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25 February 2017, Volume 26 Issue 1 Previous Issue    Next Issue

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Biomechanical effect of 2 anchorages on maxillary protraction with cleft lip and palate: a finite element analysis HAN Han, XU Ya-fen, DUAN Yu-feng, LEI Yong-hua 2017, 26 (1):  1-6.  doi: 10.19439/j.sjos.2017.01.001 Abstract ( 384 )   PDF (721KB) ( 309 )   PURPOSE: To establish cranio-maxillary complex finite element models (FEMs) in cleft lip and palate (CLP) patients with miniplate and tooth-borne anchorage (MA&TA), and to investigate the biomechanical effects on maxillary protraction. METHODS: The protracting process was simulated on FEMs established from a male patient's cone beam CT (CBCT) data to analyze the displacement and stress from different appliances. RESULTS: Four FEMs of unilateral cleft lip and palate (UCLP) or bilateral cleft lip and palate (BCLP) patients' cranio-maxillary complex with MA and TA were established. The maxillary arch on both sides of the cleft moved towards the cleft side during protraction, which was more obvious in the miniplate anchorage three-dimensional finite element models(FEM-MA) than the tooth-borne anchorage three-dimensional finite element models (FEM-TA).The amount of forward, downward displacement of the inferior orbital rim, paranasal area and middle maxilla point in the FEM-MA was larger than that in the FEM-TA, while the amount of forward displacement of premaxilla and upper canine in the FEM-TA was larger than that in the FEM-MA. The FEM-MA exhibited an orthopedic effect with more favorable stress distribution on the middle maxilla point while the FEM-TA showed a dentoalveolar effect with prominent stress distribution on the upper canine point. In addition, the FEM-MA showed a larger stress distribution area and sutural stress value than did the FEM-TA. The UCLP models showed an asymmetric pattern in stress distribution and displacement, which was larger on the cleft side than that on the non-cleft side. The amount of displacement of premaxilla in the BCLP models was smaller than that in the UCLP models. CONCLUSIONS: The established models have high geomagic and biomechanical similarities. It would be more advantageous to obtain more aesthetic outcomes and better stability using the miniplate anchorage. References | Related Articles | Metrics

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Effect of tobacco extracts on human gingival fibroblasts' proliferation and fibronectin expression SHAO Jun-ya, WANG Jian-zhong, XU Meng-rong, ZHOU Lan-fang 2017, 26 (1):  7-11.  doi: 10.19439/j.sjos.2017.01.002 Abstract ( 262 )   PDF (1068KB) ( 262 )   PURPOSE: To investigate the influence and mechanism of smokeless tobacco (ST) extracts on proliferation and fibronectin expression of human gingival fibroblasts (HGFs) adhered to titanium plates. METHODS: The cultured primary HGFs with ST of different concentrations for a period of 2h and 2, 4, 6, 8 d was separately conducted; the cell proliferation and the adhesion was assayed using CCK-8 method; enzyme-linked immunosorbent assay was used to determine the content of supernatant fibronectin (FN) at different times. The data was analyzed with SPSS 19.0 software package. RESULTS: With the increase of ST concentration, the cell adherence rate decreased accordingly. With ST concentration of 5.0 g/L and 10 g/L, the adhesion rate was (34.316±7.725)% and (25.478±10.651)%, respectively, which was significantly lower than that of the control group (100%) (P<0.01). Cell proliferation on the titanium plate started at 2 d and 4 d and the cell abundance of the control group was significantly greater than that of ST group (P<0.05) with concentrations of 2.5, 5.0, 10 g/L; The cell abundance of the control group was significantly greater than that of ST group (P<0.05) with concentrations of 0.625-10 g/L on the 6th and 8th day. In 0.625, 1.25, 2.5 g/L ST group, FN concentration was (69.352±31.640), (23.595±8.625) and (7.292±2.865) ng/mL, respectively, which was significantly lower than that of the control group (142.188 ± 28.126) ng/mL (P<0.05). CONCLUSIONS: ST can significantly inhibit the proliferation and adhesion of HGFs on pure titanium surface, and the mechanism may be related to decrease of FN secreted by HGFs. References | Related Articles | Metrics

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The mechanism of corticotomy accelerating orthodontic tooth movement in SD rats ZHU Shao-yue, YUAN Chang-yong, LIU Zong-xiang, LI Xiao-ming, WANG Peng-lai 2017, 26 (1):  12-16.  doi: 10.19439/j.sjos.2017.01.003 Abstract ( 310 )   PDF (1034KB) ( 331 )   PURPOSE: To study the influences of corticotomy on orthodontic tooth movement (OTM) and the underlying mechanism in rats. METHODS: Forty-eight female Sprague-Dawley rats were randomly assigned to corticotomy group (Cort, 24 rats) or sham-corticotomy group (Sham, 24 rats). All rats were subjected OTM after corticotomy or sham surgery. 6 rats of each group were sacrificed at 0, 1, 3 and 7 day of OTM. OTM were measured with an electronic digital caliper. Osteoclasts were counted in pressure side with TRAP. RANKL were measure by IHC at pressure side. The data were analyzed with SPSS 16.0 software package. RESULTS: OTM at the 1 and 7 day in Cort group increased compared with sham group. Number of TRAP positive osteoclasts in pressure side increased in Cort group at the 3 and 7 day. Expression of RANKL in pressure side also increased in Cort group at the 3 and 7 day. CONCLUSIONS: Corticotomy accelerates OTM in rats and it may result from promoted bone resorption via increased RANKL expression in periodontal tissue. References | Related Articles | Metrics

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Changes of TGF-β1 expression during orthodontic tooth movement in rats with osteoporosis LI Ming-he, WANG Yang, LIAO Nan-nan, LI Jin-yuan, DONG Qing 2017, 26 (1):  17-20.  doi: 10.19439/j.sjos.2017.01.004 Abstract ( 268 )   PDF (1181KB) ( 293 )   ] PURPOSES: To observe the expression and distribution of TGF-β1 in periodontal tissue under intervention of Strontium ranelate and Qianggu capsule during orthodontic tooth movement in rats, and explore the efficacy of the 2 drugs. METHODS: Seventy male SD rats of 3 months old were selected in the study, and randomly divided into control group, model control group, Strontium ranelate group, Qianggu capsule group, each group had 15 animals. Retinoic acid was given by gavage to animals in the control group, Strontium ranelate group, Qianggu capsule group for 2 weeks, and bone density was detected to determine successful establishment of osteoporosis model. All rats were installed orthodontic device, and were sacrificed at 7 days, 14 days and 21 days, respectively. The tissue blocks of the first maxillary molar and adjacent alveolar bone were taken for H-E staining, immunohistochemical staining and semi-quantitative analysis was used to detect TGF-β1 expression in periodontal tissues. The data were statistically analyzed by SPSS 17.0 software package. RESULTS: TGF- beta 1 expression was significantly increased in Strontium ranelate group and Qianggu capsule group compared with control group (P<0.05); TGF- beta 1 expression in Strontium ranelate group was significantly stronger than that of Qianggu capsule group (P<0.05). CONCLUSIONS: Strontium ranelate and Qianggu capsule could enhance the expression of TGF- beta 1 and promote bone metabolism in osteoporosis rats, which is helpful to the movement of healthy teeth; the effect of Strontium ranelate is stronger than Qianggu capsule. References | Related Articles | Metrics

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Inhibiting effect of transforming growth factor β3 on IL-6 expression in MG63 induced by lipopolysaccharide WANG Gui-ling, YU Ya-qiong, GUO Jia-jie, QIU Li-hong 2017, 26 (1):  21-25.  doi: 10.19439/j.sjos.2017.01.005 Abstract ( 285 )   PDF (678KB) ( 177 )   PURPOSE: To explore the effect of transforming growth factor β3 (TGF-β3) on IL-6 expression in inflammatory MG63, and the mechanism by which TGF-β3 exert its anti-inflammatory effect. METHODS: Cell line MG63 was stimulated by 20 μg/mL lipopolysaccharide of Porphyromonas endodontalis (P.e-LPS) to establish the inflammatory model of osteoblast. TGF-β3 or TGFβ1 varying from 5 to 20 ng/mL was added together with P.e-LPS for 24 h, then the mRNA expression of IL-6 was detected by real-time PCR, the role of TGF-β3 on IL-6 protein was further verified by ELISA. MG63 was pretreated with 10 ng/mL TGF-β3 for 30 min in RPMI 1640 medium without fetal bovine serum (FBS), then the cells were cultured for another 20 min with 20 μg/mL P.e-LPS, the phosphorylation level of ERK1/2 was measured by Western blot. Statistical analysis was performed using one-way ANOVA with SPSS13.0 software package. RESULTS: The results of real-time PCR revealed that, when MG63 was treated with 20 μg/mL P.e-LPS alone, the mRNA expression of IL-6 increased significantly(P<0.01). When TGF-β1 was added with P.e-LPS, it could barely decrease IL-6 prominently at the highest concentration (P<0.05).Whereas, the inhibition effect of TGF-β3 on IL-6 was dramatic (P<0.01), ELISA results showed that 10-20 ng/mL TGF-β3 blocked the IL-6 expression at protein level (P<0.05). 20 μg/mL P.e-LPS promoted the phosphorylation level of ERK1/2 in MG63(P<0.01), while with 10 ng/mL TGF-β3, the effect of P.e-LPS on ERK1/2 was blocked(P<0.05). CONCLUSIONS: TGF-β3 is more potent than TGF-β1 in inhibiting MG63, and ERK1/2 is involved in its anti-inflammatory effect. References | Related Articles | Metrics

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Evaluation of the effect of modified wet particle erosion on bond strength between 3Y-TZP zirconia framework and veneering porcelain GUO Jing, ZHU Jia, LIU Hon-guang, ZHU Hong-shui 2017, 26 (1):  26-31.  doi: 10.19439/j.sjos.2017.01.006 Abstract ( 221 )   PDF (962KB) ( 220 )   PURPOSE: To evaluate the effect of bond strength between 3mol% yttrium-stabilized tetragonal zirconium polycrystal (3Y-TZP) zirconia framework after modified wet particle erosion and veneering porcelain. METHODS: A total of 174 [8 mm× 8 mm× 3 mm (±0.02)] specimens were prepared and then randomly divided into different groups according to different particle size, sandblasting pressure, sandblasting time through conventional sandblasting (experimental groups); specimens in the control group were not sandblasted. The bond strength between 3Y-TZP zirconia framework and veneering porcelain was measured using a universal testing machine. Statistical analysis was performed using SPSS17.0 software package. The bond strength of specimens treated by two methods-conventional sandblasting and modified wet particle erosion under the same condition (150 μm, 0.6 MPa, 30 s) were acquired, while the surface was analyzed microscopically before the specimens were veneered with the veneering ceramic under scanning electronic microscope (SEM). RESULTS: The bond strength of conventional sandblasting group under the condition (110 μm, 0.4 MPa,30 s) was maximal, and significantly higher than the control group (P<0.05). The bond strength of modified wet particle erosion group was significantly higher than the conventional sandblasting group and control group (P<0.01); SEM showed that the surface of specimen with modified wet particle erosion was homogeneously rough; the surface specimen with conventional sandblasting was heterogeneously rough, some microcracks were seen in some areas. CONCLUSIONS: Sandblasting can slightly enhance the bond strength between 3Y-TZP zirconia framework and veneering porcelain, modified wet particle erosion is recommended for 3Y-TZP zirconia framework surface treatment. References | Related Articles | Metrics

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Effect of resveratrol on expression of TLR4 and inflammatory factors in gingival epithelial cells under high glucose environment LV Jia-shu, JIANG Xue-wei, ZHANG Yan, ZHEN Lei 2017, 26 (1):  32-36.  doi: 10.19439/j.sjos.2017.01.007 Abstract ( 265 )   PDF (571KB) ( 279 )   PURPOSE: Through a study of the molecular mechanism of the effect of resveratrol(RSV) on expression of TLR4 and inflammatory factors in gingival epithelial cells under high glucose environment, the therapeutic effect and molecular mechanism of resveratrol on periodontitis in patients with diabetes mellitus was investigated. METHODS: Gingival epithelial cells were cultured in vitro; according to the way of action, the cultured cells were divided into control group, high glucose group(HG) and HG+RSV group. The mRNA expression of TLR4 was detected by PCR; The third generation of gingival epithelial cells were pre-treated with or without RSV for 24 h under high glucose conditions, and subsequently treated with LPS at 100 ng/mL for 2 h. ELISA was used to detect the secretion of IL-1 beta, IL-6, IL-8 and TNF- alpha; the activation of TLR4 downstream signaling molecules NF-κB p65, p38 MAPK, and STAT3 was determined by Western blot. SPSS17.0 software package was used for statistical analysis. RESULTS: RSV could reverse the increase of TLR4 level in gingival epithelial cells in high glucose medium.LPS markedly increased the expression and secretion of IL-1β, IL-6, IL-8, and TNF-α in GECs cultured in high glucose medium, which was partly blocked in the presence of RSV. Furthermore, Western blot results showed that RSV significantly suppressed the phosphorylation of TLR4 downstream factors NF-κB p65, p38MAPK, and STAT3. CONCLUSIONS: RSV reduces inflammatory cytokine secretion in gingival epithelial cells, through negative regulation of TLR4 signaling pathway. References | Related Articles | Metrics

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Effect of lipopolysaccharides from Porphyromonas endodontalis on the expression of interleukin-34 in mouse osteoblasts YU Ya-qiong, GUO Jia-jie, QIU Li-hong, LI Xiao-lin, YANG Di, GUO Yan 2017, 26 (1):  37-41.  doi: 10.19439/j.sjos.2017.01.008 Abstract ( 210 )   PDF (586KB) ( 182 )   PURPOSE: To investigate the effects of lipopolysaccharides (LPS) extracted from Porphyromonas endodontalis (P.e) on the expression of interleukin-34 (IL-34) mRNA in MC3T3-E1 cells and the role of p38MAPK, ERK1/2, NF-κB and SIRT1 in the process. METHODS: MC3T3-E1 cells were treated with different concentrations of P.e-LPS(0-50 mg/L) and 20 mg/L P.e-LPS for different time (0-24 h). The expression of IL-34 mRNA was detected by real-time reverse transcription-polymerase chain reaction (real time RT-PCR). MC3T3-E1 cells were pretreated with inhibitor of NF-κB(BAY 11-7082),inhibitor of p38MAPK (SB203580), inhibitor of ERK1/2 (PD98059), agonist of sirtuin1 (SIRT1) [resveratrol (RES)] and inhibitor of SIRT1 (EX-527) for 1 h, and then were treated with 20 mg/L P.e-LPS. The expression of IL-34 mRNA was detected by real time RT-PCR. Statistical analysis was performed using one-way ANOVA and Dunnett t test with SPSS 13.0 software package. RESULTS: The level of IL-34 mRNA increased significantly after treatment with different concentrations of P.e-LPS(0-50 mg/L),which indicated that P.e-LPS induced osteoblasts to express IL-34 mRNA in a dose-dependent manner. Maximal induction of IL-34 mRNA expression was observed in MC3T3-E1 cells treated with 20 mg/L P.e-LPS for 24 h.At 48 h, the expression of IL-34 mRNA decreased gradually. The mRNA of IL-34 decreased significantly after pretreatment with 10 μmol/L BAY-117082, SB203580 and PD98059 for 1 h. P.e-LPS-induced IL-34 upregulation was attenuated by pretreatment with RES, but increased by EX-527. CONCLUSIONS: These results suggest that P.e-LPS may mediate IL-34 mRNA expression in MC3T3-E1 cells. This process is dependent, at least in part, on p38MAPK, ERK1/2, NF-κB and SIRT1 signaling pathways. References | Related Articles | Metrics

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Ginsenoside Rg1 regulates the proliferation and migration of human periodontal ligament cells via Akt/eNOS signaling under nicotine stress LIU Cai-hong, DU Li 2017, 26 (1):  42-47.  doi: 10.19439/j.sjos.2017.01.009 Abstract ( 217 )   PDF (873KB) ( 429 )   PURPOSE: To explore the effects and molecular mechanisms of ginsenoside Rg1 on the proliferation and migration of human periodontal ligament cells (HPDLCs) under nicotine stress. METHODS: HPDLCs were isolated and cultured by method of explant cell culture. The cells were cultured under nicotine stress for 7 days, and treated respectively with ginsenoside Rg1 (0.01 μmol/L), ginsenoside Rg1 and LY294002 (PI3K inhibitor, 0.5 μmol/L), ginsenoside Rg1 and Tricirbine (Akt inhibitor, 5 μmol/L), ginsenoside Rg1 and L-NAME (Akt inhibitor, 1 mmol/L) from 3rd day after nicotine stress to 7th day. MTT assay and Transwell assay were used to evaluate the proliferation and migration of HPDLCs in each group. Western blot and quantitative real-time PCR methods were used for testing the changes of PI3K/Akt/eNOS signaling expression. SPSS 20.0 software package was used for statistical analysis. RESULTS: The proliferation and migration were significantly inhibited by nicotine treatment. PI3K levels were upregulated, but Akt1/2 and eNOS levels were remarkedly reduced by nicotine. Ginsenoside Rg1 attenuated the effects of nicotine on proliferation, migration and Akt/eNOS signaling. Tricirbine and L-NAME could reduce the inhibitory effects of ginsenoside Rg1 toward nicotine. CONCLUSIONS: Ginsenoside Rg1 regulates the proliferation and migration of HPDLCs under nicotine stress via Akt/eNOS signaling. References | Related Articles | Metrics

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Effect of NaF on proliferation and mineralization of human periodontal ligament cells LI kun-qin, XU Le, HUANG Sheng-yun, ZHANG dong-sheng 2017, 26 (1):  48-53.  doi: 10.19439/j.sjos.2017.01.010 Abstract ( 352 )   PDF (1318KB) ( 305 )   PURPOSE: To investigate the effect of NaF on proliferation and mineralization of human periodontal ligament cells (hPDLCs). METHODS: hPDLCs were isolated and characterized. The proliferation of hPDLCs treated with different concentration of NaF was tested by CCK-8. Four moderate concentrations were chosen for subsequent experiments. The mineralization was investigated using ALP activity assay, Alizarin red S staining and quantitative real-time polymerase chain reaction(RT-PCR). The data were statistically analyzed with SPSS20.0 software package. RESULTS: Immunohistochemistry showed that the isolated cells were hPDLCs. 5×10-5, 1×10-4 and 5×10-4 mol/L NaF had pro-proliferation effects while 5×10-4 mol/L resulted in the best effect (P<0.05). ALP activity and calcium content was significantly enhanced by 1×10-5 mol/L NaF with osteogenic inductive medium (P<0.05). Quantitative RT-PCR data varied in genes as a result of different NaF concentrations and treatment periods. CONCLUSIONS: 5×10-5, 1×10-4, 5×10-4 mol/L NaF can stimulate proliferation in hPDLCs, 1×10-5 mol/L NaF can enhance ALP activity and calcium content formation of hPDLCs. References | Related Articles | Metrics

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Efficacy of subgingival scaling of the molars with conventional scalers in vitro CHEN Mei-hua, YIN Yuan-zheng 2017, 26 (1):  54-58.  doi: 10.19439/j.sjos.2017.01.011 Abstract ( 452 )   PDF (599KB) ( 225 )   PURPOSE: To evaluate the efficacy of traditional manual scaling and piezoelectric and magnetostrictive ultrasonic scaling in regard to periodontal pocket depth and power setting. METHODS: Thirty extracted human molars were assigned to receive manual scaling or ultrasonic scaling (both on the full or half power setting) with probing depth of 5 and 7 mm for 2 min. The remained oil materials on the roots were calculated as supplementary data. The data were compared using SAS6.12 software package. RESULTS: The procedures of ultrasonic scaling resulted in reductions of the values than manual scaling in all groups. The data of the magnetostrictive group were significantly smaller than the piezoelectric group in 5 mm pocket depth (P<0.01) on full power setting, while the opposite in 7 mm pocket depth. There was no significant difference between piezoelectric and magnetostrictive scaling in both 5 mm (P=0.217) and 7 mm (P=0.574) pocket depth on half power setting. The data increased significantly from 5 to 7 mm pocket depth (P<0.01), but no significant influence on different power settings. CONCLUSIONS: The study indicates that ultrasonic scaling instruments are more effective than a hand curette and the scaling efficacy decreased in deeper periodontal pocket.The results reveal no significant difference between magnetostrictive and piezoelectric ultrasonic instruments whether on half or full power settings. References | Related Articles | Metrics

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Fitting of the reconstructed craniofacial hard and soft tissues based on 2-D digital radiographs FENG Yao-pu, QIAO Min, ZHOU Hong, ZHANG Yan-ning, SI Xin-qin 2017, 26 (1):  59-63.  doi: 10.19439/j.sjos.2017.01.012 Abstract ( 189 )   PDF (1690KB) ( 238 )   PURPOSE: In this study, we reconstructed the craniofacial hard and soft tissues based on the data from digital cephalometric radiographs and laser scanning. The effective fitting of the craniofacial hard and soft tissues was performed in order to increase the level of orthognathic diagnosis and treatment, and promote the communication between doctors and patients. METHODS: A small lead point was put on the face of a volunteer and frontal and lateral digital cephalometric radiographs were taken. 3-D reconstruction system of the craniofacial hard tissue based on 2-D digital radiograph was used to get the craniofacial hard tissue model by means of hard tissue deformation modeling. 3-D model of facial soft tissue was obtained by using laser scanning data. By matching the lead point coordinate, the hard tissue and soft tissue were fitted. RESULTS: The 3-D model of the craniofacial hard and soft tissues was rebuilt reflecting the real craniofacial tissue structure, and effective fitting of the craniofacial hard and soft tissues was realized. CONCLUSIONS: The effective reconstruction and fitting of the 3-D craniofacial structures have been realized, which lays a foundation for further orthognathic simulation and facial appearance prediction. The fitting result is reliable, and could be used in clinical practice. References | Related Articles | Metrics

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Expression and significance of human Dachshund homolog 1 in tongue squamous cell carcinoma and tongue atypical hyperplasia ZHANG Li, LIU Fen, XIANG Feng-gang, WANG Cheng-qin 2017, 26 (1):  64-68.  doi: 10.19439/j.sjos.2017.01.013 Abstract ( 374 )   PDF (1242KB) ( 274 )   PURPOSE: To investigate the expression and role of human Dachshund homolog1(DACH1)in the development and prognosis of tongue squamous cell carcinoma(TSCC). METHODS: The expression of DACH1 was detected immunohistochemistrically in 51 samples of paraffin-embedded TSCC, paired adjacent tissues and 25 samples of atypical hyperplasia tissues of the tongue. Statistical analysis was performed using SPSS 16.0 software package. RESULTS: The results showed that 36 out of 51 TSCCs (70.6%) expressed lower levels of DACH1 compared with the paired adjacent tissues. Moreover, there was significant differences in expression of DACH1 between TSCC and paired adjacent tissues (P<0.05), and lower expression was associated with poor differentiation of tumors, advanced clinical stage and lymph node metastasis(P<0.05).In addition, the expression level of DACH1 in atypical hyperplasia tissues of tongue was also significantly lower than in tumors(P<0.05). Univariate survival analysis showed that the overall survival rate of patients with high expression of DACH1 was significantly higher than those with low expression of DACH1 (P<0.05). CONCLUSIONS: The decreased expression of DACH1 may be related to occurrence, development and poor prognosis of TSCC. It may contribute to making diagnosis for precancerous lesions in the tongue, and provide a potential effective therapeutic target for TSCC. References | Related Articles | Metrics

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Study of the relationship between congenital missing of the third molar and the development of the mandibular angle CHEN Yan-na, ZHENG Bo-wen, LIU Yi 2017, 26 (1):  69-72.  doi: 10.19439/j.sjos.2017.01.014 Abstract ( 309 )   PDF (526KB) ( 218 )   PURPOSE: Based on the research of the congenital missing of the third molar and the missing number, the relationship beteen congenital missing of the third molar and the development of the mandibular angle was evaluated. METHODS: Patients were divided into experimental group and control group, the experimental group included 227 patients, each had at least one of the third molars congenital lost; 227 patients who had four third molar were selected as control group. Winceph software was used to measure the lateral cephalograms. SPSS17.0 software package was used to perform statistical analysis. RESULTS: Gonial angle, upper Gonial angle and lower Gonial angle between the experimental group and the control group showed significant difference and the values in the experimental group were significantly smaller than in the control group, but there was no gender difference between the two groups.There was no difference between Gonial angle, upper Gonial angle,lower Gonial angle and the missing number of the third molar. CONCLUSIONS: There is a close relationship between congenital missing third molar and Gonial angle, upper Gonial angle, lower Gonial angle, but there is no significant association with gender and the patients with congenital missing third molar have shorter craniofacial structure. Congenital missing number of the third molar has no significant association with Gonial angle, upper Gonial angle and lower Gonial angle. References | Related Articles | Metrics

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Cervical skeletal abnormalities in patients with palatally displaced canine CHEN Lan-yue, NIU Lei, CHEN Yan-na, ZHENG Bo-wen, LIU Yi 2017, 26 (1):  73-75.  doi: 10.19439/j.sjos.2017.01.015 Abstract ( 244 )   PDF (413KB) ( 188 )   PURPOSE: To investigate the association between palatally displaced canines and cervical skeletal abnormalities by lateral cephalometric, panoramic radiographs and cone-beam CT. METHODS: One hundred and three patients with palatally displaced canines were chosen as the experimental group, and 103 patients with Class I and normal canines eruption were as the control group.The data of the first four cervical fusions and posterior arch defects were measured on the lateral cephalometrics. The relationship of the cervical skeletal abnormalities and palatally displaced canines was analyzed with SPSS 21.0 software package for Chi-square test. RESULTS: The incidence of cervical fusion in the experimental group was 71.84%(74 cases), while 15.53% (16 cases) in the control group; the difference between the experimental group and the control group was significant (P<0.001); the incidence of posterior arch defects in the experimental group was 10.68% (11 cases) and 4.85%（5 cases） in the control group; the difference between the experimental group and the control group was not significant. CONCLUSIONS: There is an obviously increasing occurrence rate of cervical skeletal abnormalities in patients with palatally displaced canines, and cervical vertebra bone abnormalities can be combined with other diagnostic parameters to confirm the situation of impacted canines. References | Related Articles | Metrics

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Cone-beam CT evaluation of volume and surface area changes of impacted upper central incisors before and after orthodontic treatment LIN Yan, JIANG Yin-hua, TAO Hai-biao, SUN Hao, HU Rong-dang 2017, 26 (1):  76-79.  doi: 10.19439/j.sjos.2017.01.016 Abstract ( 285 )   PDF (681KB) ( 867 )   PURPOSE: The purpose of this study was to quantitatively evaluate root resorption by cone-beam computer tomography (CBCT) after orthodontic treatment of impacted upper central incisors. METHODS: Ten patients (12 impacted incisors and 8 contralateral corresponding teeth) were included in this study. With self-designed modified nance arch and straight wire arch, the impacted incisors were treated by combined orthodontics and surgery approach. CBCT images of all patients were taken before and immediately after the treatment. Mimics software was used to build three-dimensional images. The upper central incisors were isolated. Volumes of teeth and superficial area were calculated. The difference between pre- and post- treatment was statistically evaluated with paired samples t test using SPSS13.0 software package. RESULTS: Significant difference in volume and superficial area was found between pre- and post- treatment (P<0.05). The average whole dental volume increase was (9.67±10.86) mm3, and the superficial area increase was (28.97±14.36)mm2. Statistical significance was achieved among 12 impacted incisors. The average whole dental volume increase of the control group was（12.38±10.22）mm3, and the superficial area increase was（30.64±16.74）mm2. There was no significant difference between the impacted and the control group in dental volume and superficial area before and after treatment (P>0.05). CONCLUSIONS: The treatment by combined orthodontics and surgery approach could promote tooth development for impacted incisors without causing root absorption, which can be safely performed. References | Related Articles | Metrics

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Application of key contact point management in health education at ICU for oral and maxillofacial cancer patients YANG Yue-lai, HUANG Yao, XU Zhi-xia, MAO Yue-li, WANG Hui-fen 2017, 26 (1):  80-83.  doi: 10.19439/j.sjos.2017.01.017 Abstract ( 173 )   PDF (704KB) ( 185 )   PURPOSE: To explore the effect of key contact point management in health education at ICU for oral and maxillofacial cancer patients. METHODS: Key contact point checklist was constructed by literature review, brain storm, patients review and expert consultation. The patients in the control group accepted routine health education, while patients in the experimental group accepted health education based on key contact point theory. The data were analyzed by nonparametric rank sum test using SPSS 17.0 software package. RESULTS: The key contact point checklist for oral and maxillofacial cancer patients consisted of 11 items. After intervention, the understanding rate and the satisfaction rate of patients in the experimental group were improved significantly than those in the control group. CONCLUSIONS: Health education model based on key contact point theory can effectively improve the quality of health education and patients' satisfaction. References | Related Articles | Metrics

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Measurement of temporomandibular joint space of patients with obstructive sleep apnea hypopnea syndrome ZHAO Rui, WEN Wei-sheng, YANG Ge, TAO Ye, ZHANG An-dong, JIA Rui 2017, 26 (1):  84-88.  doi: 10.19439/j.sjos.2017.01.018 Abstract ( 263 )   PDF (783KB) ( 279 )   PURPOSE: This research evaluated the morphological differences of temporomandibular joint (TMJ) between patients with obstructive sleep apnea hypopnea Syndrome (OSAHS) and normal population using magnetic resonance imaging (MRI). METHODS: Eighteen OSAHS patients were admitted from January 2014 to May 2016 and 18 healthy adults were chosen as control. OSAHS patients were divided into three sub-groups (n=6), i.e. the mild group, the moderate group and the severe group, according to apnea and hypopnea index (AHI). All subjects underwent TMJ MRI for measurement of joint space. Statistical analysis was performed using SPSS 17.0 software package. RESULTS: There was no significant difference between the two groups in age, gender, superior joint space and displacement of condyle. The left anterior joint space [(2.63±0.18)mm vs (2.48±0.17)mm, P<0.05] and right anterior joint space [(2.63±0.18) mm vs (2.48±0.17) mm, P<0.05] of the TMJ of OSAHS patients was bigger than that of healthy people. The left posterior joint space [(2.43±0.20) mm vs (2.51±0.19) mm, P<0.05] and right posterior joint space [(2.44±0.20) mm vs (2.60±0.13) mm, P<0.05] of the TMJ of OSAHS patients was smaller than that of healthy people. The left anterior joint space [(2.53±0.26) mm vs (2.73±0.07) mm, P<0.05] and right anterior joint space [(2.54±0.11) mm vs (2.74±0.14) mm, P<0.05] of the TMJ of OSAHS patients in the mild sub-group was smaller than that of the OSAHS patients in the severe sub-group; the left posterior joint space [(2.56±0.29) mm vs ( 2.29±0.09) mm, P<0.05] and right posterior joint space of OSAHS patients in the mild sub-group was bigger than that of the OSAHS patients in the severe sub-group. CONCLUSIONS: The condyle of OSAHS patients is at the posterior position of glenoid compared with heath people. The tendency of posterior position of condyle at glenoid is related to the severity of OSAHS. References | Related Articles | Metrics

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Comparison of clinical effects of Co-Cr alloy cast post-core and everStick fiber post in restoration of labially or lingually inclined maxillary central incisor QIAN Yu-mei, ZHONG Qun, CHEN Shuang 2017, 26 (1):  89-93.  doi: 10.19439/j.sjos.2017.01.019 Abstract ( 549 )   PDF (615KB) ( 362 )   PURPOSE: To compare the clinical effect of Co-Cr alloy cast post-core and everStick fiber post in restoration of maxillary central incisor with labial or lingual inclination, and provide theoretical basis for clinical application. METHODS: Ninety-seven labially or lingually inclined maxillary central incisors were treated in our hospital from March 2012 to March 2014. The patients were randomly divided into group A (n=49) and group B (n=48), and received post -core and crown restoration. Patients in group A underwent Co-Cr alloy cast post and core restoration and patients in group B underwent everStick fiber post and core restoration. After two-year of follow-up, root fracture, post break, crown or post dislodgment and gingival marginal discoloration were recorded and analyzed using SPSS 19.0 software package. RESULTS: Chi-square test showed that the success rate of restoration was significantly different between 2 groups (P<0.05). The incidence of root fracture and gingival marginal discoloration of Co-Cr alloy cast post-core was higher than that of everStick fiber post, but there was no significant difference in the incidence of post break, crown or post dislodgment. CONCLTSIONS: EverStick fiber post is better than Co-Cr alloy cast post and core to prevent root fracture and gingival marginal discoloration. Its fracture pattern is repairable and favorable for preserving tooth. References | Related Articles | Metrics

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Diversified health education mode applied in oral health care of preschool children TAO Li-min, ZAO Yu-mei, GU Lian-bin, SHEN Juan, LIU Cheng-jun 2017, 26 (1):  94-97.  doi: 10.19439/j.sjos.2017.01.020 Abstract ( 273 )   PDF (492KB) ( 339 )   PURPOSE: In regard to the current problems and deficiencies of preschool children's oral health, diversity of health education intervention was carried out, and the effect was evaluated. METHODS: Three kindergartens in Pudong New District were randomly selected. The children's age ranged from 4 to 5 years old. One hundred and ten children from one kindergarten were randomly selected as the intervention group, executing special health training and various related health education activities for a period of 1 year. Another 220 children from 2 kindergartens were chosen as control group, no special health education and behavior intervention were given. After the interventional period, the situation of children with suffering from dental caries in the intervention group and the control group, scores of oral health knowledge, and the improvement of behavior were compared. SPSS19.0 software package was used for statistical analysis. RESULTS: After 1 year of health education intervention, scores of oral knowledge and oral health behaviors in the interventional group increased significantly. However, caries prevalence and the average number of caries had no significant differences between the 2 groups. CONCLUSIONS: The diversity of oral health education plays a positive role in the kindergarten for pre-school children's oral health knowledge, attitude and behavior change. References | Related Articles | Metrics

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The impact of personality traits on adolescents' adaptation and compliance to clear retainers XU Fan, TANG Guo-hua 2017, 26 (1):  98-101.  doi: 10.19439/j.sjos.2017.01.021 Abstract ( 269 )   PDF (456KB) ( 250 )   PURPOSE: The aim of this study was to evaluate the adolescents' adaptation and compliance to clear retainers, and to investigate their associations with personality traits. METHODS: Fifty adolescents at the end of fixed orthodontic treatment were consecutively recruited. After debonding the fixed orthodontic appliances, clear retainers were used. Participants were asked to fill questionnaires 2 months after wearing the clear retainers. A questionnaire was designed to evaluate their adaptation and compliance for clear retianers. Eysenck personality questionnaire was used to assess the personality traits. Spearman rank correlation was used to analyze the associations between personality traits with the adaptation and compliance to clear retainers using SAS8.0 software package. RESULTS: Forty-two of 50 adolescents accomplished the questionnaires. 76% felt no mucous irritation, 95% felt no influence on socializing. However, 75% showed oral constraint, 71% felt impaired speech. Moreover, 40% adolescents wore the retainers less than 18 hours per day. 31% patients had their aligner lost. 83% patients did not brush their teeth after each meal. Neuroticism was positively associated with the effect of impaired chewing (r=0.32). Psychoticism was positively associated with the oral constraint (r=0.31) and facial muscular soreness (r=0.35), but negatively associated with the influence on emotion (r=-0.34). Extraversion was positively associated with the retainers' damage (r=0.31). CONCLUSIONS: Adolescents showed good adaptation for clear retainers, but unsatisfactory compliance. There are associations between adolescents' adaptation and compliance for clear retainers and personality traits. These results suggest that clinicians should pay more attention to the compliance of adolescents when using clear retainer. Personality traits could be a useful prediction to assess the compliance for clear aligners. References | Related Articles | Metrics

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Influential factors analysis of positive psychology in patients with oral and maxillofacial trauma LI Li, YUAN Wei-jun, CHEN Qiao-lu, YAO Yao, HUANG Ying-bi 2017, 26 (1):  102-105.  doi: 10.19439/j.sjos.2017.01.022 Abstract ( 231 )   PDF (438KB) ( 212 )   PURPOSE: To investigate the positive psychological reaction of patients with oral and maxillofacial trauma and related factors. METHODS: One hundred and five hospitalized patients with oral and maxillofacial trauma were investigated by self-designed general data questionnaire, positive psychological scale posttraumatic growth evaluation of quantitative PTG, and self-image questionnaire. SPSS 18.0 software package was used to analyze the data. RESULTS: Positive psychological score of the patients was 56.01±17.322, and self-image average score was 51.33±7.306. There were significant differences between male and female patients after trauma in new possibilities, personal power, self transformation and personal feeling (P<0.05); there was no significant difference between different ages in positive psychological reaction.With the improvement of educational level of patients, better personal power (P=0.031) and self transformation (P=0.01), and more positive psychological reaction were observed; Posttraumatic positive psychology of patients was negatively correlated with self-image score (r=-0.318, P<0.001). CONCLUSIONS: The male patients with oral and maxillofacial trauma have more positive attitude than female. With the improvement of educational level, more positive psychological reaction was documented in term of personal strength, self-transformation,but no obvious change in relationship with others, new possibilities and personal feeling. The better self image, the more positive psychological reaction was displayed. References | Related Articles | Metrics

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A retrospective analysis of 621 cases with craniomaxillofacial fractures LU Yang, LU Xiao-feng, FAN Xian-qun 2017, 26 (1):  106-110.  doi: 10.19439/j.sjos.2017.01.023 Abstract ( 330 )   PDF (597KB) ( 260 )   PURPOSE: To investigate the epidemiological characteristics of 621 hospitalized patients with craniomaxillofacial fractures by a retrospective study. METHODS: From July 2015 to August 2016, the medical records of 621 patients with craniomaxillofacial fractures in Shanghai Ninth People's Hospital were analyzed statistically according to age, gender, etiology and site of fracture. Chi-square test was used to analyze the causes of single and multiple fractures with SPSS 20.0 software package. RESULTS: The male to female ratio was 2.18: 1. The average age was 34.7±15.5 years with 19-29 years old group accounted for the most (28.3%). Traffic accident was the top cause of injury (49.0% ); There were 319 cases of orbital fractures (51.4%), followed by 292 cases of zygomatic complex (47.0%) and 247 cases of mandibular fractures (39.8%). CONCLUSION: The quantity and location of fractures are related to the cause of injury, the nature of stress and anatomical structure of corresponding areas. Establishing a sound system of traffic accident management and related laws is an urgent problem to be solved. References | Related Articles | Metrics

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Assessment of life quality of for patients after tongue reconstruction with radial forearm free flap, anterolateral thigh perforator flap or submental island flap ZHAO Yang, XIANG Jing-zhou, LIU Fa-yu 2017, 26 (1):  111-114.  doi: 10.19439/j.sjos.2017.01.024 Abstract ( 436 )   PDF (434KB) ( 311 )   PURPOSE: The aim of this study was to evaluate operation-related factors and quality of life (QOL) for patients after tongue reconstruction with radial forearm free flap (RFFF), anterolateral thigh perforator flap (ALT) or submental island flap (SIF). METHODS: Totally 59 patients, diagnosed as tongue carcinoma, received glossectomy and simultaneous reconstruction with free flaps including RFFF, ALT or SIF in the Department of Oral and Maxillofacial Surgery, Hospital of Stomatology, China Medical University from October 2004 to October 2014. All patients were followed up for 6 months and completed the University of Washington Quality of Life scale Version 4 questionnaires. The postoperative QOL was compared among the three groups. The data were analyzed using SPSS 21.0 software package. RESULTS: The operation duration of SIF group was significantly shorter than those of RFFF group or ALT group (P<0.05). The ALT group had a longer hospitalization time. There were statistically differences among the 3 groups regarding to the size of reconstructed defects. Action QOL score of the ALT group was significantly lower than those of RFFF group and SIF group. There was no significant difference in the total QOL score including chewing, swallowing, speech and postoperative pain among the 3 groups. CONCLUSION: In summary, there may be functional disability for patients after glossectomy and simultaneous reconstruction. The quality of life would be acceptable after tongue reconstruction with RFFF, ALT and SIF. References | Related Articles | Metrics

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Clinical study of premolar extrusion with subgingival decayed defect by one-couple orthodontic NiTi auxiliary arch QIN Fei, MA Xiao-qing, XU Pei-cheng 2017, 26 (1):  115-117.  doi: 10.19439/j.sjos.2017.01.025 Abstract ( 250 )   PDF (738KB) ( 186 )   PURPOSE: To evaluate the effect of one-couple orthodontic NiTi auxiliary arch on the premolar extrusion which had subgingival decayed defect. METHODS: A total of 30 cases with subgingival decayed defects over 2 mm under the proximal gingival margin were chosen including 18 first premolars and 12 second premolars. The first and second molars on the same side were connected steadily and the one-couple orthodontic force system was designed. The NiTi segmental arch was used to extrude the teeth. Student's t test was performed with SPSS 8.0 software package. RESULTS: All the defect margins were 1mm over the gingival margins and the extrusion distance was 2.6~4.1 mm. After extrusion, the crown-root ratio was 1.24±0.30, the depth of the gingival sulcus was 1.87±0.28 mm. There was no significant difference before and after treatment in the angle between the axis of the extruded teeth and that of the first molar (P>0.05). The anchorage teeth kept almost the same relationship with the opposite. CONCLUSION: One-couple orthodontic NiTi auxiliary arch could extrude the premolars with subgingival decayed defects effectively and precisely. The designed force system had little effect on the anchorage teeth. References | Related Articles | Metrics

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Survey on dental caries prevalence among 3-year-old children in Jing'an District of Shanghai YUAN Shuang, SHI Le, LV Jin 2017, 26 (1):  118-120.  doi: 10.19439/j.sjos.2017.01.026 Abstract ( 240 )   PDF (354KB) ( 366 )   PURPOSE: To analyze the dental caries prevalence and severity in 3-year-old children from Jing'an district of Shanghai, and provide epidemiologic evidence for monitoring dental decay for establishing policies of preventive and treatment. METHODS: The surveillance was conducted using random cluster sampling method, 959 3-year-old children from Jing'an district was investigated in regard to dental caries. SPSS 15.0 software package was used for statistical analysis. RESULTES: The caries prevalence rate of deciduous tooth in 3-year-old children was 28.05.%. The incidence in males was significantly higher than that in females (P<0.05). The index of decayed, missing or filled-teeth（dmft）was 0.87, there was no significant difference between different genders.The caries filling ratio was 5.44%, with no significant difference was noted between different genders. Dental caries was mostly seen in the primary mandibular second molars,and least seen in the primary mandibular lateral incisor. CONCLUSIONS: Caries prevalence is high in 3-years-old children, and the majority is left untreated. Oral health care should be strengthened in this population. References | Related Articles | Metrics

Clinical Reports

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A retrospective study on incisor root resorption in patients treated with bracketless invisible appliance and straight wire appliance WANG Guan, YANG Lu, ZHANG Yu-feng, LUO San-lian, ZHENG Ji-wei 2017, 26 (1):  121-124.  doi: 10.19439/j.sjos.2017.01.027 Abstract ( 436 )   PDF (726KB) ( 476 )   PURPOSE: To assess root resorptions in patients treated with bracketless invisible appliance and straight wire appliance using cone-beam CT (CBCT). METHODS: Twenty-eight patients treated with bracketless invisible appliance (as experimental group) or straight wire appliance (as control group) were randomly selected. CBCT images were analyzed at 3 time points (pre-operation, 6 month after operation, post-operation). Root resorption was calculated using root length at 3 time points. The difference between the 2 groups was analyzed with SPSS16.0 software package. To those teeth with no root length reduction, the bone defect was evaluated using CBCT. RESULTS: After 6-month of treatment, 47.3% teeth from the experimental group had root resorption, while 68.3% in the control group. There was significant difference between the 2 groups (P<0.05). Root absorption of maxillary central incisors from the 2 groups was more severe than other teeth (55% in the experimental group, and 75% in the control group). After orthodontic treatment, the incidence of root resorption in the control groups increased to be 85.3% and 68.3% in the experimental group (P<0.05). To those teeth with no root resorption, bone defect was more common in the palatal side (18% in the experimental group, 14% in the control group). CONCLUSIONS: Compared with straight wire appliance, patients using bracketless invisible appliance suffer from less root resorption. References | Related Articles | Metrics

Dental Education

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Application of objective structured clinical examination system in pediatric dental education for 8-year-program and 5-year-program students WANG Lu-lu, JIANG Yang, ZHOU Zhi-fei, YUAN Shuai, WANG Xiao-jing 2017, 26 (1):  125-128.  doi: 10.19439/j.sjos.2017.01.028 Abstract ( 300 )   PDF (461KB) ( 213 )   PURPOSE: To explore a more comprehensive and objective method for dental students examination, and improve the quality of pediatric dental education. METHODS: Fifteen 8-year-program students and 30 5-year-program dental students from School of Stomatology, the Fourth Military Medical University were enrolled in this study. Objective structured clinical examination (OSCE), traditional diadactic test and questionnaires were carried out in all students. The scores of the two testing methods between students in 2 groups were compared using SPSS 11.5 software package. RESULTS: The average score of OSCE for 8-year-program students was significantly higher than that of 5-year-program students. In contrast, the traditional test score of 8-year-program students was significantly lower than that of 5-year-program students. Most students accepted OSCE and approved the evaluation system combining OSCE with traditional test. CONCLUSIONS: As a comprehensive, objective and effective evaluation system, OSCE is helpful for students to master knowledge and improve clinical ability. References | Related Articles | Metrics