Instrument separation is one of the common complications in the process of root canal therapy, which is closely related to the complex anatomical morphology of the root canal, the performance of instrument and the factors of the operator, and cannot be avoided under the existing medical technology conditions. In addition to the failure of root canal treatment, instrument separation can also cause psychological burden to both doctors and patients, and easily lead to medical disputes. Although the instrument separation is not a medical accident, the doctor should also take some responsibility. Comprehensive preoperative evaluation and standardized operation can reduce the occurrence of instrument separation. Preoperative notification, detailed medical records and making the best clinical decision after instrument separation to reduce adverse consequences are beneficial to reduce medical disputes.

Objective To prepare porous titanium surface loaded with funme peptide (FP) and explore its biocompatibility and antibacterial properties. Methods The sandblast and acid-etching (SLA) titanium was set as the control group, and the FP was loaded on the SLA titanium by alkali heating and silanization treatment. Three experimental groups were set up according to different concentrations of FP, and the surface elements of each group were analyzed. MC3T3-E1 cells were inoculated on the surface of each sample to investigate their biocompatibility. Staphylococcus aureus was inoculated on the surface of each group to detect their antibacterial property. Results All the experimental groups were silanized successfully, and FP molecule adhered stably on the surface of silanized titanium. Compared with SLA titanium, titanium in experimental groups had significant antibacterial performance, and the 5 mg/mL group was better. Meanwhile, it had good biocompatibility and could significantly up-regulate the adhesion and proliferation of MC3T3-E1 cells. Conclusion The porous titanium surface of FP has good biocompatibility and antibacterial property.

Objective To evaluate and compare the effects of zoledronate on bone remodeling of maxillofacial and peripheral bones after trauma in rats. Methods Sprague-Dawley rats were randomly divided into experimental group and control group, and then injected intravenously with zoledronate (80 μg/kg every week) and PBS via the tail vein, respectively. Two weeks later, the first molar from maxilla was extracted, and cylindrical bone defect was prepared on the ipsilateral tibia under general anesthesia. Drugs were continuously injected for 1, 4, and 12 weeks after surgery. Thereafter, rats were sacrificed by parcel, and bone samples were collected. New bone formation in the bone defect area was investigated with Micro-CT. Soft tissue healing, new bone formation, inflammatory response, dead bone formation and other indicators were observed using HE and Masson staining. The expressions of RANKL and OPG involved in bone remodeling were detected using ELISA. Results Rats in experimental maxillofacial group showed non-healed bone defect and exposed necrotic bone, while rats in control group exhibited continuous cortical bone and normal bone remodeling according to Micro-CT results. The experimental tibial bones showed thicker bone cortex, denser mineral density and faster bone remodeling progress than that of the control group. BV/TV ratio in the experimental tibial group 4 weeks and 12 weeks after surgery increased significantly compared with the control group (P<0.05), while the difference between the two groups in maxillofacial bones has no statistical significance. Histological staining presented major clinical and histopathological manifestations of the human bisphosphonate-related osteonecrosis of the jaw(BRONJ), including non-healed or delay-healed mucosa, exposed necrotic bone, osseous sclerosis and inflammatory infiltration in zoledronate-treated rats. While rats in control group exhibited normal reepithelialization and bone remodeling, the experimental tibial bones showed increased cortical thickness, bone formation, trabecular bone volume and bone mineral density compared with the control group. Cytokines results showed that RANKL/OPG ratio in the experimental maxillofacial bones decreased significantly compared with the control group (P<0.05), while RANKL/OPG ratio in the experimental tibial bones increased significantly (P<0.05). Conclusion Zoledronate suppresses maxillofacial bone remodeling after tooth extraction, and causes BRONJ-like disease in rats, but promotes peripheral bone remodeling after bone trauma. RANKL/OPG ratio may play an essential role in the occurrence of BRONJ.

Objective To investigate effects of Tideglusib on the osteo/odontogenic differentiation of stem cells from the apical papilla stimulated by lipopolysaccharide(LPS). Methods Human stem cells from the apical papilla (SCAPs) were isolated and cultured from human dental papilla, and the surface molecules were identified by flow cytometry. CCK-8 kit was used to detect whether Tideglusib affected cell proliferation of SCAPs. The optimal concentration of Tideglusib promoting ALP activity of SCAPs was screened by alkaline phosphatase (ALP) activity and ALP staining. LPS of Escherichia coli were used to create an inflammatory microenvironment. Western blot and RT-qPCR were applied to investigate changes of proteins (OSX, OCN, COL-Ⅰ, DSP, RUNX2) and genes (OSX, OCN, COL-Ⅰ, DSPP, RUNX2) associated with osteo/odontogenic differentiation. Results CCK-8 results showed that Tideglusib with the concentration below 50 nmol/L had no cytotoxin (P>0.05); ALP results showed that the ALP activity of SCAPs stimulated by LPS treated with 1 nmol/L Tideglusib increased the most significantly (P<0.05); Western blot and RT-qPCR showed that the expression of osteo/odontogenic related proteins (OSX、OCN、COL-Ⅰ、DSP、RUNX2) and genes (OSX, OCN, COL-Ⅰ, DSPP, RUNX2) of SCAPs stimulated by LPS treated with 1 nmol/L Tideglusib markedly increased (P<0.05). Conclusion Tideglusib (1 nmol/L) can promote the osteo/odontogenic differentiation ability of SCAPs stimulated by LPS.

Objective To observe the spatial and temporal expression of FAM20C in condylar cartilage at different stages of condylar development in mice and explore its possible mechanism. Methods HE staining and modified safranin O-fast green staining were used to observe morphological changes of condylar cartilage and subchondral bone in 17.5 days of embryo and 0, 7, and 21 days after birth. Immunohistochemical staining was used to observe the localization and expression of FAM20C in mouse condylar cartilage tissues at corresponding time points. The mean optical density values of FAM20C positive expression were measured and subjected to one-way ANOVA. Results Results of HE staining and modified safranin O-fast green staining showed that with the progression of endochondral ossification, the length of condylar chondrocyte layer decreased; the volume of subchondral bone increased, and the volume of mandibular condyle increased. The immunohistochemical results showed that FAM20C was positively expressed in condylar cartilage tissue of the four groups of mice. FAM20C was mainly expressed in the proliferating chondrocyte layer, and pre-hypertrophic chondrocyte layer of condylar cartilage and a small amount was expressed in the hypertrophic chondrocyte layer and subchondral bone layer. With the development of condyle, the expression of FAM20C gradually decreased. Results of statistical analysis showed that there was a significant difference in FAM20C positive expression at each time point (P<0.01). Conclusion FAM20C is involved in mandibular condyle development in mice and may play an important role in condyle formation by regulating the proliferation and differentiation of condylar chondrocytes.

Objective To explore the expression and role of Claudin-7 in oral squamous cell carcinoma (OSCC). Methods Expression of Claudin-7 in OSCC was detected by immunohistochemistry experiment and western blot experiment, and the relationship between Claudin-7 and pathological parameters was analyzed. Lentiviral was used to transfect Cal27 and HN6 cell line to increase the expression of Claudin-7. CCK-8 assay and Transwell assay were used to detect changes in cell proliferation and migration ability. Western blot experiments and RT-qPCR experiments were used to detect the effect of up-regulated Claudin-7 on the index of epithelial-mesenchymal transition. Results Claudin-7 was decreased in OSCC (P<0.05) and its expression level was related to patient′s tumor size, differentiation degree and lymph node metastasis (P<0.05). Overexpression of Claudin-7 could inhibit the proliferation and migration of Cal27 and HN6 cells, up-regulate the expression of E-cadherin protein and mRNA, and down-regulate the expression of N-cadherin and Vimentin protein and mRNA (P<0.05). Conclusion Claudin-7 is expressed at low levels in OSCC. Up-regulating the expression of Claudin-7 can inhibit the proliferation and migration of OSCC cells by regulating epithelial-mesenchymal transition. Claudin-7 can be used as a new target for the treatment of OSCC.

Objective To evaluate the clinical and microbiological effects of systemic azithromycin (AZI) as an adjunct to scaling and root planing (SRP) in the treatment of stage Ⅲ/Ⅳ periodontitis. Methods Forty patients were randomized into SRP group and AZI group. Clinical examinations and saliva collection were performed at baseline, 3 days and 6 weeks after SRP. Clinical examinations analyzed the treatment effects. Salivary microbiomes were analyzed through 16S rRNA sequencing, and the differences in richness, diversity, and relative abundance of each taxon were determined. Results All the clinical parameters were significantly improved after treatment in both groups compared to baseline(P<0.001). Greater clinical attachment loss(CAL)and bleeding on probing (BOP) improvements were found in the AZI group at 3 days and 6 weeks after treatment (P<0.05); improvement in probing depth (PD)was only found at the 6^th week(P<0.05). Results of site-level stratified statistics showed that periodontal indexes at the site level in the AZI group after treatment were better than those in the SRP group. All the alpha diversity indices were significantly reduced after treatment in the AZI group(P<0.05), while in SRP group, only Sobs index had a transient reduction 3 days after treatment. The proportion of Lactobacillus microbiota increased in both groups post-SRP, and was higher in the AZI group. Besides, the proportion of Treponema, and Fusobacterium decreased significantly in AZI group (P<0.05); at 3 days after treatment, the proportion of Porphyromonas decreased significantly (P<0.05), while the proportion of Prevotella increased significantly (P<0.05). However, at 6 weeks after treatment, the proportion of both regressed close to the baseline level (P>0.05). Conclusion AZI combined with non-surgical periodontal therapy, can improve clinical outcomes of severe periodontitis, change flora composition, and inhibit Treponema, Fusobacterium and Porphyromonas in periodontal red and orange pathogenic complexes.

Objective To conduct a three-dimensional comparative study on upper airway symmetry between patients with non-syndromic cleft lip and palate and populations with skeletal Class Ⅰ. Methods Fifty-one cases of non-syndromic cleft lip and palate patients (37 males, 14 females, average age (17.40±5.93) years) and 53 cases of skeletal Class Ⅰ populations (39 males, 14 females, average age (17.40±6.07) years) were included. Cone-beam CT was taken, and Dolphin 3D 11.9 software was used for three-dimensional measurement and analysis. SPSS 25.0 software package was used for independent sample t-test to conduct the analysis of upper airway symmetry. Results The nasopharyngeal and velopharyngeal segments of the upper airway in patients with unilateral cleft lip and palate were asymmetrical structures (P<0.05), and the cross-sectional diameter of the affected side was smaller than that of the healthy side; while the patients with bilateral cleft lip and palate and skeletal Class Ⅰ populations had an asymmetric structure (P<0.05). The nasopharyngeal and velopharyngeal segments of the upper airway were basically symmetrical (P<0.05). Conclusion In the cross-sectional diameter of the upper airway in patients with unilateral cleft lip and palate, the affected side tends to be biased toward the healthy side, and attention should be paid to the ventilation and respiration of the affected side of cleft lip and palate.

Objective To evaluate the efficacy of concentrated growth factor (CGF) in combination with minocycline hydrochloride ointment in relieving pain, controlling inflammation, and promoting the growth of new granulation tissue in tooth sockets. Methods A total of 40 patients with dry socket who were admitted to the Maxillofacial Surgery Department of The Affiliated Stomatological Hospital of Xinjiang Medical University from March to September 2021 were randomly assigned to two groups. Twenty cases of CGF combined with minocycline hydrochloride ointment (group A) and 20 cases of iodoform gauze (group B) were used to study and compare the clinical efficacy of two different treatment methods for dry socket. Patients were followed up on day 0, 1, 4, 7, 14, and 21. Visual analogue scale (VAS) was used to evaluate the degree of pain. Gingival index (GI) was used to evaluate the degree of gingival inflammation. Granulation tissue (GT) was used to evaluate the degree of soft tissue growth in tooth socket. Results Compared with group B, group A was more effective in relieving pain, controlling inflammation and promoting the growth of new granulation tissue in tooth socket, and the results were statistically different (P<0.05). Conclusion CGF combined with minocycline hydrochloride ointment has a good clinical effect on the treatment of dry socket, which is worthy of reference in clinical practice.

Objective To understand the effect of cone-beam CT(CBCT) voxel overlap at different stages on the accuracy of quantitative analysis during longitudinal efficacy assessment of two-dimensional images. Methods Thirty-six adult patients with bimaxillary protrusion who had finished extraction orthodontic treatment were selected, and CBCT data before and after treatment were imported into Dolphin software. The experimental group underwent voxel overlap based on the anterior cranial base, then were reconstructed respectively in layers to form the combined lateral film. In the control group they were directly converted to lateral films after cranial repositioning. 16 indexes were selected for measurement and one senior orthodontist completed all the measurements. All the data were measured twice. Differences of the indexes before and after treatment were calculated respectively. Paired t-test was used for inter-group analysis. Results Voxel overlap helped improve the fitting degree of skull base and the marker points in the experimental group were easier to identify. Inter-group comparison of the differences showed that there were significant differences in SNA, U1-NA, U1-Y, U6-Y, L1-Y and L6-Y (P<0.05). Conclusion CBCT voxel overlap can reduce errors and improve the accuracy of longitudinal studies.

Objective To investigate morphological characteristics of maxillary arches of unilateral complete cleft lip-and-palate (UCLP) newborns, and confirm the reliability and repeatability of a novel 3D measurement. Methods A total of 60 newborns with UCLP up to the mustard were selected. An intraoral scanner was applied to collect digital models of their initial maxillary arches and measurements were completed with Mimics software. In all, 25 items of maxillary alveolus were measured for each model twice, and then Bland-Altman analysis was done to check the consistency. All samples were divided into three groups according to morphological features, and comparative analysis was completed to study morphological differences between different groups. Results All measurements were in accordance with normal distribution and this novel 3D measurement showed clinically acceptable consistency. Length of the anterior segment of alveolus and angles of both the anterior and posterior segments of alveolus on the none-cleft side (NCS) were all greater than those on the cleft side (CS). Length of the anterior segment of alveolus on the NCS in Group 1 and 2 was significantly greater than that in Group 3. Besides, samples in Group 1 showed smaller width of the cleft and the arch in both anterior and middle parts, compared with other groups. Angular values showed that angle of the anterior segment of alveolus on the NCS in Group 1 was smaller than that of other groups. Conclusion The research summarizes average dimensions of the maxillary arches of non-syndromic UCLP newborns. Besides, it is observed that severity of cleft depends on both the insufficient length and the rotation angle of the anterior segment of alveolus on the NCS.

Objective To evaluate the clinical value of retrograde excision of sublingual gland from posterior to anterior for the treatment of oral ranulas. Methods A retrospective analysis of 86 oral ranulas patients, who had excised ipslateral sublingual gland in our hospital, was conducted to compare traditional sublingual gland excision with retrograde sublingual gland excision in loss of blood, duration and incidence of complications in surgery. Results Compared to traditional sublingual gland excision, the loss of blood in retrograde sublingual gland excison was significantly reduced and the difference was statistically significant (t=8.89, P＜0.01). The duration in surgery was significantly shortened and the difference was statistically significant (t=14.85, P＜0.01). The incidence of complications decreased greatly (from 10.7% to 0%), but the difference was not statistically significant. Conclusion Retrograde excision of sublingual gland from posterior to anterior can reduce the incidence of surgical complications and loss of blood, shorten the duration and improve the safety of surgery. It is suitable to be applied in sublingual gland excision.

Traditional plaque removal methods mainly include ultrasonic cleaning and manualscaling, but the plaque control effect is limited in the root surface depression, root bifurcation and deep and complex periodontal pocket due to the difficulty of access with instruments, and repeated treatment will cause great damage to periodontal tissue. Glycine air polishing with pressurized air and water as carrier mixed with glycine sandblasting powder is an ideal treatment for plaque control, which has the characteristics of safety, high efficiency and high comfort for patients. This paper describes the application of glycine air polishing in plaque control.

Clinically, it is common for children to have large-area defects of young permanent molars, which affect the masticatory function and jaw development of children. However, due to characteristics of mixed dentition, the repair method is different from that of adults. With commonly used clinical methods for the treatment of large-area defects of young permanent molars listed, this article reviews current methods for repairing dental defects of young permanent molars in children, and discusses the advantages and disadvantages of each method, hoping to provide reference for the choice of clinical restoration methods.

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor in the oral and maxillofacial region, but when OSCC patients seek medical advice, the disease has often reached an advanced stage and tumor metastasis has appeared, resulting in a poor prognosis. Its pathogenesis is still unclear, and there is still demand for effective diagnostic and therapeutic targets to monitor the invasion, metastasis and recurrence of OSCC. Studies show that histone modification changes chromatin structure, thereby affecting transcriptional activity of related downstream genes and regulating gene expression levels, which plays an important role in biological detection, pathological grading and staging, prognosis of OSCC. This article reviews current research progress of histone modification including methylation, acetylation, phosphorylation, ubiquitination and ADP-ribosylation in oral squamous cell carcinoma.

N⁶-methyladenosine (m⁶A) is the most abundant epigenetic modification in eukaryotes and plays a significant regulatory role in mammalian growth and disease control. Studies have found that m⁶A modification can accurately regulate the gene expression related to bone remodeling and development no matter in a physiological or pathological state, thus affecting bone metabolism balance. In this systematic review, we summarized regulatory mechanisms of m⁶A modification in osteogenic differentiation, in order to provide new ideas and potential targets for promoting bone formation and preventing or treating diseases related to bone metabolism.

Transverse maxillary hypoplasia is one of the common malocclusions in clinic, which affects not only the arrangement and occlusion of the upper and lower teeth but also the dental arch shape, face shape and aspiration. Transverse maxillary hypoplasia is an important part of clinical diagnosis and treatment plan of malocclusion in children. Maxillary expansion is the main method to solve the problem of transverse maxillary hypoplasia in orthodontic patients. The clinical effect of maxillary expansion has already been proved. Scientific and Objective evaluation of its clinical effect is helpful for doctors to deepen their understanding of the mechanism of dental arch width deficiency, optimize the design and selection of clinical treatment, and improve the effectiveness and stability of maxillary expansion treatment. At present, there are many methods to evaluate the curative effect of maxillary expansion, and this paper reviews its evaluation methods and development direction.

Oral squamous cell carcinoma (OSCC) is one of the major malignant tumors affecting human health. Due to the lack of biomarkers for early detection and risk assessment, more than 50% patients are often diagnosed at the late stage. Exosomes are nano-sized vesicles secreted and released by cells to the outside,which are widely present in the saliva. Exosomes carry various bioactive substances and mediate the interaction between tumor cells and tumor microenvironment. With the development of exosomes research, scientists found that exosomes are closely related to the diagnosis and treatment of oral diseases. And exosomes can be used as ideal oral disease biomarkers for early diagnosis. This articles reviews the research development of salivary exosomes in Oral squamous cell carcinoma,in order to provide the reference for studies on early diagnosis of oral carcinoma.

Temporomandibular joint is the only mobile joint in oral and maxillofacial region. Temporomandibular joint disorder is one of the most common diseases in maxillofacial region. Intra-articular pressure changes with the changes of intra-articular structure and functional movement. The change of intra-articular pressure is an important factor causing temporomandibular joint disorder. The research and measurement of intra-articular pressure has certain guiding significance for the development and treatment of the disease. In this paper, we summarized research on temporomandibular joint intra-articular pressure in recent years, focusing on the mechanism of intra-articular pressure, influencing factors, measurement of intra-articular pressure and its significance for clinical treatment.