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    25 December 2022, Volume 31 Issue 6 Previous Issue    Next Issue
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    Editorial
    Malocclusions with mandibular positional deviation: etiological factors, therapeutic restorations and clinical fundamentals
    SHEN Gang
    2022, 31 (6):  561-568.  doi: 10.19439/j.sjos.2022.06.001
    Abstract ( 790 )   PDF (1987KB) ( 181 )  
    The definition for a normal mandibular position in orthodontic regime includes two perspectives: an occlusion with maximum contacts with Class I inter-digitation, and an integrated relation between the components within temporomandibular joint (TMJ). Any displacement or deviation of the mandible from its normal position may result in anomalies in occlusion. Mandibular displacement can occur due to either physiological or pathological factors. The physiological deviation of the mandible at sagittal dimension is often caused by the phenomenon where the mandible moves forward or backward to coordinate and match the transverse width with the upper dentition. The physiological deviation of the mandible at transverse dimension, on the other hand, is mainly generated by the scenario where the mandible relocates its position to avoid some regional occlusal irregularities. The pathological deviation of the mandible at sagittal dimension is often taking place when condylar resorption progresses, leading the mandible to retrude backwards. Nevertheless, if the pathological degrading or hyperplasia of the condyles between two sides are unparalleled and asymmetrical, mandibular shift at transverse dimension would occur. The therapeutic restoration of the malpostioned mandible aims to relocate the deviated lower jaw into its relatively normal position, enabling a subsequent correction of the malocclusion. Bite registration and recording based on mandibular re-localization remain the vital and critical procedures in clinical practice. With the advent of clear aligner orthodontics, the clear versions of orthopedic modalities, namely, S8, S9 and S10, are specifically designed to alleviate mandibular displacement, therefore escalating the treatment efficacy by repositioning the mandible and correcting the individual teeth simultaneously. Condylar endochondral ossification triggered by mandibular repositioning not only consolidates the restorative posture of the mandible, but more importantly, repairs the deteriorating condyles and subsequently relieves temporomandibular disorder (TMD) conditions.
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    Original Articles
    The hemostasis effect and cell compatibility of a chitosan-calcium alginate-laponite nanosheet composite membrane: in vitro and in vivo evaluation
    WU Jing, ZOU Duo-hong, ZHANG Zhi-yuan
    2022, 31 (6):  569-575.  doi: 10.19439/j.sjos.2022.06.002
    Abstract ( 262 )   PDF (1557KB) ( 77 )  
    PURPOSE: To explore the feasibility of a chitosan-calcium alginate-laponite nanosheet composite membrane being used as a new hemostatic membrane for wounds in oral cavity. METHODS: The composite membrane was prepared in a layered fashion: the lower layer of chitosan membrane was made through self-evaporation and the upper layer of calcium alginate-laponite nanosheet sponge was made via freeze-drying. The microstructure of the composite membrane was observed under scanning electron microscopy (SEM) and transmission electron microscopy (TEM). X-ray diffraction was used as a means of identifying the compounds. Clotting time of composite membrane, medical gauze and Chitin dressing in vitro was measured by the plate method for blood coagulation. Cytotoxicity tests were quantified through co-culturing NIH/3T3 cells with chitosan-calcium alginate extract, composite hemostatic membrane extract and DMEM. Superficial buccal mucosal wound models and tooth extraction models were created on beagles dogs, the hemostatic effect and adhesion to oral mucosa were evaluated on these models. Statistical analysis was performed using SPSS 18.0 software package. RESULTS: The composite hemostatic membrane consisted of double-layer in microstructure, the upper layer was a foam layer consisting of calcium alginate and laponite nanosheet, the substratum was formed by uniform chitosan film. X-ray diffraction results showed that laponite nanosheet can be found in the composite membrane. Coagulation test showed that the composite hemostatic membrane group significantly shortened clotting time in vitro compared to pure calcium alginate group, commercial hemostatic membrane and blank control group(P<0.001). CCK-8 test of NIH/3T3 cell showed that there was no significant difference in absorbance between the experimental group, negative control group and blank control group (P>0.05). In addition, composite hemostatic membrane displayed a good hemostatic effect and strong adhesion to oral mucosa in animal models. CONCLUSIONS: The composite hemostatic membrane showed great hemostatic effects and had no significant cytotoxicity, which has the potential for clinical application as hemostatic membrane for wounds in oral cavity.
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    Effect of shikonin on proliferation, apoptosis, migration and angiogenesis of hemangioma endothelial cell
    YANG En-li, WANG Na, LI Ming-yang, LI Yi-ming, GENG Yi-ming, ZHANG Dong-sheng, WU Hai-wei
    2022, 31 (6):  576-580.  doi: 10.19439/j.sjos.2022.06.003
    Abstract ( 231 )   PDF (1178KB) ( 79 )  
    PURPOSE: To investigate the effect of shikonin (SKN) on proliferation, apoptosis, migration and angiogenesis of hemangioma endothelial cell (HemEC). METHODS: CCK-8 and EdU assays were used to detect the effect of SKN on proliferation of HemEC. The effect of SKN on apoptosis of HemEC was detected by flow cytometry. Wound healing assay was used to detect the effect of SKN on migration ability of HemEC. The effect of SKN on angiogenesis ability of HemEC was detected by tube formation assay. SPSS 22.0 software package was used for statistical analysis of the data. RESULTS: SKN inhibited proliferation (P<0.001) and promoted apoptosis (P<0.001) of HemEC in a concentration-dependent manner. In additon, SKN inhibited HemEC migration(P<0.01) and angiogenesis(P<0.001). CONCLUSIONS: SKN can inhibit proliferation, migration, angiogenesis and promote apoptosis of HemEC.
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    Experimental study on transplantation of MIRB labeled human deciduous dental pulp stem cells to repair periodontal bone defects in rats
    XU Li, BU Chun-qing, KANG Jie, JIA Guo-tao, SONG Hao, ZHANG Chuan-chen, ZHANG Nan, HAN Fa-bin
    2022, 31 (6):  581-587.  doi: 10.19439/j.sjos.2022.06.004
    Abstract ( 254 )   PDF (2457KB) ( 80 )  
    PURPOSE: To trace the fate of transplanted stem cells from human exfoliated deciduous teeth (SHED) in the repair of periodontal bone defects, Molday ION rhodamine B (MIRB) was used to label SHED and explore the mechanism of SHED in the repair of periodontal bone defects. METHODS: In vitro cultured SHED were labeled by MIRB. The labeling efficiency, cell survival, proliferation and osteogenic differentiation of MIRB-labelled SHED were detected. The labeled cells were transplanted into the rat model with periodontal bone defect. The survival, differentiation and improvement of host periodontal bone healing of MIRB labeled SHED in vivo were analyzed by immunohistochemistry and fluorescence co-staining, nuclear magnetic imaging dual-mode tracking and H-E staining. The data were statistically analyzed with SPSS 24.0 software package. RESULTS: MIRB labeled SHED did not affect its growth and osteogenic differentiation. The optimal labeling concentration was 25 μg/mL, the labeling efficiency of SHED reached 100%. The transplantation of MIRB labeled SHED in vivo can survive for more than 8 weeks. It was found that MIRB labeled SHED could differentiate into osteoblasts in vivo and significantly promote the repair of alveolar bone defects. CONCLUSIONS: MIRB labeled SHED can be traced in vivo, and the effect of labeled SHED on the repair of defective alveolar bone was observed.
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    Effect of local corticotomies on mesenchymal stem cells and growth factors of bone marrow aspirate concentrate
    SHI Lei, WANG Jun
    2022, 31 (6):  588-596.  doi: 10.19439/j.sjos.2022.06.005
    Abstract ( 235 )   PDF (1601KB) ( 68 )  
    PURPOSE: This study investigated the impact of local corticotomies on mesenchymal stem cells (MSCs) and pro-regenerative growth factors contained in bone marrow aspirate concentrate(BMAC). METHODS: Five domestic pigs (Sus Scrofa), 4-5 months of age, either sex, were included. Each pig underwent operations for creation of two 1cm-long corticotomies at one randomly chosen tibia (as experimental), with the other tibia left intact (as control). At postoperative day-14, bone marrow was aspirated from both tibiae and processed into BMAC samples, from which MSCs and plasmas were separated. MSCs quantity, proliferative and osteogenic differentiation properties, as well as several regenerative growth factors contained in BMAC samples, were assessed and compared between the two sides. Statistical analysis was performed with SPSS 25.0 software package. RESULTS: Creation of corticotomy, bone marrow aspiration and corticotomy healing all occurred uneventfully. The quantity of MSCs assessed by colony-forming fibroblast unit assay and flow cytometry was significantly higher on the corticotomy side (P<0.05). MSCs from the corticotomy side also proliferated significantly faster (P<0.05) and showed a tendency of stronger osteogenic differentiation potential although only mRNA expression of osteocalcin reached statistical significance(P<0.05). The concentration of TGF-β, BMP2 and PDGF contained in BMAC tended to be higher on corticotomy side than the control side but the difference did not reach statistical significance. CONCLUSIONS: Local corticotomies are able to boost the quantity and proliferative/osteogenic differentiation property of MSC contained in BMAC.
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    Effect of grape seed extract on oxidative stress and pathological changes of aorta in rats with chronic periodontitis and arteriosclerosis
    XU Jia-li, SUN Kan-da, ZHU Ya-qi
    2022, 31 (6):  597-601.  doi: 10.19439/j.sjos.2022.06.006
    Abstract ( 209 )   PDF (737KB) ( 65 )  
    PURPOSE: To investigate the effect of grape seed extract on pathological changes of aorta in rats with chronic periodontitis and arteriosclerosis, and to analyze the possible mechanism. METHODS: Fifteen SPF male rats with chronic periodontitis and arteriosclerosis were randomly divided into three groups, i.e., model group(n=5), low dose of grape seed extract group (n=5), high dose of grape seed extract group (n=5) , and control group (n=10). The rats in the low and high dose groups were treated with 40 mg·kg-1·d-1 and 80 mg·kg-1·d-1 for 4 weeks respectively, while the rats in the normal control group and the model group were treated with the same amount of normal saline at the same time. The maximal intima-media thickness(IMT) of abdominal aorta was measured by H-E staining, the activity of SOD and the content of MDA in serum were measured by colorimetry, the content of GSH-px in serum and serum levels of inflammatory factor (TNF-α) and interleukin-6(IL-6) were detected by ELISA. p38 mitogen-activated protein kinase/nuclear transcription factor Kappa B p65(p38 MAPK/NF-κB p65) pathway was detected by Western blotting. SPSS 20.0 software package was used for statistical analysis. RESULTS: In the model group, the intima of abdominal aorta was irregularly thickened, with a lot of inflammatory cell infiltration, and arterial lesions appeared. In the low-and high-dose groups of grape seed extract, the plaque of abdominal aorta intima decreased and inflammatory cells reduced significantly, arterial vascular disease was improved, and the improvement was more obvious in high dose group than in low dose group. Compared with the control group, the levels of IMT, serum MDA, TNF-α, IL-6, p-p38MAPK/p38MAPK, NF-κB p65 and serum SOD and GSH-px in the model group were increased, while those in the model group were decreased(P<0.05); the levels of IMT, serum MDA, TNF-α, IL-6, p-p38MAPK/p38MAPK, NF-κB p65 and SOD, GSH-px were decreased in the low and high dose groups(P<0.05). CONCLUSIONS: Grape seed extract can inhibit the oxidative stress level and inflammatory reaction in serum of chronic periodontitis with arteriosclerosis rats, thus improving the intimal lesion of aorta, possibly by inhibiting the activation of p38MAPK/NF-κB p65 pathway.
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    Effect of dragon's blood extract on periodontal tissue repair and TLR4 / NF-κB signal pathway
    WANG Yan-hong, YE Ming-fu, LIU Fan
    2022, 31 (6):  602-606.  doi: 10.19439/j.sjos.2022.06.007
    Abstract ( 223 )   PDF (703KB) ( 68 )  
    PURPOSE: To discuss the effects of dragon's blood extract, a Chinese herb, on periodontal tissue repair and toll like receptor 4/nuclear transcription factor kappa B(TLR4/NF-κB) in gingivitis rats. METHODS: Sixty rats were randomly divided into control group, gingivitis group and low, medium and high dose groups of dragon's blood extract, with 10 rats in each group. Except the control group, the gingivitis rat model was established by silk thread ligation in other groups. The model was established successfully. The low, medium and high dose groups rats were given 150, 300 and 600 mg·kg-1·d-1 dragon's blood extract successively by gavage (once a day for 4 weeks). Rats in the model group and the control group were given the same amount of normal saline by gavage at the same time. After the rats were sacrificed under anesthesia, the jaw tissue of the left maxillary second molar was stained with methylene blue to observe and measure the loss of alveolar bone (ABL), H-E staining was used to observe the pathological changes of periodontal tissue (jaw tissue). The levels of IL-17 and IL-4 in periodontal tissue (jaw tissue) of rats in each group were detected by enzyme-linked immunosorbent assay (ELISA). Bone morphogenetic protein-2(BMP-2), TLR4 and NF-κB p65 protein level in rat periodontal tissue were detected by Western blot. SPSS 19.0 software package was used to analyze the data. RESULTS: Compared with the control group, IL-17, IL-4, TLR4 and NF-κB p65 protein and ABL in jaw tissue of model group were significantly increased (P<0.05), and the level of BMP-2 protein in jaw tissue significantly decreased (P<0.05). Compared with the model group, IL-17, IL-4, TLR4 and NF-κB p65 protein and ABL in jaw tissue of rats in low, medium and high dose groups of dragon's blood extract were significantly increased, and the level of BMP-2 protein significantly decreased(P<0.05). CONCLUSIONS: Dragon's blood extract can inhibit TLR4/NF- κB. Activation of B pathway inhibits inflammatory response and promotes periodontal tissue repair in gingivitis rats.
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    Pilose antler polypeptide CNT14 promoted proliferation and migration of human oral mucosa fibroblast cells
    NA Fei, ZHOU Jian-zhong, HE Yong-wen, XIE Zhi-gang, WANG Quan, LI Zi-liang
    2022, 31 (6):  607-614.  doi: 10.19439/j.sjos.2022.06.008
    Abstract ( 241 )   PDF (2539KB) ( 87 )  
    PURPOSE: To explore the effect of pilose antler polypeptides CNT14 on proliferation and migration of human oral mucosa fibroblast (hOMF) cells and the related molecular mechanism. METHODS: The biosafety of pilose antler polypeptides CNT14 on hOMF cells was verified by live-dead cell staining kit.CCK-8 assay was used to detect the effect of pilose antler polypeptides CNT14 on hOMF cell proliferation. The effect of pilose antler polypeptides CNT14 on hOMF cell migration was detected by scratch test. Western blot was used to detect the expression of α-SMA, TGF-β1, Smad2 and p-Smad2 proteins in hOMF cells stimulated by pilose antler polypeptides CNT14. The effect of Smad2 inhibitors on fibroblast activation induced by pilose antler polypeptides CNT14 was evaluated.The model of keratinized gingival defect was established in New Zealand white rabbits, and the regenerated gingival tissue was stained with H-E. The expression levels of α-SMA, TGF-β1, Smad2 and p-Smad2 proteins in the gingival tissues of regenerated New Zealand white rabbits were detected by immunohistochemistry, and the ability of pilose antler polypeptides CNT14 to promote regeneration of oral gingival tissues was verified. Statistical analysis was performed with SPSS 20.0 software package. RESULTS: The survival rate of hOMF cells was above 95% after treated with pilose antler polypeptides CNT14. After stimulation of hOMF cells with pilose antler polypeptides CNT14, the proliferation and migration rates of hOMF cells were increased compared with the control group (P<0.05). The expression of α-SMA, TGF-β1, Smad2 and p-Smad2 proteins in hOMF cells stimulated by pilose antler peptide CNT14 was increased, and the difference was statistically significant(P<0.05). The expression of α-SMA in fibroblasts induced by Smad2 inhibitor was decreased. In animal experiments, H-E staining showed that the inflammatory response of oral mucosal wounds of New Zealand white rabbits treated with CNT14 was less than that of the control group. Immunohistochemical staining results showed that the expressions of α-SMA, TGF-β1, Smad2 and p-Smad2 in the regenerated gingival tissues of New Zealand white rabbits treated with CNT14 were significantly increased compared with those in the control group on the 9th and 11th days within the gingival wounds(P<0.05). CONCLUSIONS: Pilose antler polypeptides CNT14 has good biosafety and can promote the proliferation and migration of human oral mucosa fibroblast cells, and the expression levels of α-SMA, TGF-β1, Smad2 and p-Smad2 were increased, promoting the regeneration of gingival tissues.
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    Estimation of biomechanical behavior in deep wedge-shaped defects restored by different methods under static and dynamic loads: a 3D finite analysis
    WANG Jing, YIN Jin-ping, LIN Hua-jie, SUN Ya-li
    2022, 31 (6):  615-620.  doi: 10.19439/j.sjos.2022.06.009
    Abstract ( 174 )   PDF (1065KB) ( 98 )  
    PURPOSE: To analyze the biomechanical properties of the right mandibular second premolar with deep wedge-shaped defects under static and dynamic loads by finite element method, so as to select appropriate repair method in clinic. METHODS: To establish the deep wedge-shaped defect model of the right mandibular second premolar, the unrepaired model after root canal treatment was used as the control group, and resin filling (group A), resin filling after post restoration (group B), crown restoration after resin filling (group C), post and crown restoration after resin filling (group D) were used as the experimental groups. According to different materials, group B and group D were further divided into fiber post (B1, D1) group and pure Ti post (B2, D2) group. Static and dynamic loading were applied by three dimensional finite element analysis software, and the stress and strain were analyzed before and after restoration. RESULTS: Compared with the control group, the stress values under static loading was much lower than that under dynamic loading. Von Mises and the maximum principal stress in each experimental group decreased significantly under static and dynamic loading. In the post group, the stress distribution of fiber post was more uniform than that of pure Ti post. CONCLUSIONS: Dynamic load has great influence on the stress distribution. Full crown restoration is beneficial to the stress distribution of the teeth with deep wedge-shaped defects. If a post is necessary, fiber post should be selected.
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    Three-dimensional finite element analysis of three-material endocrown in the restoration of dental defects of mandibular second molars
    GAO Lin, HAN Xiang-yong, XU Xiao-ming
    2022, 31 (6):  621-624.  doi: 10.19439/j.sjos.2022.06.010
    Abstract ( 225 )   PDF (1531KB) ( 89 )  
    PURPOSE: To analyse the effect of restoration and tooth tissue stress distribution under different occlusal preparation thickness, based on three-dimensional finite element modal of the mandibular second molar with root canal therapy and endocrown restorations. METHODS: A mandibular second molar was scanned by cone-beam CT (CBCT) and a three-dimensional finite element model with endocrown restortions was established. Three kinds of endocrown restorations materials with different elastic modulus (glass ceramic, lithium disilicate ceramic and zirconia), and three types of occluscal thickness (1, 2 and 3 mm) were adopted. With a 200 N force loaded vertically and obliquely, the distribution and magnitude of stress in the tooth tissue and endocrown restorations were investigated by three-dimensional finite element analysis. RESULTS: The restoration and tooth tissue maximum stress values were increased firstly and then decreased with the increasing of occlusal thickness; the base material maximum stress values were decreased with the increasing of occlusal thickness; the maximum stress values of tooth tissue and base material were increased with the increasing of restoration material's Young's modulus. Compared to the loading in vertical direction, the maximum stress values were increased with loading in oblique direction. CONCLUSIONS: It's beneficial for tooth tissue to reduce the stress concentration under 2mm thickness. The stress on endocrown will be more concentrated with the increasing of restoration material’s Young's modulus.
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    The role of semaphorin 4D in the mechanism of bisphosphonate-related osteonecrosis of the jaw in rats
    PAN Qiao-ting, ZANG Xiao-long, SUN Zhao-wei, PAN Meng-qi, ZHU Xin-mei, LI Zhi-yong
    2022, 31 (6):  625-631.  doi: 10.19439/j.sjos.2022.06.011
    Abstract ( 228 )   PDF (1559KB) ( 86 )  
    PURPOSE: To study the expression level of semaphorin 4D (Sema4D) in bisphosphonate-related osteonecrosis of the jaw (BRONJ) and to explore its possible role in the occurrence of BRONJ. METHODS: BRONJ-like rat model was established by intraperitoneal injection of zoledronic acid assisted with tooth extraction. The maxillary specimens were extracted for imaging and histological examination, and bone marrow mononuclear cells(BMMs) and bone marrow mesenchymal stem cells(BMSCs) of each group were obtained in vitro for co-culture. Trap staining and counting were performed on monocytes after osteoclast induction. RAW264.7 cells were induced by osteoclast orientation under bisphosphonates(BPs) environment, and Sema4D expression was detected. Similarly, MC3T3-E1 cells and BMSCs were induced to osteogenic orientation in vitro, and the expression level of osteogenic and osteoclastic related genes ALP, Runx2, and RANKL was detected under the intervention of BPs, Sema4D and Sema4D antibody. Statistical analysis of the data was performed using GraphPad Prism 8.0 software. RESULTS: BRONJ-like rat model was successfully constructed. Two weeks after tooth extraction, the healing of the tooth extraction wound in the experimental group was significantly limited, and the tooth extraction wound was exposed. H-E staining results showed that regeneration of new bone in the extraction socket of the experimental group was significantly restricted, dead bone was formed, and the healing of the soft tissue was limited. The results of trap staining showed that the number of osteoclasts in the experimental group was significantly less than that in the control group. Micro-CT results showed that bone mineral density and bone volume fraction in the extraction socket of the experimental group were significantly lower than those of the control group. Immunohistochemical results showed that compared with the control group, the expression level of Sema4D in the experimental group was significantly increased. In vitro studies showed that compared with the control group, the osteoclast induction of BMMs in the experimental group was significantly lower than that in the control group. BMSCs in the experimental group significantly reduced the induction of osteoclasts. Osteoclastic induction experiments revealed that bisphosphonates could effectively inhibit the formation of osteoclasts, and the expression of Sema4D was significantly reduced. Osteogenic induction experiment found that Sema4D significantly reduced the expression of Runx2 and RANKL genes in osteoblasts, while the expression of ALP gene decreased and the expression of RANKL up-regulated after adding Sema4D antibody. CONCLUSIONS: BPs can interfere with normal bone healing time by up-regulating the expression of Sema4D in tissues, leading to coupling disorder between osteoclasts and osteoblasts with inhibition of the maturation of osteoclasts, thereby inhibiting the growth of osteoblasts. Differentiation and expression of related osteogenic factors mediate the development of BRONJ.
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    Prevalence of torque teno mini virus (TTMV) and epstein-barr virus (EBV) in gingival tissues in 80 patients with periodontitis
    YU Tian, ZHANG Yu, PAN Shao-kun, YANG Bin, FENG Xi-ping
    2022, 31 (6):  632-637.  doi: 10.19439/j.sjos.2022.06.012
    Abstract ( 558 )   PDF (624KB) ( 115 )  
    PURPOSE: To study the prevalence of torque teno mini virus (TTMV) and epstein-barr virus(EBV) in patients with periodontitis. METHODS: Gingival tissue samples were collected from 80 patients with periodontitis and 40 periodontal healthy volunteers. The presence of EBV and TTMV-222 were detected by nested PCR, and the virus loads were detected by real-time PCR. Statistical analysis was performed by SPSS 16.0 software package. RESULTS: The detection rates and virus loads of EBV and TTMV-222 in periodontitis group were significantly higher than those in periodontal health group (P<0.05), and the detection rate of TTMV-222 in EBV positive group was significantly higher than that in EBV negative group (P<0.01). There was a positive correlation between EBV and TTMV-222 in gingival tissues(P<0.01). CONCLUSIONS: TTMV infection and co-infection of EBV and TTMV may be related to periodontal disease, but the pathogenic mechanism of the interaction between the two viruses needs further studies.
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    Analysis of correlation between maxillary molars and maxillary sinus mucosal thickening
    SONG Jue, LIU Hao-hao, LIU Jia-liang, CHEN Mei-hua
    2022, 31 (6):  638-642.  doi: 10.19439/j.sjos.2022.06.013
    Abstract ( 503 )   PDF (627KB) ( 76 )  
    PURPOSE: To investigate the influence of maxillary molars on the thickening of maxillary sinus mucosa by cone-beam CT (CBCT). METHODS: A total of 72 patients with periodontitis were included in the study and 137 cases of maxillary sinus were evaluated using CBCT for the following parameters: location, tooth, maximal mucosal thickness, alveolar bone loss, vertical intrabony pockets and minimal residual bone height. The maxillary sinus mucosal thickness ≥2 mm was defined as mucosal thickening. The parameters that could influence the dimensions of the maxillary sinus membrane were assessed. The data were analyzed using univariate analysis and binary logistic regression by SPSS 25.0 software package. RESULTS: Mucosal thickening was present in 56.2% of 137 cases and increased in frequency as the alveolar bone loss of the corresponding molar progressed from mild (21.1%) to moderate (56.1%) to severe (69.2%), and the risk of maxillary sinus mucosal thickening increased by 6-7 times (moderate OR=7.13, 95%CI: 1.37-37.21; severe OR=6.29, 95%CI: 1.06-37.37). The severity of vertical intrabony pockets was correlated with the presence of mucosal thickness (no intrabony pockets 38.7%; type Ⅰ 63.4%; type Ⅱ 79.4%), with an increased risk of maxillary sinus mucosal thickening (type Ⅰ OR=3.72, 95%CI: 1.01-13.70; type Ⅱ OR=5.39, 95%CI: 1.15-25.30). The minimal residual bone height was negatively correlated with the presence of mucosal thickness(≤4 mm OR=99.00, 95%CI: 17.42-562.79). CONCLUSIONS: Alveolar bone loss, vertical intrabony pockets and the minimal residual bone height in maxillary molars were significantly associated with mucosal thickening of the maxillary sinus.
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    Clinical effect of cortical incision with rapid maxillary expansion to assist orthodontic-orthognathic treatment of skeletal Class Ⅲ malocclusion
    DOU Wei-wei, YUE Cong-lei, ZHANG Jia-kun, ZHANG Guang-de, SHA Yao-li, LIU Juan, JIN Xia, DU Yan-xiao
    2022, 31 (6):  643-647.  doi: 10.19439/j.sjos.2022.06.014
    Abstract ( 275 )   PDF (605KB) ( 73 )  
    PURPOSE: To investigate the clinical effect of rapid maxillary expansion with cortical osteotomy combined with orthodontic- orthognathic treatment for skeletal Class Ⅲ malocclusion. METHODS: A total of 84 patients with skeletal Class Ⅲ malocclusion admitted to Jining Dental Hospital from March 2018 to May 2020 were randomly divided into experimental group and control group, with 42 cases in each group. The control group was treated with orthodontic-orthognathic treatment, while the experimental group was treated with orthodontic-orthognathic treatment with rapid maxillary arch expansion by cortical incision. The time of closing gap, alignment time, maxillary first molar and maxillary central incisor tooth movement distance in the sagittal direction were compared between the two groups. Before treatment and 4 weeks after treatment, the vertical distance from the end of the upper central incisor edge to the horizontal plane(U1I-HP), the distance from the apex of the upper central incisor to the coronal plane(U1I-CP), the vertical distance from the edge of the upper pressure groove to the coronal plane(Sd-CP), the vertical distance from the upper alveolar seat point to the horizontal plane(A-HP), the vertical distance from the point of the upper lip to the coronal plane(Ls-CP), and the vertical distance from the inferior point of nose to coronal plane(Sn-CP) were measured, and the relevant changes were calculated. During the treatment period, the complications of the two groups were compared. SPSS 20.0 software package was used for statistical analysis of the data. RESULTS: There was no significant difference in alignment time, A-HP change, Sn-CP change, maxillary first molar movement distance and maxillary central incisor movement distance between the two groups (P>0.05). The closing interval in the experimental group was significantly shorter than that of the control group (P<0.05). The changes of U1I-HP, U1I-CP, Sd-CP, and Ls-CP in the experimental group were significantly higher than those in the control group (P<0.05). There was no significant difference in the incidence of complications between the two groups during treatment (P>0.05). CONCLUSIONS: Rapid maxillary expansion of cortical incision assisted orthodontic-orthognathic treatment of skeletal Class Ⅲ malocclusion patients can shorten the closing gap time and improve the treatment effect, which has no obvious influence on the sagittal direction of the teeth.
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    Construction and application of an appraisement system of oral surgery difficulty by Delphi method
    BAI Jin-xin, YANG Yi-duo, ZHANG Hong, CHEN Ya-zhen, LIN Lu
    2022, 31 (6):  648-652.  doi: 10.19439/j.sjos.2022.06.015
    Abstract ( 221 )   PDF (597KB) ( 58 )  
    PURPOSE: To build an appraisement system of oral surgery difficulty by Delphi method in order to provide basis for evaluation of oral surgery level and performance appraisal methods. METHODS: Delphi method was used to perform two rounds of expert selection, combination of critical value method and synthetical index method was used to select the index, and the weight of the index system was determined by superiority chart. RESULTS: The final evaluation index system of oral surgery difficulty included 4 first-level indexes and 20 second-level indexes. Index evaluation, index meaning and index weight were included in the index system. CONCLUSIONS: The evaluation index system of oral surgery difficulty has its particularity compared with traditional operation index system.
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    Cone beam CT imaging findings in patients with temporomandibular joint disorder syndrome and unilateral chewing
    LYU Yun-song, LI Zhao-hui
    2022, 31 (6):  653-656.  doi: 10.19439/j.sjos.2022.06.016
    Abstract ( 268 )   PDF (488KB) ( 96 )  
    PURPOSE: To analyze the cone beam CT (CBCT) features in patients with temporomandibular disorder syndrome (TMD) and unilateral chewing. METHODS: A total of 80 patients with temporomandibular disorder syndrome (TMD) and unilateral chewing were selected as the experimental group, and 40 healthy volunteers were selected as the control group. Both groups underwent bilateral CBCT scans to obtain three-dimensional images, and the temporomandibular joint(TMJ) parameters were measured and compared between the two groups. The data were analyzed performed using SPSS 22.0 software package. RESULTS: There was no significant difference in bilateral TMJ parameters in the control group(P>0.05). The inner and outer diameter of the condyle on the unilateral chewing side of the experimental group was significantly lower than that on the non-unilateral chewing side, and the condyle horizontal angle and condyle height were significantly higher than those on the non-unilateral chewing side(P<0.05). The anteroposterior diameter of the condyle, the inner and outer diameter of the condyle, the horizontal angle of the condyle, the vertical angle of the condyle, the intra-articular space and the post-articular space of the experimental group were significantly lower than those of the control group, while the pre-articular space was significantly higher than that of the control group(P<0.05). The anteroposterior diameter and retro-articular space of the condyle on the non-unilateral chewing side were significantly lower than those in the control group, and the inner and outer diameters of the condyle were significantly higher than those on the unilateral chewing side, and the height of the condyle was significantly lower than that on the unilateral chewing side(P<0.05). CONCLUSIONS: Patients with TMD syndrome and unilateral chewing have abnormal changes in bilateral TMJ structure, showing medial and posterior displacement of the condyle on the unilateral chewing side and a compensatory increase in the pre-articular space on the non-unilateral chewing side.
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    Effect of special oral care mode on periodontal health in adolescent orthodontic patients
    JU Ya-qiong, XU Xiao-ming, HAN Xiang-yong, MA Yin, WANG Gui-xiang
    2022, 31 (6):  657-660.  doi: 10.19439/j.sjos.2022.06.017
    Abstract ( 182 )   PDF (522KB) ( 62 )  
    PURPOSE: To investigate the effect of special oral care mode on periodontal health of adolescent orthodontic patients. METHODS: From January 2019 to January 2020, one hundred adolescent orthodontic patients who received treatment in our hospital were randomly divided into experimental group and control group according to the principle of completely random number table, with 50 cases in each group. Patients in the control group were given routine oral care, while those in the experimental group were given special oral care; three months later, the periodontal health status of the two groups were compared using SPSS 21.0 software package. RESULTS: There was no significant difference in PLI and GI between the two groups before treatment (P>0.05). After treatment, PLI and GI in the experimental group were significantly lower than those in the control group(P<0.01). There was no significance difference in SBI and EDI before treatment between the two groups(P>0.05). After treatment, SBI and EDI in the experimental group were significantly lower than those in the control group(P<0.01). There was no significant difference in the scores of periodontal health knowledge before treatment between the two groups(P>0.05). After treatment, the scores of the two groups were significantly increased(P< 0.01), and the scores of the experimental group were significantly higher than those of the control group (P<0.01). The patients' satisfaction in the experimental group was significantly higher than that in the control group (90.00% vs 72.00%, P=0.022). CONCLUSIONS: Special oral care mode can significantly improve periodontal health status of adolescent orthodontic patients.
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    Impact of maxillary sinus floor on the mesial movement of maxillary first molar
    ZHOU Zi-qian, CHEN Zhen-qi
    2022, 31 (6):  661-667.  doi: 10.19439/j.sjos.2022.06.018
    Abstract ( 322 )   PDF (914KB) ( 120 )  
    PURPOSE: To investigate the impact of maxillary sinus floor on the mesial movement of maxillary first molar. METHODS: Orthodontic patients with maxillary first premolars extracted were selected. Their maxillary first molars were divided into case group and control group according to whether their roots were in contact with the maxillary sinus floor. The case group was further divided into three subtypes according to the depth of the root extruded into the maxillary sinus. A total of 64 maxillary first molars from 32 patients were enrolled in this study, including 34 in the case group (five in subtype Ⅱ, fourteen in subtype Ⅲ, and 15 in subtype Ⅳ) and 30 in the control group. The mesial movement distance of each root and crown and the inclination of each root long axis were measured, and resorption of each root was evaluated. SPSS 22.0 software package was used for data analysis. RESULTS: After orthodontic treatment, the mesial movement distance of roots from both groups were all lager than 2mm. The mesial movement distance of the crown was not statistically different between the two groups (P>0.05), while the mesial movement distance of the roots in the control group was significantly larger than in the case group(P<0.05). Inclined movement towards the mesial direction was found in both groups, and the inclination angle was significantly larger in the case group(P<0.05). The inclination angle of the first molars in the subtype Ⅳ was significantly larger than that in the subtype Ⅲ and the control group. Most of the maxillary first molars from both groups had no obvious root resorption(P>0.05). CONCLUSIONS: With the proper force system, maxillary first molars with roots extruded into the maxillary sinus floor can be moved mesialy with mild or no root resorption, while a larger inclination can be found compared with maxillary first molars without root extruding into the maxillary sinus floor. The deeper the root extruding into the maxillary sinus, the larger the inclination angle will be.
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    Evaluation of the effect of repairing unilateral cleft lip nose deformity with autogenous concha cartilage
    LIU Xiao-lin, WANG Yu, REN Qun, FENG Xiao-wei, DI Lu, LI Xiang-jun
    2022, 31 (6):  668-672.  doi: 10.19439/j.sjos.2022.06.019
    Abstract ( 187 )   PDF (1537KB) ( 81 )  
    PURPOSE: To explore the effect of nasal deformity correction after unilateral cleft lip repair with autogenous concha cartilage transplantation. METHODS: Thirteen patients with nasal deformity after unilateral cleft lip surgery were collected, who were treated with autogenous concha cartilage and nasal septum deviation correction at the same time. Their chin-lifting photos were taken before operation, five days, one month and six months after operation. The nasal morphology was evaluated by subjective evaluation and objective measurement, and statistical analysis was performed using SPSS 21.0 software package. RESULTS: Subjective evaluation showed that there was significant difference in nasal morphology between prior to operation and 5 days postoperatively (P=0.000), but there was no significant difference between 5 days postoperatively and 1 month and 6 months postoperatively(P=0.110, 0.053). In objective measurement, there was no significant difference in the symmetry rate of nasal tip between prior to operation and 5 days, 1 month and 6 months after operation(P=0.051, 0.136, 0.204), but there was significant difference in the symmetry rate of nasal base, nasal columella, extranasal convex angle and nasal alar base inclination angle between prior to operation and 5 days postoperatively(P=0.000, 0.000, 0.000, 0.000). However, there was no significant difference in symmetry rate of the above four indexes between 5 days after operation and 1 month and 6 months after operation(P>0.05). CONCLUSIONS: Autogenous concha cartilage transplantation can effectively improve the symmetry of nasal floor, columella and alar after operation, and the effect is stable half a year after operation.
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