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25 February 2016, Volume 25 Issue 1 Previous Issue    Next Issue

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The effect of glass fiber volume content on the flexural property of fiber-reinforced composite YANG Jie, SONG Xin, LIU Mei, ZHANG Fei-min. 2016, 25 (1):  1-5.  Abstract ( 208 )   HTML ( 4 )   PURPOSE: To investigate the effect of glass fiber volume content on the flexural property of fiber-reinforced composite. METHODS： The specimens of composite were fabricated with 4 different glass fiber volume contents by changing roving winded number of strands dipped in resin matrix, and the mechanical properties were tested by 3-point flexural test in order to determine the optimal fiber volume content. The data was analyzed statistically with SPSS20.0 software package. RESULTS: Self-made fiber-reinforced composites with the glass fiber volume content percentage of 60.4% achieved the maximal flexural strength and the maximal elastic modulus. CONCLUSIONS: As the glass fiber content in matrix of composite material is increased in certain range, the flexural strength and the elastic modulus can be improved，then reaches the peak. However, the flexural property decreases rather than rises when the fiber content is more than 60.4%. References | Related Articles | Metrics

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Comparative study of root canal morphology of mandibular incisors by cone-beam CT and canal staining and clearing technique WEN Shan-hui, LIN Zi-tong, ZHU Min. 2016, 25 (1):  6-10.  Abstract ( 200 )   HTML ( 3 )   PURPOSE: To compare the root canal morphology of mandibular incisors by using cone-beam CT (CBCT) and canal staining and clearing technique. METHODS： Sixty-one extracted mandibular incisors with complete dental root and apex which received no endodontic treatment and no post crown restoration were selected. Each tooth was radiographed with CBCT, and the root canal system was stained by canal staining and clearing technique. The consistency of the number of root canal, root canal Vertucci type of mandibular permanent incisors between the two methods were compared, and the differences of the detection rate on root canal branch structure between the two methods were analyzed. The results were statistically analyzed with SPSS 17.0 software package. RESULTS: The Kappa value of single and double root canal types between CBCT and canal staining and clearing technique was 0.847 (P<0.001) .The Kappa value of Vertucci root canal types between CBCT and canal staining and clearing technique was 0.861 (P<0.001). The detection rates of root canal branch structure were 8.19% and 22.95%, respectively, with significant difference between the two methods (P=0.025). The canal staining and clearing technique was significantly better than CBCT in detection of root canal branch structure. CONCLUSIONS: CBCT can reflect the root canal types nearly perfectly, but inferior to canal staining and clearing technique in detection of root canal branch structure, CBCT is a relatively accurate clinical diagnosis tool of root canal morphology. References | Related Articles | Metrics

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The effect of a combined nanoparticulate/calcium hydroxide medication on the biofilm of Enterococcus faecalis in starvation phase ZHANG Fu-hua, LI Mao, WEI Zhi-jun, ZHAO Bing. 2016, 25 (1):  11-15.  Abstract ( 246 )   HTML ( 5 )   PURPOSE: To evaluate the efficacy of Ca(OH)2 with a silver nanoparticle suspension to eliminate the biofilm of Enterococcus faecalis (E. faecalis) in starvation phase. METHODS： The biofilm models of E.faecalis in the starvation phase were built in vitro with 256 extracted human single-rooted teeth, and the methods of plate culture count and crystal violet biofilm assay were applied to determine the effect of the inhibition of different intracanal medicament (silver nanoparticle with calcium hydroxide, silver nanoparticle alone, calcium hydroxide alone ) to the biofilm of E. faecalis in starvation phase at 1 and 7 days. The negative control group was treated with sterile water only. Statistical analysis was carried out with SPSS 13.0 software package. RESULTS: The inhibitory effect of Ca（OH）2 + nanosilver on the biofilms of E. faecalis was found more significant than that of silver nanoparticle alone and calcium hydroxide alone at 1 and 7 days, and silver nanoparticle alone was more effective than calcium hydroxide alone. No difference in antimicrobial properties was observed between the two time points in the Ca(OH)2 + silver nanoparticle group and silver nanoparticle group, while higher antimicrobial efficacy was observed in the Ca(OH)2 group after 7 days than 1 day. CONCLUSIONS: Silver nanoparticle with calcium hydroxide has an obvious inhibitory effect on the biofilm of E.faecalis in the starvation phase. References | Related Articles | Metrics

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The relationship between the effects of MTA on mRNA expression of four iconic proteins in cells of fetal rat skull and cell culture environment ZHENG Jun-Yuan, HE Li, HU Tu-qiang. 2016, 25 (1):  16-21.  Abstract ( 216 )   HTML ( 0 )   PURPOSE: To discuss the influence of MTA on mRNA expression of Cbfa1, ALP, Col-Ⅰand BGP which are 4 kinds of iconic protein in cells of fetal rats skull, and explore its influence on cell culture environment and association of changes of calcium, phosphorus. METHODS： Cells were obtained by 2 kinds of mixed enzymatic digestion for 3 steps from gestation fetal rat calvarial bone. The expression of Cbfa1mRNA, ALPmRNA, Col-1mRNA, BGP mRNA and extracellular calcium were detected. Phosphorus (P) and calcium concentration of fetal rat skull cells co-cultured with MTA for 3 weeks at different stages of cell differentiation was assessed atomic absorption spectrophotometry. The data was statistically analyzed using SPSS10.0 software package. RESULTS: At the 4th day, P3- content decreased significantly (P<0.05), while ALPmRNA in MTA group increased most greatly and was 40 times of the control group. At the 14th to 18th day, the Ca2+ and P3- content reduced significantly (P < 0.05), and then the BGPmRNA in MTA group rised most greatly which was about 7.71 times of the control group. Then Cbfalpha l mRNA in MTA group increased most strongly later which was about 7.38 times of the control group. Col Ⅰ mRNA increased minimally in all time points. CONCLUSIONS: The change of P3- content may be the initiating factor when MTA promoted differentiation of fetal rats skull cells in vitro, and Ca2+ could greatly accelerate the process of mineralization when accumulated to a certain extent. At the same time, the expression of ALPmRNA, BGPmRNA, Col Ⅰ mRNA and Cbfalpha lmRNA were regulated accordingly, which is the key to explain osteogenetic mechanism of MTA. References | Related Articles | Metrics

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Fibre-type differences in masseter muscle of Beagle dogs with implanted functional appliance therapy SUN Xu-rong, LIN Xin-ping. 2016, 25 (1):  22-26.  Abstract ( 185 )   HTML ( 0 )   PURPOSE: To observe the changes of MyHC-I expression in masseter muscle of Beagle dogs with implanted functional appliance therapy，and to investigate the adaptive remodeling of masticatory muscle. METHODS： Eight, seven-month-old, male Beagle dogs were randomly assigned to experimental group and control group and were killed at 4,8,12 weeks during treatment and 4 weeks after the appliance removed(16 weeks). Serial cross-sections of superficial masseter muscle were cut and stained with MyHC-I antibodies.SPSS11.5 software package was used for statistical analysis. RESULTS: The positive expression rate of MyHC-I was 7.61% in the control group, and 20.43% in the experimental groups at 4 weeks﹙P<0.01﹚. The amount of type I fibres reached to peak at 8 weeks. With increase of treatment time, the amount of type I fibres gradually reduced. At 16 weeks, the amount of type I fibres was similar to the control groups. CONCLUSIONS: The expression of MyHC-I is significantly changed in masseter muscles of Beagle dogs with implanted functional appliance therapy. Implanted functional appliance forward mandibular displacement therapy can obviously promote the adaptive remodeling of masticatory muscle. References | Related Articles | Metrics

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Expressions of EMMPRIN and its ligand CyPA in gingival crevicular fluid of chronic periodontitis patients HE Yan-ping, JIAO Ting. 2016, 25 (1):  27-31.  Abstract ( 225 )   HTML ( 0 )   PURPOSE: To detect the expressions of EMMPRIN and its ligand CyPA in gingival crevicular fluid (GCF) of chronic periodontitis (CP) patients and explore their possible relation to the status of periodontal inflammation. METHODS： GCF of CP patients (group CP) and periodontitis-free patients with intact dentition (the control group) were collected and assayed for EMMPRIN and CyPA expressions by ELISA. The clinical periodontal status of these patients were examined. Statistical analysis was performed by use of SPSS 17.0 software package. Spearman’s correlation analysis was utilized to determine the relationships between the expressions of EMMPRIN and CyPA in GCF and the clinical parameters. In addition, analysis of variance(ANOVA) was used for comparing the difference between group CP and the control group. RESULTS: In group CP, GCF volume was positively correlated with EMMPRIN total amount, CyPA total amount and some clinical periodontal indexes (GI,SBI,AL). EMMPRIN total amount was positively correlated with GCF volume, CyPA total amount and some of clinical periodontal indexes (GI,SBI,AL), but it was negatively correlated with smoking status (P<0.05). Moreover, CyPA total amount was positively correlated with GCF volume, EMMPRIN total amount and some of clinical periodontal indexes (GI,SBI,AL). In the control group,there were significant positive correlations among GCF volume, EMMPRIN total amount and CyPA total amount. The difference of GCF, EMMPRIN and CyPA between the 2 groups were statistically significant (P<0.05). CONCLUSIONS: EMMPRIN and its ligand CyPA in GCF of periodontitis-free patients with intact dentition and CP patients were all detected. As the progress of periodontal inflammation, GCF secretion increases, as well as the expressions of EMMPRIN and CyPA in GCF. References | Related Articles | Metrics

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The effect of calcium hydroxide on IL-6 and TNF-α expression of osteoblast in periapical tissues MENG Ling-jiao, QIU Li-hong, YU Ya-qiong, GUO Jia-jie, ZHAN Fu-liang, ZHANG Ling, ZHANG Xiao-fang. 2016, 25 (1):  32-37.  Abstract ( 269 )   HTML ( 3 )   PURPOSE: To compare the effect of calcium hydroxide in different position on pH and inflammation factor expression of periapical osteoblasts. METHODS： 140 sterilized single-rooted human teeth models were randomly divided into 6 experiment groups and one control group: Group 1-3:calcium hydroxide paste was placed in the apical half of root canal, the upper half of root canal and the pulp champer; Group 4-6:Apexcal was placed in the apical half of root canal, the upper half of root canal and the pulp champer; Group 7: the control group without medication. 10 teeth of each group were placed in P.e suspension, the IL-6 and TNF-α expression of MC3T3-E1 was tested at 3 d and 7 d. The other teeth of each group were placed in distilled water, and the pH in periapical region was tested at 3, 7, 14 and 21 d. SPSS 13.0 software package was used for statistical analysis. RESULTS: Calcium hydroxide placed in different position of the root canal increased periapical pH value and reached its peak at 14 d. The group in which calcium hydroxide paste was placed in pulp chamber gained lower pH level than other experimental groups. IL-6, TNF-α expression of MC3T3-E1 pretreated by P.e suspension of experimental groups was significantly reduced compared with control group, and there was no significant difference between the experimental groups. CONCLUSIONS: Calcium hydroxide placed in different position of the root canal could increase periapical pH value and reduce IL - 6, TNF-α expression of periapical osteoblasts. References | Related Articles | Metrics

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Influence of different acid etching modes on bond strengths to non-carious sclerotic dentin LIU Ke-le, ZHANG Xiao-fang, WEI Xin. 2016, 25 (1):  38-41.  Abstract ( 169 )   HTML ( 3 )   PURPOSE: To evaluate the effect of different acid etching modes on bond strength between composite resin and non-carious sclerotic dentin, and to provide references for clinical application. MOTHODS: Thirty premolars with naturally-occurring non-carious cervical lesions were divided into 2 groups based on self-etch adhesive system AdperTM Easy one (AEO) and total-etch adhesive system AdperTM Single Bond2 (ASB2). Each group was further divided into 3 subgroups (ASB21, ASB22, ASB23, AEO1, AEO2, AEO3) and subjected to the following processing: ASB21 subgroup was etched for 15 s with 35% phosphoric acid and coated with binder for 15 s; ASB22 subgroup was etched for 30 s with 35% phosphoric acid and coated with binder for 15 s; ASB23 subgroup was etched for 15 s with 35% phosphoric acid and coated with binder for 30 s; AEO1 subgroup was only etched with binder for 20 s; AEO2 subgroup was etched with binder for 40 s; AEO3 subgroup was etched for 15 s with 35% phosphoric acid and coated with binder for 20 s. The samples were restored with composite resin; 24 h after saved in distilled water at room temperature, the teeth were cut into dumbbell-shaped specimens with surface areas of approximately 1.0 mm2. The microtensile bond strength (μTBS) was detected and evaluated by one-way ANOVA and SNK-q test using SPSS 17.0 software package. RESULTS: μTBS was given in MPa: AEO3> ASB22> ASB23> ASB21>AEO2>AEO1, AEO3 resulted in statistically highest bond strength and AEO1 had the lowest bond strength(P<0.05), ASB22 acquired bond strength just lower than AEO3 (P<0.05). CONCLUSIONS: Use of total-etch adhesive system increasing the etching time of phosphoric time can enhance bond strength. For self-etch adhesive system, both duplicated the time of adhesive treatment and use of phosphoric acid can improve the bond strength. Use of phosphoric acid to etch for 15 s and coated with self-etch adhesive system for 20 s achieved the highest bond strength. In either self-etch or total-etch adhesive system, use of phosphoric acid to etch for 15 s and coated with self-etch adhesive system for 20 s achieved optimal bond strength, there was the lowest bond strength when the self-etch adhesive system used as recommended time. References | Related Articles | Metrics

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Study on enhancement effect and mechanism of the acid resistance of enamel by Fe2+ and F- ZHANG-Yue,2. 2016, 25 (1):  42-46.  Abstract ( 280 )   HTML ( 3 )   PURPOSE: The phase of new substances and the effect on enamel lattice was analysed after ferrous sulfate ,sodium fluoride treatment through X-ray diffraction, in order to explore the mechanism of Fe2+ and F- reinforced enamel acid resistance. METHODS： Fragments of enamel obtained from fifty molars were ground into powder and randomly divided into four groups: C (control,deionized water); Fe2+ (15 mmol/L FeSO4); F- (1.23% NaF) and Fe2+ + F- (15 mmol/L FeSO4 and 1.23% NaF ). Before exposure to acid, the samples were incubated in one of the experimental solutions for 48 hours. After that, the samples were submitted to six alternating remineralization and demineralization cycles.A complete cycle consisted of the following steps:① demineralization in 5 mL of the beverage (Coca-Cola, pH=2.58) for 5 minutes under gentle agitation;② remineralization in 5 mL of artificial saliva for 1 hour at 37℃. X-ray diffraction was employed to identify precipitates and estimate their lattice constants before enamel power dried at 40℃. RESULTS: The XRD pattern of the group of ferrous sulfate was not sharper than control while the full width half maximum of peak increased and became more gentle. The enamel crystal grain size and crystallinity decreased. Secondary phase retrieval showed there was new phase formed which was iron phosphate. Diffraction spectrum of ferrous sulfate with fluoride group was similar to fluoride alone, the full width half maximum of peak became sharper and more narrow.The enamel crystal grain crystallinity improved and there was new phase of calcium fluoride formed. CONCLUSIONS: Fe2+ and F- both had certain influence on the crystal structure of enamel. However, the impact of Fe2+ was concealed when reacted with high concentration F-. Fe2+ may participate in the nucleation of apatite through substitution of calcium in apatite. Acid-resistant enamel surfaces are established due to precipitation of ferric phosphates on the enamel surface, and combination of Fe2+ with PO43- dissolved on enamel surface.F- may participate in the nucleation of apatite through substitution of OH-; at the same time, the calcium fluoride precipitation was established. References | Related Articles | Metrics

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Clinical effect of a new low-shrinkage composite on restoring dental wedge-shaped defects ZHANG Yao, GE Wen-shu, LIU Chang, CAO Yu 2016, 25 (1):  47-52.  Abstract ( 232 )   HTML ( 2 )   PURPOSE: To evaluate the clinical effect of a new low-shrinkage composite FiltekTM P90 on restoring dental wedge-shaped defects. METHODS: Fifty-two patients with at least two equivalent non-carious cervical lesions on bilateral teeth (180 teeth with wedge-shaped defect) were enrolled in this study. Self-control design was used in this study. The teeth were randomly divided into experimental group which were restored with low-shrinkage composite FiltekTM P90 in one side, and the control group which were filled with FiltekTM Z350 XT composite resin in the other side. The modified USPHS / Ryge criteria were used to evaluate the treatment effects 6 months and 1 year after treatment. SPSS19.0 software package was used for statistical analysis. RESULTS: The 6-months successful rate in FiltekTM P90 group was 96.55% and 95.40% in control group. The 1 year successful rate in FiltekTM P90 group was 94.05% and 90.48% in control group. There were no significant differences in main indexes, including successful rates ,retention, marginal discoloration, marginal adaptation, surface texture, color match, secondary caries and postoperative sensitivity between the 2 groups (P>0.05). CONCLUSIONS: Low-shrinkage composite FiltekTM P90 is a good choice for treating dental wedge-shaped defects. References | Related Articles | Metrics

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Expression of IL-34 in chronic periapical lesions and its clinical significance MA Nan, QU Liu, XU Li-ya, YU Ya-qiong, QIU Li-hong. 2016, 25 (1):  53-57.  Abstract ( 149 )   HTML ( 0 )   PURPOSE: To observe the expression of IL-34 mRNA in chronic periapical lesions and healthy periodontal ligaments and discuss the role of IL-34 in the etiology of chronic apical periodontitis. METHODS： A total of 25 periapical tissues from chronic apical periodontitis and 22 normal periodontal ligament tissue from extracted healthy teeth for orthodontic reason were selected. The expression of IL-34mRNA was detected by real-time PCR; the expression of IL-34 protein was detected by immunohistochemical analysis. Statistical analysis was performed using SPSS 13.0 software package. RESULTS: The level of IL-34 mRNA expression in periapical lesions (3.53±3.07) was significantly higher than that of the normal control (1.07±0.76); IL-34 was positively expressed in lymphocytes, plasma cells and macrophages. Image analysis software indicated that the level of IL-34 protein was significantly higher in periapical lesions than that in normal control (P<0.01). CONCLUSIONS: IL-34 may be closely related to inflammation of chronic apical periodontitis. References | Related Articles | Metrics

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The influence of porcelain-fused-to-metal on the expression level of IL-23 in gingival crevicular fluid FANG Xu, JIN Ying, GAO Ke-bei, WANG Yu, LIN Xiao-ping. 2016, 25 (1):  58-62.  Abstract ( 198 )   HTML ( 0 )   PURPOSE: To investigate the role of IL-23 in the pathogenesis of periodontitis, and the influence of porcelain-fused-to-metal (PFM) on periodontal tissue and the expression level of IL-23. METHODS： The gingival crevicular fluid (GCF) samples were collected in 10 periodontally healthy individuals, 14 cases with gingivitis, 14 cases with gingivitis and PFM, and 14 cases with periodontitis and PFM. The teeth were detected and recorded the clinical parameters（GI, SBI, AL, PD）by Florida probe. The concentration of IL-23 in GCF was detected by ELISA assays.SPSS13.0 software package was used for statistical analysis. RESULTS: The expression of IL-23 in GCF of normal group (227.047±29.880)pg/mL was below inflammatory groups. A significant overexpression of IL-23 in GCF was detected in periodontitis with PFM group(511.327±138.846)pg/mL compared to gingivitis group (330.353±196.266)pg/mL (P<0.01) and gingivitis with PFM group (347.359±218.260)pg/mL (P<0.05). The expression level of IL-23 in GCF was positively correlated with clinical parameters (GI, SBI, AL, PD) (r>0.4, P<0.05). There was a high degree of periodontal destruction in gingivitis with PFM group compared to gingivitis group, and significant difference existed in AL (P<0.05) and PD (P<0.01). The change of IL-23 expression was most positively correlated with PD (r>0.5, P<0.01). CONCLUSIONS: IL-23 might play an important role in the pathogenesis of periodontitis. PFM could have influence on the destruction of periodontal tissues and the expression level of IL-23. References | Related Articles | Metrics

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Quality of life and its influential factors of children and adolescents with congenital cleft lip and palate ZHOU Meng, LIU Zong-xiang, LIU Chao. 2016, 25 (1):  63-67.  Abstract ( 236 )   HTML ( 2 )   PURPOSE: To investigate the quality of life of children undergoing clef lip or and palate repair as well as the influential factors of the quality of life, and provide theoretical foundation for future studies such as psychological interventions. METHODS： Totally 164 children and young adolescent patients with cleft lip and palate undergoing maxillofacial surgery and orthodontic treatment in Xuzhou Stomatology Hospital were selected as experimental group, and 102 normal children and young adolescents were selected as control group. Both groups were investigated by general information questionnaire and child and adolescents’ quality of life scale (CAQOL). The results were analyzed and the influential factors on quality of life were evaluated by multivariate regression analysis with SPSS 19.0 software package. RESULTS: The overall CAQOL scores and most of the subscale scores (teacher-student relationship, peer relationships, parent-child relationship, self-awareness, physical discomfort, negative emotions, attitude about homework, access to transportation from home, extra curricular activities, self-esteem) in the experimental group were significantly lower compared with the control group (P<0.05). Single factor analysis of the quality of life showed that there was no significant difference between gender distribution; on the contrary, residential areas, parents’ level of education, the main caregivers, family income and types of the disease had significant difference (P<0.05). Multiple linear regression equation showed that mother’s education level of patients, cleft lip and palate category, family income, the main caregivers and residential areas were the important influential factors on children’ quality of life. Among them, the type of disease was the most important influential factor (beta=0.260), followed by mother’s education level (beta=0.215). CONCLUSIONS: The quality of life of children with cleft lip/palate is poor. Patients’ scores of CAQOL are closely related with mothers’ education level, type of cleft lip/palate, family income, the main caregivers and residential areas. References | Related Articles | Metrics

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Morphological characteristics of upper alveolar bone around central incisor in Class Ⅱ division 1 and division 2 malocclusion on cone-beam CT XIA Wen-qian, GU Yong-jia, GAO Mei-qin. 2016, 25 (1):  68-71.  Abstract ( 454 )   HTML ( 8 )   PURPOSE: During orthodontic treatment, the incisors in patients with Class Ⅱ division 1 and division 2 malocclusion showed different clinical features, which determine the different ways to move the teeth to the suitable position. This study analyzed the morphology of alveolar bone around upper central incisor with cone-beam CT (CBCT). METHODS： The sample consisted of 20 normal malocclusion and 40 patients with Class Ⅱ malocclusion （division 1 20 cases and division 2 20 cases）. CBCT images before orthodontic treatment were reconstructed by INVIVO 5.0 image processing software. Paired t test was used for statistical analysis with SPSS 19.0 software package. RESULTS: At the upper central incisors, the alveolar thickness between normal malocclusion and Class Ⅱ division 1 and division 2 malocclusion had significant difference except the palate thickness between normal malocclusion and Class Ⅱ division 2 malocclusion (P<0.05). CONCLUSIONS: Orthodontist should consider the relationship between the teeth position and alveolar bone shape comprehensively, choose the correct plan in order to avoid root desorption, alveolar bone loss, fenestration and other adverse reactions. References | Related Articles | Metrics

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Root shape changes of impacted upper central incisor before and after orthodontic traction DONG Hong-wei, LIANG Qin,2. 2016, 25 (1):  72-76.  Abstract ( 416 )   HTML ( 3 )   PURPOSE: Changes of root shape of impacted upper central incisor before and after orthodontic traction were observed with dental cone-beam CT(CBCT), the timing for traction of impacted upper central incisor was investigated. METHODS： Ten impacted maxillary central incisors were diagnosed via panoramic radiograph. CBCT images were taken preoperatively for accurate localization. Following combined treatment of dental surgery and orthodontic traction, ten impacted maxillary central incisors were guided out and aligned well. Final treatment results and the root development status were evaluated via CBCT. RESULTS: Ten impacted maxillary central incisors were tracted to normal position. CBCT images before and after treatment showed that the root of impacted incisors with completed root apex had no change in shape, while the root of impacted incisors with uncompleted root apex developed continually with obviously improved shape and length. CONCLUSIONS: Optimistic results can be achieved if the traction of impacted upper central incisor is carried out before root development completed. References | Related Articles | Metrics

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Cone-beam CT study of bone septa during maxillary sinus lift among Changzhou population CHEN Min-zhen, HE Jia-cai. 2016, 25 (1):  77-81.  Abstract ( 363 )   HTML ( 0 )   PURPOSE: To observe the incidence, location, morphological characteristics of sinus septa among Changzhou population, and to investigate the relationship between maxillary posterior teeth loss and bony septum, and the guiding significance for sinus lift. METHODS： One hundred and twenty-four subjects were selected, the preoperative cone-beam CT (CBCT) data was analyzed by NNT software, which provided a three-dimensional measurement of the maxillary sinus septa. SPSS 13.0 software package was used for statistical analysis. RESULTS: 33.87%（42/124）subjects had sinus septa, 27.42%（68/248）sinus had septa. 66.18% (45/68) of the septa were located in the middle region, 22.06% （15/68）in the posterior region, 11.76%（8/68） in the anterior region. The occurrence of sinus septa had no relation with gender, age and loss of teeth. CONCLUSIONS: The sinus septa can be observed by CBCT for the position, pattern, to predict the difficulty of the surgery, and enhance the success rate. References | Related Articles | Metrics

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Soft tissue angle evaluation of fixed Twin-Block appliance treatment and tooth extraction treatment in skeletal Class Ⅱ malocclusion GONG Yao, LI Pei-lun, WANG Hong-hong, YU Quan, WEI Bin. 2016, 25 (1):  82-86.  Abstract ( 241 )   HTML ( 8 )   PURPOSE: This cephalometric study was designed to evaluate the soft tissue profile effects of Twin-Block combined with straight wire appliances in the treatment of skeletal Class Ⅱ malocclusion with mandibular retrognathia in growing individuals by angulation. METHODS： The sample comprised 31 growing individuals with skeletal Class Ⅱ and mandibular retrognathia, which were divided into 2 groups. One group (18 patients) was treated with fixed Twin-Block combined with fixed appliance， the other group (13 patients) was only treated with fixed appliance after tooth extraction. Pretreatment and posttreatment lateral cephalograms were taken before and after Twin-Block treatment and after all the fixed appliance treatment. Angular cephalometric measurements of soft tissue were analyzed statistically. Intragroup and intergroup changes of the 2 groups were evaluated by Student’s t test using SPSS 15.0 software package. RESULTS: Significant difference of FH-N’Pg’, G-Pn-Pg’, LiSi-SN and SnLs-SiLi were discovered in both groups (P<0.05). With Twin-Block combined with fixed appliance, N’-Sn-Pg’, Sn-N’-Si and Si-N’-S changed significantly, while LsSn-SN and Z angle differed significantly before and after treatment with extraction and fixed appliance. After treatment of Twin-Block combined with fixed appliance, Sn-N’-Si decreased significantly, and the difference between the change of the 2 groups was significant. Meanwhile LsSn-SN was stable in combined treatment group while it decreased greatly after extraction. CONCLUSIONS: Compared with extraction with fixed appliance treatment, Twin-Block combined with fixed appliance treatment is more favorable in promoting lower facial profile in growing skeletal Class Ⅱ individuals with mandibular retrognathia. References | Related Articles | Metrics

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A retrospective clinical analysis of endodontic treatment of maxillary first molars ZHANG De-hui, ZHENG Yao, SUN Hai-tao. 2016, 25 (1):  87-90.  Abstract ( 333 )   HTML ( 2 )   PURPOSE: To evaluate the effect of root canal therapy (RCT) of maxillary first molars and the relevant influential factors. METHODS： A total of 170 maxillary first molars undergoing endodontic treatment were retrospectively studied. 100 molars were treated with vertical compaction technique (VCT) using warm gutta- percha under dental operating microscope(DOM),while 70 molars with traditional lateral compaction technique(LCT) under naked eyes. All patients were asked to revisit 5 years later and 5- year success rate was evaluated. Reversion 3.0.2 software package was used to analyze the data. RESULTS: The immediate high quality rates of RCT of VCT and LCT were 91% and 75.7%, respectively, which has significant difference (P<0.05). After 5 years, VCT kept high quality rate of RCT, while the high quality rate of RCT with LCT dropped from75.7% to 68.6%. The 5-year clinical success rates of RCT with VCT and LCT were 98% and 81.4%, respectively; which had significant difference (P<0.05). CONCLUSIONS: VCT has excellent clinical effect in RCT of maxillary first molars. The use of DOM can increase the detection rate of the second mesiobuccal canal (MB2). References | Related Articles | Metrics

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Effects of different psychological interventions on relieving orthodontic pain in patients with different personalities: a preliminary study ZHENG Qian, ZHANG Li-hua, WANG Guang-ping, YUAN Xiao-ping, XU Xiao-mei. 2016, 25 (1):  91-96.  Abstract ( 183 )   HTML ( 4 )   PURPOSE: To investigate the effects of different psychological interventions on relieving orthodontic pain in patients with different personalities. METHODS： Three hundred patients were involved and randomized into five groups:control group, cognitive therapy group, music therapy group, muscle relaxation group and suggestion therapy group. Eysenck personality questionnaire was used to evaluate personality traits of patients, and visual analogue scale (VAS) was used to assess patients’ intensity of orthodontic pain at 2, 6, 12, 24, 48 and 72 h after initial archwire placement.The VAS scores were analyzed via repeated measures analysis of variance with SPSS 16.0 software package. RESULTS: The cognitive group,music group, muscle relaxation group and suggestion group were reported lower pain than control group (P<0.001). The music group showed a greater decrease in VAS than other four groups in patients with a tendency of extroversion and stable mood (P<0.01).The suggestion group showed less pain than cognitive group in patients with a tendency of extroversion and unstable mood (P<0.05).For patients with other personality traits, there was no significant difference among the four intervention groups. CONCLUSIONS: Cognitive therapy, music therapy, muscle relaxation and suggestion therapy could relieve orthodontic pain effectively. For patients with a tendency of extroversion and stable mood, music therapy was the first choice to control orthodontic pain. Cognitive therapy could be used for patients with other personality traits. References | Related Articles | Metrics

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Analysis of HIV antibody positive cases in Peking University Hospital of Stomatology during 9 years DING Jian-fen, QIU Juan, SHEN Shu-ming. 2016, 25 (1):  97-100.  Abstract ( 623 )   HTML ( 1 )   PURPOSE: To investigate the prevalence and characteristics of HIV patients found in Peking University Hospital of Stomatology during 9 years, and provide management strategy for early diagnosis and control of HIV in Stomatology Hospital. METHODS： A retrospective study of the HIV positive patients diagnosed by HIV antibody screening was carried out. The related information about these patients found in Peking University School of Stomatology during 2005-2013 was obtained from China Disease Control Information System. RESULTS: 68562 patients accepted HIV antibody screening in Peking University Hospital of Stomatology during 2005-2013. Thirty one patients were found HIV antibody positive. The ratio of HIV antibody positive was about 0.045%, which was composed of 25 males and 6 females. 61.29% patients aged between 20-40 years, and their career was mainly commercial service with a education level of junior high school. The proportion of sexual route of transmission was about 74.91%, and 34.78% of them were male homosexuality. Most of the patients with HIV antibody positive were found in the out-patient clinic, especially in the department of oral mucosal diseases, accounting for 70.97%.CONCLUSIONS: HIV antibody positive rate in Peking University School of Stomatology was slightly lower than that in general hospitals. Medical staff should increase their awareness of AIDS prevention and control, for higher HIV risk departments, such as oral mucosal diseases and periodontal disease, efforts should be made to increase HIV screening, expand the scope of screening, and promote provider-initiated HIV testing and counseling. References | Related Articles | Metrics

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Effects of remifentanil and dexmedetomidine on recovery profiles after oral and maxillofacial surgery CHEN Jia-wei, LV Xiang, ZHANG Lin, CHEN Zhi-feng. 2016, 25 (1):  101-104.  Abstract ( 169 )   HTML ( 3 )   PURPOSE: To investigate the effects of remifentanil and dexmedetomidine on recovery period after oral and maxillofacial surgery. METHODS： Sixty cases undergoing oral and maxillofacial surgery were randomly divided into 3 groups, including remifentanil group (group R), dexmedetomidine group (group D) and normal saline group (group C). Ten minutes before the end of surgery, the patients were given target control infusion of remifentanil at effect-site concentration of 1.5 ng/mL in group R or dexmedetomidine 0.5 μg/kg in group D or normal saline in group C, respectively. The haemodynamic parameters, Ramsay scales, coughing, agitation were recorded. Extubation time and incidence of adverse events were observed as well. Statistical analysis was performed using SPSS20.0 software package. RESULTS: The mean arterial pressure and heart rate at the time of extubation were significantly lower in group D and group R than those in group C (P<0.05). The Ramsay scores were significantly better in group D and group R than in group C at the time point of 5 minutes and 10 minutes after extubation , and the score in group D was better than in group R at the same time (P<0.05). The incidences of coughing and agitation were significantly lower in group D and group R than in group C (P<0.05). There was no significant difference in extubation time. CONCLUSIONS: Dexmedetomidine and remifentanil can reduce the haemodynamic responsiveness, coughing and agitation during the recovery period of oral and maxillofacial surgery without extending the extubation time. Dexmedetomidine can provide longer sedation time than TCI of remifentanil. References | Related Articles | Metrics

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Investigation of malocclusion and orthodontic treatment proportion of middle school students in Hailing district, Taizhou city LI Wen-yan, FENG Li, TANG Bing, DUAN Yi-feng. 2016, 25 (1):  105-107.  Abstract ( 218 )   HTML ( 1 )   PURPOSE: To investigate the prevalence of malocclusion and orthodontic treatment proportion of middle school students in Hailing district, Taizhou city. METHODS： Standard investigation form was made based on the individual normal occlusion and Angle’s classification of malocclusion. 9018 middle school students were investigated. SPSS 19.0 software package was used for Chi-square test. RESULTS: The prevalence of malocclusion was 69.38%. ClassⅠ, ClassⅡ and Class Ⅲ malocclusions were observed in 52.48%, 30.62% and 16.90% of the sample, respectively. The correction rate was lower than those reported for other cities. CONCLUSIONS: The findings of the investigation reveal the need to improve public health plans for orthodontic treatment and to increase the rate of correction in Hailing district, Taizhou city. References | Related Articles | Metrics

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Comparative study on bilateral temporomandibular joint of patients with unilateral multiple symptoms in cone-beam computed tomography HAN Yi-shi, LI Yan-feng，LV Yuan，GUO Xiao-qian，LIU Bin，LIU Yan，HAN Wei-li，HU Min，LIU Hong-chen. 2016, 25 (1):  108-111.  Abstract ( 392 )   HTML ( 0 )   PURPOSE: To investigate bilateral temporomandibular joint of patients with unilateral multiple symptoms in cone-beam computed tomography (CBCT) and explore the reference planes that may be different,providing reference for the diagnosis of temporomandibular disorders and comparative study. METHODS： 50 cases with unilateral multiple symptoms（except for cases with unilateral single symptom）were examined by CBCT and the following indexes were observed and analyzed,including horizontal angles of the cross-sectional condyle after the reconstruction in the same patient, joint space, macroaxis diameter of condyle and vertical angles of condyle, which were commonly used at oblique position parallelled to the long axis of condyle, the gradient of articular tubercle and the joint space,which could be obtained at sagittal and oblique position vertical to the long axis of condyle.The data obtained was analyzed by paired t test with SPSS13.0 software package. RESULTS: There was significant difference between the bilateral measured value of joint space when the angle was 60° in sagittal plane (P<0.05).The difference was more significant when the angle was 120° in parallel plane and 90° in sagittal plane(P<0.01). The other measured parameters were not significant different. CONCLUSIONS: For patients with TMD, it is more easily to observe differences between the bilateral measured value of joint space in the sagittal or vertical plane,where the increase of the front joint space can be seen and construction was more significant. References | Related Articles | Metrics

Clinical Reports

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Clinical analysis of 35 flap crisis in anterolateral thigh free flaps REN Zhen-hu,2, WU Han-jiang2, TAN Hong-Yu2, WANG Kai2, GONG Zhao-jian2, ZHANG Sheng2. 2016, 25 (1):  112-116.  Abstract ( 227 )   HTML ( 2 )   PURPOSE： The aim of this study was to analyze the causes of anterolateral thigh (ALT) free flap compromise and improve the success rate of ALT. METHODS： Patients were recruited from September 2005 to December 2012 in the Department of Oral and Maxillofacial Surgery of Central South University. All patients underwent reconstructive surgery using ALT free flaps. Outcome measures included ethnicity, defect type, incidence and timing of flap compromise, type of flap compromise (i.e. arterial or venous), causes of vascular occlusion and salvage rate. The data was analyzed using SPSS 16.0 software package. RESULTS: There were a total of 812 ALT free flaps transplanted during 7 years. Among the 812 transferred flaps, 794 survived and 18 showed necrosis, the overall survival rate was 97.8%. 35 flap compromises due to vascular obstruction were identified and 18 flaps were salvaged completely after exploration. Venous occlusions occurred in 31 flaps (88.6%) and arterial occlusion in 4 flaps (11.4%). The successful salvage rate within 16 h was significantly higher than those over 16 h (70.6%: 27.8%, P=0.011). The successful salvage rate of venous occlusions was higher than that of arterial occlusion, but there was no significant difference. CONCLUSIONS: Early detection, re-exploration, and effective handling of the flap crisis increase the rate of flap salvage tremendously. Prick test is the gold standard for early detection of flap compromise. References | Related Articles | Metrics

Dental Education

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Application of animal models in gingival retraction experimental curriculum CAI He, YANG Shu-ying, ZENG Yong-xiang, QIN Han, HU Shan-shan, WANG Jian2. 2016, 25 (1):  117-120.  Abstract ( 230 )   HTML ( 6 )   PURPOSE: To introduce a teaching method for gingival retraction, and evaluate its efficacy for implementation into experimental curricula. METHODS： First, two kinds of animal models using pigs and cows(below 6 months of age) were established. Twenty-two experienced prosthodontists were then asked to apply gingival retraction on each animal model and evaluate the biofidelity of the 2 models’ dento-gingival environment. The data was analyzed with SPSS19.0 software package for paired t test.Then, eighty pre-internship students were randomly divided into 2 groups. Besides the traditional teaching(lecture-based teaching), the experimental group (group A) also had access to skill training(using animal models to practice gingival retraction), while the control group (group B) only used the traditional teaching modality. All students’ performance in gingival retraction and impression taking were evaluated in their internship. The data was analyzed with SPSS19.0 software package for Chi-square test. RESULTS: Both pig and cow’s dento-gingival environment were similar to that of human being, and there was no significant difference between the two models’biofidelities (P>0.05). In addition, both the effect of gingival retraction and the quality of impression in group A were significantly better than those in group B (P<0.05). CONCLUSIONS: Compared with the traditional strategy,practising gingival retraction on animal models can offer greater opportunities for skill development,and be implemented for a wider range of applications. References | Related Articles | Metrics

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Application of diversified teaching methods to improve the teaching effects in the course of oral histology and pathology TIAN Zhen, LI Lei, WANG Li-zhen, HU Yu-hua, ZHANG Chun-ye, LI Jiang. 2016, 25 (1):  121-124.  Abstract ( 187 )   HTML ( 0 )   Oral histology and pathology is one of the most important courses in stomatological education which works as a bridge between basic medical courses and clinical courses of oral science. The knowledge of oral histopathology may help the students to correctly understand the histogenesis and development of oral diseases and provide the information for correct treatment and prevention. In order to make the students grasp the necessary basic theories, increase the interest in learning, and improve the teaching effect, we explored a diversified teaching system which included diverse teaching modes, online courses and courseware construction. The application of this system offered the interaction between students and teachers and combination of classes with the internet, and made the boring pathological knowledge be associated with clinical practice. These diversified teaching methods had been used in practice and obtained good teaching results. References | Related Articles | Metrics

Case Reports

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Removal of the displaced implant from the maxillary sinus: report of one case ZHOU Qin, ZHU Zhen-kun, SUN Rui-nan, MA Yue. 2016, 25 (1):  125-128.  Abstract ( 359 )   HTML ( 4 )   Accidental displacement of end osseous implants into the maxillary sinus is an uncommon but potential complication in implant surgery due to the special features of the posterior aspect of the maxillary bone. The authors reported one case implant displacement into the maxillary sinus by lateral window technique. The causes for displacement, preventive measures were summarized, in order to avoid this kind of complication. References | Related Articles | Metrics