Dysbiotic periodontal microbiota is closely associated with periodontal diseases and many systemic diseases. Here we briefly summarize the roles of periodontitis and dysbiotic periodontal microbiota in cardiocerebrovascular diseases including hypertension, atherosclerosis, myocardial infarction, cardiac hypertrophy, heart failure and stroke. Correlations between periodontitis and these cardiocerebrovascular diseases have been established in recent years. There are a few data supporting causal relationships between periodontitis and some cardiocerebrovascular diseases such as hypertension and atherosclerosis, but more evidence is warranted. Furthermore, causal relationships between periodontitis and other cardiocerebrovascular diseases are yet to be established. The importance of dysbiotic periodontal microbiota in cardiocerebrovascular diseases except stroke has been supported by some data. However, research in more depth is required to fully comprehend the critical function and mechanism of dysbiotic periodontal microbiota in these diseases. Results of these studies will provide more evidence and ideas for joint prevention and control of oral diseases and cardiocerebrovascular diseases.

Objective To investigate the spatial and temporal expression of transcriptional coactivator with PDZbinding motif(Taz) and Runtrelated transcription factor 2(Runx2) during the development of first molar in rat mandibular and analyze the function of Taz in tooth development and the interrelation between Taz and Runx2. Methods Samples were collected from Wistar rat at various stages. Immunohistochemical method was used to observe the expression pattern and localization of Taz and Runx2. Results At the bud stage, cap stage and early bell stage, the positive expression of Taz was detected in the oral epithelium and dental mesenchyme. With the development of tooth germ, the strongest staining of Taz appeared in early bell stage. Strongly positive expression of Taz was found in the inner enamel epithelium, outer enamel epithelium, stratum intermedium and dental follicle. The expression of Taz was positive in postnatal odontoblasts and predentin, and its expression level in ameloblasts decreased with the mineralization of enamel. Runx2 in different stages presented different expression and localization in embryonic samples. At the bud and cap stage, Runx2 was found in the oral epithelium and dental mesenchyme. At the early bell stage, positive staining was detected in the inner enamel epithelium, stratum intermedium, dental papilla and dental follicle, in addition to oral epithelium and dental mesenchyme. Runx2 expression in odontoblasts which was in secretory phase was positive and the staining gradually reduced with the differentiation of odontoblasts. Conclusion The expression of Taz during the development of first molars in rat mandibular is spatiotemporal. The result suggests that Taz may be an important regulatory factor in tooth development. The expression and localization of Taz was similar to Runx2, indicating that there is certain correlation between Taz and Runx2 in regulating tooth development of rat.

Objective To investigate the regulatory effects of hyperbaric oxygen (HBO) on cell apoptosis and apoptosis factors expression of diabetesassociated periodontitis (DAP). Methods Sixty cases of DAP were divided into 3 groups, 20 cases in each group. The first group was treated with 0.25 MPa hyperbaric oxygen (HBO) for 2 weeks; the second group was treated with periodontal scaling and root planning (SRP); the third group was treated with HBO combining SRP. Periodontal clinical indicators（PLI, SBI, GI, PD, AL） in each group before and one month after treatment were measured. The apoptosis of gingival cells was observed by HE staining, TUNNEL staining and transmission electron microscopy. The IL1β, TNFα, PGE2 and Caspase3 expression in gingival tissues were detected by immunohistochemistry (IHC). Results The periodontal indices of SBI, GI, PD significantly decreased in HBO group, SRP group and HBO+SRP group at one month after treatment than pretreatment. Cell apoptosis and percentage of cell apoptosis in gingival epithelium and lamina propria decreased significantly. The expressions of IL1β, TNFα, PGE2 and Caspase3 in gingival at one month after treatment significantly decreased than pretreatment. There were significantly differences between the clinical indices (SBI, GI, PD, AL) and the percentage of apoptotic cells. The expressions of IL1β, TNFα, PGE2 and Caspase3 in gingival of HBO+SRP group were significantly lower than those of HBO group and SRP group. The positive expressions of IL1β, TNFα, PGE2 were macrophages and lymphocytes, and the positive expressions of Caspase3 were epithelial basal cells and spinous cells. Conclusion HBO could reduce the expression of IL1β, TNFα, PGE2 and Caspase3 in gingival to reduce cell apoptosis. HBO combined with SRP displays better efficacy which could maintain for more than one month.

Objective To explore the effects of injectable platelet rich fibrin on the biological behavior of human stem cells from apical papilla (hSCAPs)in vitro. Methods The content of growth factors in injectable platelet rich fibrin extract (iPRFe) was quantified by enzyme linked immunosorbent assay(ELISA). The effects of iPRFe on the proliferation of hSCAPs were detected by CCK8 and the migration of hSCAPs was evaluated via Transwell assay. The mineralized nodules were observed by alizarin red staining and the realtime PCR was used to explore the expression levels of odonto/osteogenicrelated mRNA. Results Platelet derived growth factorBB (PDGFBB), insulinlike growth factor 1 (IGF1) and transforming growth factor β1 (TGFβ1)were detected in iPRFe. iPRFe promoted the proliferation of hSCAPs, and the optimum concentration for cell proliferation was 1/4×. The migration and mineralization of hSCAPs were also promoted by 1/4× concentration of iPRFe. iPRFe significantly promoted mRNA expression levels of alkaline phosphatase (ALP), dentin matrix protein 1 (DMP1), dentin sialophosphoprotein (DSPP) and osteocalcin (OCN)(P<005). Conclusion iPRF can promote the proliferation, migration and mineralization of hSCAPs, which is expected to provide possibility for pulp regeneration.

Objective To evaluate the influence of penetration time on the microleakage, penetration ability and atomic force microscope (AFM) of pit and fissure sealants in vitro. Methods Fifty extracted third molars of human mandibular were randomly divided into five groups with ten in each group. Occlusal surfaces of the teeth in all groups were prepared using enameloplasty, etched, rinsed and dried. In group 1-5, the fissure sealant was applied onto the surface and allowed to penetrate for 0 s, 15 s, 30 s, 45 s and 60 s respectively. Each tooth was subjected to dye immersion (1% methylene blue). Microleakage and penetration ability were examined after sectioning. The quality of tag formation was examined using an AFM. Results The penetration time of 30 s, 45 s and 60 s resulted in significantly more (P<0.05) penetration depths compared to 0 s and 15 s. AFM showed that 0 s group and 30 s group had obvious, dense and regular resin tags. Conclusion The findings reveal that it should permit a penetration time around 30 s before lightcure in clinical treatment.

Objective To analyze the differences of bone mass between sides of distalextended tooth missing and nondistalextended tooth missing in the maxilla and to provide the basis for pterygomaxillary implant placement as a common method for dental implant in the posterior atrophic maxilla. Methods At the Affiliated Stomatological Hospital of Nanjing Medical University from January to June of 2018, patients with one side of distalextended tooth missing to the premolar region with the bone height less than 5 mm and the other side of nondistalextended tooth missing in the maxilla (26 cases in total) were selected. Their cone beam computed tomography files were collected to compare the width, height, pterygoid process height and volume of pterygomaxillary area between sides of distalextended tooth missing and nondistalextended tooth missing. Results Aside from the height of pterygoid process, the width, height and volume of pterygomaxillary area were significantly reduced for the absence of maxillary posterior tooth (P=0.000). The width, height and volume of pterygomaxillary area were （6.11±1.05）mm and （6.81±0.99）mm, （15.16±1.39）mm and（16.73±1.44）mm, （388.84±81.26）mm3 and（465.85±91.98）mm3 respectively on the sides of distalextended tooth missing and nondistalextended tooth missing. Conclusion The bone mass of pterygomaxillary area is significantly different between sides of distalextended tooth missing and nondistalextended tooth missing. However, this area is still sufficient for long implant placement, which should be combined with short implants and/or abutment teeth in the anterior maxilla to solve the difficulties in implant restoration caused by severe atrophy of posterior maxilla

Objective To analyze the differences in the marks of soft and hard facial tissues in patients with the jaw relationships of Class Ⅰ,Ⅱ,Ⅲ, and provide references for occlusal reconstruction or restoration treatment of edentulous patients. Methods A total of 329 cases were collected from January 2019 to September 2020 who went to the Affiliated Stomatological Hospital of Tongji University to take lateral cephalometric radiograph. According to ANB, they were divided into Class Ⅰ patients (2°~5°), Class Ⅱ patients (＞5°), and Class Ⅲ patients (＜2°). According to the mandibular plane angle (FHMP), they were divided into hyperdivergent patients (>32°), normal patients (22°~32°), and hypodivergent patients (＜22°). Cephalometric analysis was performed to measure and analyze the height, angle and proportion of soft and hard tissues. Results ① In the total population, 22 measured values of ClassⅠ, Ⅱ and Ⅲ patients showed statistical differences (P<0.05). The ANSMe was the largest in Class Ⅲ patients, followed by Class I patients, and Class Ⅱ patients were the smallest. ② In the hyperdivergent patients, normal patients and the hypodivergent patients, there were still 11 measured values showing statistical differences in Class Ⅰ, Ⅱ and Ⅲ patients (P<0.05). ③Correlation analysis showed that ANSMe was correlated with other facial measurements, and the correlation coefficient of ArGn was 0.839 in Class Ⅰ patients, 0.732 in Class Ⅱ patients, and 0.806 in Class Ⅲ patients, all of which had a high correlation. Conclusion There are differences in the facial measurements of people with the jaw relationships of Class Ⅰ,Ⅱ,Ⅲ,so relationship should be considered during restoration treatment

Objective To evaluate and compare the clinical effects and patients′ satisfaction with treatment of Miller Ⅰ or Ⅱ gingival recession by coronally advanced flap alone or with platelet rich fibrin(PRF). Methods Thirty patients with Miller Ⅰ or Ⅱ gingival recession and willing to undergo surgical treatment were selected and divided into experimental group (coronally advanced flap combined with PRF) and control group (coronally advanced flap). Periodontal probing depth, keratinized gingiva width, gingival recession depth and root coverage were recorded before surgery, 3 months and 6 months after surgery. The clinical efficacy of the two groups was analyzed, and the satisfaction questionnaire was filled out and analyzed. Results The clinical indexes of gingival recession depth and keratinized gingiva width at 3 and 6 months after surgery were significantly improved compared with those before operation in the experimental group and the control group, and the differences were statistically significant (P<0.05). The width of keratinized gingiva between the two groups was statistically different at 3 and 6 months after surgery (P<0.05). There were no statistically significant differences in the periodontal probing depth, gingival recession depth, and root coverage between the two groups at 3 months and 6 months after surgery (P>0.05). There was no significant difference in the periodontal probing depth between the two groups at 3 months and 6 months after surgery compared with that before the operation (P>0.05). The satisfaction of patients in the experimental group was significantly higher than that in the control group, and the difference was statistically significant (P<0.05). Conclusion The results of this study further confirm that these two methods are effective for the treatment of Miller Ⅰand Ⅱ gingival recession, and the adjuvant application of PRF can increase the width of postoperative keratinized gingiva and improve patients′ satisfaction.

Objective To apply digital analysis to compare the clinical gingival retraction effects, including gingival pain degree, sulcus width (SW) and gingival recession (GR), between diode laser method and single cord method. Methods A total of 52 teeth were selected from 42 patients who needed fixed partial denture restoration. They were randomly divided into two groups, diode laser gingival retraction group and single cord gingival retraction group. Twentysix normal teeth were selected as blank control group. VRS digital pain grading method was used to evaluate the pain degree of the two gingival retraction methods, and 3shape scanner was chosen to rebuild digital models before and after gingival retraction at the time point of 0 week, 1st week and 6th week. Finally, the acquired data was input into geomagic qualify 2014 software to compare the gingival effects SW, GR0, GR1 and GR6 before and after gingival displacement. Results The pain level of the diode laser group was lower than that of the single cord group (P<0.05); the SW of diode laser group (buccal (0.394 2±0.087 3)mm, palatal (0.397 4±0.086 8)mm) was greater than the single cord group (buccal (0.322 8±0.057 3) mm, palatal side (0.306 0±0.050 6)mm) (P<0.05); the GR0 (0.342 5±0.027 9)mm, GR1 (0.162 5±0.056 9)mm, and GR6 (0.239 3±0.020 6)mm of the diode laser group were larger than those of the single cord group, GR0 (0.273 0±0.018 7)mm, GR1 (0.145 9±0.030 8)mm, GR6 (0.162 5±0.015 9)mm (P<0.05). Conclusion The diode laser method can lead to lower pain degree. Both two methods can achieve ideal sulcus width, but permanent gingival recession will be caused. The amount of gingival recession after diode laser gingival retraction is larger. Therefore, it is recommended to use single cord method for patients with thick gums, while for patients sensitive to pain, laser method could also be considered.

Objective To observe whether the tongue muscle functional training can decrease the tongue retraction and improve the retention of mandibular complete denture. Methods Thirty edentulous patients with tongue retraction were selected. The complete dentures were manufactured with biofunctional prosthetic system（BPS） technique, additionally with 3 resin tubers, 5 mm wide and 2 mm high, on the mandibular labial polishing surface with an interval of 10 mm. Patients were instructed to lick the resin balls with the tip of their tongue before breakfast, lunch, dinner and going to bed. They were asked to maintain the action for 3 seconds, then relax, repeating 10-12 times/min, 10 minutes each time for 2 weeks. Results After the tongue muscle functional training, the distance from the tip of the tongue to the alveolar crest of the anterior mandibular was reduced from （28.2±5.8）mm (before training) to （18.1±7.3）mm; the score of patients′ satisfaction with retention increased from 7.2±1.1 (before training) to 8.1±1.4, both with significant statistical difference (P<0.01). Conclusion The tongue muscle functional training can decrease the tongue retraction and improve patients satisfaction with retention of mandibular complete denture.

Objective To study the positional relationship between the incisive canal and the maxillary central incisors, in order to provide reference for clinical treatment and subsequent research. Methods Seventysix adults undergoing orthodontic treatment were selected. Three measurement levels were defined on the CBCT image, and the measurement level paralleling to PP plane included:nasopalatine foramen level (N), root tip level (R), incisive foramen level (I). The following measuring projects were defined, the N level incisive canal lip side alveolar bone plate thickness (NT), R level incisive canal lip side alveolar bone plate thickness (RT), I level incisive canal lip side alveolar bone plate thickness (IT), N level incisive canal width (NW), R level incisive canal width (RW), I level incisive canal width (IW), the maxillary central incisor apex distance (RR), R level UR1 to incisive canal distance (RRD), R level UL1 to incisive canal distance RLD, I level UR1 to incisive canal distance (IRD), I level UL1 to incisive canal distance (ILD). The above projects were measured on CBCT images and the results were statistically analyzed. Results RRD was g reater than IRD, RLD was greater than ILD, and the difference was statistically significant (P<0.05). There was no significant difference between RRD and RLD, IRD and ILD (P>0.05). NW was less than RW; RW was less than IW, and there was a statistical difference (P<0.05). NT was greater than RT, with a statistical difference (P<0.05). There was no significant difference between NT and IT (P>0.05). There was no significant difference between RT and IT (P>0.05). Conclusion The average distance from the root tip of U1 to the incisive canal is only 3.5 mm, while the Ilevel average distance from the root of the U1 to the incisive canal is only 2.4 mm. It should be noted that the retraction of the maxillary anterior teeth may lead to the absorption of the root apex and the lateral side of the root. When the retraction of the maxillary anterior teeth is especially matched with the intrusion movement, attention should be paid to the possibility of the absorption of the mesial surface of the roots.

Objective To evaluate the correlation between temporomandibular disorder (TMD) MRI staging and clinical symptoms. Methods Through a retrospective cohort study, basic information, MRI images, VAS score sheets, and mouth opening were collected from 160 patients attending maxillofacial surgery in our hospital from December 2018 to December 2019. Patients were divided into different age groups (12-18,18-40,40-70 years old). The distribution of TMD patients in different stages was analyzed. The correlation between patient gender and TMD staging, the correlation between TMD patient stage (stage Ⅱ-Ⅳ) and VAS, maximum opening degree were analyzed. SAS9.0 software package was used for Wilcoxon rank sum test. Results The opening degree of Ⅱ-Ⅳ patients was (31.22±9.40), (20.77±6.51), (29.39±5.81) and (22.41±9.18)mm respectively. There was a significant difference in opening degree between stage Ⅱ, stage Ⅲ and Ⅴ (P<0.05). The VAS scores of patients in Ⅱ-Ⅴ period were 20.47±11.30, 64.48±23.51, 51.34±20.47 and 45.61±16.38 respectively, and stage Ⅲ was statistically different from stage Ⅱ(P<0.05). Conclusion MRI can accurately reflect the relationship of the disc condyle in TMD patients. MRI staging has a correlation with TMD clinical symptoms. Patients in stage Ⅲ and Ⅴ have limited mouth opening, and patients in stage Ⅲ have obvious joint pain according to the MRI image of TMD patients.

Skeletal malocclusion is characterized by the dissonance between the maxillary and mandibular. According to its abnormal sagittal relationship, it can be divided into skeletal Class Ⅰ, skeletal Class Ⅱ and skeletal Class Ⅲ. The pathogenesis of skeletal malocclusion is complex, mainly composed of genetic factors and acquired environmental factors. This paper will review the progress of genetic research on these three kinds of skeletal malocclusion.

Microbes can regulate the physiological function of infected hosts during hostmicrobe interaction. One of the important regulations is epigenetic regulation. Epigenetic inheritance relates to changes in gene expression and function that are not encoded in the DNA sequences and inducible heritable phenotypes. The epigenetic regulation plays an essential role in host immune response caused by microbe challenges. Clarifying the epigenetic regulation mechanisms of microbes in the host is beneficial to carry out clinical targeted therapies, enhance the clinical application of epigenetic regulators and provide new strategies for the prevention and treatment of related diseases. This review summarizes the epigenetic changes in hosts caused by several common oral microbes and related mechanisms.

Bone morphogenetic protein 1 (BMP1) and mammalian tolloidlike 1(mTLL1), members of astacin family, are extracellular matrix metalloproteinases that are coexpressed in various tissues including teeth. BMP1 and mTLL1 are functionally redundant, playing an important role in cutting and activating extracellular matrix (ECM) proteins. They regulate ECM deposition by hydrolyzing and pruning precursors of various ECM proteins. Previous studies have shown that BMP1 and mTLL1 play an important role in tooth development through promoting the differentiation of odontoblasts and osteoblast, as well as maintaining the balance of collagen and noncollagen proteins in ECM. The research progress of BMP1 and mTLL1 in tooth development is reviewed in this paper.

The autogenous bone grafts harvesting from mandibular chin or ramus are the most frequently used to reconstruct the anterior maxillary ridge. However, some complications are reported in the donor sites. Bone grafts harvesting from anterior maxillary edentulous sites or nearby can save time, reduce the donor morbidity and increase patients′ acceptance. This review focuses on the potential bone harvesting zone and collection techniques in anterior maxilla, and provides a reference for reconstructing bone defects of different sizes with insitu autogenous bone grafts.

In recent years, bone tissue engineering has provided the possibility of repairing large maxillofacial bone defects. As a key point in bone tissue engineering, scaffolds provide structural support for cellular adhesion, proliferation and bone tissue regeneration. Crosslinking technology is often used to modify scaffold materials to improve their mechanical properties and antidegradation properties, among which chemical crosslinking is more commonly used. In this paper, the characteristics and application of chemical crosslinkers in oral bone tissue engineering are reviewed.

Threedimensional finite element analysis has been widely used to solve biomechanical problems in stomatology. The mechanical analysis of finite element analysis by means of computer simulation of oral condition is efficient and fast, and avoids ethical problems at the same time. It has unique technical advantages and important clinical significance. This paper reviews the application of threedimensional finite element analysis in periodontics, endodontics, prosthodontics, tooth implant, orthodontics and maxillofacial surgery in recent years.

Salivary adenoid cystic carcinoma (SACC) is a common clinical malignancy of salivary glands. The tumor tends to grow slowly, has a highly neurotropic character, is aggressive and easily invades blood vessels, leading to hematogenous metastasis. In recent years, some advances have been made in the study of the pathogenesis and molecular phenotype of the disease. With the application of various in vitro experimental methods, researchers have gradually realized that exosomes play an important role in the proliferation, migration and invasion of solid tumors. It is of great significance to further explore the function of exosomes in adenoid cystic carcinoma, which can open up new ideas for research on the pathogenesis of adenoid cystic carcinoma.

In the immediate oral implant surgery, the matching problem between the individualized alveolar fossa and the standardized implant has always troubled implant doctors. The emergence of root analogue implant (RAI) efficiently solves this problem. This paper reviews the literature on RAI at home and abroad, and systematically introduces the historical development, manufacturing methods and research progress of RAI. It is expected to inspire implant doctors to carry out the research in this field and expand the domestic customized implanting field.