Objective To construct Myo1h gene homologous to human exon 30 knockout model mice (Myo1h mice) and to verify its knockout efficiency. Methods The F0 generation of Myo1h knockout mice was established with Crispr/Cas9 technology and homozygous F2 generation mice were obtained after breeding and genotype identification. Knockout efficiency at mRNA level and protein level was validated by real-time fluorescence quantitative PCR and Western Blot. Immunofluorescence assay was used to observe the expression of Myo1h in the condyle of mice to verify the knockout efficiency in vivo. Phenotypic assessment of F2 generation mice was carried out by measuring effective mandibular length through Micro-CT 3D reconstruction. Prism 8.0 software package was used for statistical analysis. Results Real-time quantitative PCR and western blot results showed that the mRNA level of Myo1h gene was significantly decreased (P<0.05), and protein expression was reduced. Immunofluorescence assay results showed that the expression of Myo1h in brain, lung tissues and condyle of Myo1h mice was significantly decreased (P<0.05). Phenotypic assessment by Micro-CT and length measurement analysis revealed that the effective body length of Myo1h knockout mice was shorter than that of control group (P<0.05). Conclusion In this study, model of Myo1h gene knockout mice is successfully constructed and the body length development of knockout mice is inhibited compared to control group. With further study on developmental effects of the Myo1h gene, it may provide new ideas for study on cranio-maxillofacial bone growth and development.

Objective To observe the effects of Ghrelin on proliferation and apoptosis of periodontal ligament stem cells (PDLSCs) and explore its possible mechanism. Methods Surface antigens of cultured PDLSCs were identified by flow cytometry, and the multi-directional differentiation ability of PDLSCs was identified by alizarin red staining and oil red O staining. The effect of Ghrelin on the proliferation of PDLSCs was detected by cell counting kit-8 (CCK-8) assay.The effect of Ghrelin on cell state of PDLSCs was detected by live/dead cell staining. Apoptotic effects of Ghrelin and its receptor GHS-R1α antagonist D-Lys3-GHRP-6 (DLS) on starvation-induced PDLSCs were detected by flow cytometry AnnexinV-FITC/PI double staining and TUNEL staining, respectively. Results Cells cultured in this study were mesenchymal-derived pluripotent stem cells. Moreover, 100 and 200 ng/mL Ghrelin significantly promoted the proliferation of PDLSCs (P<0.05). Moreover, Ghrelin inhibited starvation-induced cell death and apoptosis, and this anti-apoptotic effect was reversed by DLS. Conclusion Ghrelin promotes the proliferation of PDLSCs and inhibits serum-free starvation-induced apoptosis. This process might be related to the binding of Ghrelin to PDLSCs surface receptor GHS-R1α.

Objective To investigate the expression and biological function of non-SMC condensin Ⅰ complex subunit D2 (NCAPD2) in oral squamous cell carcinoma (OSCC). Methods Database was first used to analyze the expression of NCAPD2 in head and neck squamous cell carcinoma (HNSCC), and then immunohistochemistry was used to verify the expression in OSCC specimens. High-content screening (HCS), flow cytometry and Western Blot were used to detect the proliferation and apoptosis of OSCC cells and the expression of apoptosis-related proteins. Results NCAPD2 was highly expressed in HNSCC, and was related to clinical stage, pathological grade and lymph node metastasis of HNSCC. Immunohistochemistry showed that NCAPD2 expression in OSCC tissue was significantly higher than that in healthy oral tissue (P<0.001), and there was a significant correlation between NCAPD2 expression and OSCC pathological grade. Knockdown of NCAPD2 could inhibit the proliferation and promote apoptosis of OSCC cells. In addition, expressions of BCL-2 and p21 were down-regulated, and expressions of BAX and p53 were up-regulated. Conclusion NCAPD2 may be a therapeutic target for OSCC.

Objective To evaluate therapeutic effects of BMSCs on BRONJ in rats. Methods SD rats were injected intravenously with zoledronate (80 μg/kg/week) via the tail vein. After two weeks of administration, under general anesthesia, the first molars from bilateral maxillae were extracted. Drugs were continuously injected for 12 weeks to establish a rat BRONJ model. The 3rd generation of isolated BMSCs from peripheral bones were cultivated in the Bio-Oss scaffold for later use. BRONJ rats were randomly divided into four groups, and treated with surgical debridement under general anesthesia. Then, BMSCs/scaffold and scaffold were transplanted into operation sites of BRONJ rats under aseptic conditions, respectively. Rats with or without surgical debridement were used as negative control and blank control. Thereafter, rats were sacrificed at 4 and 8 weeks in batches, and bone samples were collected. New bone formation was observed by Micro-CT scanning and histological analysis. Expressions of signaling pathway related factors including RANKL and OPG were detected using ELISA testing. Results Micro-CT and histological analysis showed that bone repair effect of the BMSCs/scaffold group was optimal, presenting rapid scaffold degradation, active new bone formation and high bone mineral density (P<0.05). Bone repair effect of the scaffold group was the second, presenting slower degradation, less new bone formation and lower bone mineral density compared with the BMSCs/scaffold group. Bone repair effect of the debridement group was the worst, showing pit-like bone defect and exposed dead bone. Even worse, the bone defect was enlarged after surgical debridement. The control group presented major histopathological manifestations of human BRONJ, including non-healed or delay-healed mucosa, exposed necrotic bone, osseous sclerosis and inflammatory infiltration. Cytokines results showed that RANKL/OPG ratio was the lowest in BMSCs/scaffold group and the highest in debridement group at 4 and 8 weeks. The RANKL/OPG ratio of BMSCs/scaffold group and scaffold group significantly decreased than that of control group (P<0.05), but the ratio of debridement group significantly increased compared with the control group (P<0.05). Conclusion BMSCs from peripheral bones have a therapeutic effect on BRONJ, which can promote the repair of bone defect after debridement in BRONJ rats. RANKL/RANK/OPG signaling pathway may play an essential role in the development of BRONJ.

Objective To provide experimental data for finding effective cleaning methods to remove zinc oxide eugenol cement (ZOE Cement) from dental instruments with rough surfaces. Methods Dental TR-13 diamond burs were subjects of this study. The well-distribution of ZOE cement on the diamond burs’ surfaces mimicked the daily situation in clinical practice. The cleaning effects of different methods were compared by analyzing residual ZOE cement weight and its clearance rate, observing the surface of TR-13 diamond burs with scanning electron microscope. The anti-bacterial effect within a short time of different methods was also investigated. Results The TR-13 diamond burs wrapped with ZOE cement were randomly divided into four groups, including water soaking group, multi-enzyme soaking group, moisturizer soaking group and eugenol soaking group. Each group was ultrasonicated with multi-enzyme cleaning solution posterior to the soak. The cleaning effect of the eugenol soaking group was significantly better than other groups. Compared with the group processed by eugenol soak and then multi-enzyme ultrasound, the direct ultrasonic cleaning with eugenol exhibited no differences in the cleaning effect, but had poor performance in bacteriostasis. This defect would be ameliorated by multi-enzyme solution soaking after the ultrasonic cleaning. Conclusion The application of eugenol ultrasonic cleaning could clean ZOE cement contaminated dental instruments efficiently. Followed by multi-enzyme cleaning solution immersion, the proliferation of pathogenic bacteria could be inhibited effectively as well. This cleaning strategy is easy, effective and suitable for clinical application and promotion.

Objective To introduce a new method for distal movement of unilateral mandibular first permanent molar and evaluation of its clinical efficacy. Methods Fifteen cases in mixed dentition were selected, where mandibular anterior teeth were crowded, and the first permanent molar moved mesially. A new type of molar distalization appliance was used to move the unilateral first permanent molar that moved mesially to distal, and the analysis of gypsum model measurement and cephalometry before and after the orthodontic treatment and the data was processed by statistical software. Results After 3-7 months of treatment, the ipsilateral first permanent molar moved to distal (4.85±2.07) mm; the crowding degree of mandibular anterior teeth decreased by (1.25±1.32) mm. The anterior and inferior intersection angle formed by the long axis of the ipsilateral mandibular first permanent molar on the panoramic film and the reference plane decreased by (10. 40°±4.70°); the lower incisor axis was labial inclination by (2.51°±3.33°), and the overjet decreased by (0.92±1.79) mm. The difference was statistically significant (P<0.05). Conclusion The new method for distal movement of unilateral mandibular first permanent molar can move the mandibular first permanent molar faster, but it should be noted that when pushing the first permanent molar to distal in, it can also cause distal tilting movement and labial inclination of the mandibular incisor.

Objective To investigate the influence of cortical bone thickness (CBT) in mandibular posterior region on dental implantation accuracy. Methods A total of 30 patients at an average age of 43.1 with 37 implants in mandibular posterior dental area who were admitted to Stomatology Center of the First Affiliated Hospital of University of Science and Technology of China from June to December 2020 were included. CBT of bone in the implant area was measured in postoperative CBCT, and implants were divided into two groups according to CBT (group A, CBT≥1.5 mm; group B, CBT<1.5 mm). The deviation of implantations in the implant neck and apex as well as the angular errors were analyzed with precision verification software. Results The implant accuracy of CBT≥1.5 mm group was better than that of CBT<1.5 mm group in terms of implant point, implant end and implant angle (P<0.05). Conclusion When the thickness of bone cortex in the proposed planting area is low, precision of dental implantation may be reduced. Therefore, such patients should be treated with more caution in clinical practice.

Objective To evaluate the clinical effect of osteotome sinus floor elevation (OSFE) and simultaneous implant placement in limited alveolar bone of posterior maxilla without bone grafting when residual bone height (RBH) was about 4 mm. Methods A total of 46 patients (51 implants) from 2017 to 2019 were selected. Patients were divided into three groups (without bone grafting group (21), bone grafting group (15) and concentrated growth factor (CGF) group(15)). Changes of bone increment, implant stability quotient (ISQ), mechanical and biological complications of implants were tested and observed immediately after surgery, 6 months, 1 year and 2 years after surgery. Patient satisfaction questionnaire was conducted immediately after surgery and 2 weeks later. SPSS 21.0 software was used for statistical analysis of data. Results There was no significant difference in ISQ value among the three groups immediately or 6 months after surgery (P>0.05). In terms of maxillary sinus bone increment, there was statistically significant difference from data before surgery in three groups (P<0.05), and the increment in the bone graft group and CGF group was greater than that in the non-graft group, with statistically significant difference (P<0.05). In the follow-up questionnaire, patients were more satisfied with osteotome sinus floor elevation without bone grafting, and the difference was statistically significant (P<0.05). Conclusion When the RBH is about 4 mm in the maxillary posterior region, osteotome sinus floor elevation without bone grafting has good clinical effects and is more easily accepted by patients.

Objective To compare the effect of triple antibiotic paste and double antibiotic paste on pulp revascularization of young permanent teeth and the level of bFGF/VEGF. Methods One hundred and sisteen patients (116 teeth) with pulpitis who underwent pulp revascularization of young permanent teeth in our hospital were randomly divided into two groups (58 cases in each group). Triple antibiotic paste (triple group) and double antibiotic paste (double group) were used for root canal sealing respectively. The surgical efficacy, the level of cytokines in gingival crevicular fluid and the rate of root canal infection were compared between two groups. Results Compared with before treatment, VAS scores of two groups at 3, 6 and 12 months after operation decreased significantly with the extension of postoperative time (P<0.05), but there was no statistically significant difference between the two groups at 3, 6 and 12 months after operation (P＞0.05). Compared with before operation, levels of bFGF and VEGF in gingival crevicular fluid, root canal wall thickness and root length increased significantly 6 months after operation (P<0.05), but there was no significant difference between the two groups (P＞0.05). The total effective rate of triple group was 96.55%; compared with that of double group (94.83%), the difference was not statistically significant (P＞0.05). There was no significant difference in the incidence of filling material falling off, periapical periodontitis, root canal infection and root fracture between the triple group and the double group (P＞0.05), but the tooth discoloration rate in the triple group was significantly higher than that in the double group (P<0.05). Conclusion Triple antibiotic paste and double antibiotic paste used in pulp revascularization of young permanent teeth can both obtain good revascularization effect. They have same curative effects and good safety, but the tooth discoloration rate of double antibiotic paste is lower and the aesthetics of affected teeth is better.

With the development of soft and hard tissue augmentation, indications of implant restoration are more and more extensive. Patients with periodontitis in stage Ⅳ have more teeth loss and destruction of soft and hard tissue, and therefore when conducting implant restoration, clinicians need to comprehensively consider and evaluate the amount of soft and hard tissue in order to achieve peri-implant health. This paper reports a patient with periodontitis in stage Ⅳ and grade C with distal-extension absence. Through periodontal system treatment, implant restoration and free gingival graft, oral function of the patient has been restored and good clinical effect has been achieved.

Micro-osteoperforations (MOPs) are less invasive, safer, and cheaper interventions that orthodontists can perform alone at the side of chairs to assist orthodontic tooth movement. The theory is based on regional accelerated phenomenon (RAP), in which surgical destruction of bone tissue leads to a decrease in bone density around the surgical site, and the cell regulation mechanism stimulated by trauma accelerates bone reconstruction. Thus, the purpose of accelerating orthodontic tooth movement is achieved. At present, most of the research verifies that it can effectively accelerate tooth movement and be operated repeatedly, but the result remains controversial. Compared with other interventions, it has advantages and disadvantages. In this paper, the origin, biological reaction, application status and possible side effects of the micro-osteoperforations (MOPs) technique are discussed, which can provide a scientific reference for its latest development and clinical application.

Tooth development is a complex process induced by epithelium and mesenchymal mutually and involves many kinds of molecular interactions. It has been found that FAM20C is one of the major molecules involved in tooth development, and it can phosphorylate secretory calcium-binding phosphoprotein (SCPP), promote the differentiation of odontoblasts, ameloblasts, osteoblasts and fibroblasts, as well as the mineralization of enamel and dentin, and maintain the normal shape and health of periodontium. In this paper, the local role of FAM20C in tooth formation is reviewed.

Exosomes are nano vesicles secreted by a variety of cells under physiological or pathological conditions. Rich in bioactive substances such as protein, nucleic acid and lipid, they are an important medium for information exchange and material transfer between cells. Studies have confirmed that exosomes can regulate the proliferation and differentiation of stem cells through proteins and miRNAs, and play an important regulatory role in the process of immune response and inflammatory response. This paper reviews the biological properties of exosomes from different cell sources in inflammatory environment and their role in osteogenic differentiation, so as to provide reference for the treatment of bone defect caused by periodontitis.

Congenital condyle deformity is a common manifestation in the first and second branchial arch syndrome. The clinical feature, surgical treatment and prognosis of this syndrome have been reported by a few studies. Understanding the etiology and treatment of congenital condyle deformities is conducive to its prevention, diagnosis, improving postoperative outcomes and mental health of patients, even providing better operation conditions for orthognathic surgery. This article briefly reviews discussions on the etiology and treatment of congenital condyle deformity, in order to provide reference for clinical diagnosis and treatment planning.

In recent years, with the concept of minimally invasive surgery gradually gaining popularity, endocrown has been favored by many doctors as a simple and fast repair method after root canal treatment, because it can retain more tooth tissues without excessively cutting healthy dentin. The strength of endocrown is very important to survival rate of teeth. Therefore, a series of experiments were conducted by scholars at home and abroad to study the fracture strength of endocrown. In this paper, factors influencing the fracture strength of endocrown were reviewed, including materials, preparation methods, length of the pulp chamber extension and thickness of the prosthesis crown, in order to provide some clinical reference for dental restoration after root canal treatment.

Asthma is a common chronic respiratory disease. It is mainly characterized by chronic airway inflammation. Patients can experience symptoms such as coughing, wheezing, and reversible airflow limitation. Studies have shown that asthma has an impact not only on the respiratory system, but also on oral microecology and health, such as changes in salivary flow rate, pH, buffering capacity, and salivary composition. These changes lead to changes in the oral flora of patients and increases the risk of oral diseases such as dental caries and periodontal disease. Asthma medication, the severity and duration of asthma and asthma-related secondary diseases are also important factors that affect oral health of asthma patients. Therefore, this article reviews the impact of asthma on oral health through literature review, and provides clinical reference for both asthma patients and dentists.

Denture soft lining material is a kind of resin-based or silicon-based elastic liner, which can help the uniform distribution of occlusal load, reduce local excessive stress and improve patients′ comfort level. It is often used in removable denture restoration. However, the surface structure and properties of soft lining materials can easily lead to microbial adhesion and colonization, especially Candida albicans, which can lead to denture stomatitis. Therefore, the antibacterial modification of soft lining material can greatly improve its clinical application value. At present, main measures include adding antibacterial fillers, such as traditional antimicrobial agents, natural extracts, inorganic metal antimicrobial agents, photodynamic antimicrobial chemotherapy, protective non-thermal plasma treatments and so on. In this paper, main measures and progress of research on antibacterial modification of denture soft lining materials were summarized, and its antibacterial mechanism and effect on the physical and chemical properties of materials were discussed.

The use of dental CAD/CAM system for indirect restorations has increased considerably. Mostly, the CAD/CAM blocks consist of silicate ceramics or of resin composites. Recently, a novel resin-ceramic hybrid material for indirect restorations has been developed. This material combines the advantages of resin and ceramic and becomes a new choice for indirect restorations.The bonding performance of the prosthesis is an important index to evaluate whether it can meet clinical needs. The successful bonding of indirect prosthesis has a profound influence on the service life. The aim of this article is to review current scientific evidence about the adhesive property of novel resin-ceramic hybrid materials.