ovariectomized group (Ovx), ovariectomized and Daidzein group (Da). Bilateral maxillary first molars of all rats were extracted at the 7th day post ovarian surgery. The values of serum calcium, phosphorus and alkaline phosphatase (ALP) were recorded at the 12th week. Meanwhile, bone tissue sections of the left side of alveolar bone were made to observe bone rebuilding. Results: The value of serum calcium(2.49±0.02) and ALP(5.31±0.5) of ovariectomized rats decreased significantly(P<0.01), Daidzein could significantly improve the value of calcium(2.27±0.05)and the activity of ALP(4.49±0.38) in serum of ovariectomized rats(P< 0.01).Morphological observation in alveolar bone tissue around the tooth fossa showed that the function of bone preservation of Daidzein was similar to estrogen, and was relatively similar to that of Sham group. Conclusion: Daidzein can remarkably improve the value of calcium and ALP in serum, reduce resorption of alveolar bone around the tooth fossa, and rebuild the bone morphology after extraction in osteoporotic-model rats. References | Related Articles | Metrics

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Expression of Periostin in Oral Squamous Cell Carcinoma and Its Role in Epithehial-mesenchymal Transition. ZHANG Yang-an, GUAN Wei-qun, LI Qun, OU YANG Qi-ming 2017, 33(3): 262-265.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.007 Abstract ( 213 )   PDF (3221KB) ( 353 )   Objective: To investigate the expression of Periostin in oral squamous cell carcinoma (OSCC) and explore its role in epithehial-mesenchymal transition (EMT). Methods: Immunohistochemistry was used to detect the expression of Periostin, E-cadherin and Vimentin in 59 cases of oral squamous cell carcinoma specimens and 15 cases of normal oral mucosa specimens. The relationship between Periostin expression and EMT was also analyzed. Results: The positive rate of Periostin, E-cadherin and Vimentin in the specimens of OSCC patients was 71.2%, 52.5% and 39.0%, respectively. And the expression of Periostin was significantly correlated with TNM stage, tumor differentiation degree and lymph node metastasis (P＜0.05). Also, Periostin expression was negatively correlated with E-cadherin expression and positively correlated with Vimentin expression (P＜0.01). Conclusion: Periostin may promote the invasion and metastasis of oral squamous cell carcinoma through regulating epithehial-mesenchymal transition. References | Related Articles | Metrics

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Effect of Orthodontic Tooth Movement on Estrogen Levels in Serum and Local Periodontal Tissues of Rats. SHEN Lan-hua, MENG Ling-na, ZHANG Rui. 2017, 33(3): 266-268.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.008 Abstract ( 218 )   PDF (761KB) ( 208 )   Objective: To study the effect of orthodontic tooth movement on the level of estrogen in serum and local periodontal tissues in rats. Methods: One hundred and five female wistar rats were selected for the orthodontic tooth movement model and randomly divided into A (sham group), B (afterburner experiment group) and C (control group) group. Each group was also divided into four subgroups of proestrus, estrus, metestrus, and diestrus. Rat serum and local dental periodontal tissue estrogen levels were measured by radioimmunoassay and immunohistochemical methods, respectively. Results: Compared with the rats in proestrus and estrus periods, estrogen levels in serum and local periodontal tissue of rats in the late diestrus showed differences with statistical significance (P<0.05). In addition, from proestrus to estrus, metestrus, and then diestrus period, orthodontic tooth movement led to remarkable increase of estrogen levels in serum and local dental periodontal tissue (P<0.05). Conclusion: The increase of estrogen levels caused by orthodontic tooth movement can be attributed to the systemic stress response. The increased estrogen levels in local periodontal tissue resulted from periodontal reconstruction by local stress. References | Related Articles | Metrics

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Effects of 1,25-dihydroxyvitamin D3 on Neutrophil Apoptosis and Inflammatory Mediators in Type 2 Diabetic Patients with Chronic Periodontitis. YAN Yan-mei, TANG Ya-ping, HE Tao, MA Can-can, FANG Hui, ZHONG Wen-yi, LIU Qi. 2017, 33(3): 269-272.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.009 Abstract ( 246 )   PDF (1632KB) ( 230 )   Objective: To investigate the effect of 1,25 (OH)2D3 on neutrophils apoptosis and inflammatory mediators expression in Type 2 diabetic patients with chronic periodontitis. Methods: Neutrophils were isolated by density gradient centrifugation from Type 2 diabetic patients with chronic periodontitis peripheral blood and cultured in media with or without 1,25 (OH)2D3 for 24h. The apoptosis rate of neutrophils was detected by flow cytometry (FCM). Expressions of tumor necrosis factor-α, interleukin-1β, interleukin-6, and neutrophil elastase in supernatants were tested by enzyme-linked immunosorbent assay (ELISA). Results: Flow cytometry analysis showed that 1,25(OH)2D3 intervention group neutrophil apoptosis rate was increased significantly (P<0.05). Multiple comparison revealed that there were significant differences among groups with different concentrations (10-8 mol/L intervention group>10-6 mol/L intervention group>10-10mol/L intervention group). ELISA results showed thattumor necrosis factor-α, interleukin -1β, and interleukin-6 content were decreased in 1,25(OH)2D3 intervention group (P<0.05). Conclusion: 1,25(OH)2D3 may promote the neutrophil apoptosis and decrease the expression of inflammatory mediators, and play an immune regulatory role in the occurrence and development in Type 2 diabetic patients with chronic periodontitis. References | Related Articles | Metrics

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Three-dimensional Finite Element Analysis of Different Root Canals Restored with 3D Printing Fiber Post. XIAO Yan, SHEN Kai-qi. 2017, 33(3): 273-277.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.010 Abstract ( 247 )   PDF (2803KB) ( 306 )   Objective: To investigate the effect of different maxillary canine root canals on the stress distribution of 3D printing post and core by three-dimensional finite element analysis. Methods: Micro-CT scan, reverse engineering software MIMICS, model reconstructing software MAGICS and Unigraphics (UG) software were employed to reconstruct the three-dimensional finite element models of maxillary canines. Results: For normal root canals, the stress distribution of 3D printing post and core system was better than that of prefabricated fiber post system by reducing the failure probability of bond. For funnel-shape root canals, the stress distribution of 3D printing post and core system was better than that of prefabricated fiber post system by increasing the fracture resistance of teeth. Conclusion: 3D printing posts are better than pre fiber post system to restore the maxillary canine. References | Related Articles | Metrics

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Draining and Guiding Eruption Management for Maxillary Osseous Impacted Incisors with Dentigerous Cysts. HE Wu-cheng, CHENG Lei, GU Yu-jia, ZHANG Wei-bing, ZHAO Chun-yang. 2017, 33(3): 278-281.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.011 Abstract ( 242 )   PDF (1920KB) ( 291 )   Objective: To investigate the early management for maxillary osseous impacted incisors with dentigerous cysts by using draining and guiding eruption method. Methods: Eight patients who had unilateral maxillary impacted incisor with dentigerous cyst in the early mixed dentition were selected. Eigth impacted teeth were treated with the draining and guiding eruption technique simultaneously after the cyst excision. All patients were taken CBCT scan examination at pre- and post-treatment time. The crown-root lengths of the impacted and the contralateral teeth were measured with Dolphin 11.0 software. Results: The average treatment duration was 6.7 months. After treatment, the crown-root lengths of both the impacted teeth and the contralateral teeth were greater than their pretreatment values. The crown-root lengths of impacted teeth were significantly shorter than that of the contralateral teeth (P<0.05). Conclusion: The draining and guiding eruption technique in the research provided a new safety and effective approach for the management of the impacted teeth with dentigerous cysts. References | Related Articles | Metrics

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Analysis of Maxillary Sinus Septa in Population of Qinghai by Cone-beam CT. SONG Juan, ZHANG Zhi-qing, KANG Hong-yu, CAO Yan-ying, MA Chen-lin, CHEN Ning. 2017, 33(3): 282-285.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.012 Abstract ( 230 )   PDF (1087KB) ( 261 )   Objective: To investigate the anatomical variation of maxillary sinus septa by cone-beam CT and provide guidance to sinus floor elevation. Methods: Cone-beam CT scans of 300 adult subjects were evaluated to assess the prevalence, location, height, orientation, and morphology of the maxillary sinus septa. The data were analyzed with SPSS17.0. Results: Sinus septa were present in 80 out of 300 subjects (26.7%). The prevalence of septa was not significantly correlated with gender, age, and presence of tooth loss. 41.4% of the septa were located in the middle of maxillary sinus. The mean height of sinus septa was (6.60±4.08)mm and (6.81±4.24)mm in the right and left maxillary sinus, respectively. The mean length of sinus septa was (9.28±2.99)mm and (9.00±3.00)mm in the right and left maxillary sinus, respectively. 85.2% of the septa orientated buccopalatally. 80.5% of the septa were complete. Conclusion: 26.7% of population in Qinghai have maxillary sinus septa. Much more attention should be paid in maxillary sinus floor elevation to avoid complications. References | Related Articles | Metrics

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Comparison of Shaping Ability of Five Ni-Ti Rotary Instruments in Simulated Root Canals. YU Xiao-qing, LIU Yu-fei, GUO Shi-bo, FENG Rui-ming, ZHU Meng-ying, XUE Ming. 2017, 33(3): 286-289.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.013 Abstract ( 344 )   PDF (884KB) ( 403 )   Objective: To compare the shaping ability of five Ni-Ti rotary instruments in simulated root canals. Methods: Fifty resin blocks were distributed into five groups (n=10), and prepared using ProTaper (group 1), Reciproc (group 2), TFA (group 3), WaveOne Gold (group 4), and M3 (group 5) respectively. The preparation time of each group was measured. Standardized photographs were taken before and after the instrumentation, and then they were superimposed using Adobe photoshop. The changes of the canal curvature and the centering ability were measured. Data were analyzed by SPSS 17.0. Results: The preparation time of group 3 was the shortest. Group 1 had the highest apical transportation. At the curved part, the canal transportation of group 3 and group 5 were significantly smaller than the other systems (P<0.05). Conclusion: TFA was capable of preparing the root canal quickly and efficiently. M3 showed excellent shaping ability and the ProTaper system showed the highest canal transportation. References | Related Articles | Metrics

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Analysis of Influencing Factors on the Treatment of Intracapsular Condylar Fracture in Children. LI Xin-lei, YAO Zhi-tao, WANG Qiang, LIU Xiao-li, JIANG Zhi-xin, Adili·Moming. 2017, 33(3): 290-294.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.014 Abstract ( 219 )   PDF (1671KB) ( 239 )   Objective: To investigate the influencing factors on the treatment of intracapsular condylar fracture, and compare the clinical and radiographic outcomes between operative and conservative treatments of condylar fractures of mandible in children. Methods: Between January 2008 and October 2013, 78 patients with 104 sides of intracapsular condylar fracture diagnosed by panoramic and CT scan in the first Affiliated Hospital of Xinjiang Medical University were selected. All patients received MRI to check the presence or absence of injury and the position of TMJ disc. Follow up period ranged from 1 to 3 years. The clinical information and data of treatment outcome were collected and analyzed. Results: Radiological examination: The completely rehabilitative rate was 78.9% in the operation group, and 72.4% in the conservative group. No significant difference was found between two methods. The mandibular symmetry rate was 93.1% in the operation group, and 80.0% in the conservative group, no significant difference was found either between two groups. Clinical examination: The complications of operation treatment were significantly less than those of the conservative treatment (P<0.05). Both treatment methods showed high cure rate of condylar remodeling and functional recovery to intracapsular condyle fracture. Conclusion: Based on the present investigation, 1) the presence or absence of obvious shortening of mandibular ramus 2) the presence or absence of injury and displacement of TMJ discs 3) the presence or absence of limited mouth opening and malocclusion 4) the presence or absence of attachment loss to lateral pterygoid have important influences on the treatment choice and plan for the intracapsular condylar fracture. References | Related Articles | Metrics

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Study on the Relevance of Palatal Impacted Canine and Sella Bridges. CHEN Lan-yue, ZHAO Yang, ZHENG Bo-wen, CHEN Yan-na, AN Na, LIU Yi. 2017, 33(3): 295-297.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.015 Abstract ( 190 )   PDF (857KB) ( 213 )   Objective:To investigate the relevance of sella bridges and palatal impacted canine by comparing the size of sella turcica on patients with palatal impacted canines and normal canines. Methods:One hundred and three cases with palatal impacted canines were selected as experimental group, while 103 cases with normal canines were selected as control group. The length, depth and diameter of sella turcica were measured. Based on the calcification of sella turcica, cases were divided into type I, II and III. Results:Significant differences were found in the length and diameter between two groups. In the experimental group, the depth of sella turcica in male was larger than female, besides, there was no difference in the length and diameter between genders. However, there was no difference in the size of sella turcica between genders in the control group. The part and total calcification of sella turcica in the experimental group were 41.75% and 15.53%, which showed no significant difference between genders; while the part and total calcification of sella turcica in the control group were 8.73% and 4.85%. The incidence of sella turcica in the control group was 8.52 times of the experimental group. Conclusion:Length and diameter of sella turcica in the experiment group were larger, when compared to the control group. The incidence of sella bridges in the experimental group significantly increased, which showed no significant difference between genders. References | Related Articles | Metrics

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Visualization of the Mandibular Canal: a Consistency Evaluation using Digital Panoramic Radiographs and Cone-beam Computerized Tomography. XIE Cheng, WU Run-fa, FENG Bin, ZHANG Xian-hua. 2017, 33(3): 298-302.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.016 Abstract ( 246 )   PDF (2439KB) ( 307 )   Objective: To analyze the visualization consistency of mandibular canal on panoramic images and CBCT images, and to discuss the non-pathological factors influencing the visualization of mandibular canal. Methods: Using digital panoramic images and cone-beam computerized tomography images from 92 patients shooting in Hospital of Stomatology, Sichuan University during December 2013 to February 2014 and these images were evaluated by two radiologists. The mandibular canal was divided into 3 equal width areas from mental foramen to anterior border of ramus. The visibility of the mandibular canal borders was assessed using 4 point visibility scoring system, with lower scores for worse visibility. Results: The internal consistency inspection of two doctors conformed to the standard. In CBCT, average score of area 1 was 2.120, area 2 was 2.337, and area 3 was 2.533. In panoramic average, score of area 1 was 1.772, area 2 was 1.973, and area 3 was 2.207. Conclusion: CBCT remarkably improve the visualization of the mandibular canal in the area 1. The visualization of the mandibular canal in CBCT is significantly higher than in panoramic, while only 1％ of the mandibular canal in panoramic is visible and is invisible in CBCT. There is a close correlation between age and visualization, and the visualization gets poor with age. References | Related Articles | Metrics

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Application of CT Angiography in the Clinical Designing of Vascularized Iliac Crest Flap. LAN Yu-yan,SUN Li-bo,ZHANG Li,ZHOU Hang-yu. 2017, 33(3): 303-306.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.017 Abstract ( 192 )   PDF (1576KB) ( 166 )   Objective:To investigate the applicative value of CT angiography in the clinical designing of vascularized iliac crest flap. Methods:From August 2014 to September 2015,12 patients with mandibular defects were treated with vascularized iliac crest flap. Preoperative CTA was conducted. Imaging workstation (Philips Medical System) was used to observe and measure the diameter of deep circumflex iliac artery (DCI) at the starting point,the angle between the starting segment of DCI and the line from one anterior superior iliac spine to the other,and the length from the starting point of DCI to anterior superior iliac spine. The body surface location of the starting point of DCI was determined according to the angle and the length,and then iliac crest flap harvesting was simulated. Results:The diameter of DCI at the starting point was (2.8±0.61) mm,the angle and the length were (55±1.7) degree and (65.1±1.24) mm, respectively.Iliac crest flap harvesting was simulated successfully according to the reconstructed image. Conclusion:CTA can accurately determine the anatomical location of DCI,and it can effectively guide the designing of the iliac crest flap. References | Related Articles | Metrics

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Individualized Implants Selection Based on Finite Element Analysis (FEA) and Mechanical Properties Evaluation. WANG Qian-qian, CHEN Zhong-zhong, YANG Ya-ru, ZHANG Jian-fei, ZHANG Peng 2017, 33(3): 307-310.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.018 Abstract ( 218 )   PDF (1776KB) ( 273 )   Objective:To provide dentist with principles for implant selection based on finite element analysis (FEA). Methods:The jaw bone was reconstructed by using an oral virtual dental implant system. Implants were chosen based on this model. They were implanted virtually simulating the implants’ position and orientation in different edentulous conditions.The stress distribution of different implants in chewing process was analyzed by FEA, and mechanical properties were evaluated. Results:The dental implants with optimal length and diameter were chosen with FEA analysis. Conclusion:FEA analysis can provide help for physicians to select personalized dental implants. References | Related Articles | Metrics

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Evaluation of Hot Gutta-percha Root Canal Filling Quality of Mandibular Molar in the Elderly by Cone Beam CT. XUE Li-qiu, ZHENG Li-juan, LI Qiu-shi. 2017, 33(3): 311-314.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.019 Abstract ( 229 )   PDF (960KB) ( 154 )   Objective: To evaluate the quality of hot gutta-percha root canal filling in the mandibular molar in the elderly by cone-beam CT. Methods: Eighty molars with 253 root canals in 51 geriatric patients from June 2015 to August 2016 in the Stomatology Hospital of Dalian were selected. Before the operation, the molars were scanned with cone-beam CT. The root canals were filled with hot gutta-percha and vertical pressurized. The quality of root canal filling were evaluated by cone-beam CT and digital images. Results: The error rate of root canal length observed by digital images was 9.1%. The difference of evaluation result of digital images in mouth and cone-beam CT was statistical significance (P＜0.05). The error rate of the root canal adaptation of digital images at 2.0% was evaluated. The differences of digital images and cone-beam CT results were no statistical significance. Conclusion: Cone-beam CT has a higher accuracy in evaluating the hot gutta-percha root-filling quality of mandibular molar of the geriatric patients than digital images. References | Related Articles | Metrics

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Expression and Clinical Significance of ALDH1A1 in Tongue Squamous Cell Carcinoma and Lymph Node. WU De-bao, HAO Wei-liang, YANG Li, SHEN Jun 2017, 33(3): 315-319.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.020 Abstract ( 252 )   PDF (1823KB) ( 266 )   Objective: To detect the expression of aldehyde dehydrogenase1A1 (ALDH1A1) in the primary lesions and lymph nodes of tongue squamous cell carcinoma (TSCC) patients, and analyze the their relationship with clinicopathological features and prognosis. Methods: The expression of ALDH1A1 was evaluated by SP immunohistochemistry in 50 cases of TSCC primary lesions, 10 cases of normal tongue tissue and 29 metastatic lymph nodes, 9 non-metastatic lymph nodes. Results: Expression of ALDH1A1 in TSCC primary lesions was significantly higher than that in normal tongue tissue (P<0.05). Expression of ALDH1A1 in metastatic lymph nodes was significantly higher than that in non-metastatic lymph nodes (P<0.05). In primary TSCC lesions, the expression level of ALDH1A1 was associated with clinical stage, lymph node metastasis, tumor size and histological grade (P<0.05). In lymph nodes, the expression level of ALDH1A1 was associated with clinical stage, lymph node metastasis and tumor size (P<0.05). The Kaplan-Meier analysis demonstrated that ALDH1A1 overexpression was associated with poor prognosis in TSCC patients. Conclusion: ALDH1A1 was closely correlated with the biological behavior and prognosis of patients in TSCC, and may provide new therapeutic targets for TSCC. References | Related Articles | Metrics

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Establishment of Three-dimensional Finite Element Model and Stress Analysis for Physiological Anchorage Spee-wire System Appliance in Upper Arch. LIU Guang-mei, LIU Hai-xia, WU Xiao-ya, WANG Wei. 2017, 33(3): 320-323.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.021 Abstract ( 223 )   PDF (1105KB) ( 204 )   Objective: To establish a three-dimensional finite element model for physiological anchorage Spee-wire System appliance and analyze the stress. Methods: A Volunteer of individual normal occlusion was selected. The data of the person by CT scanning was imported into the software of Mimics l7.0, to obtain three dimensional model of teeth and jaw bone (cortical bone and cancellous bone) by three dimensional reconstruction method. The three dimensional model was put into reversely engineering software Geomagic studio through the format of STL and refined. The appliance of three-dimensional model was obtained by the design of NX software. Arch wire was defined as geometrically nonlinear. Teeth, jaws, appliance and wire model were imported into the NX software by the format of stp to assemble and meshed with ANSYS l5.0 software. Ultimately, a whole model of three dimensional finite element of the teeth, jaws, physiological anchorage Spee-wire System appliance and arch wire was built. Results: A whole model of three dimensional finite element of the teeth, jaws, physiological anchorage Spee-wire System appliance and arch wire was built. The situation of force and tooth movement in orthodontic clinic was simulated. Conclusion: The finite element model with physiological resistance controlling appliance was authentic, accurate and strong similarity of geometric, which could simulate distribution of stress and displacement trend in clinical and be conducive to the understanding application of the technology in clinic. References | Related Articles | Metrics

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Application of Synchrotron Radiation Based Diffraction Enhanced Imaging CT on Evaluation of Root Canal Obturation Quality. CONG Chang-hong, CHEN Ning, TIAN Hui, ZOU Zhao-hui, WANG Ying-hui 2017, 33(3): 324-327.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.022 Abstract ( 186 )   PDF (1547KB) ( 239 )   Objective: To investigate the quality of root canal obturation using synchrotron radiation based diffraction enhanced imaging CT. Methods: Ten lower premolars were collected, and the root canals were prepared and obturated. All teeth were scanned with synchrotron radiation based diffraction enhanced imaging CT and reconstruction of the obturated root canals was performed. Results: Root canals and lateral canals were observed and interface voids and gaps around dentin were surveyed. Conclusion: Synchrotron radiation based diffraction enhanced imaging CT has the potential benefit on analyzing the effects of root canal obturation. References | Related Articles | Metrics

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Research on Cement Caries Intervention Model for Elderly People in Shenzhen Futian Community YANG Yu-hui, ZHAO Yun-peng, XIANG Ying-jun. 2017, 33(3): 328-330.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.023 Abstract ( 234 )   PDF (755KB) ( 227 )   Objective: To study the intervention effect of cement caries in the elders of Yitian community in Shenzhen, Futian District. Methods: From January 2013 to January 2015, 100 elders with aged 65 in Yitian community of Futian district were randomly divided into intervention group (n=50) and the control group (n=50). A baseline survey was conducted to understand the root caries in older adults and to assess the risk during the process of social health center physical examination for 65-year-old or older each year. The intervention group was given comprehensive intervention with health education combined with the glass ion diaphragm, while the control group received no intervention. The effect of root caries prevention in two groups after 18 months' followed up was observed. Results: The main factors affecting the incidence of root caries in the elderly were the factors such as eating sweets, brushing teeth before going to bed and brushing frequency, the success rate of root surface caries prevention in the elderly of intervention group (92.0%) was significantly higher than that of control group (64.0%), which was significant statistical difference (P<0.05). Conclusion: Health education combined root surface coated glass ion diaphragm intervention can effectively improve the community elderly root caries prevention effect. For the influence factors of root surface caries in the elderly, the elderly should be instructed to pay attention to the improvement of daily habits, strengthened health education guidance, and taken root surface coated glass ion coating protective measures at the same time, with aim to maximally reduce the incidence of senile cement caries. References | Related Articles | Metrics

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Preparation and Properties of Zirconia Nano-powders. ZHENG Ying-qiu, GUO Xiao-jin, WANG Jian, XU Ran-ran, WU Wen-hui 2017, 33(3): 331-335.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.024 Abstract ( 218 )   PDF (2371KB) ( 350 )   Objective: To prepare the 3mol% yttria-stabilized tetragonal polycrystalline zirconia (3Y-TZP) nano-powders by using salt-assisted solution combustion synthesis (SSCS) method. Methods: 3Y-TZP nano-powders were prepared via the SSCS and freeze drying method. Thermogravimetry differential thermal analysis (TG-DTA), x-ray diffraction (XRD) and transmission electron microscopy (TEM) were employed to evaluate the ignition temperature of the precursors, the phase structure, the crystallite size, morphology, and size distribution of 3Y-TZP nano-powders. Effects of the density of zirconium ion, the ignition temperature of the precursors, the molar ratios of metal ion to urea and metal ion to KCL on size of powders were determined by orthogonal test. Results: The optimal conditions were determined as follows: 0.085 mol/L zirconium ion, 1 molar ratio of metal ion to urea, 3 molar ratio of metal ion to KCL, and ignition temperature 400℃.The products were tetragonal polycrystalline zirconia and 2.9~9.0nm in crystalline size analyzed via XRD. Under the optimal conditions, the micrographs of nano-particles were sphericity, well dispersion and low-agglomeration. The particle size was 5.38nm on the average. Conclusion: 3Y-TZP nano-powders can be prepared by the SSCS method and have high-purity, small crystalline size, narrow size distribution and low-agglomeration. References | Related Articles | Metrics

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Application of Coarse Core Biopsy Guided by Colour Doppler Ultrasound in Diagnosis of Parotid Tumors. TONG Guo-yong, YU Qin-zhou, GE Chun-cheng. 2017, 33(3): 336-338.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.025 Abstract ( 218 )   PDF (938KB) ( 271 )   Objective: To investigate the clinical application of colour Doppler ultrasound guided core biopsy (USCB) in the preoperative diagnosis of parotid tumors. Methods: Sixty-threepatients with parotid glandtumor, who had received USCB before operation, were included in this study from 2013-2015. The USCB results were compared with the postoperative pathological examinations. Results: In these 63 patients with parotid gland tumor, there were 56 cases whowere diagnosed with benign tumor by USCB, including 1 cases of mucoepidermoid carcinoma reported by postoperative pathological examination.The preoperative diagnostic coincidence rate was 98.2%. And 7 cases were diagnosed with malignant tumor by USCB and the preoperative diagnostic coincidence rate was 100%. There were 11 cases who had complicationafter the operation of USCB, 6 patients felt pain in the operation areaand 5 patients had swelling in the operation area and no injury to the facial nerve after USCB. Conclusion: USCB is quite effective in diagnosis of parotid tumors with less postoperativecomplications and non-reversible damage. References | Related Articles | Metrics

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Research Progress of B-1 Cells in Periodontitis. WANG Yi-xiong, ZHANG Jin-cai 2017, 33(3): 339-341.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.026 Abstract ( 293 )   PDF (778KB) ( 258 )   Periodontal local bacterial infection can cause inflammation of periodontal tissue, resulting in the destruction of periodontal tissue and tooth loss. In recent years, scholars found that a large proportion of B-1 cells accounted for periodontitis lesion infiltrating cells and conducted researches on the effect of B-1 cells in periodontitis. In this article, we performed a systematic review of B-1 cell in periodontitis in order to understand the research progress in this field and obtain the new ideas for the treatment of periodontitis. References | Related Articles | Metrics

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Application of 3-dimensional Finite Element Method in Lingual Orthodontics. GAO Xue, ZHANG Dong-liang. 2017, 33(3): 342-344.  DOI: 10.13701/j.cnki.kqyxyj.2017.03.027 Abstract ( 275 )   PDF (769KB) ( 292 )   Lingual orthodontics has many therapeutic odvantages over labial orthodontics, however, its biomechanical mechanism is inadequately understood. In recent years, many researchers set up finite element models of lingual appliance and studied the biomechanics of lingual orthodontics. This paper is a review about the application of 3-dimensional finite element method in lingual orthodontics. References | Related Articles | Metrics