Objectives To study the characteristics of salivary microflora in the children with severe early childhood caries by metaproteomic technique. Methods We collected non-stimulating saliva from the children with severe early childhood caries and with free caries. All the salivary proteins were extracted and zymolysised into polypeptides for mass spectrometry analysis so as to analyze the characteristics of microbial community in childhood. Results The salivary microflora in the children with free caries originated from 19 phylums, or 1216 species. The high abundant oral microbiota are the 5 phylums of Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Fusobacteria and the 11 species of Neisseria lactamica, Streptococcus pneumoniae, Neisseria sicca, Haemophilus parainfluenzae, Neisseria meningitis, Haemophilus influenzae, Neisseria flavescens, Neisseria gonorrhoeae, Kingella kingae, Neisseria mucosa, Neisseria polysaccharea. The salivary microflora in the children with severe early childhood caries originated from 24 phylums, or 1698 species. The high abundant oral microbiota are the 5 phylums of Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Cyanobacteria and the 4 species of Streptococcus pneumoniae, Neisseria lactamica, Neisseria sicca, Haemophilus influenzae. Conclusions Metaproteomics can be used to analyze the composition of oral saliva microbial community. The structure of saliva microflora in children with severe dental caries is more complicated than that in the children with free caries, which may be related to the dental caries and dysbiosis of the oral microecology.

Objective　To analyze the differentially expressed genes of patients with oral squamous cell carcinoma (OSCC) from normal people through biological information analysis, to discuss the key genes and pathways from molecular level, and to preliminarily investigate the gene landmarks of the occurrence and development of OSCC. Methods Differentially expressed genes (DEGs) between OSCC and control tissue samples from the GSE3524 and GSE6631 gene expression profile dataset were screened. The Gene Ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and protein-protein interaction (PPI) network analyses were performed. Furthermore, key genes on the survival of patients with OSCC were analyzed. Results A total of 129 DEGs were identified, including 45 up-regulated and 84 down-regulated genes. GO, KEGG and PPI network analyses were performed. In addition, the high expression of the hub genes from the PPI network (including secreted phosphoprotein 1, matrix metalloproteinase 1, serpin family E member 1 and plasminogen activator, urokinase; P= 0.045, 0.046, 0.0024 and 0.00049, respectively) was associated with a decrease in overall survival for patients with OSCC as identified using survival and expression data. Conclusion The identified hub genes and pathways may help to elucidate the molecular mechanisms of OSCC occurrence and development. Additionally, they may be useful as therapeutic targets or serve as novel biomarkers for OSCC prognosis prediction.

Abstract：　Objective　To evaluate effect of different decontaminations on bond strength of salivary contaminated dentin of primary teeth after light curing of the universal adhesive. Methods　Extracted human primary molars (60) were ground to mid-coronal dentin. The dentin specimens were randomly divided into 6 groups (n = 10/group/molar type) for a one-step universal adhesive (Single Bond Universal Adhesive): no saliva contamination (group A); saliva contamination after light curing of the adhesive followed by air drying (group B), rinsing with water spray/air drying (group C), direct reapplication of the adhesive and light curing (group D), air drying/reapplication of the adhesive and light curing(group E) or rinsing with water spray/air drying/reapplication of the adhesive and light curing(group F). Resin composite (Filtek Z250) was applied on the treated dentin surfaces. The specimens were stored at 37°C and 100% humidity for 24 h. After storage,micro-tensile strength(μTBS) and scanning electron microscope observation(SEM) was measured. Results　The μTBS of the group of E is the highest, and that of the group of D is the weakest. The fracture of the group of B、C and D is mostly at the bottom of mixed layer, and resin is not obvious. The fracture of the group of A、E and F is mostly at middle of mixed layer, and resin is obvious. Conclusions　When saliva contamination happened after light curing of the universal adhesive, the reapplication of the adhesive after cleaning the dentin surface was necessary for restoring the bond strength.

Objective: This study is aimed to analyze the morphology of soft tissue profile in adult skeletal Class III malocclusion. Methods: 53 adult patients (female 32, male 21) with skeletal Class III malocclusion and 53 adult patients with skeletal Class I malocclusion were taken cone beam CT (CBCT) before treatment, the lateral cephalometric radiographs were rebuilt by Dolphin imaging 11.0 and measured using soft tissue analysis of Holdaway. The results were divided into different groups based on gender and sagittal skeletal pattern. Statistical analysis was carried out with SPSS 20.0. Results: The skeletal Class III patients had sunken mid facial soft tissue (skeletal profile convexity, Sn - H line), protrusive upper lip (upper lip sulcus depth, upper lip strain measurement), protrusive lower lip (Li – H line), protrusive chin and shallow mentolabial sulcus (soft tissue facial angle, H angle, mentolabial sulcus depth, soft tissue chin thickness) compared to adult skeletal Class I malocclusion. The differences of soft tissue profile in adult skeletal Class III malocclusion between different genders were among soft tissue facial angle, upper lip sulcus depth and upper lip strain measurement. These differences revealed that females had better soft tissue compensation. Conclusion: Because of the inharmonious relationship between jaws, the soft tissue profile in adult skeletal Class III patients has remarkable different features compared with skeletal Class I patients. Orthodontists should know these features well in order to make more suitable and comprehensive treatment plan and improve the dissatisfactory soft tissue profile in skeletal Class III patients.

Objective To investigate the factors that influence the clinical efficacy of non-extraction treatment to moderate crowding with Damon self-ligating system. Materials and methods Forty cases with moderate crowding were selected and all of them were treated with Damon Q self-ligating appliances. Fourteen hard-tissue and nine soft-tissue measurements from cephalometric radiophotographs were analyzed before and after crowding correction. According to chin lip Z angle, all cases were divided into two groups (successful group and failure group). The characteristics of soft and hard tissues were analyzed with paired-samples t test and independent-samples t test between two groups using SPSS 19.0 software. Results of 40 cases, 22 cases were included in successful group, 18 cases were allotted in failure group. There was no significant difference in gender and age distributions between two groups. L1-AP angle significantly increased after treatment in two groups, while FMIA significantly decreased. Lower lip to E line distance significantly increased and Z angle was significantly decreased in failure group after treatment. L1-NB distance, mandibular plane angle (FMA), lower/upper lip to E line distance, as well as soft/hard tissue facial angle in failure group were more than that in successful group in both T1 and T2. The distribution of individuals with low angle, average angle and high angle was significantly different between two groups and the low angle cases achieved better therapeutic effects. Conclusion The upright lower incisor, ideal lip protrusions and lower mandibular plane angle are favorable prerequisites for the successful non-extraction treatment to moderate crowding with Damon self-ligating system.

Abstract：　Objective　Comparative study of three-dimensional of the upper airway in patients with non-syndromic cleft lip and palate Methods　51 patients with non-syndromic cleft lip and palate were selected (37 males, 14 females, mean age 17.4±5.93 years) and 53 patients with skeletal class I population from department of Orthodontics(39 males and 14 females, mean age 17.4±6.07 years). The cone beam CT was taken, and the three-dimensional measurement analysis was performed using Dolphin 3D 11.9 software. The SPSS 25.0 software package was used for statistical analysis to compare the volume and minimum area of the upper airway. Results　The upper airway volume of the nasopharyngeal segment of patients with non-syndromic cleft lip and palate was larger than that of skeletal class I population(P<0.01), but there was no significant difference between the rest of the airway and the total volume (P>0.05); The minimum area of the nasopharyngeal and pharyngeal segments of patients with non-syndromic cleft lip and palate was greater than that of skeletal class I population(P<0.05). Conclusions　The upper airway three-dimensional structure of patients with non-syndromic cleft lip and palate may be similar to the skeletal class I population,the upper airway respiratory function in patients with non-syndromic cleft lip and palate may be affected by multifunctional factor.

[Abstract]Objective: To investigate the expression of matrix metalloproteinase 3 (MMP-3) in the labial glands and saliva of patients with Sjogren's syndrome and to determine whether its expression level is correlated with pathological grade. Method: The glandular glands and saliva of 35 patients with Sjogren's syndrome (experimental group) and 20 patients with mucinous gland cysts (control group) are collected. The enzyme-linked immunosorbent assay (ELISA) is used to detect the expression level of MMP-3 in the saliva of the two groups. Using immunohistochemical method to observe the expression of MMP - 3 in labial gland.The intensity of MMP-3 expression in the labial glands is quantified by using image analysis software (IPP 6.0). The pathological grade is divided into two groups of grade 1, grade 2 and grade 3 and grade 4. Results: The expression of mmp-3 in saliva and labial glands of the experimental group is higher than that of the control group, and the difference is statistically significant (p<0.05). The expression level of MMP-3 in the saliva and labial glands of patients with high pathological grade is higher than that of pathology. Patients with low grades has statistically significant difference (p<0.05). Conclusion: MMP-3 in the labial glands of patients with Sjorgen’s syndrome may be involved in the destruction of acinar and glandular stroma, leading to the occurrence of disease. The expression level of MMP-3 in saliva and labial glands may be an indicator of Sjorgen’s syndrome and provide a reference for clinical diagnosis and treatment.

Objective: To evaluate the retreatment efficiency of three root canal filling technique with Mtwo-R using cone beam computer tomography(CBCT) scan. Methods: 30 human mandibular premolar with a single straight root canal was prepared with MTwo.They were divided into three groups randomly, each group had 10 teeth, obturated with GuttaFlow, iRoot SP with single point and cold lateral condensation. Mtwo-R file was used to remove the filling material, the treatment time was recorded, CBCT scanning was performed before and after retreatment. Ultrasonic swings for 2 minutes, and then CBCT scan again. Volume changes of root canal filling materials after Mtwo-R treatment and ultrasonic swallowing were observed, and volume percentage of remaining root canal filling materials was calculated. Results:The operation time of GuttaFlow group < cold lateral condensation group <iRoot SP group, there was significant difference between each group(P>0.05).After Mtwo-R treatment, the volume percentage of residual material of GuttaFlow group <cold lateral condensation group <iRoot SP group.There was significant difference between GuttaFlow group and the other 2 groups(P<0.05), while there was no significant difference between the cold lateral condensation group and the iRoot SP group (P>0.05). After ultrasonic wash,the volume percentage of residual material of GuttaFlow group <iRoot SP group < cold lateral condensation group.The GuttaFlow group was significantly lower than the other 2 groups(P<0.05).There was no significant difference between the iRoot SP group and cold lateral condensation group (P>0.05).The volume percentage of the 3 groups of residual materials decreased after auxiliary ultrasonic wash were significantly decreased (P<0.05). Conclusion:Residual root canal filling materials were retained in all 3 groups.GuttaFlow was easier to be removed and iRoot SP was not easy to be removed.Additional ultrasonic wash could improve the clearance rate of iRoot SP.

Objective To observe the influence of different space settings on the marginal adaptation of chair-side CAD/CAM IPS e.max all ceramic crowns to provide experimental evidence for clinical application. Methods A right maxillary first molar in the ivoclar vivadent standard model was used and subsequently replicated into silicone rubber negative mold. Respectively, twenty-five preparations of die stone were irrigated. Twenty-five digital images were obtained by using optical impression of Sirona Cerec AC system. Twenty-five of them were randomly divided into 5 groups，and luting spaces were set to 30 μm(A group)，60 μm(B group)，90 μm(C group)，120 μm(D group)and 50 μm(E group) by CEREC version 4.4.4 computer software. Twenty-five all-ceramic crowns with five ones in each group were obtained according to space settings by Digital Control Cutting equipment．The Variolink N system was used for bonding. The vertical marginal gaps of four datum points, buccal, lingual, mesio and distal points were measured by Leica microscope. The mans and standard deviations were calculated. And the data were analyzed by LSD -test using SPSS 20.0, and the inter-group and intra-group comparison was examined by LSD．Results The marginal adaptations of bucco-lingual and mesio-distal sides were higher than 120 μm in A group，and the marginal adaptations of bucco-lingual and mesio-distal sides were lower than 30 μm in E group. The marginal adaptations of bucco-lingual and mesio-distal sides in B, C and D groups were between 30 μm ~120 μm. There were statistically significant differences(P<0.05) comparing A group with B, C or D groups in the marginal adaptation of bucco-lingual and mesio-distal sides. There were statistically significant differences(P<0.05) comparing E group with B, C or D groups in the marginal adaptation of bucco-lingual and mesio-distal sides. There were no statistically significant differences(P>0.05) among B, C and D groups in the marginal adaptation of bucco-lingual and mesio-distal sides. There were no statistically significant differences(P>0.05) in the marginal adaptation of bucco-lingual and mesio-distal sides in each group. Conclusion The chair-side CAD/CAM IPS e.max all-ceramic crowns can obtain the clinical acceptable marginal adaptation when the space settings are set at 60,90,120 μm while using CEREC version 4.4.4.

Objective　To discuss the methods and efficacy of digital guide to assist accurate reduction and fixation of mandibular comminuted fracture. Methods 10 patients of mandibular comminuted fracture from January 2016 to December 2017 were involved. Preoperative design was made by digital technology and surgery guides were manufactured using 3D printer. By means of surgery guides, mandibular comminuted fractures were fixed with reconstruction titanium plate in surgery. Image fusion and clinical evaluation were conducted to investigate treatment after surgery. Results Primary healing was obtained in all patients. Image fusion showed a less-than-2mm deviation. Occlusion relation recovery and reduction of fracture were in good condition, and nothing abnormal was detected in the mouth opening. Conclusion Surgery guide can shorten the operation time, precisely restore mandibular comminuted fractures and has definite clinical application efficacy.

Objective To evaluate the clinical effect of posterior teeth occlusion veneer with lithium disilicate ceramic. Methods 12 cases, 160 severely worn premolars and molars were reconstructed with occlusion veneer with lithium disilicate ceramic. After 3 years of observation, according to the revised standards of public health service in the United States, the color matching, edge coloring, fracture of restorations, secondary caries and marginal fitness of the prostheses were evaluated. Results 95.62% of the colors of the occlusion veneer in the posterior teeth were Class A. 93.75% of the prosthesis had no edge coloring. 98.13% of the restorations were intact. No secondary caries were found in all the prostheses. 92.5% of the prosthesis edge fitness was Class A. Conclusion The posterior teeth occlusion veneer with lithium disilicate ceramic has good clinical effects recently.

0bjective To investigate the prevalence and distribution of teeth number abnormalities in school-age children at the mixed dentition stage by performing panoramic radiographs analysis．Methods A total of 3432 panoramic radiographs of pediatric patients aged 5 years to 12 years who were admitted to the hospitals from January 2013 to June 2017 were reviewed．The presence of teeth number abnormalities were recorded as follow：congenitally absent teeth，supernumerary teeth，odontoma. SPSS 13.0 software was used for statistical analysis．Results The prevalence of teeth number abnormalities in pediatric patients’permanent teeth was 25.52%. The prevalence was higher in males. Significant difference between the genders was observed（P<0.05）．Tooth agenesis，the most frequent dental anomaly（13.43%），was considerably common in females；supernumerary teeth(11.74%)followed，which was significantly common in males．Both differences were statistically significant（P<0.05）．The prevalence of odontoma was 0.35%. Conclusion The prevalence of teeth morphology abnormalities in children’s permanent teeth at the mixed dentition stage is apparently high. Panoramic radiograph is an efficient method for the early diagnosis of teeth number abnormalities．

Objective To establish a database of the proximal surface morphology of maxillary premolars among the adolescents and provide references for clinical practice and the preparation and modification of the related appliance such as matrix bands. Methods 219 patients who met the inclusion criteria were randomly selected from the CT image database of Anyang Stomatological Hospital. The images were adjusted to appropriate position to capture the screen. Then the screenshots were imported into ArtForm 2.0, the points were fixed and the five curvature radiuses were measured. Results All the measurements were positive except for the horizontal-gingiva of mesial surface of the first maxillary premolar. All the three vertical curvature radiuses of mesial surface of the second maxillary premolar of male were larger than those of the female. Conclusions There is a depression on the mesial surface close to cervix of the first maxillary premolar. The longitudinal mesial surface of the second maxillary premolar of male is flatter than that of the female.

Bone loss is always a quite difficult problem in prosthodontics and oral implantology. A special group of small osteoinductive molecules was found to guide osteogenic differentiation, promote bone formation and mineralization. Owing to their small sizes that are capable of regulating cell functions, higher stability and non-immunogenicity, small osteoinductive molecules have gained lots of attention. Phenamil, statins, Purmorphamine, cAMP analogues, Oxysterols and Melatonin are proved to have ability to control osteogenesis through various osteogenic signaling pathways and increase the osteogenic gene expression. This review is going to show the types, functions and the functional mechanisms of these small osteoinductive molecules.

The stability of marginal bone level is an important indicator of long-term success of implants. The mucosal thickness has been studied and discussed as a factor influencing the implant marginal bone loss (MBL). Most clinical and animal studies have demonstrated that there is less implant MBL in the thick mucosa (>2mm) than in the thin mucosa (≤2mm). Based on the speculation that mucosal thickness would be involved in the reconstruction of implant biologic width (BW), thereby affecting implant MBL, the researchers try to adjust clinical implantation procedures according to the initial mucosal thickness. Some scholars have achieved the goal of reducing implant MBL by increasing the thickness of the mucosa, while others have achieved the goal of avoiding early exposure of the implant surface by adjusting the implant depth according to the thickness of the mucosa. The research progress of the effect of initial mucosal thickness on MBL around the neck of implant and its significance for clinical implantation is reviewed as follows in this paper.

B10 cell（IL-10 producing B cell）exerts significant immunomodulatory effects through the production of interleukin (IL)-10 and the expression of CD1d, CD80, CD86, FasL. It plays an important immunomodulatory role in autoimmune diseases and infection disease. Recent studies show that local induction of the expression of B10 cell and adoptive transfer of B10 cell can alleviate inflammation of periodontal tissue and alveolar bone resorption. Thus, the research on the function of B10 cell in periodontitis will be of great help for the further study on the therapy of periodontal diseases.

Polymethyl methacrylate (PMMA) denture base material is the most widely used to fabricate denture bases due to its various advantages. However, this material is still far from ideal in fulfilling the mechanical requirements of a prosthesis. Therefore，scholars have devoted themselves to its modification in recent years. Many studies have reported improvement of PMMA denture base material with the addition of fibers reinforcement. This paper reviews polymethyl methacrylate denture base material enhancement combined with the articles published during the recent decades. Specific attention is given to the effect of fibers on polymethyl methacrylate properties.

Oral health is closely related to general health. Periodontal disease, an oral infectious disease occurring at periodontal tissues, might be related to some systemic diseases. Some studies show that male infertility might be related to some oral diseases, especially to periodontal diseases. However, its mechanism of action remains uncertain and there are two hypotheses supporting this association，namely，the chronic infection of periodontal bacteria and the effect of cytokines. This article aims to review the association between periodontal condition and male infertility and the possible mechanism of the action.

Fracture of the anterior teeth by trauma is a more common clinical problem.With the improvement of the performance of the adhesive system,the reattachment of dental fragments becomes a better choice to restore fractured teeth, which is bonding the fragments with the tooth. The clinical procedure retains the original shape and colour of enamel.It provides total aesthetical recovery ,low cost and provides the patient with highly positive emotional.The progress of dental fragments reattachment technology in recent years will be reviewed in this paper.