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Table of Content

    20 December 2014, Volume 23 Issue 6 Previous Issue    Next Issue
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    Basic Study
    Changes of the microarchitecture of alveolar bone due to different duration of ovariectomy: a Micro-CT study in rats
    DAI Qing-gang, FANG Bing, ZHANG Peng, YANG Xiao, WANG Jie, OUYANG Ning-juan, WU Yu-qiong, JIANG Ling-yong
    2014, 23 (6):  641-645. 
    Abstract ( 297 )   HTML ( 3 )   PDF (780KB) ( 261 )  
    PURPOSE: To study the changes of microarchitecture of alveolar bone due to different duration of ovariectomy in rats. METHODS: Twenty-four virgin Sprague-Dawley rats were randomly assigned to ovariectomy group (OVX) or sham-ovariectomy group (sham). OVX rats were subjected to bilateral ovariectomy and sham-ovariectomy was conducted in sham rats. Six rats of each group were sacrificed respectively 3 months and 6 months after surgery. The right semi-maxilla of all rats were scanned by Micro-CT, and the inter-radicular alveolar bone of the maxillary first molar was analyzed. Statistical analysis was carried out with SPSS 16.0 software package. RESULTS: Two-dimensional and three-dimensional reconstructed images of the alveolar bone showed porotic changes in rats both 3 months and 6 months after ovariectomy, including thinner, looser trabeculae and expanded bone marrow. When compared with corresponding sham rats, BMD, BV/TV and Tb.Th of alveolar bone significantly decreased in OVX rats both 3 months and 6 months after ovariectomy (P<0.05). Tb.N and Tb.Sp significantly increased in both OVX groups (P<0.05). When compared with 3 months after ovariectomy, the rats 6 months after ovaroectomy shared deceased BMD, BV/TV and Tb.Th (P<0.05) and increased Tb.N (P<0.05). CONCLUSIONS: Bone loss and deterioration of trabeculae of alveolar bone aggravates with the extended duration of ovariectomy in OVX rats.
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    Effect of high glucose on migration of BMSCs through inhibiting CXCR-4
    ZHANG Bo, LIU Na, GU Bin, WU Hao, GAO Yu-xuan, WANG Dong-sheng, LIU Hong-chen
    2014, 23 (6):  646-650. 
    Abstract ( 180 )   HTML ( 2 )   PDF (717KB) ( 193 )  
    PURPOSE: To explore the effect of high glucose on migration of BMSCs through inhibiting CXCR-4. METHODS: Bone marrow stromal cells (BMSCs) were obtained from the mandible of Wistar rats and stimulated with different concentrations of glucose (5.5, 16.5 mmol/L). The optimum concentration of SDF-1 was evaluated by Transwell assay in physiological glucose concentration (5.5 mmol/L). In the optimum concentration of SDF-1 condition, we detected the effect of SDF-1 and AMD3100 on migration of BMSCs in different concentrations of glucose (5.5, 16.5 mmol/L). CXCR-4 protein levels were determined by Western blot. The mRNA expression of CXCR-4 and MMP-2 were tested by RT-PCR. SPSS 11.0 software package was used for statistical analysis. RESULTS: The optimum concentration of SDF-1 was 100 ng/mL. High glucose could inhibit the migration of BMSCs. In different concentrations of glucose, SDF-1 could promote the migration of BMSCs, but AMD3100 could inhibit this promotion. High glucose condition could inhibit the secretion of CXCR-4 and mRNA expression of CXCR-4 and MMP-2. CONCLUSIONS: High glucose inhibits migration of BMSCs by inhibiting CXCR-4 through SDF-1/CXCR-4 pathway.
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    Study of the mechanical properties of CP Ti ceramic alloy after recasts
    YANG Song1, CHENG Hui1, LI Xiu-rong2, WU Wei-qing3, ZHENG Ming1, WANG Ying-hui1
    2014, 23 (6):  651-653. 
    Abstract ( 176 )   HTML ( 0 )   PDF (374KB) ( 225 )  
    PURPOSE: To investigate the influences of repeated casting on the mechanical properties of CP Ti ceramic alloy. METHODS: CP Ti ceramic alloy samples were prepared and recast 3 times without adding any new CP Ti ceramic alloy. The physical properties of each specimen were measured. SPPPSS13.0 software package was used for statistical analysis. RESULTS: No significant difference was found on the flexural strength of the CP Ti ceramic alloys that had been cast 2 or 3 times, compared with that of the alloys being cast only 1 time (P>0.05). However, the flexural modulus, tensile strength, 0.2% yield strength and surface microhardness of the CP Ti alloys being cast 2 or 3 times were significantly higher than those of the alloys being cast only 1 time (P<0.05). Elongation of the CP Ti alloys being cast 2 or 3 times was significantly lower than that of the alloys being cast only 1 time (P<0.05). CONCLUSIONS: Recasting may cause decreases in tensile properties of CP Ti ceramic alloy.
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    The effect of estrogen on proliferation and osteogenic differentiation of rat bone marrow mesenchymal stem cells
    WANG Jie, ZHANG Peng, DAI Qing-gang, OUYANG Ning-juan, JIANG Ling-yong, FANG Bing
    2014, 23 (6):  654-660. 
    Abstract ( 254 )   HTML ( 0 )   PDF (1487KB) ( 271 )  
    PURPOSE: Different concentrations of 17 β-estradiol (E2) were applied in the osteogenic differentiation of rat bone mesenchymal stem cells (BMSCs), and the proliferation and apoptosis of BMSCs were explored. METHODS: BMSCs were obtained from the femurs and tibias of SD rats. The proliferation curve was conducted to rBMSCs in culture medium containing 0, 10-9, and 10-7 mol/L 17 β-estradiol by CCK-8 for 7 days. Annexin V and PI for flow cytometry were applied to detect the impact of E2 on apoptosis of rBMSCs. After 1, 7, 11 and 14 days of osteogenic induction, the activity of alkaline phosphatase (ALP) was assayed; ALP staining was performed on day 7 and day 14; Alizarin red staining for calcium deposits was carried out on day 21. Concentrations of 0, 10-9, and 10-7 mol/L 17 β-estradiol were administrated to rBMSCs for real-time PCR of osteogenic related genes on day 1, 3, 5, 7, 14, and day 21. The data was statistically analyzed using SPSS 19.0 software package. RESULTS: The effect of 17 β-estradiol on proliferation and apoptosis of rBMSCs was not obvious. However, after osteogenic induction, the ALP activity and Alizarin red staining were significantly stronger in the groups containing 17 β-estradiol. Especially, the use of 17 β-estradiol with the concentration of 10-9 mol/L enhanced the expression of osteogenic related genes like RUNX2, ALP, COL I, and OCN, which was significantly higher than other groups. CONCLUSIONS: 17 β-estradiol promotes osteogenic differentiation of BMSCs in a dose-dependent pattern in vitro.
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    The effect of different factors on forming-dentin differentiation of rat dental mesenchymal cells
    ZHAO Zheng1, LIU Hong-chen2, HUANG Zheng-nan1, E Ling-ling2, YANG Hai-qing1
    2014, 23 (6):  661-668. 
    Abstract ( 199 )   HTML ( 0 )   PDF (1927KB) ( 233 )  
    PURPOSE: To investigate the effects of combined use of bFGF, IGF1, BMP4 and TGF-β1 on forming-dentin differentiation of rat dental mesenchymal cells (rDMCs). METHODS: Enzyme and differential digestions were performed to isolate and culture rDECs and rDMCs, and immunofluorescence staining against cytokeratin and vimentin were carried out to identify cell sources. Then alizarin red staining and Gomori calcium-cobalt method were used to detect the mineralization ability of rDMCs after mineralized induction. Immunohistochemistry, image analysis, real-time PCR and Western blot were utilized to determine the expression differences of DSPP/CAP/OPN/OCN in rDMCs after induction by bFGF+IGF1 (group 1), TGF-β1+BMP4 (group 2) and bFGF+IGF1+TGF-β1+BMP4 (group 3), respectively. Statistical analysis was performed with SPSS 14.0 software package. RESULTS: The rDECs and rDMCs were isolated, cultured and identified successfully. Calcium nodus and ALP staining were positive in cytoplasms of rDMCs after being induced by mineralization liquid. In groups 1 and 2, the expression levels of DSPP/CAP/OPN/OCN mRNA and protein were notably higher than those of control group, significant differences were found between groups (P<0.01). Among them, the expression levels of CAP/OCN in group 1 and DSPP/OPN in group 2 were the highest, respectively. CONCLUSIONS: The rDMCs possess osteogenesis property after mineralization induction. bFGF+IGF1 can notably promote the expressions of CAP/OCN, and accelerate rDMCs to differentiate into cementoblast and osteoblast, and the mineralization of cementum matrix and bone matrix. TGF-β1+BMP4 can markedly increase the expressions of DSPP/OPN, and quicken rDMCs to differentiate into odontoblast and osteoblast, and the mineralization of dentinal matrix and bone matrix which display osteogenesis trend. Combined use of four factors had no significant synergism.
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    Characteristics of the immune status in aged mice with experimental periodontitis
    JIN Ying, WANG Lin-yuan, LIU Di-xin, LIN Xiao-ping
    2014, 23 (6):  669-674. 
    Abstract ( 225 )   HTML ( 2 )   PDF (1096KB) ( 259 )  
    PURPOSE: To establish mice model with periodontitis by oral infection with Porphyromonas gingivalis, simulating human periodontal disease. The immune status of youth and aged mice were compared, and the cytokines expression of regulatory T cells and Th17 cells in this model were analyzed. METHODS: Entity microscope was used to evaluate the extent of periodontal bone resorption. H-E staining was used to observe infiltration of inflammatory cells in periodontal lesions. TRAP staining was used to observe osteoclastes in alveolar bone. The expression levels of TGF-β1, IL-10, IL-17A and RANKL mRNA in periodontal tissues were detected by real-time quantitative PCR. SPSS 17.0 software package was used for statistical analysis. RESULTS: At 4-week after infection, the distance of cemento-enamel junction to the alveolar crest was significantly increased in the periodontal disease group compared with the normal control group (P<0.01); In the aged mice, the cemento-enamel junction to the alveolar crest distance significantly increased compared with youth mice (P<0.01). Periodontal tissues had inflammatory cell infiltration, and deep periodontal pockets. Moreover, the expression levels of TGF-β1 and IL-10 mRNA were significantly decreased (P<0.01) and the expression levels of IL-17A, RANKL mRNA significantly increased (P<0.01). CONCLUSIONS: The expression of inflammation mediator is abnormal in aged mice with more serious periodontal lesions than youth mice. It is suggested that the inflammatory status of periodontitis not only has a relationship with the decreased expression of inhibitory cytokines, but also relates to aging.
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    Effect of tensile strain on perlecan expression of human periodontal ligament cells
    WANG Yi1, SUN Chao-fan1, CHEN Li-jiao1, WANG Yan-liang2, HU Rong-dang1
    2014, 23 (6):  675-680. 
    Abstract ( 125 )   HTML ( 0 )   PDF (1227KB) ( 171 )  
    PURPOSE: To investigate the perlecan expression of human periodontal ligament cells (hPDLCs) under cyclic tensile strain in vitro, and learn the molecular mechanism of periodontal remolding during tooth movement. METHODS: hPDLCs isolated by enzyme digestion were loaded with 12% elongation, 1 Hz of uniaxial tensile strain for 12, 24 and 48 h. The unloaded cells were used as control. Real-time PCR and enzyme-linked immune sorbent assay (ELISA) were applied to analyze the mRNA and protein expression of perlecen in each sample respectively. The data was analyzed with SPSS 19.0 software package. RESULTS: Within 12 h, mRNA expression was transiently elevated, but no significant difference was detected compared with the control. After 12 h, the mRNA expression was significantly decreased. It would decreased to (0.28±0.049) at lowest level of control at lowest level at 48 h (P<0.05). The protein expression of perlecan was time-dependently decreased. Specifically, it was downregulated from (14.03±0.71) pg/mL (control) to (11.06±0.15) pg/mL at lowest level at 48 h (P<0.05). CONCLUSIONS: Tensile strain time-dependently down-regulates perlecan expression, indicating perlecan may play a pivot role in PDLCS responding to mechanical loading in vitro.
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    Cytotoxicity of a novel endodontic treatment material iRoot BP Plus to human gingival fibroblasts
    SHI Shuang1, BAO Zhi-fan1, 2, CHEN Xu1, 2, ZHANG Dan-dan1
    2014, 23 (6):  681-684. 
    Abstract ( 451 )   HTML ( 3 )   PDF (490KB) ( 985 )  
    PURPOSE: To compare the cytotoxicity of a novel endodontic treatment material iRoot BP Plus and mineral trioxide aggregate (MTA) to human gingival fibroblasts in vitro. METHODS: Cultured human gingival fibroblasts were exposed to multiple concentrations of material elutes (no dilution, 1:2 dilution, and 1:5 dilution). The test material samples were immersed and incubated in the culture medium for 1, 3 or 7 days at 37℃. The proliferation rate was evaluated using methylthiazol tetrazolium (MTT) assay. Cell relative growth rates were presented as . The data was statistically analyzed by factorial design ANOVA using SPSS 20.0 software package. RESULTS: Cell relative growth rates of the eluates of iRoot BP Plus and MTA in different concentrations ranged from 77.31% to 113.82%. The cytotoxicity grade of both materials was 0 or 1 (no cytotoxicity). There was no significant difference in the relative growth rate in different concentrations of iRoot BP plus and MTA eluates under different elution times (Fconcentration*time*material=1.393, P=0.256). CONCLUSIONS: Both iRoot BP Plus and MTA exhibit minimal level of cytotoxicity.
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    The effect of curvatures on the accuracy of the electronic apex locator
    TIAN A-lin1, LI Xiao-chuan1, LU Yu-tong1, YE Jing-jing1, LIU Yan1, HE Li2
    2014, 23 (6):  685-688. 
    Abstract ( 229 )   HTML ( 1 )   PDF (578KB) ( 237 )  
    PURPOSE: To investigate the effect of canal curvatures on the accuracy of 3 electronic apex locators (EAL) in vitro. METHODS: Alginate and 123 canals were used to mimic the situation in vitro. Three kinds of electronic apex locators including Raypex5?, PropexⅡ? and Rider? were applied to determine the length of the canals divided into 3 groups including straight (<5°), middle (>10°,<20°) and severe (>20°)according to the root canal curvatures. Experimental measurements and the distances (IF value) between experimental and ideal actual measurements under the same measurement environment were recorded. Paired sample t test was applied to analyze the results by using SPSS11.5 software package. RESULTS: The results showed that with the allowance of ±0.5 mm, the accuracy ratios of straight canal, moderate and severe curvature canal were 84.6%, 81.6%, 87.5% for Raypex?5,76.9%,89.8%, 91.7% for PropexⅡ?, and 92.3%, 89.8%, 87.5% for Rider?, respectively. There was no significant difference in the accuracy between the EALs regarding three degrees of root canal curvatures. CONCLUSIONS: The curvatures of the root canals have no influence on the accuracy of the EALs, though the difference exists in the accuracy rate among the EALs.
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    Effect of different surface treatments on the bond strength of fiber posts to resin cement
    ZHENG Hu1, GUO Jian-qing1, ZHANG Xian-fang2
    2014, 23 (6):  689-694. 
    Abstract ( 157 )   HTML ( 0 )   PDF (999KB) ( 252 )  
    PURPOSE: To evaluate the effects of five different surface treatments on the bond strength between fiber posts and resin cement. METHODS: Fifty fiber posts were randomly divided into 5 groups for different surface treatments. Group A was treated with silane coupling agent (Clearfil Porcelain Bond Activator,Kuraray); Group B was treated with silane coupling agent and then coated with dentin bonding agent (Clearfil SE Bond,Kuraray); Group C was immersed in 30%H2O2; Group D was immersed in 30%H2O2 and then treated with silane coupling agent; Group E received no surface treatment (control group). After bonding to resin cement, each group was then divided into 2 subgroups equally,while one group was stored in sodium chloride for 24 h at 37℃, and the other group was stored in sodium chloride for 24 h at 37℃ and then subjected to thermal cycling for 10000 times. Microtensile bond strengths were tested and the data was statistically analyzed using SPSS17.0 software package. RESULTS: The microtensile bond strength before thermal cycling was(6.7±0.7) MPa for group A,(14.4±1.1) MPa for group B,(10.7±0.9) MPa for group C,(16.0±1.0) MPa for group D and (6.7±1.0) MPa for group E. After thermal cycling, the microtensile bond strength was (6.7±0.7) MPa for group A, (13.1±0.7) MPa for group B, (9.0±0.7) MPa for group C, (15.0±0.9) MPa for group D and (5.6±0.7) MPa for group E. The results showed that surface treatments had significant impact on the bond strength (P<0.05). There was no significant difference between group A and group E. Group D had the highest bond strength compared with the other groups. Microtensile bond strengths were significantly different before and after thermalcycling treatment in each group (P<0.05). CONCLUSIONS: Thermocycling treatment decreases the bond strength of fiber posts to resin cement with these 5 surface treatments. Coupled with 30%H2O2 solution and silanization, the bonding strength of fiber posts to resin cement can increase significantly.
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    The effect of various irrigants on apically extruded debris: an in vitro study
    ZHANG Ling, ZHU Lin-lin, ZHANG Meng-long
    2014, 23 (6):  695-698. 
    Abstract ( 129 )   HTML ( 1 )   PDF (562KB) ( 219 )  
    PURPOSE: To compare the amount of debris extruded apically from root canals when different irrigants were used. METHODS: Fifty-eight extracted single-rooted human mandibular premolars with straight root canals were used. The teeth were randomly divided into control group (group A, n=7) and 3 experimental groups (group B,C,D,n=17). All teeth were prepared for root canal therapy, and 3 different irrigants were used (group B: 1% sodium hypochlorite; group C: 2.5% sodium hypochlorite; group D: 17% EDTA). Debris extruded from the apical foramen during root canal irrigation was collected into tubes and the amount of debris extruded was counted and analyzed. Statistical significance was assessed by Student-Newman-Keuls test with SPSS 13.0 software package. RESULTS: Group B, C, D had more amount of extruded debris, which was significantly different from the control group (P<0.05). Group C had the highest amount of extruded debris,which was significantly different from the other group (P<0.05). CONCLUSIONS: The type of irrigants used can affect the amount of apically extruded debris. 2.5% sodium hypochlorite can produce more apically extruded debris. 1% sodium hypochlorite and 17% EDTA are better than 2.5% sodium hypochlorite in terms of irrigation efficacy.
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    Clinical Study
    Three dimensional measurement and analysis of maxillary protraction treatment in skeletal Class Ⅲ malocclusion
    QIN Yan-jun1, SHEN Yun-juan1, GU Yan2, WANG Shan2, LIU Ke3, ZHAO Chun-yang2
    2014, 23 (6):  699-703. 
    Abstract ( 356 )   HTML ( 1 )   PDF (960KB) ( 250 )  
    PURPOSE: To study the three-dimensional mechanism of maxillary protraction in skeletal Class Ⅲ malocclusion by cone-beam CT (CBCT). METHODS: Fourteen patients (6 males and 8 females with a mean age of 10.9 years) of early permanent dentition with skeletal Class Ⅲ malocclusion were treated with maxillary protraction. CBCT was used to obtain the Dicom data both before and after treatment, and then digitized with the software Dolphin 11.0 was used to reconstruct and establish the tridimensional coordinate system. 23 landmarks were chosen for measurement and analysis. The data was analyzed using SPSS 17.0 software package. RESULTS: After maxillary protraction, A- coronal plane distance, SNA and ANB increased significantly (P<0.01); A- horizontal plane distance, ANS-PNS increased significantly (P<0.05), suggest maxillary growth was forward and downward. Po-S-N increased significantly (P<0.01), while SNB decreased significantly (P<0.05), suggesting that the chin was rotated downward and backward, and mandibular growth was inhibited. U1j - the coronal plane distance increased significantly (P<0.01), suggesting that the upper incisor moved forward; U1-SN angle increased significantly (P<0.05), suggesting anterior teeth inclined labially. The distance between U6j- horizontal plane and U6j- the coronal plane increased significantly (P<0.05), suggesting that maxillary molar elongated and moved mesially. Frontomaxillary suture changed on the three-dimensional direction, but without significant difference (P>0.05). CONCLUSIONS: Three-dimensional measurements confirm that growth and remodeling of bone suture (such as pterygopalatine suture) play an important role in maxilla development. The maxilla and maxillary teeth move forward and downward, while the mandibular growth is inhibited after maxillary protraction.
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    Inter-relationship between mandibular rotation center and maxillary Le Fort I impaction osteotomies
    LOU Xin-tian1, SHEN Guo-fang2, FENG Yi-miao3, FANG Bing2, WU Yong2, ZHU Min2
    2014, 23 (6):  704-707. 
    Abstract ( 396 )   HTML ( 0 )   PDF (573KB) ( 195 )  
    PURPOSE: The purpose of the present investigation was to locate the instantaneous rotation center of the mandible during maxillary surgical impaction, and explore the relationship between automatic rotation center of the mandible and maxillary elevation amount, the length of the mandible and mandibular plane angle. METHODS: Twenty-five patients who underwent maxillary Le Fort I impaction without concomitant major mandibular ramus split osteotomies were included. The preoperative and postoperative lateral cephalograms were used to evaluate the surgical changes and locate the mandibular autorotation center with Reuleaux method. The automatic rotation center of the mandible was compared to the maxillary elevation amount, the length of the mandible and mandibular plane angle with Pearson correlation and linear regression analysis. The data was analyzed by SPSS 13.0 software package. RESULTS: The mandibular automatic rotation center was located in average 15.64 mm below and 0.82 mm behind the center of the condylar head in these 25 patients. The correlation analysis demonstrated a positive correlation between maxillary elevation amount, the length of the mandible and the position of the rotation center of the mandible. Similar positive correlation was presented between the mandibular plane angle and the vertical position of the rotation center of the mandible. CONCLUSIONS: The rotation center in 25 cases were located outside the condylar head. The maxillary elevation amount, the length of the mandible and the mandibular plane angle was positively correlated to the position of the rotation center of the mandible.
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    Influence of root canal working length on the clinical effect evaluated by periapical radiography and cone-beam computed tomography
    ZHAO Li-qin, XU Xin-yi
    2014, 23 (6):  708-712. 
    Abstract ( 294 )   HTML ( 1 )   PDF (658KB) ( 209 )  
    PURPOSE: The verification of the best length of root canal instrumentation and obturation is still controversial in endodontics. The purpose of this study was to determine the influence of root canal working length on the clinical effect evaluated by periapical radiography and cone-beam computed tomography (CBCT). METHODS: A total of 503 root canal obturations were evaluated by using periapical radiography and CBCT. Distances from the radiographic apex to the tip of filling material were measured and classified as 1-2 mm, less than 1 mm, beyond apex, and at the apex. Odds ratio, confidence intervals, and Chi-square test were used for statistical analyses with SPSS 13.0 software package. RESULTS: Periapical radiographs showed that root canal obturations were 1-2 mm short of the apex in 88%, 89.3%, and 95% of the anterior teeth, premolars, and molars, respectively. CBCT images showed obturations had the same length in 70%, 73.7%, and 79% of anterior teeth, premolars, and molars, respectively. The frequency of AP was significantly greater in molars than in the other tooth, regardless of diagnostic tools. AP was detected more frequently when CBCT was used. CONCLUSIONS: AP is detected at all lengths of root canal obturation. The analysis of diagnostic methods show that AP is detected more frequently using CBCT.
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    Comparison of the efficacy of 2 types of mandibular advancement device in severe obstructive sleep apnea hypopnea syndrome
    WANG Lan1, LIU Ye-hai2
    2014, 23 (6):  713-717. 
    Abstract ( 438 )   HTML ( 0 )   PDF (769KB) ( 240 )  
    PURPOSE: To evaluate the efficacy of 2 mandibular advancement devices in 6-week treatment of patient with severe obstructive sleep apnea hypopnea syndrome (OSAHS) who refused to CPAP or CPAP therapy. METHODS: A randomized cross-over study was designed and conducted. Twenty-two male patients with severe OSAHS were included for treatment. Rod type and controllable type mandibular advancement devices (MADs) were used respectively in 6 weeks with 2-week interval, while the whole experimental duration was 14 weeks. The differences of the indexes of the polysomnography (PSG) were analyzed, which were gained before the intervention and 6 weeks after use of 2 types of MADs. Questionnaires with Epworth sleep and SCL-90 symptoms self evaluation scales were proceeded. Meanwhile, the parameters such as the stability of the MADs、the adverse reaction and the subjective symptom relief were assessed. The result was statistically analyzed by SPSS19.0 software package. RESULTS: Compared with the apnea hypopnea index (AHI) before the intervention (48.16±13.99 times/hr), both the AHI of the rod type (19.16±2.74 times/hr) and the controllable type (18.93±2.57 times/hr) were reduced by 50%. The remaining parameters showed that both types of MADs had a significant effect on mandibular advancement. There was significant different decrease in each index of the SCL-90(P<0.01), while significant differences were found in somatization, interpersonal sensitivity and anxiety compared with those before intervention(P<0.05). At the same time, there were significant differences in the indexes of stability and results occlusive comfort between the rod type and the controllable MADs (P<0.05). CONCLUSIONS: The objective results and the patients’ physical and mental health are improved obviously by using the 2 types of MADs. Controllable MADs have more advantages in compliance; however, further research should be conducted for long-time outcome.
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    Preliminary study of palatal lengthening by levator veli palatini retropositioning according to Sommerlad palatoplasty
    XIAO Wen-lin1, YUAN Cong1, SHI Bing2
    2014, 23 (6):  718-721. 
    Abstract ( 278 )   HTML ( 0 )   PDF (569KB) ( 284 )  
    PURPOSE: To research whether palate lengthening can be achieved after palatoplasty with levator veli palatini retropositioning according to Sommerlad palatoplasty. METHODS: Sixty-five cases with incomplete cleft palate were selected randomly, with the age ranged from 10 to 13 months. Sommerlad palatoplasty was performed by the same surgeon with operating loupes. A paper ruler was used to measure the straight-line and the curved distance of palatal length starting from the meeting point between the center of the 2 medial incisor teeth and the lingual gingiva up to the uvular tip while the patient was under general anesthesia before and immediately after palatoplasty. The data was analyzed with SPSS 19.0 software package. RESULTS: Through measurements, the straight-line distance of the palate was about (44.24±0.76) mm, and the curve-line distance of the palate was about (53.11±0.74) mm before Sommerlad palatoplasty. The straight-line distance of the palate was (48.81±0.72) mm, and the curve-line distance of the palate was (59.41±0.8) mm after Sommerlad palatoplasty. The straight-line elongation was about (4.56±0.27) mm, with the mean elongation ratio of 10.31% (P<0.01). The curve-line elongation was about (6.30±0.43) mm, with the mean elongation ratio of 11.86% (P<0.01). CONCLUSIONS: Significant elongation in palate length is obtained after Sommerlad palatoplasty, which may be beneficial to recover the patients’ normal speech and improve velopharyngeal competence.
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    Investigation on knowledge, attitudes and practice of oral heath in 275 Kazak people in Changji district
    GAO Rui1, WANG Xue-jing1, YOU Qing-ling2
    2014, 23 (6):  722-726. 
    Abstract ( 190 )   HTML ( 0 )   PDF (623KB) ( 154 )  
    PURPOSE: To explore the situation of Kazak people’s knowledge, attitude and practice (KAP) about oral health and to offer scientific evidence for carrying out oral health education for Kazak people in Xinjiang Changji district. METHODS: Three hundred Kazak people were randomly included from those who went to the People’s Hospital, Department of Stomatology in Xinjiang Changji district for oral examination to conduct a survey on oral KAP. Two hundred seventy-five valid questionnaires were obtained. The data was inputted individually into Excel 2003 on 2 computers, and SPSS 17.0 software package was used for χ2 test. RESULTS: The percentage of the examined Kazak people in Xinjiang Changji district who obtained oral health knowledge through media was 69.4%. Only 8.7% of the subjects had their oral cavity examined regularly. 44% of the subjects achieved oral heath knowledge positively and 64.4% of the subjects believed in health education. 56% of the subjects brushed teeth twice or more per day and only 4% of the subjects used dental floss. Regarding the attitude towards treating dental diseases, 69.5% of the subjects would like to choose the departments of stomatology in the central hospitals, and 6.9% of the subjects didn’t care about the doctors. The unbalanced development of oral health knowledge, attitude and practice and the difference in education and income were statistically significant in oral health behavior such as the times of brushing teeth, the choice of doctors and hospitals. CONCLUSIONS: The Kazak responders in Xinjiang Changji district have little knowledge about oral health, although their attitude towards oral health is very positive. Because their oral health behavior is not satisfactory, it is very important to provide with them further education of oral health.
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    Effect of “Xinjingjie mouthrinse” on prevention and treatment of radiation-induced oral mucositis
    XU Xuan-li, YE Chen, ZHANG Lin, LI Rong-rong, SHAO Zi-yang, TU Wen-yong
    2014, 23 (6):  727-730. 
    Abstract ( 629 )   HTML ( 0 )   PDF (572KB) ( 324 )  
    PURPOSE: To investigate the effect of "Xinjingjie compound lysostaphin antibacterial collutorium" on prevention and treatment of radiation-induced oral mucositis in a prospective, randomized and double-blind clinical trial. METHODS: Sixty patients with oral cancer to be treated with radiotherapy were randomized into the experimental and control group. The experimental group (30 patients) was treated with "Xinjingjie mouthrinse" during the full course of radiotherapy, 4 times daily with 5 mL and 5 min each time. The control group (30 patients) rinsed the mouth in the same way with normal saline. Oral mucositis was assessed according to the RTOG criteria. The severity of mucositis and the degree of pain were recorded and photographed. Patients shouldn't be treated with other drugs until the level of oral mucositis reached above grade III. The results were statistically analyzed using Stata 12.0 software packages. RESULTS: Age, gender, radiotherapy techniques and dose showed no significant difference between the 2 groups (P>0.05). The first onset of oral mucositis in the experimental group was later than that in the control group (11.0 times:9.1 times,P<0.05), and the incidence of pain at the early time of radiotherapy was lower (36.7%: 70.0%, P<0.05). Also, the onset time of grade III oral mucositis in the emperimental group was later than that in the control group (18.9 times:15.9 times,P<0.05), and the incidence of grade III oral mucositis in the experimental group was lower (63.3% vs. 90.0%, P<0.05). CONCLUSIONS: “Xinjingjie mouthrinse” is worthwhile to be used in clinic because it can delay the occurrence time of radiation-induced oral mucositis, alleviate pain and reduce the indication of grade III oral mucositis.
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    Study on the correlation of epidermal growth factor and Sjögren’s syndrome with atrophic glossitis
    YUAN Chang-qing1, CAO Ying-xiu2, LIU Bin3, DONG jing3, DENG Jing1, GENG Guo-liang1
    2014, 23 (6):  731-735. 
    Abstract ( 292 )   HTML ( 0 )   PDF (679KB) ( 180 )  
    PURPOSE: To investigate the correlation between epidermal growth factor (EFG) and atrophic glossitis (AG) in patients with Sjögren’s syndromes (SS) and explore its pathogenesis. METHODS: Ninety-three patients with SS (60 with AG and 33 without AG) and 20 normal were selected. The concentrations of EGF in saliva were analyzed by ELISA. The expressions of EGF receptor (EGFR) in the epithelial cells of the tongue were assayed by immunohistochemistry. The differences among each group were analyzed with SPSS19.0 software package. RESULTS: The saliva EGF concentrations in SS was lower than that in normal control group(P<0.0001),and EGF concentrations in SS with AG was significantly lower than that in SS without AG (P=0.024). EGF levels in saliva gradually decreased in the mild, moderate and severe atrophic glossitis groups, and there were significant differences among each group(P<0.05). EGFR in the epithelial cells of tongue was lower in SS with moderate and severe AG than in the control group(P=0.009, P=0.037), and there was a significant correlation between EGF and the degree of AG (r=-0.673, P<0.01). CONCLUSIONS: Saliva EGF concentrations decrease significantly in patients with SS and it is closely related to the morbidity of atrophic glossitis.
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    Effectiveness of 3 different methods in prevention of dental caries in permanent teeth among children
    TANG Li-hong1, SHI Le1, YUAN Shuang1, LV Jin1, LU Hai-xia2
    2014, 23 (6):  736-739. 
    Abstract ( 192 )   HTML ( 11 )   PDF (537KB) ( 378 )  
    PURPOSE: To compare the effectiveness of fluoride vanish, fluoride foam, pit and fissure sealant with fluoride in prevention of dental caries, and investigate appropriate approach to prevent dental caries at schools. METHODS: A randomized controlled clinical trial with 4 parallel groups was conducted. Totally 1016 children from 4 schools and 33 classes with a mean age of 7 to 8 years were included. They were randomly allocated into 4 groups: ① fluoride vanish, semi-annual application; ② fluoride foam, semi-annual application; ③ resin sealant, single placement; and ④ placebo control with oral hygiene instruction. Follow-up examinations were conducted after 2 years to monitor dental caries increment of first molars among these children. Data analysis was performed using SPSS 18.0 software package. RESULTS: Two years later, 977 children (96.2%) were examined. The results of multiple factor ANCOVA showed that fluoride vanish and resin sealant had significantly lower mean dental caries increment on tooth surface compared with control group (P<0.05). No significant difference of mean dental caries increment on tooth surface was found between fluoride foam and control group (P>0.05). CONCLUSIONS: The placement of resin sealant with fluoride and annual application of fluoride protector are effective in prevention of dental caries in permanent teeth of children.
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    Evaluation of sagittal temporomandibular condyle position in adolescent Angle Class Ⅱ division 1 patients by cone-beam CT
    FANG Hai-Jun1, TAO Lie2
    2014, 23 (6):  740-743. 
    Abstract ( 255 )   HTML ( 2 )   PDF (688KB) ( 212 )  
    PURPOSE: To evaluate condyle-fossa relationship and provide some evidences for functional orthopedic treatment in adolescent Angle Class Ⅱ division 1 patients. METHODS: Forty adolescent Angle Class II division 1 patients (18 males, 22 females) who have to temporomandibular symptom were involved in this study and 42 adolescent Angle Class I patients (19 males, 23 females) served as control which had impacted teeth needed to take cone-beam CT (CBCT). Mimics 10.01 software was used to measure the depth of the mandibular fossa, the angulation of the posterior wall of the articular tubercle, anterior joint space, superior joint space, posterior joint space in CBCT imaging. Paired t test was applied for comparison between 2 groups using SPSS 15.0 software package. RESULTS: The measured data on left and right side in both Angle Class Ⅱ division 1 patients and Angle Class I patients had no significant differences (P>0.05). The depth of the mandibular fossa, the angulation of the posterior wall of the articular tubercle, the superior joint space have no significant difference (P>0.05). The anterior joint space decreased significantly (P<0.05) and posterior joint space increased significantly (P<0.05) in adolescent Angle Class Ⅱ division 1 patients compared with adolescent Angle Class ⅠI patients. CONCLUSIONS: In adolescent Angle Class Ⅱ division 1 patients, anterior joint space decreased and posterior joint space increased compared with Angle Class Ⅰpatients. And the condyle may move forward for compensation. Orthodontists should pay attention to condyle-fossa relationship in adolescent Angle Class II division 1 patients before functional orthopedic treatment.
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    The value of ultrasound in diagnosis of IgG4-related sialadenitis
    LIN Qian, LI Jun-lai, WANG Jie, ZHANG Shun-xin, LIU Cui, CAO Xiao-lin
    2014, 23 (6):  744-748. 
    Abstract ( 245 )   HTML ( 0 )   PDF (1134KB) ( 241 )  
    PURPOSE: To study the ultrasonic manifestation of IgG4-related sialadenitis, and improve sonographers’ understanding of this disease. METHODS: Based on the clinical serological test and histopathologic diagnosis, the features were evaluated by sonography in 25 cases of IgG4-related sialadenitis, including the shape and border of the gland, internal echo texture, presence and distribution of vascularity, duct dilatation, presence/absence of calculi and submandibular lymph nodes. The changes on ultrasonography in 14 patients with IgG4-related sialadenitis before and after steroid treatment were evaluated. RESULTS: There were 20 men and 5 women ranging between 42-89 years old with an average age of 64.5 years old. The sites of involvement were submandibular gland (20 cases) and parotid gland (5 cases). Of the 10 patients with diffuse involvement, the lesions showed bilateral symmetrical distribution in 9 patients and unilateral involvement in 1 patient with multiple hypoechoic lesions against a heterogeneous background. The ducts were dilated in 3 patients, and had calculus in 2 patients. Doppler sonography in all patients with diffuse involvement of the gland showed prominent intraglandular vessels. Of the 15 patients with focal involvement, 14 patients showed unilateral involvement and only one showed bilateral involvement of the submandibular gland with hypoechoic heterogeneous. The vessels showed a radial pattern within the lesions. There were definite submandibular lymph nodes involvement by IgG4-related disease in 4 of the 8 patients. After steroid treatment, the prominent sonographic feature of IgG4-related sialadenitis gradually receded. CONCLUSIONS: Sonologist must be aware of sonographic appearances in patients with IgG4-related sialadenitis, which can help correct diagnosis and treatment.
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    Dental Education
    An introduction of DentSim in pre-clinical dental training and practice
    ZHENG Jia-wei, CAO Xia, LIN Yu-hua, ZHANG Jian-zhong, FENG Xi-ping
    2014, 23 (6):  749-754. 
    Abstract ( 350 )   HTML ( 10 )   PDF (1562KB) ( 422 )  
    [Summary] DentSim is a revolutionary computerized dental training system developed by joint contributions from companies in Israel and America. It is a high-tech unit developed from the classic dental simulator. Not only can this system standardize and improve the students’ dexterity, but also does the training module make preparations easier to be visualized and provide immediate feedback, real time user-generated evaluation by using advanced imaging and simulation technologies via the built-in 3D scanning system. Since the debut of the first generation product in 1993, and throughout consistent practice and refinement over many years, the fourth generation system is now available and utilized by many schools of stomatology worldwide. DentSim has become an important teaching modality in the preclinical training of dental students.
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    Clinical Reports
    The diagnosis and treatment of arsenic trioxide induced necrosis of jaws: report of 10 consecutive cases
    WU Ye, LIN Li-song, NIU Gang, XIE Fu-ping
    2014, 23 (6):  755-758. 
    Abstract ( 214 )   HTML ( 0 )   PDF (1354KB) ( 216 )  
    PURPOSE: To discuss the diagnosis and treatment of necrosis of jaws caused by leakage of arsenite trioxide, and to emphasize the consequences of its use. METHODS: Ten cases of arsenical necrosis of the jaws from Jan, 2009 to Jun, 2014 treated in our department were collected and analyzed, with emphasis on the key points of diagnosis and treatment. RESULTS: Diagnosis was based on medical history, clinical examinations, X-ray findings, and preoperative or intraoperative cone-beam CT (CBCT) scans. Nine patients were cured with primary operation, one patient was cured by secondary extended surgery. CONCLUSIONS: Because of the high toxicity, there is no justification for the use of arsenite trioxide in clinic.
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    The effect evaluation of suction drainage to prevent fistula after superficial parotidectomy
    JIANG Jin1, JIA Mu-yun1, CAI Zhen2, YUAN Rong-tao1, WANG Ke1, ZHANG Kui3, BU Ling-xue1
    2014, 23 (6):  759-762. 
    Abstract ( 239 )   HTML ( 0 )   PDF (479KB) ( 231 )  
    PURPOSE: To evaluate the clinical value of suction drainage to prevent fistula after parotidectomy, and seek the best opportunity to remove the drainage according to the draining output and duration. METHODS: One hundred and ninety-four patients with parotid diseases after superficial parotidectomy were assigned into pressure dressing group and suction drainage group. Pressure dressing was used after suction drainage tube was removed in the pressure group, while suction drainage tube was fixed through the process in the suction group. Postoperative salivary fistula occurrence between the 2 groups was analyzed with Pearson chi-square test, and the contribution of the output and duration resulting in salivary fistula was analyzed by Fisher’s exact test with SPSS 19.0 software package. RESULTS: The occurrence of salivary fistula in the pressure dressing group and suction group was 11.6% and 15.5%, respectively in the suction group. No significance difference was found between the 2 groups (P>0.05). In the suction drainage group, significant correlation of the draining duration and salivary fistula was not found (P>0.05). However, the draining output less than 20 mL resulted in lower salivary fistula rate compared with the draining output of 20-30 mL. CONCLUSIONS: According to our findings, suction drainage can be used as a substitute for pressure dressing after parotidectomy in preventing salivary fistula, and the best timing of drainage extubation is when the draining output is less than 20 mL within 24 hours.
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    Review Article
    Research advances in peri-implantitis relevant factors and therapy
    SHEN Yi-han1, ZOU Duo-hong2, WU Yi-qun1
    2014, 23 (6):  763-768. 
    Abstract ( 342 )   HTML ( 1 )   PDF (651KB) ( 382 )  
    [Summary] Peri-implantitis has been defined as an inflammatory process affecting tissues around an osseo-integrated implant in function, and resulting in the loss of supportive alveolar bone. As it was one of the main causes which led to the failure of implant treatment, its risk factors and treatment were attracting more and more attention. This review summarized the progress of clinical research on peri-implantitis risk factors and treatments. [Key words] Peri-implantitis; Interleukin; Periodontitis
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