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25 October 2019, Volume 28 Issue 5 Previous Issue    Next Issue

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Classification for retrognathism malocclusions and its predictive assessment of progressive growth patterns SHEN Gang 2019, 28 (5):  449-454.  doi: 10.19439/j.sjos.2019.05.001 Abstract ( 467 )   PDF (4496KB) ( 649 )   Classification for retrognathism malocclusions, assessed and determined by facial concavity, dento-basal compensation, skeletal discrepancy and mandibular morphology, includes dento-alveolar, mandibular positioning and skeletal categories. The skeletal category further consists of 3 subtypes, namely, maxillary originated, mandibular originated and maxillo-mandibular originated. The inspection of cephalometric images reveals that the mandibular contours in dento-alveolar, mandibular positioning and skeleto-maxillary originated categories present with flat and rectangular shapes; and in skeleto-mandibular originated and maxillo-mandibular originated subtypes, massive triangular shapes are distinctive. A longitudinal observation indicates that, spanning the course from the onset to the cessation of pubertal growth spurt, the prognosis of growth patterns remains stable and relatively favorable in dento-alveolar, mandibular positioning and skeleto-maxillary originated categories, but deteriorates and becomes unfavorable in skeleto-mandibular originated and maxillo-mandibular originated subtypes. The skeletal categories with triangle mandible coupled with deep curvature of symphysis hold high likelihood of relapse and are expected to achieve optimal correction by surgical interventions,although the orthopedic therapies are still advisable in the early stage. References | Related Articles | Metrics

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Effect of psoralen on the stability after orthodontic tooth movement in rats LIU Xiao-can, WANG Xu-xia, WU Xiao-xiao, LIU Yue, YAN Zhao-yue, ZHANG Jun 2019, 28 (5):  455-459.  doi: 10.19439/j.sjos.2019.05.002 Abstract ( 295 )   PDF (4011KB) ( 185 )   PURPOSE: This study was designed to investigate the effect of psoralen on periodontal tissue reconstruction after orthodontic tooth movement(OTM) in rats. METHODS: Thirty-six male 6-week-old Wistar rats were randomly divided into 2 groups: the experimental group and the control group. The experimental group and the control group were all installed between the central incisor and the left maxillary first molars to pull the first molars away from the force device; after 21 days, the force was removed and the rats in 2 groups were given drug gavage. Rats in the experimental group were given a gavage of psoralen 8 mg/kg per day, while rats in the control group were given the same amount of 0.9% sodium chloride everyday. Maxillary casts were made every week during the experimental and were scanned by 3D Scanner to measure relapse distance, and histologic examination was conducted. After 28 days, the rats were sacrificed and rats' upper jaw was separated. The remaining sections were immunohistochemically stained with BMP2 and BMP4. SPSS 19.0 software package was used for statistical analysis. RESULTS: Both groups had relapse after the force device was removed. Significant decrease of relapse percentage was observed in the experimental group compared with the control group at day 7,day 14,day 21 and day 28（P<0.05）. The speed of relapse of both groups were fastest in the first week and slowed down in the second, third and fourth week gradually. The speed of relapse in the experimental group in the first week was significantly less than in the control group(P<0.05).The expression of BMP2 and BMP4 within periodontal membrane and alveolar bone was significantly higher in the experimental group than in the control group(P<0.05). CONCLUSIONS: Psoralen can accelerate the reconstruction of periodontal tissues of orthodontic tooth and reduce relapse. References | Related Articles | Metrics

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Research of TC-PHBHHx/β-TCP compounds for treatment of dry socket in SD rats SUN Xiao-juan, LIU Ping-ping, ZHOU Zhong-wei, QIN Li-ye, FU Hao, ZHENG Lan-tian, CAO Kun 2019, 28 (5):  460-466.  doi: 10.19439/j.sjos.2019.05.003 Abstract ( 281 )   PDF (6279KB) ( 196 )   PURPOSE: The effects of different compounds on dry socket were evaluated in order to find a new method that can both be antibacterial and osteogenic,providing experimental evidence for future clinical application. METHODS: Seventy-two male SD rats, with upper left anterior teeth been extracted, were infected by pus to result in dry socket.Seven days later, they were allocated randomly and evenly into 4 groups and received different treatment, i.e. group A: debridement; group B: debridement and filled with iodoform gauzes; group C: debridement and filled with periocline; group D: debridement and filled with TC-PHBHHx/β-TCP. After being treated for 1,4,8 weeks, sequential fluorescent labeling was performed. The animals were sacrificed after the procedure and hard tissue and decalcified sections were harvested for histological and histomorphometrical evaluation. Statistical analysis was performed using SPSS 19.0 software package. RESULTS: At the same time point, the results of osteogenesis in group A, B and C were not significantly different while the results in group D was significantly different from other groups; accordingly, significant new bone formation was observed. At different observation time, the bone area in group B and C were not significant different over time. In group A, little new bone formation was found but surrounded by a large amount of inflammatory cells at 8 week. However, group D showed bone area increasing gradually with time. CONCLUSIONS: TC-PHBHHx/β-TCP has significant anti-inflammatory and osteogenic effects. Iodoform gauzes and periocline have good anti-inflammatory results but not significant osteogenic effects. References | Related Articles | Metrics

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Mechanical properties and cytotoxicity of three-dimensional printing polycarbonate for occlusal splints LIN Rui, YU Chun-hua, SUN Jian 2019, 28 (5):  467-471.  doi: 10.19439/j.sjos.2019.05.004 Abstract ( 285 )   PDF (3867KB) ( 305 )   PURPOSE: To evaluate the mechanical properties and cytotoxicity of a 3D printing polycarbonate material used in digital occlusal splints, and to use this material to manufacture a splint with CAD/CAM technology. METHODS: Specimen of two different materials, 3D printing polycarbonate(PC-plus) and transparent base resin (PMMA) were processed. The flexural strength, elastic modulus, microhardness, hygroscopicity and water-solubility of these materials then were evaluated. According to the standard of GBT16886.5-2003, cell culture and cytotoxicity test in vitro were conducted to evaluate the target materials on the morphology, growth and proliferation of cultured cells (L929). By using 3D printing technology, a splint was made of this 3D printing polycarbonate material. Statistical analysis was performed using SPSS 24.0 software package. RESULTS: For the group of PC-plus, the flexural strength ranged from 89.4 to 109.8 MPa, the elastic modulus from 1939.4 to 2470.9 GPa, the microhardness from 15.6 to 24.7 MPa, hygroscopicity from 2.43 to 11.42 μg/mm3 and water-solubility from 0.11 to 0.30 μg/mm3. For PMMA group, the flexural strength ranged from 75.2 to 88.4 MPa, the elastic modulus from 1349.2 to 2470.2 GPa, the microhardness from 17.5 to 35.3 MPa, hygroscopicity from 12.80 to 16.16 μg/mm3 and water-solubility from 4.74 to 7.44 μg/mm3. The difference between 3D printing PC-plus group and PMMA base resin group was statistically significant (P<0.05). L929 cells showed normal morphology and proliferation increased with culture time. The toxicity grade of all groups was 0-1, and the 3D printing splint was made successfully. CONCLUSIONS: The polycarbonate material for 3D printing has adequate mechanical properties and biocompatibility to meet the requiement of clinical application. References | Related Articles | Metrics

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Combined effect of rhTGF-β1 and rhPDGF-BB on the expression of Pyk2 protein and mRNA gene during orthodontic tooth movement in SD rats MEI Mei, YI Jie, ZHANG Jiang-tao, HUANG Jin, JIANG Ce, FENG Lei 2019, 28 (5):  472-477.  doi: 10.19439/j.sjos.2019.05.005 Abstract ( 241 )   PDF (4465KB) ( 185 )   PURPOSE: To explore the combined effect of recombinant human transforming growth factor-β1 (rhTGF-β1) and recombinant human platelet derived growth factor-BB (rhPDGF-BB) on the expression of Pyk2 in the osteoclasts of the pressure side of orthodontic tooth in rats. METHODS: One hundred and sixty male Sprague-Dawley rats were randomly divided into 2 groups: experimental group(A) and control group(B) to establish orthodontic tooth movement model. Rats in the experimental group received combined injection of 5 ng rhTGF-β1 and 10 ng rhPDGF-BB in the buccal submucosal area of the left upper first molar every other day, while rats in the control group received equivalent volumes of PBS. Rats in each group were sacrificed at each of 5 time points(1,4,7,10 and 14 days) after appliance placement. The distance of the tooth movement was measured with stereomicroscope, the change of the amount of osteoclasts was detected with tartrate-resistant acid phosphatase histochemistry (TRAP), the protein and mRNA expression of Pyk2 was detected by immunohistochemistry and real time PCR(RT-PCR). SPSS19.0 software package was used for statistical analysis. RESULTS: The distance of teeth in group A moved more rapidly than in group B, except for the first day, significant differences were found (P<0.05) in all time points.The number of osteoclasts in group A was significantly higher than that in group B, except for the 14th day, compared with the control group(P<0.05). Pyk2 protein and gene expression of group A was significantly higher than group B, both groups reached a peak in 7 days and gradually decreased thereafter, except in the first day, the expression of protein Pyk2 was significantly different at other time points (P<0.05). CONCLUSIONS: rhTGF-β1 and rhPDGF-BB up-regulated the expression of Pyk2 protein and mRNA gene on the pressure side of orthodontic tooth in rats, which may be one of the reasons for accelerating the rate of orthodontic tooth movement. References | Related Articles | Metrics

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Effect of low-magnitude high frequency vibration on osteogenic differentiation of human periodontal ligament stem cells BAI Kun-hong, HU Cheng, LI Qing-qing, WANG Fei 2019, 28 (5):  478-483.  doi: 10.19439/j.sjos.2019.05.006 Abstract ( 220 )   PDF (4207KB) ( 155 )   PURPOSE: To investigate the effect of low-magnitude high frequency vibration (LMHFV) on proliferation, migration ability and osteogenic differentiation of human periodontal ligament stem cells(hPDLSCs). METHODS: hPDLSCs were isolated from premolar and randomized into vibration culture group (magnitude：0.3 g; frequency：40 Hz; time：15 min/24 h) and static culture group. CCK-8 was used to identity the proliferation of hPDLSCs. Wound-healing assay was used to evaluate migration ability of hPDLSCs. The osteogenesis gene expression was analyzed by RT-PCR, and the osteogenesis protein expression was analyzed by Western blot. The osteogenesis differentiation capability was evaluated by alizarin red staining. The data were analyzed using SPSS 21.0 software package. RESULTS: After LMHFV, the proliferation and migration ability of hPDLSCs were increased. The expression level of RUNX2, ALP, Col-1, and OCN was significantly augmented under LMHFV. Alizarin red staining and Western blot proved the same trend. CONCLUSIONS: The results demonstrate that LMHFV can promote hPDLSCs proliferation, migration ability and osteogenic differentiation. References | Related Articles | Metrics

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Study on energy absorption of mouthguard splints by impact test BAO Shi-jie, REN Xiao-wei, LI Yi-han, YE Sheng-jia, DONG Jian-hui, WEI Bin 2019, 28 (5):  484-489.  doi: 10.19439/j.sjos.2019.05.007 Abstract ( 263 )   PDF (4306KB) ( 153 )   PURPOSE: Using impact test to study energy absorption ability of mouthguard splints of different thickness and materials. METHODS: In this experiment, group 1 was BIOPLAST 5 mm splint, group 2 was BIOPLAST 4 mm splint, group 3 was BIOPLAST 3 mm splint,group 4 was BIOPLAST 2 mm splint and group 7 was BIOPLAST 1 mm splint. Group 5 was ERKOLOC-PRO 2 mm splint, group 6 was DURAN 2 mm splint. Mouthguard splints were clashed by impact head from different heights. Digital Image Correlation System was used to record the process of the test. Images were transferred to data processing software, to analyze incident speed, incident depth and rebound height of the impact head. Absorbed energy and energy absorption ratio were calculated to analyze energy absorption ability of mouthguard splints of different thickness and materials. The data were analyzed using SPSS 22.0 software package for one-way analysis of variance and LSD. RESULTS: The higher impact head fell, the larger energy absorption ratio was. There was significant difference among group 1, 2, 3, 4, 7 in average energy absorption ratio（P<0.05）, and group 7 was the largest. There was significant difference among group 4, 5, 6 in average energy absorption ratio（P<0.05）, among which group 4 and group 5 were larger. CONCLUSIONS: 3 mm splint is good enough to be used to make mouthguard, which is also thinner and more comfortable. Splint of soft material is more suitable for mouthguard than splint of hard material. References | Related Articles | Metrics

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The influence of zoledronic acid on proliferation, migration and apoptosis of fibroblasts LANG Miao-jie, OU Yue-jian 2019, 28 (5):  490-493.  doi: 10.19439/j.sjos.2019.05.008 Abstract ( 363 )   PDF (3210KB) ( 271 )   PURPOSE: Bisphosphonates are commonly used to treat bone-derived malignant tumors currently. In recent years, with the widespread use of these drugs, reports on the difficulty of wound healing (DWH) increase remarkably. However, the mechanism is still unclear. The soft tissue injury was suspected to cause DWH in many recent reports. This experiment was designed to explore the influence of zoledronic acid on fibroblast, and investigate the possible mechanisms leading to DWH. METHODS: NIH 3T3 fibroblasts were routinely cultured in vitro. The influence of zoledronic acid on apoptosis, proliferation and migration of fibroblast were tested with flow cytometry, MTT and cell migration assay, respectively. The results of each experimental group were compared with the control group using SPSS 17.0 software package. RESULTS: At a concentration of 5~50 μmol/L, zoledronic acid could dose-dependently inhibit the activity of fibroblast proliferation and migration, and up-regulate apoptosis with significant difference (P<0.05). CONCLUSIONS: Zoledronic acid can up-regulate cell apoptosis, inhibit proliferation and migration of fibroblast, suggesting that soft tissue impairment might contribute to the occurrence of DWH. References | Related Articles | Metrics

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Effects of dimethylamine tetracycline combined with tea polyphenols on the levels of IL-1β and IL-17F in patients with early peri-implant soft tissue inflammation LI Yu-leng, WANG Wei-zhong, GONG Zhong-cheng 2019, 28 (5):  494-498.  doi: 10.19439/j.sjos.2019.05.009 Abstract ( 230 )   PDF (3644KB) ( 155 )   PURPOSE: To study the effect of dimethylamine tetracycline combined with tea polyphenols on the levels of interleukin-1 β (IL-1β) and interleukin-17F (IL-17F) in patients with early peri-implant soft tissue inflammation. METHODS: Ninety-six patients with early peri-implant soft tissue inflammation were selected from May 2016 to May 2018. They were randomly divided into dimethylamine tetracycline group and combination group, 48 cases in each group. Patients in the dimethylamine tetracycline group were treated with dimethylamine tetracycline hydrochloride ointment, while patients in the combined group were treated with tea polyphenols on the basis of dimethylamine tetracycline group. Plaque index (PLI), sulcus bleeding index (SBI), attachment loss (AL), gingival crevicular fluid (GCF), probing depth (PD), IL-1β and IL-17F levels were detected. The data were analyzed using SPSS 20.0 software package. RESULTS: After treatment, PLI, SBI, AL, GCF and PD in both groups were significantly lower than those before treatment (P<0.05). The levels of PLI, SBI, AL, GCF and PD in the combined group were significantly lower than those in the dimethylamine tetracycline group after treatment (P<0.05). After treatment, the levels of IL-1beta and IL-17F in both groups were significantly lower than those before treatment (P<0.05). After treatment, the levels of IL-1β and IL-17F in the combined group were significantly lower than those in the dimethylamine tetracycline group (P<0.05). The effective rate of combined group was 93.75%, which was significantly higher than that of dimethylamine tetracycline group (77.08%, P<0.05). The adverse reaction rate of the combined group was 6.25% ,significantly lower than that of the dimethylamine tetracycline group (20.83%, P<0.05). CONCLUSIONS: Dimethylamine tetracycline combined with tea polyphenols in the treatment of early peri-implant soft tissue inflammation has significant effect. It can improve the clinical symptoms of patients, reduce the levels of IL-1β and IL-17F, and decrease the occurrence of adverse effects. References | Related Articles | Metrics

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Expression of mTOR mRNA and Tfr1 mRNA in mucoepidermoid carcinoma of parotid gland and their relationship with prognosis CHANG Pan-hui, AKBEL Turgesjon, LI Wei-wei 2019, 28 (5):  499-503.  doi: 10.19439/j.sjos.2019.05.010 Abstract ( 275 )   PDF (3433KB) ( 174 )   PURPOSE: To investigate the expression of rapamycin target protein (mTOR) mRNA and transferrin receptor 1(Tfr1) mRNA in mucoepidermoid carcinoma of parotid gland and its relationship with prognosis. METHODS: From June 2013 to July 2015 in Tangshan Workers' Hospital, 35 patients with mucoepidermoid carcinoma of parotid gland were selected. The relative expression of mTOR and Tfr1 mRNA in mucoepidermoid carcinoma of parotid gland was detected. The relationship between mTOR mRNA, Tfr1 mRNA and the clinicopathology and prognosis of mucoepidermoid carcinoma of parotid gland was analyzed using SPSS19.0 software package. RESULTS: The relative expression levels of mTOR mRNA and Tfr1 mRNA in mucoepidermoid carcinoma of parotid gland were significantly higher than those in adjacent tissues(P<0.05). The relative expression of mTOR mRNA and Tfr1 mRNA was correlated with invasion depth, tumor grade, TNM stage and cervical lymphatic metastasis(P<0.05). The relative expressions of mTOR and Tfr1 in patients with good prognosis were significantly lower than those in patients with poor prognosis (P<0.05). The AUC of mTOR mRNA was 0.815, higher than that of Tfr1 mRNA(0.813). The AUC of mTOR mRNA combined with Tfr1 mRNA was 0.922, higher than that of mTOR mRNA and Tfr1 mRNA alone. Cox univariate and multivariate analysis showed that differentiation, TNM stage, mTOR mRNA and Tfr1 mRNA were closely related to poor prognosis of mucoepidermoid carcinoma of parotid gland. CONCLUSIONS: The relative expression of mTOR mRNA and Tfr1 mRNA in patients with mucoepidermoid carcinoma of parotid gland was significantly increased, which can be used to evaluate the prognosis of patients. References | Related Articles | Metrics

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Effects of basic periodontal treatment on endothelin, vascular endothelial growth factor-A and tumor necrosis factor-α levels in gingival crevicular fluid and serum LIN Zhe-jing, LUO Ren-hui, XIE Li-li, WU Xiao-yu 2019, 28 (5):  504-508.  doi: 10.19439/j.sjos.2019.05.011 Abstract ( 309 )   PDF (3682KB) ( 380 )   PURPOSE: To investigate the effects of basic periodontal treatment on the levels of endothelin (ET), vascular endothelial growth factor-A (VEGF-A) and tumor necrosis factor-α (TNF-α) in gingival crevicular fluid and serum. METHODS: A total of 57 patients with periodontitis (experimental group) and 43 healthy examinees (control group) admitted to Shenzhen Hospital of Guangzhou University of Chinese Medicine from October to May 2018 were selected. Patients received subgingival scaling and root planing for 6 weeks. Then various indexes were compared, including bleeding on probing (BOP), plaque index (PI), probe depth (PD), clinical attachment level (CAL) and gingival index (GI), as well as the levels of ET, VEGF-A and TNF-α in gingival crevicular fluid and serum. The correlation between ET, VEGF-A and TNF-α was analyzed. The data were analyzed with SPSS 21.0 software package. RESULTS: Periodontal indexes including BOP, PI, PD, CAL and GI in the experimental group were significantly increased after treatment (P<0.05), but still significantly lower than those in the control group (P<0.05). The levels of ET, VEGF-A and TNF-α in gingival crevicular fluid and serum were significantly decreased in the experimental group after treatment (P<0.05), but significantly higher than those in the control group (P<0.05). The level of ET in gingival crevicular fluid was not significantly correlated with VEGF-A level in patients with periodontitis (P>0.05), while was positively correlated with VEGF-A levels (P<0.05). CONCLUSIONS: Basic periodontal treatment can reduce the levels of ET, VEGF-A and TNF-α in gingival crevicular fluid and serum of patients with periodontitis, and improve the periodontal status; moreover, ET level in gingival crevicular fluid is positively correlated with TNF-α level. References | Related Articles | Metrics

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Downs cephalometric analysis between juveniles of She and Han nationality in Lishui area of Zhejiang province XU Pin-pin, LIN Yan, LIU Xiao-min 2019, 28 (5):  509-512.  doi: 10.19439/j.sjos.2019.05.012 Abstract ( 305 )   PDF (2611KB) ( 331 )   PURPOSE: To investigate the clinical normal values of juveniles with normal occlusions of She and Han nationality in Lishui area of Zhejiang province, and compare the craniofacial characteristics between She and Han nationality. METHODS: Two hundred juveniles of She nationality and 200 juveniles of Han nationality with normal occlusion were recruited. Lateral cephalometric radiographs were taken, and Downs cephalometric analysis was performed. The data were compared using paired samples t test with SPSS 12.0 software package. RESULTS: There was no significant difference between males and females in the values of juveniles of both She and Han nationality. Compared to the male and female juveniles of Han nationality, MP-FH and U1-L1 of the She juveniles increased (P<0.05), while convexity decreased significantly (P<0.05). In addition, L1-MP of She female juveniles decreased significantly in comparison to that of Han female juveniles (P<0.05). There was no significant difference in other values between She and Han nationality. CONCLUSIONS: Compared to Han juveniles, She juveniles present an orthognathous and long face with vertical growth pattern. Sex differences are not apparent in juveniles of both She and Han nationality. References | Related Articles | Metrics

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Qualitative study on the decision-making of orthognathic surgery in adult patients with malocclusion HU Xiang-ying, XIAO Yan, WANG Bi-xia, RUAN Hong, YUAN Wei-jun 2019, 28 (5):  513-517.  doi: 10.19439/j.sjos.2019.05.013 Abstract ( 284 )   PDF (3685KB) ( 285 )   PURPOSE: The main purpose of this study was to explore the experience associated with patient's decision to have or not have orthognathic treatment. METHODS: Phenomenological methodology was used in this study. Ten patients were collected from January 2018 to March 2018, who were consulted in the Department of Oral and Craniomaxillofacial Surgery, Center of Craniofacial Orthodontics in Shanghai Ninth People's Hospital. They were interviewed by semi-structured, face to face in-depth interviews. Data were organized and analyzed by Colaizzi methods. RESULTS: By reading, analysis and extraction, two topics, i.e, motivation and interference factor were obtained. CONCLUSIONS: The treatment information service was limited. Further research is needed to improve the information services that support the treatment decision of malocclusion patients and help them to make the best choice. References | Related Articles | Metrics

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Assessing the influence of chin prominence on perceived facial aesthetics among three groups of observers DONG Ting, YE Nian-song, YUAN Ling-jun, WU Si-cheng, XIA Lun-guo, FANG Bing 2019, 28 (5):  518-522.  doi: 10.19439/j.sjos.2019.05.014 Abstract ( 694 )   PDF (3844KB) ( 339 )   PURPOSE: To assess the influence of chin prominence on facial aesthetics with 3D images, to investigate the cognitive boundaries of chin prominence among orthodontists, general dentists and laypeople and compare the variance of their cognitive data, in order to provide quantitative reference for selection of clinical treatment. METHODS: A 3D facial image was obtained by 3dMD. The soft tissue pogonion point was altered in 2 mm increments from -10 to 10 mm with Geomagic Wrap 2015, in order to represent retrusion and protrusion of the chin. These images were rated by orthodontists, general dentists and laypeople with VAS scores. Multivariate mixed linear regression was used to analyze the influence of gender, age and chin prominence on VAS scores, and whether there were differences among different groups with SAS 9.4 software package. ANOVA was also applied for comparison of each prominence. RESULTS: This study was composed of 243 subjects, including 90 orthodontists, 101 general dentists and 52 laypeople. Chin prominence had significant effect on VAS scores. VAS scores decreased by 0.8910 for each unit increase in chin retrusion and decreased by 1.0958 for each unit increase in chin protrusion（P<0.01）. Desire for treatment started when chin retrusion exceeded 6 mm in orthodontist group and layperson group, 4 mm in general dentist group, and chin protrusion reached 6 mm in all groups（VAS scores <5）. There was no significant difference in the scores among orthodontists, general dentists and laypeople with the variance of chin prominence, and there was no significant difference in gender and age. CONCLUSIONS: Chin prominence had significant effect on facial aesthetics. Soft tissue pogonion point located on the zero meridian was considered as the most attractive. Treatment needs increased significantly when chin protrusion reached 6 mm or chin retrusion exceeded 6 mm. There was no significant difference in the assessment among orthodontists, general dentists and laypeople. References | Related Articles | Metrics

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Evaluation of condylar asymmetry in different skeletal patterns with cone-beam CT LI Wen-yan, CHEN Wen-jing, HOU Wei, QIN Jin-wei, DUAN Yi-feng, MU Jin-quan 2019, 28 (5):  523-528.  doi: 10.19439/j.sjos.2019.05.015 Abstract ( 399 )   PDF (4276KB) ( 240 )   PURPOSE: The aim of this study was to evaluate condylar asymmetry in different skeletal patterns with cone-beam CT (CBCT). METHODS: A total of 110 subjects aged from 18 to 30 years were selected from patients who had undergone CBCT examinations retrospectively. All the subjects were divided into three groups according to their skeletal patterns: Class Ⅰ (Cl Ⅰ: 0°≤ANB≤5°), Class Ⅱ (Cl Ⅱ: ANB>5°) and Class Ⅲ (Cl Ⅲ: ANB<0°). In addition, each group was further divided into two subgroups according to genders. Condylar (Co-Sig), ramus (Go-Sig) and condyle-plus-ramus (Co-Go) asymmetry were assessed by identifying landmarks on the reconstructed images with a 3-dimentional (3D) reference plane. The coordinates of the landmarks were calculated statistically. The data were analyzed statistically with SPSS17.0 software package. RESULTS: The condyle-plus-ramus and ramus asymmetry (Co-Go R-L and Go-Sig R-L) were affected by the ANB angle (P<0.05) respectively, and the differences mainly came from the y coordinate (P<0.05). When comparing the two sides of the three groups respectively, the Co-Go, Go-Sig and Co-Sig of some patients had gender difference and left-right difference. The z coordinate of point Menton (Me) had significant difference (P<0.05) caused by different skeletal patterns, while the coordinates of x and y were similar (P>0.05). CONCLUSIONS: Condyle-plus-ramus and the ramus asymmetry were affected by different skeletal patterns and the differences were caused by the height primarily. Patients of Class Ⅲ usually manifest mandibular protrusion while Class Ⅱ with mandibular retrognathism. Whether the degree of chin deviation differs according to the condylar asymmetry needs further investigation. References | Related Articles | Metrics

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Correlation between adenoid hypertrophy, maxillary sinus mucosal thickening and dentofacial development in children XU Ya-fen, XU Yi-li, LI Zhe-hang, LEI Yong-hua 2019, 28 (5):  529-535.  doi: 10.19439/j.sjos.2019.05.016 Abstract ( 1359 )   PDF (5189KB) ( 220 )   PURPOSE: To investigate the effects of adenoid hypertrophy and maxillary sinus mucosal thickening on dentofacial development. METHODS: The selected subjects were divided into 4 groups according to the inclusion criteria: group A (adenoid hypertrophy with maxillary sinus mucosal thickening), group B (adenoid hypertrophy without maxillary sinus mucosal thickening), group C (normal adenoid with maxillary sinus mucosal thickening), and group D (normal adenoid without maxillary sinus mucosal thickening). There were 20 subjects in each group, aging from 12 to 14 years old. The volume of maxillary sinus was measured by Mimics software. The adenoid, dental arch width, basal bone width and palatal height were measured by Dolphin software and dentofacial measurements were performed in the lateral cephalograms derived from cone-beam CT (CBCT). The data were analyzed with SPSS 24.0 software package. RESULTS: There was no significant difference in dentofacial measurements between group B and group D or group C and group D,except for ANB angle (P<0.05). Compared with group D, SNB, ANB, Wits appraisal, NA-APo, MP-HP, N-Me, S-Go/N-Me, N-ANS (perp HP), sum of three angles, Ar-Go of group A were significantly different (P<0.05). Neither left nor right maxillary sinus bony volume had significant difference between group B and D or group C and D. CONCLUSIONS: Both adenoid hypertrophy and maxillary sinus mucosal thickening have impact on dentofacial development. Moderate or more severe adenoid hypertrophy with maxillary sinus mucosal thickening has greater impact on dentofacial development over adenoid hypertrophy or maxillary sinus mucosal thickening alone. References | Related Articles | Metrics

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Independent prognostic factors and survival prediction model for 117 patients with advanced oral squamous cell carcinoma DING Hong-zhong, XU Cong-ping, ZHOU Yong-min 2019, 28 (5):  536-540.  doi: 10.19439/j.sjos.2019.05.017 Abstract ( 569 )   PDF (3492KB) ( 197 )   PURPOSE: To investigate the independent prognostic factors and establish survival prediction model for advanced oral squamous cell carcinoma (OSCC). METHODS: At the time of admission, the general information and past medical history of 177 patients with advanced OSCC were collected in detail. All patients underwent radical resection. After surgery, radiotherapy and chemotherapy with hydroxycampothecin (HCPT) and pingyangmycin (PYM) were performed according to the patient's condition. All patients were followed up for 5 years after surgery, and the survival rate during that period and the risk factors for prognosis were analyzed. The data were analyzed by SPSS 20.0 software package. RESULTS: During the follow-up period, 2 patients died due to other causes, 4 were excluded due to lost to follow-up, 42 of the remaining 111 patients died, 69 survived, the total survival rate was 62.16%. The survival status of patients with advanced OSCC with different age, T stage and M stage had no significant difference (P>0.05), while significant difference was found among patients with different gender, tissue differentiation degree, N stage and chemotherapy (P<0.05). Gender, N stage and HCPT in combination of PYM chemotherapy were independent risk factors (P<0.05), while histological differentiation degree was not an independent risk factor for survival of patients (P>0.05). The survival curves of gender, N stage and HCPT in combination of PYM chemotherapy had certain predictive value on the survival of patients with advanced OSCC. CONCLUSIONS: Gender, N stage and HCPT in combination of PYM chemotherapy are independent risk factors for the survival of patients with advanced OSCC, and their survival curves can be used as a survival prediction model. References | Related Articles | Metrics

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The influence of different modes of delivering postoperative instructions on the side effects of wisdom tooth extraction LU Can, WU Xiao-shan, JIAN Xin-chun 2019, 28 (5):  541-544.  doi: 10.19439/j.sjos.2019.05.018 Abstract ( 371 )   PDF (2611KB) ( 186 )   PURPOSE: To study the difference between the distinct ways of delivering postoperative instructions to reduce the side effects of wisdom tooth extraction, including pain, bleeding and swelling, and improve the degree of satisfaction of the patients. METHODS: A group of 150 patients who underwent wisdom tooth extraction in the Department of Oral and Maxillofacial Surgery of Xiangya Hospital, Central South University between Jan. 2018 to Oct. 2018 were selected in this research randomly. They were divided into 3 groups randomly and 50 patients in each group. Patients in group 1 received verbal postoperative instructions, patients in group 2 received written postoperative instructions, and patients in group 3 received verbal plus written postoperative instructions. The information of age, sex and education level was collected for each patient. The side effects of pain, bleeding and swelling, and the satisfactory degree of the patients were recorded 7 days after surgery. SPSS 22.0 software package was used for statistical analysis. RESULTS: There were 81 women and 69 men among 150 patients. The mean age was 24.6±; 2.6 years. The results showed that the degree of pain of group 1 was significantly higher than group 2 (P=0.001) and group 3 (P=0.000). The satisfactory degree of group 1 was the lowest, and group 3 was the highest. CONCLUSIONS: The way of delivering postoperative instructions affects pain and satisfactory degree after wisdom tooth extraction. References | Related Articles | Metrics

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Clustering analysis in the pattern of KAP model on the application of oral health among students aged 12-15 in Shanghai YU Jin, ZHANG Ying, WANG Yan, ZENG Xiao-li, JIANG Yi-wei, DA Dong-xin, ZHANG Qi, ZHANG Hao 2019, 28 (5):  545-548.  doi: 10.19439/j.sjos.2019.05.019 Abstract ( 248 )   PDF (3023KB) ( 172 )   PURPOSE: To assess the relation of oral health knowledge, attitude and practice(KAP) of the students aged 12-15 in Shanghai, and provide data support for intervention strategies of oral health. METHODS: A total of 2927 subjects aged 12-15 years old were selected according to the method of the Fourth National Oral Health Epidemiological Survey and the questionnaire was filled. SAS 9.4 software package was used for statistical analysis. RESULTS: The subjects were divided into 2 categories according to their knowledge and attitude of oral prevention and oral health. TypeⅠgroup, with high cognitive attitude, had more teeth brushing times than those of typeⅡgroup with poor cognitive attitudes( χ2=22.9, P<0.01). TypeⅠgroup had more people knowing and using toothpaste with fluoride. ( χ2=23.7, P<0.01). The frequency of type I group using dental floss was significantly higher than typeⅡgroup( χ2=15.1, P<0.01), while the frequency of having deserts was relatively lower than typeⅡgroup ( χ2=22.1, P<0.01), and the frequency of having drinks was lower than type Ⅱ( χ2=26.4, P<0.01). The two groups had no significant difference in the frequency of consumption of other drinks with sugar ( χ2=10.5, P=0.11). CONCLUSIONS: Oral related risk behaviors are quite common among 12-15 years students in Shanghai, which are closely related to the knowledge and attitude. References | Related Articles | Metrics

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Effect of single low level laser therapy on initial pain during fixed orthodontic treatment XIAO Ling, CHEN Rui-xia, LUO Na 2019, 28 (5):  549-552.  doi: 10.19439/j.sjos.2019.05.020 Abstract ( 289 )   PDF (2779KB) ( 200 )   PURPOSE: To investigate the effect of single low level laser therapy on initial pain during fixed orthodontic treatment. METHODS: Sixty patients who underwent fixed orthodontic treatment in our hospital from January 2015 to December 2017 were enrolled.Patients were divided into 2 groups by random number table method, 30 in each group. Patients in the experimental group were treated with a single low level laser therapy ,while patients in the control group were treated with a placebo.The results of the 2 groups were compared in regard to spontaneous pain and chewing pain during the day and night using SPSS 22.0 software package. RESULTS: Spontaneous pain during day and night with 0.012, 0.014 inch superelastic nickel-titanium (NiTi) line was significantly lower in the experimental group than in the control group(P<0.05), and there was no significant difference with 0.016 and 0.018 inch NiTi (P>0.05).Chewing pain with 0.012, 0.014, 0.016, and 0.018 inch NiTi lines in the experimental group was significantly lower than that in the control group(P<0.05). CONCLUSIONS: Single low level laser therapy significantly reduced postoperative pain while placing a superelastic NiTi wire for initial alignment and correction. References | Related Articles | Metrics

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Evaluation of the efficacy of sodium fluoride dental protective agent combined with pit and fissure sealant in prevention of dental caries in preschool children ZHANG Ai-hua, LI Jing 2019, 28 (5):  553-556.  doi: 10.19439/j.sjos.2019.05.021 Abstract ( 565 )   PDF (2810KB) ( 260 )   PURPOSE: To explore the effect of sodium fluoride tooth protector combined with pit and fissure sealing to prevent caries in preschool children. METHODS: Two hundred preschool children who were treated with pit and fissure closure from January 2014 to September 2014 were selected as subjects. According to random number table method, 100 cases were divided into the combined group and the control group. Children in the control group were treated with pit and fissure sealant for prevention of caries, while children in the combined group were treated with sodium fluoride tooth protector combined with pit and fissure sealant for caries prevention. The incidence of dental caries, proximal caries, mean DMFT, and expulsion rate of the sealants were compared between the two groups at 1 year and 2 years. Data analysis was performed using SPSS 16.0 software package for t test and χ2 test. RESULTS: At 1 year of follow-up, there was no significant difference in the incidence of dental caries, proximal caries, and mean DMFT between the two groups (P>0.05). The incidence of caries and mean DMFT in the combined group were significantly lower than those in the control group at 2 years of follow-up (P<0.05). The incidence of proximal caries in the combined group was not significantly different from that in the control group (P>0.05). The retension rate of the pit and fissure sealant in the combined group was significantly higher than that in the control group (P<0.05). There was no significant difference in the partial shedding rate and complete expulsion rate between the two groups (P>0.05). CONCLUSIONS: Sodium fluoride tooth protector combined with pit and fissure sealing has better anti-caries effect than the use of pit and fissure sealant alone in preschool children. References | Related Articles | Metrics

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Construction of clinical practice system of oral pathology for long-term program students in stomatology WANG Li-zhen, ZHANG Chun-ye, HU Yu-hua, XIA Rong-hui, SUN Jing-jing, TIAN Zhen, LI Jiang 2019, 28 (5):  557-560.  doi: 10.19439/j.sjos.2019.05.022 Abstract ( 242 )   PDF (2957KB) ( 196 )   PURPOSE: To construct clinical practice system, making up for the shortcomings in the instructional framework of oral histology and pathology, promoting the integration of theory and clinical practice, and enhancing teaching quality of long-term students of stomatology. METHODS: Laying down clinical practice plans and formulating technical operation criteria for pathological experiments, constructing a complete database and training high-level teachers, and evaluating through the following three aspects: practice assessment, teacher-student symposium and questionnaire survey. RESULTS: After completing the clinical practice, the students got the average score of 89.37. In questionnaire survey, the students generally expressed that they had a better understanding of the specialized characteristics and routine skills of the speciality, and improved their practical ability, thus stimulating their interest in self-directed learning. CONCLUSIONS: The construction and practice of clinical practice system of oral histology and pathology can effectively improve the educational objectives and teaching quality of this discipline, which will play a positive role in scientific research and future medical work of long-term students majoring in stomatology. References | Related Articles | Metrics