Objective　To study the effects of two kinds of new collagen membrane (fish collagen and porcine collagen) on the osteogenic differentiation of SD rat bone marrow mesenchymal stem cells (rBMSCs) and observe their repair effects on the cranial parietal defects of SD rat. Methods　The surface morphology and water contact angle of the two membranes were measured by scanning electron microscopy (SEM) and contact angle measuring instrument. rBMSCs were cultured on membranes, and cells were also seeded on blank well plates as a blank control group. The effects of the two membranes on the proliferation of rBMSCs at 1, 3, 5 and 7 days were examined by CCK-8 and the adhesion and extension of the cells were observed by laser confocal microscopy at 24h. The osteogenic properties in vitro of the two membranes were evaluated by alkaline phosphatase (ALP) staining and activity assay, alizarin red staining and semi-quantitative determination of calcium nodules and real-time fluorescent quantitative PCR. In vivo experiments, bone defects with diameter of 5mm were prepared on both sides of the cranial suture of SD rats. The left bone defect area was implanted with fish collagen membrane or porcine collagen membrane. The right bone defect area was used as a blank control group. After 3 months, micro-CT was used to detect the bone regeneration in the cranial parietal defect area. Results　SEM: The surface of the fish collagen membrane was dense, and the porcine collagen membrane had a loose porous surface. Contact angle measuring instrument: The hydrophilicity of porcine collagen membrane was better than fish collagen membrane (P<0.05). CCK-8 and laser confocal microscopy: The cells spread well at 24h and stably proliferated within 7 days on both membranes and blank well plates. Osteogenic properties in vitro: ALP activity of rBMSCs on porcine collagen membrane at 5d, extracellular matrix mineralization at 14d, and the expression of cell-associated osteogenic genes Bmp2, Col1, Runx2 at 7d were higher than fish collagen group and blank control group (P<0.05). In vivo osteogenic experiment (3 months): Porcine collagen membrane promoted bone regeneration significantly better than fish collagen membrane and blank control group (P<0.05). There was no significant difference between fish collagen membrane group and blank control group. Conclusion　The effects of porcine collagen membrane on promoting bone regeneration in vivo and in vitro are significantly better than fish collagen membrane, and it has the potential as a membrane for guiding bone tissue regeneration.

Objective To study the dynamic changes of RNAKL/OPG expression in orthodontic alveolar bone remodeling and its effects on osteoclast formation and bone tissue remodeling. Methods the left maxillary orthodontic model of mice was established and observed continuously on day 5, day 7, day 14 and day 21 after orthodontic treatment. The distance of first molar movement and the change of alveolar bone in distal root pressure were analyzed by Micro CT. HE staining and TRAP staining were used to detect the histological and osteoclastic changes of the distal root pressure side at different time points. The expression of RANKL,OPG and Caspase3 were detected by immunohistochemical staining and immunofluorescence staining at different time points.Results after the orthodontic force was applied, the distance between the left first molar and the second molar increased gradually, and the expression of RNAKL and OPG increased gradually in the distal root pressure side of the first molar, and the expression of RANKL reached a peak on the 7th day after the application of orthodontic force. Then the peak of OPG expression appeared on the 14th day, the expression peak of RANKL was earlier than that of OPG, and accompanied by osteoclast formation peak. At the same time, the number of apoptosis in periodontal tissue increased gradually, tooth movement was obvious. Conclusion During orthodontic treatment, the expression changes of RANKL/OPG showed temporal characteristic changes, accompanied by changes in the expression of key apoptotic molecules, and these changes were closely related to alveolar bone remodeling and tooth movement.

Objective　To investigate the expression changes of TRAF6 and c-fos mRNA on orthodontic tooth movement after mandibular ramus osteotomy regulated by parathyroid hormone (PTH）. Methods Forty eight rabbits were randomly divided into experimental group and control group. An experimental model of mandibular ramus osteotomy with installation of an orthodontic tooth movement device was established. The experimental group received intermittent subcutaneous injections of PTH 40 μg/kg and the control group received injections of normal saline postoperatively. The mesio movement speed of the first molars in the lower jaw was measured after surgery. The histomorphological changes on the compression side of orthodontic teeth was observed by HE staining. The number of osteoclasts on the compression side of periodontal tissue was counted by TRAP staining. Changes in expression of TRAF6 mRNA and c-fos mRNA in the periodontal tissues of the first molars were evaluated by quantitative fluorescence polymerase chain reaction. Results The movement of the first molars was more rapid in experimental group than in control group in the 21 days postoperatively. The number of osteoclasts on the compression side of orthodontic teeth in the experimental group was larger. Significantly higher TRAF6 and c-fos mRNA levels were detected on the compression side of the periodontal tissues in experimental group than in the control group. Conclusions Administration of PTH can increase TRAF6 and c-fos mRNA expression in the compressed periodontal tissues, thereby promoting maturity and differentiation of osteoclasts and accelerating orthodontic tooth movement after mandibular ramus osteotomy.

Objective　To evaluate the cytotoxicity of AlCoCrCuFeTix (x=0,0.25,0.5,1) series high entropy alloys and explore the effect on apoptosis and type I collagen synthesis in L929 Cells by flow cytometry and immunofluorescence. Methods　The AlCoCrCuFeTix (x=0, 0.25, 0.5, 1) series of high entropy alloys were tested by MTT test to evaluate the cytotoxicity of series of alloys. Annexin V-FITC/PI staining with flow cytometry was used to evaluate the effect of series of materials on apoptosis of L929 cells. Immunofluorescence staining was used to detect the level of collagen I synthesis to evaluate the effect of materials on cell proliferation. Results　The cytotoxicity series of high entropy alloys showed an increasing trend with the increase of Ti elements. At the same time, the proliferation rate of L929 cells decreased, the rate of apoptosis increased and the expression level of type I collagen in L929 cells decreased. The metal of AlCoCrCuFe had good cell compatibility, the cytotoxicity was Grade 1 at each time, and there was no statistical difference in the apoptotic rate and type I collagen expression level compared with the blank control group. Conclusions　AlCoCrCuFe alloy in the series of AlCoCrCuFeTix (x=0, 0.25, 0.5, 1) high entropy alloys has good cell compatibility and can preliminarily meet the basic requirements of the application of dental materials.

Objective　 To investigate whether there are intraductal or oral dysbacteriosis in patients with sialolithiasis, and to explore the relationship between bacteria and the occurrence of sialolithiasis. Method A total of 20 patients with sialolithiasis (1 parotid and 19 submandibular gland) were enrolled in the study as the experimental group. Samples of stone, salivary in oral cavity or intraduct were collected. A total of 20 healthy volunteers were included in the study as the control group. Samples of salivary in oral cavity or intraduct were collected. The bacterial DNA of the extracted samples was amplified by enzyme chain polymerization. The Roche high-throughput 454 pyrosequencing technology was used to sequence the PCR amplicons of the 16S rRNA V1-V3 variable region of bacteria. The sequencing data were further analyzed by using bioinformatics methods to identify the bacterial components and communities. The differences between the experimental and control groups were compared. Result DNA sequencing of saliva and stone samples was successfully performed. Sample sparse curves showed that the sequencing depth was sufficient, and the coverage coverage depth (Coverage index) met the experimental requirements. There was no difference in the biological diversity of intraductal saliva and intraoral microbiota between the experimental group and the control group. There was also no difference in the biological diversity between the stone sample and the intraductal saliva (P>0.05). The Shanno index, Chao index, and ACE index were higher in intraductal saliva than oral cavity (P<0.05). Intraductal microbiota structure comparison showed that Fusobacterium in the experimental group was significantly higher than the control group (p <0.05). At genus level, Prevotella, Porphyromonas and Neisseria were significantly reduced in the experimental group (P<0.05). The comparison of bacterial structures in the oral cavity showed that at the phylum level, Proteobacteria was significantly higher in the experimental group than in the control group (P<0.05). At genus level, Proteus, Streptococcus, and Veillonococcus in the experimental group were significantly lower than the control group (P<0.05). Conclusions The structure and diversity of microbiota in the stone sample are similar to salivary gland duct. The microbial diversity in the salivary gland duct is significantly higher than oral cavity. There is a significant difference in the microbial community between sialolithiasis patients and controlled subjects. There is a dysbacteriosis in the oral and salivary gland ducts of sialolithiasis patients.

Abstract：　Objective　Using CBCT to evaluate the amount of labial and palatal alveolar in the root apex area of the maxillary central incisor in the skeletal class II adults before orthodontic treatment, and analyzing the related factors about the labial and palatal alveolar of the maxillary central incisors. Methods　The apical horizontal reference plane was the LA plane. The plane 3mm above the LA plane was the LU plane and the plane 3mm below the LA plane was the LL plane. In the LA plane, the distances from the apex to the labial and palatal alveolar are L1 and L2 respectively and LT1 was L1 and L2. In the LU plane, the distances from the intersection of the long axial of the incisor and the LU plane to the labial and palatal alveolar are L3 and L4 respectively and LT2 was L3 and L4. In the LL plane, the distance from the intersection point of the LL plane and the labial side to the labial alveolar was L5, the distance from the intersection point of the LL plane and the palatal side to the palatal alveolar was L6, and the distance from the intersection point of the LL plane to the labial and palatal alveolar was LT3.θ1 was the Angle between the palatal plane and the axis of the incisor, andθ2 was the angle between the palatal plane and the perpendicular line of the midpoint of the lip and palate alveolar crest. Results　θ1 was positively correlated with L1、L3 and L5.θ2 was positively correlated with L2、LT1、L4、LT2、L6、LT3 and negatively correlated with L1、L3、L5. SN-MP is negatively correlated with L1、LT1、L3 and LT2. SNA is positively correlated with L2、L4、L6 and LT3. Conclusions　The results showed that the thickness of maxillary central incisors labial and palatal alveolar in skeletal class II adults was closely correlated with the inclination of maxillary central incisors，the inclination of alveolar crest and the vertical dimension, among which the inclination of maxillary central incisors and the vertical dimension had the greatest influence on the thickness of maxillary central incisors labial alveolar bone.

Objective　To explore the clinical effect and mechanism of orthodontic treatment for Class II Division 2 with miniscrew. Methods　A total of 12 adult patients with retroclined maxillary incisors and deep overbite were selected. Anterior teeth were intruded by miniscrews. The changes of upper incisors in CBCT images were measured. Results　The inclination of the upper incisors returned to normal in 12 patients. The vertical distance from incisor edge to palatal plane decreased by（1.59±2.05）mm, and incisors labially inclined 19.34°±7.96°. Conclusions　In the maxillary anterior region, miniscrew can simultaneously intrude and labially incline upper incisors.

OBJECTIVE: The thesis compare the effects of alternate rapid maxillary expansion and constriction before maxillary traction and direct anterior traction in the early permanent dentition skeletal class Ⅲ. Simultaneously compare the stability of upper anterior teeth.Accordingly explore a more suitable treatment method. METHODS: Twenty patients with Class III malocclusion were selected from the Department of Orthodontics, Stomatology Hospital of Shanxi Medical University. They were randomly divided into an expandsion and contraction group and unexpanded group. The sample in expansion and contraction group was repeatedly expanded for 8 weeks. 8 weeks later,the anterior traction was started at the same time as the unexpanded group, the cephalometric measurement indicators before and after treatment were analyzed and compared after 3 months. RESULTS: The values of SNA, ANB, U1-SN, MP-SN and UL-EP increased after treatment in the expansion group (P<0.05). SNA, ANB, U1 after treatment in the non-expanded group The values of -SN, MP-SN and UL-EP were all increased, and the differences were statistically significant (P<0.05). The changes of SNA, ANB, U1-SN, MP-SN and UL-EP before and after treatment in the two groups. The difference was statistically significant (P<0.05). The degree of change in the expansion and contraction group was higher than that in the non-expanded group. The correlation between the anterior teeth and the lingual direction of the expansion and contraction group was only related to the degree of ANB change before and after treatment. Statistically significant, the two are positively correlated. Conclusion: Repeated expansion and contraction of the skeletal class III malocclusion before volition in the dentition period has a better clinical effect than direct anterior traction, but it will cause a certain degree of loosening of the upper anterior teeth.

Objective To evaluate the efficacy of combined total glucosides of paeony capsules in the treatment of oral lichen planus. Methods Multiple electronic databases including Chinese databases such as China Knowledge Network, Wanfang Database, and foreign websites such as PubMed and Web of Science were screened for relevant studies using the following key words “white glucosides”, “Pavlin”, “oral lichen”, “total glucosides of paeony” and “oral lichen planus”. All randomized controlled trials comparing the effect of conventional therapy of OLP and combined therapy with total glucosides of paeony (TGP) were included in this meta-analysis. We named the conventional therapy as the conventional control group and the combined therapy with total glucosides of paeony (TGP) as the combined group. Results The search identified 20 studies, which included 1567 cases. The analysis of the effective rate showed the combined group (89.91%) was significantly higher than the conventional control group (P<0.01). When the observation period was extended to three months, the effectiveness of the combined group was improved; however, the conventional group did not make any obvious improvement. Concerning the recurrence rate, the combined group was lower than the conventional group (P<0.01); and the pain relief was better in the combined group (P<0.01). Conclusions The combination of total glucosides of paeony capsules and conventional therapy can improve the therapeutic efficiency and reduce the recurrence rate of OLP, and relieve the pain of OLP patients without severe adverse reactions. Prolonged medication time can also improve the treatment effect and the recommended period is 3 months.

Objective　 To compare the pharyngeal closure between articulation and cheek blowing of normal adult speakers. Methods　 Comparative analysis of pharyngeal closure rates between [i] sounds and cheek blowing in 26 healthy adults using Nasopharyngeal fiberscope (NPF) was carried out. Results　 The mean value of the rate of velopharygeal incompletition during pronouciation state (RVPIp） was 4.88%, the standard deviation was 2.31%, and the mean value of the rate of velopharygeal incompletition during cheek blowing state (RVPIb） was 50.60% and the standard deviation was 16.80%. After statistical analysis, the RVPIb was higher than the RVPIp, and there was a significant difference between the two. Conclusion Under non-speech activities (taking the cheek blowing as an example), the degree of pharyngeal closure is not as good as the speech activities, suggesting that speech tools are more effective than non-speech tools in training the pharyngeal closure function.

Endochondral ossification is one of the main modes of bone repair, which follows specific biological steps and involves complex regulatory mechanisms. Currently, it has attracted particular attention in the field of regenerative medicine. A better understanding into the mechanism of endochondral ossification, will allow us to devise strategies to improve bone regeneration. In this context, we reviewed the regulation mechanism of osteochondral ossification in bone repair.

Oral cancer is a malignant tumor of the lips or mouth. It is one of the 10 most common cancers in the world. 90% of oral cancer cases are Oral squamous cell carcinoma (OSCC) . PI3K/AKT signal transduction pathway is one of the important signal transduction pathways in cells, and has close relationship with the occurrence and development of many malignant tumors (including OSCC) . This article mainly reviews the PI3K/AKT pathway mediating the occurrence, development and metastasis of oral squamous cell carcinoma.

Hyperlipidemia is a common systemic metabolic disease that often occurs in the elderly people with a high incidence. It is one of the risk factors for implant treatment, which can cause poor implant osseointegration, and, in turn, affect the clinical efficacy of implant denture. In this paper, advances in the effects of hyperlipidemia on osseointegration of titanium implants are reviewed.

Vertical root fracture often occurs in the teeth after RCT（root canal therapy）, and it is more common in the oval-shaped root canals. The fracture resistance of teeth can be changed by many steps of RCT, especially root canal preparation and obturation. The stress introduced and the microcracks produced during the treatment play a decisive role in the subsequent root fracture. In addition to the morphological characteristics between the oval root canal and the circular root canal, their respective responses to RCT result in a large difference in the fracture resistance of teeth. At present, the studies about the changes in the root fracture resistance of teeth with oval root canals after RCT have not been reported. In order to improve the success rate and the prognosis of root canal treatment, it is important to understand the effect of RCT on the resistance of root with oval canals. This article will make a summary in this field.

Currently, the orthodontic arch wire is mainly made of metal materials. This kind of arch wire not only has poor aesthetics but also gradually releases metal elements which are easy to cause allergic reactions of patients. Although some metal orthodontic wires are coated with enamel-like coatings in clinical practice, the chemical coatings on the surface of the wires will wear and peel off and age over time，which can not meet the aesthetic requirements of patients . In recent years, glass fiber reinforced composites and polyphenylene polymers have been used as a new generation of metal-free transparent arch wires.

[Abstract] As one of the most common treatment for discolored teeth, tooth bleaching has expertly applied in clinic. However, the tooth sensitivity happened intraoperative or postoperative is always an unavoidable complication. This review introduces the mechanisms of tooth sensitivity and the categories、effects and relative research progresses of the medicines combining with tooth bleaching.

Oral bad habits during Children's growth and development may lead to the unbalance in their facial muscles and increase the risk of malocclusion In dental and maxillofacial system. The aim of early correction and muscle function training in children is to remove the etiology of malformation and to correct abnormal craniofacial structure and occlusion. Preformed muscle functional appliance is an appliance that promotes occlusion development and craniofacial growth by changing the function of oral-facial system. It can prevent the patients' bad habits and the risk of craniofacial malformation during their mixed dentition. Preformed muscle functional appliance has been widely used recently by doctors and patients for its preforming,rapid curative effect ,comfort and other advantages. This article will review the preformed muscle functional appliance.