Maxillary sinus cystic lesions can often be found in cone-beam computed tomography (CBCT) images. However, whether this change affects the implementation of maxillary sinus floor augmentation remains unclear. Combining the common cystic change performance of CBCT, image classification diagnosis of maxillary sinus cystic change was introduced, and the indications and surgical methods of maxillary sinus floor augmentation and postoperative radiographic changes of mucous were analyzed. This procedure may help clinicians evaluate the feasibility and methods of maxillary sinus augmentation in maxillary sinus cystic changes.

Objective To investigate the mechanism of the participation of osteocytes in the formation of osteoclasts under hypoxia. Methods The hypoxia culture system of osteocyte-like cell line MLO-Y4 was established by deferoxamine mesylate (DFO) in vitro. The proliferation of MLO-Y4 cells was examined by CCK-8 cell proliferation/toxicity assay. RAW264.7 cells were induced to osteoclasts by the conditioned medium containing the cultured MLO-Y4. Tartrate-resistant acid phosphatase (TRAP) staining was performed on day 7. Quantitative real-time fluorescence polymerase chain reaction, immunofluorescence, and Western blot were used to detect the expression levels of hypoxia-inducible factor (HIF)-1α and receptor activator of nuclear factor-κB ligand (RANKL) in MLO-Y4 under hypoxia. The effects of siHIF-1α on the expression levels of HIF-1α and RANKL in MLO-Y4 under the same conditions were detected. Results DFO (100 μmol·L ^-1) promoted the proliferation of MLO-Y4 at 24 h, which decreased with time (P<0.01). After the addition of soluble sRANKL, the formation of osteoclasts was significantly increased in the DFO group (P<0.001). The expression of RANKL mRNA in MLO-Y4 under 100 μmol·L ^-1 DFO increased first and then decreased with the duration of hypoxia. This expression reached a peak at 24 h (P<0.01). Hypoxia up-regulated the expression of HIF-1α and RANKL protein (P<0.01). Under hypoxia, siHIF-1α downregulated the expression of HIF-1α and RANKL (P<0.01). siHIF-1α also decreased the number of osteoclasts (P<0.01). Conclusion Under hypoxia, MLO-Y4 could facilitate the formation of RANKL through upregulating the expression of HIF-1α protein, thereby accelerate the differentiation of RAW264.7 cells into osteoclasts.

Objective This study aims to compare the osteogenic differentiation capability of stem cells derived from human inflammatory periodontal ligament tissues (iPDLSCs) with those of stem cells derived from healthy periodontal ligament tissues (hPDLSCs). Both types of tissues were induced by stromal cell derived factor (SDF-1) in vitro. Methods iPDLSCs and hPDLSCs were primarily cultured by tissue digestion method and purified by limited dilution cloning. The cells were passaged and identified by stem cell surface marker expression through flow cytometry. Then, we used thiazolyl blue tetrazolium bromide to detect and compare the proliferation capabilities of the iPDLSCs and hPDLSCs. Express of bone volumes were detected by alizarin red staining after SDF-1 was added to the cells. Using alkaline phosphatase, we evaluated the osteogenic differentiation capability of the cells induced by SDF-1. The expression levels of the osteogenesis-related genes of the cells induced by SDF-1 were determined by reverse transcription-polymerase chain reaction. Results After purification, both iPDLSCs and hPDLSCs expressed stem cell markers. hPDLCSs had a higher proliferation capability than iPDLSCs. Osteogenesis-related genes had higher expression levels in the cells induced by SDF-1 than in those without induction (P<0.05). SDF-1 at 50 and 200 ng·mL ^-1 concentration greatly affected the differentiation capabilities of iPDLSCs and hPDLSCs respectively. Conclusion iPDLSCs and hPDLSCs had osteogenic differentiation capability. The level of osteogenic differentiation in normal and inflamed periodontal ligament stem cells increases after SDF-1 induction.

Objective To study the effects of universal adhesives and resin cement on the shear bond strength and durability of zirconia ceramics. Methods Zirconia ceramics were sintered into 20 mm×10 mm×10 mm and 10 mm×10 mm×10 mm specimens. The experiment was divided into 12 groups. The two types of specimens were bonded using two variants of resin cement (RelyX Ultimate and Clearfil SAC self-adhesive resin cement), universal adhesives (non-adhesive, Scotchbond universal adhesive, and Clearfil SE One adhesive), and storage conditions (water bath and water bath-thermal cycling). The shear bond strengths were tested, and the fracture morphologies were analyzed. Results The cement (F=8.41, P<0.01) and adhesive (F=30.34, P<0.01) exerted a significant effect on the shear bond strength of zirconia, whereas storage condition showed no significant effect on this property (F=1.83, P=0.18). The lowest shear bond strength (14.02 MPa±6.86 MPa) was exhibited by the group treated with RelyX Ultimate resin cement, non-adhesive, and water bath-thermal cycling, whereas the highest shear bond strength (54.12 MPa±8.37 MPa) was displayed by the group treated with RelyX Ultimate resin cement, Scotchbond universal adhesive, and water bath-thermal cycling. Conclusion Universal adhesives can improve the durability of the bonding of resin cement to zirconia. If non-self-adhesive resin cement is used without a universal adhesive, the durability of the bond will be greatly reduced.

Objective This study aimed to evaluate the stress distribution of the mandibular first molar with different thicknesses and heights of the axial wall restored by the endocrown with two marginal designs and thus provide a theoretical basis for selecting clinical preparation through the finite-element method. Methods Two marginal endocrowns of the mandibular first molar with different axial-wall thicknesses (t=1, 2, 3 mm) and heights (h=2, 3, 4 mm) were established. Group A was the butt-joint design, whereas group B was the shoulder-surrounded design. After applying vertical and oblique loads , the size and distribution of the maximum principal stress and equivalent stress of residual tooth tissue were recorded. Results The maximum principal stress and equivalent stress distribution of residual tooth tissue were similar among different models. Group A showed a lower maximum principal stress and equivalent stress than group B at the same thickness and height under vertical load. Meanwhile, under oblique load, the maximum principal stress values of groups A and B decreased with increased thickness at constant height. Group A showed lower equivalent stress than group B at the same thickness and height of 2 and 3 mm. However, when the height was 4 mm, the trend was reversed. Conclusion In mastication, when bearing the vertical force, the retention of the butt-joint marginal endocrown preferred to the shoulder-surrounded one. Given the higher axial wall of the shoulder-surrounded marginal endocrown, it showed better ability to bear the oblique force than the butt-joint one.

Objective To explore the mechanism of smoking that promotes chronic periodontitis from the perspective of gingival microcirculation. Methods In experiment one, upper anterior teeth (n=102) from smokers with chronic periodontitis (Group A), nonsmokers with chronic periodontitis (Group B), and nonsmokers with healthy periodontal conditions (Group C) were selected to undergo gingival blood flow (GBF) through laser doppler flowmetry. In experiment two, the tissues obtained from gums during periodontal flap surgery were divided into smoking (Group A’) and nonsmoking (Group B’) groups, and the gingival tissue obtained from periodontal healthy nonsmokers treated with crown lengthening surgery or impacted wisdom tooth extraction served as the control group (Group C’). The microvessels density (MVD) of the gingival tissue from the three groups was determined in the tissue sections. SPSS 22.0 was used for statistical analysis. Results Compared with group C, GBF of all teeth increased in group B, and there were significant differences among 12, 21 and 23 teeth. MVD significantly differed between Group B’ and C’ (P<0.05), but they did not significantly differ between Group A’ and B’. Conclusion Periodontitis can increase GBF and MVD, but smoking does not cause significant changes. However, the mechanism by which smoking promotes the occurrence and development of chronic periodontitis by influencing gingival microcirculation has not been discussed in this research.

Objective To compare the clinical effects of a modified socket shield technique (SST) and the conventional immediate implant placement in the esthetic zone. Methods Twenty-four patients with one hopeless upper incisor were conse-cutively enrolled in this study. All patients were scheduled for immediate implant placement. Twelve patients under-went a modified SST (experimental group) whereas the others underwent conventional procedures (control group). Radiogra-phic and clinical data were obtained preoperatively, immediately after surgery, and 12 months after surgery. The success rate of the implants, the pink esthetic score (PES) and patient satisfaction were analyzed. Statistical analysis was conducted using SPSS 21.0 software. Results One year after operation, the success rate of the implants was 100% in both groups. The PES and patient satisfaction of the experimental group were significantly higher than those of the control group (P<0.05). The buccal bone plate resorbed less in the experimental group than in the control group (P<0.05). Conclusion The modified SST is advantageous over the conventional immediate implant placement in terms of buccal bone and soft tissue maintenance.

Objective This study aimed to investigate the clinical effect of modified tunnel technique (MTUN) in the treatment of gingival recession with non-carious cervical lesion (NCCL). Methods Forty-two teeth with Miller I degree gingival recession were divided into the NCCL group or control group depending on whether NCCL was present. Both groups were treated with MTUN plus subepithelial connective tissue. The periodontal probing depth (PD), gingival recession height (GRH), gingival recession width (GRW), attached gingival width (AGW), and clinical attachment loss (CAL) were recorded before and at 3 and 6 months after operation. The mean root coverage (MRC) at 6 months after operation was calculated and analyzed. A root coverage esthetic scoring system was used to record aesthetic scores. Results GRH, GRW, and CAL of the two groups after surgery were significantly lower than those before surgery, and no significant changes in PD and AGW were observed. The MRC in the NCCL group was 63.40%±28.02%, whereas that in the control group was 67.00%±21.72%; no significant difference between the two groups was found. In terms of aesthetic outcomes, no significant difference between groups was reported. Conclusion MTUN can effectively improve gingival recession, and the presence of shallow NCCL (≤1 mm) will not affect the surgical effect of MTUN.

Objective This study aimed to determine the clinical effectiveness of double-shaft classification and sequential diagnosis and treatment of food impaction. Methods A total of 227 patients with food impactionwere subjected to double-shaft classification and subsequently treated by sequential diagnosis and treatment method. Treatment effectiveness was evaluated according to the subjective feelings of patientsat five time points (immediately after treatment and at 1, 3, 6, and 12 months after treatment). Results The average scores of patient’s subjective perception were 2.00, 1.93, 1.59, 1.20, and 0.98 immediately and at 1, 3, 6, and 12 months after treatment, with treatment-efficiency values of 87.17%, 81.70%, 73.21%, 55.80%, and 44.59%, respectively. There were differences in scores of patient’s subjective perception at each time point (P< 0.05). Conclusion Double-shaft classification and sequential diagnosis and treatment can effectively guide the treatment of food impaction.

Objective To study the clinical features and treatments of congenital submandibular duct dilatation. Methods Seven children with congenital submandibular duct dilatation from January 2008 to March 2018 were included in this study, whose average age was 5 months and 22 days. The clinical manifestations are unilateral swelling of the mouth floor. All seven children underwent sublingual gland resection, submandibular gland dilatation catheter resection, and catheter reroute under general anesthesia. Intraoperatively, the orifice of the submandibular gland was constricted and part of the catheter was dilated. Results All seven patients had good healing without swelling or cyst formation. Conclusion Congenital submandibular duct dilatation occurs at a young age. Early diagnosis and treatment can help prevent further expansion of the catheter and avoid gland atrophy, feeding difficulty, and breathing obstruction. Simultaneous excision of the sublingual gland can avoid the formation of postoperative sublingual cyst.

Objective To investigate the effect of circular RNA hsa_circ_0002203 on the malignant biological behavior of oral squamous cell carcinoma (OSCC) cell lines. Methods Forty patients with oral squamous cell carcinoma were included. Real-time fluorescent polymerase chain reaction (PCR） was used to detect the expression level of circular RNA hsa_circ_ 0002203 in OSCC and corresponding adjacent tissues, OSCC cell lines, and human oral keratinocytes (HOK). SCC15 and CAL27 cells were transfected with lentivirus. The expression level of circular RNA hsa_circ_0002203 was detected by real-time fluorescent PCR. Cell proliferation was detected by cell counting assay (CCK-8). Cell migration and invasion ability was detected by scratch assay and Transwell migration and invasion assay. Apoptosis level was detected by flow cytometry. The expression of corresponding protein was detected by Western blot. Murine tumor formation experiments were performed to observe the effect of hsa_circ_0002203 on the tumorigenesis of SCC15 cells in vivo. Results The expression of circular RNA hsa_circ_0002203 in OSCC tissues was lower than that in adjacent tissues (P<0.01), and the expression in OSCC cell lines was lower than that in HOK (P<0.001). Hsa_circ_ 0002203 expression increased after the lentiviral infection of SCC15 and CAL27. The proliferation, migration, and invasion of SCC15 and CAL27 reduced, and apoptosis level was promoted. The tumor volume, weight decreased, and growth rate of nude mice decreased. Conclusion The low expression of circular RNA hsa_circ_0002203 in oral squamous cell carcinoma can enhance the proliferation, migration, and invasion of cancer cells and inhibit tumor cell apoptosis.

Objective This study aimed to construct a network of programmed celldeath ligand 1 (PD-L1) co-expression genes and screen potential biomarkers for PD-L1 expression in head and neck squamous cell carcinoma (HNSCC) by bioinformatics analysis. Moreover, the genes and pathways participating in PD-L1 and regulating the tumor immune status were determined. Methods The HNSCC transcriptomic dataset in TCGA was selected to retrieve gene sets on the cBioPortal platform, where PD-L1 co-expressional genes were acquired. With these genes, GO-BP, KEGG, and string analyses were performed in R clusterProfiler. Cytoscape was used for network analysis and hub gene screening. Results A total of 117 co-expression genes were obtained, most of which were enriched in immune regulation and response to viral processes. Node degree analysis indicated that STAT1, IFNG, CXCL10, CCR5, FCGR3A, CXCL9, GBP5, CD86, GZMB, IRF1 were the highest connected genes and functioned as hub genes. Survival analysis of these hub genes resulted in CCR5, CXCL9, and GZMB as the prognostic biomarkers for patients with HNSCC, all of which were involved in immune regulation and their expression levels were related to PD-L1 (Pearson correlation coefficient was 0.30, 0.35, 0.39; P<0.01). High expression levels of these three hub genes were protective factors in patients with HNSCC. Conclusion PD-L1 co-expression hub genes are related to immunity, among which CCR5, CXCL9, and GZMB are prognostic markers with the possibility to be involved in programmed cell death protein 1 (PD-1)/PD-L1-induced tumor immune escape. These genes provide new clues to study the mechanism and precision target medicine of PD-1/PD-L1 in HNSCC.

The malignant tumors including oral cancer, colorectal cancer, pancreatic cancer, and esophageal cancer, of the digestive system are a common high-fatal malignancy. Porphyromonas gingivalis, as the most important pathogen of periodontal disease, has been gradually proved that its invasiveness occurs not only in the mouth but also in other parts of the digestive system. Moreover, the relevant pathogenic mechanism is increasingly attracting the reseachers’ attention. In this study, the role and possible pathogenesis of Porphyromonas gingivalis in the digestive system are described in a systematic and comprehensive way.

Centric relation (CR) is one of the core research contents in orthodontics, prosthodontics, and gnathology, acting as an important physiological factor in reconstructing the occlusion and adjusting the occlusal relationship. For over a century, CR is still a controversial subject in dentistry. CR has been redefined for several times, and recently, its application has been widened in orthodontics, including orthodontic diagnosis, clinical examination and analysis, and treatment goals. The purpose of this article is to review the definition of CR, its relationship with malocclusion, and the application of this relationship in orthodontic treatment.

Objective This study aims to compare the effects of fast and slow expansion on nasal cavity structure. Methods A total of 40 patients were selected and randomly divided into two groups. Cone-beam computer tomography (CBCT) was obtained before and after surgery and used for comparing the changes in nasal structure before and after treatment. Results Fast expansion had resulted in greater changes in the basilar and nasal bone arch extension structures than slow expansion. No significant difference at maxillary width and nasal parenchyma. Conclusion Rapid expansion therapy has more beneficial effects on nasal function.

Objective To examine the expression of myofibroblast in gingival after orthodontic loading. Methods Eight patients were selected as experimental group and treated with orthodontic force for 4 months. Ten patients were selected as the control group, were not loaded. The gingival protein expressions of collagen typeⅠ, collagen type Ⅲ, α-smooth muscle actin (α-SMA) were evaluated by immunohistochemistry method. Results Positive expressions of collagen typeⅠ, collagen type Ⅲ were founded, while no positive staining for α-SMA in the gingival tissue except vascular epithelium before loading. In experimental group, collagen type I and collagen type Ⅲ were increased after orthodontic loading (P<0.05), the expression of α-SMA was detected and statistically significant (P<0.05). Conclusion The myofibroblast exists in gingival tissue after orthodontic loading, and it may be concerned with orthodontic teeth relapse.

Objective We provided baseline data for oral public health through epidemiological surveys to investigate the prevalence of malocclusion and orthodontic treatment proportion in 12- to 14-year-old adolescents in Jiangxi province, China. Methods Multi-stage random cluster sampling was used. A total of 5 387 12- to 14-year-old adolescents were exa-mined by three professional dentists according to Angle’s classification of malocclusion. The subjects were recruited from 30 secondary schools in five counties in Jiangxi Province. Results were statistically analyzed by SPSS19.0. Results The prevalence of malocclusion was 79.67% among adolescents aged 12-14 years in Jiangxi province. The composition ratios of ClassⅠ, Class Ⅱ Division 1, Class Ⅱ Division 2, and Class Ⅲ malocclusion were 30.96%, 16.36%, 12.78%, and 19.13% respectively. ClassⅠmalocclusion had the highest composition ratio, and the most common clinical manifestation of malocclu-sion was dentition crowding with a prevalence of 91.30%. The prevalence rate of malocclusion was higher in boys than in girls at 81.16% and 78.21%, respectively (P<0.05). This condition had different prevalence rates in Nanchang, Yi-chun, Jiujiang, Shangrao, and Ganzhou (P<0.05) with the highest in Nanchang and lowest in Ganzhou. Malocclusion was related to caries, and its prevalence rate was higher in patients with caries than in those without caries (P<0.05). The ortho-dontic rate of malocclusion was 2.63%, and the value was higher for girls than that for boys (P<0.05). The rate of orthodontic in urban areas was higher than that in rural areas (P<0.05). Conclusion Compared with local and international findings on malocclusion of adolescents, high prevalence and low orthodontic rate were found in Jiangxi province. Strengthening the combination of prevention and treatment is important for the physical and mental health of adolescents. We should actively conduct oral health education, popularize the knowledge of malocclusion, and actively treat caries.

Though the mechanism of non-syndromic cleft lip and palate is not completely clear, the disease is affected by the combination of environment and genetics. Special environmental factors have the affect on the incidence of cleft palate. In this paper, the environmental factors related to the occurrence of non-syndromic cleft lip and palate were summarize from three aspects: poor living habits, chemical factors, age and health status of pregnant women during pregnancy. Based on the analysis of this paper, it will help to improve the health and living environment of pregnant women, so as to reduce the incidence of cleft palate.

Crown lengthening is one of the most common surgeries in clinical practice. Under the premise of ensuring the biologic width, the adequate crown is exposed by resecting the periodontal soft tissue and (or) hard tissue to meet the prosthodontic and (or) aesthetic requirements. Considering the various advantages of oral laser, such as safe, precise, minimally invasive and comfort, laser has become a promising technology which can be used to improve the traditional crown lengthening. In this review, the principles and characteristics of laser application in crown lengthening, especially in the minimally invasive or flapless crown lengthening will be reviewed. Its pros and cons will also be discussed.

Human microbiome refers to the total microorganism genetic information of human body surface and internal, which is closely related to human health and disease. Oral and gut microbiomes are the most diverse microbial communities, which can interact and play a role in the development of the disease, and can reflect the health and disease state in real time. Type 2 diabetes mellitus is a metabolic disorder caused by both genetic and environmental factors. Recent research has shown a link between microbes and diabetes. This article reviewed the latest research on the changes of oral and gut microbiomes in type 2 diabetes mellitus patients, which expects to provide a reference for exploring the development of the disease model for prediction, diagnosis and prognosis of type 2 diabetes mellitus based on human microbiome characteristics.

This case presents vertical root fracture with vital pulp in mandibular right first molar. Examinations of the history, clinical tests, laser Doppler flowmetry, and radiographs revealed that the tooth showed positive response to electric pulp testing and was normal compared with the healthy control tooth. This study aimed to use a novel vital preserving surgical technique (microapical surgery and nanometer bioactive materials) to make an effective therapeutic decision for the vital tooth with vertical root fracture.

Dens invaginatusis a rare malformation of the teeth, resulting in frequent pulp necrosis and chronic apical periodontitis. In this paper, the apical barrier technology was used to treat a case of chronic apical periodontitis caused by type Ⅱ dens invaginatus.