Alveolar bone is an important anatomic basis for implant-supported denture restoration, and its different degrees of defects determine the choices of bone augmentation surgeries. Therefore, the reconstruction of alveolar bone defects is an important technology in the clinical practice of implant restoration. However, the final reconstructive effect of bone quality, bone quantity and bone morphology is affected by many factors. Clinicians need to master the standardized diagnosis and treatment principles and methods to improve the treatment effect and achieve the goal of both aesthetic and functional reconstruction of both jaws. Based on the current clinical experience of domestic experts and the relevant academic guidelines of foreign counterparts, this expert consensus systematically and comprehensively summarized the augmentation strategies of alveolar bone defects from two aspects: the classification of alveolar bone defects and the appropriate selection of bone augmentation surgeries. The following consensus are reached: alveolar bone defects can be divided into five types (Ⅰ-0, Ⅰ-Ⅰ, Ⅱ-0, Ⅱ-Ⅰ and Ⅱ-Ⅱ) according to the relationship between alveolar bone defects and the expected position of dental implants. A typeⅠ-0 bone defect is a bone defect on one side of the alveolar bone that does not exceed 50% of the expected implant length, and there is no obvious defect on the other side; guided bone regeneration with simultaneous implant implantation is preferred. Type Ⅰ-Ⅰ bone defects refer to bone defects on both sides of alveolar bone those do not exceed 50% of the expected implant length; the first choice is autologous bone block onlay grafting for bone increments with staged implant placement or transcrestal sinus floor elevation with simultaneous implant implantation. Type Ⅱ-0 bone defects show that the bone defect on one side of alveolar bone exceeds 50% of the expected implant length, and there’s no obvious defect on the other side; autologous bone block onlay grafting (thickness ≤ 4 mm) or alveolar ridge splitting (thickness > 4 mm) is preferred for bone augmentation with staged implant placement. Type Ⅱ-Ⅰ bone defects indicate that the bone plate defect on one side exceeds 50% of the expected implant length and the bone defect on the other side does not exceed 50% of the expected implant length; autologous bone block onlay grafting or tenting techniques is preferred for bone increments with staged implant implantation. Type Ⅱ-Ⅱ bone defects are bone plates on both sides of alveolar bone those exceed 50% of the expected implant length; guided bone regeneration with rigid mesh or maxillary sinus floor elevation or cortical autologous bone tenting is preferred for bone increments with staged implant implantation. This consensus will provide clinical physicians with appropriate augmentation strategies for alveolar bone defects.

The reconstruction effect of peri-implantitis bone defects depends on their morphological characteristics. This paper reviews the morphological classification and treatment of peri-implantitis bone defects. A literature review shows that the morphological classification of bone defects in peri-implantitis includes morphology classification and clinical classification. At present, the Renvert classification is more commonly used in the clinic and is divided into four-wall bone pockets, three-wall bone pockets, two-wall bone pockets, one-wall bone pocket and dehiscence according to the number of bone walls. This has guiding significance in the treatment plan of peri-implantitis. The treatment of peri-implantitis depends on the severity of peri-implant bone defects. Peri-implantitis with mild bone defects is treated by nonsurgical treatment, peri-implantitis with severe bone defects is recommended to remove the implant, and peri-implantitis with moderate bone defects is further judged according to the shape of the bone defects. Four-wall bone pockets, three-wall bone pockets and dehiscence are mostly treated by bone regenerative surgery. For shallow two-wall bone pockets, one-wall bone pockets and horizontal bone resorption, bone resection is often used. However, most peri-implantitis has a variety of bone defect forms at the same time, which need to be treated with bone regenerative surgery and bone resection surgery.

In recent years, artificial intelligence technology has developed rapidly and has been gradually applied to the fields of clinical image data processing, auxiliary diagnosis and prognosis evaluation. Research has shown that it can simplify doctors’ clinical tasks, quickly provide analysis and processing results, and has high accuracy. In terms of orthodontic diagnosis and treatment, artificial intelligence can assist in the rapid fixation of two-dimensional and three-dimensional cephalometric measurements. In addition, it is also widely used in the efficient processing and analysis of three-dimensional dental molds data, and shows considerable advantages in determining deciding whether orthodontic treatment needs tooth extraction, thus assisting in judging the stage of growth and development, orthodontic prognosis and aesthetic evaluation. Although the application of artificial intelligence technology is limited by the quantity and quality of training data, combining it with orthodontic clinical diagnosis and treatment can provide faster and more effective analysis and diagnosis and support more accurate diagnosis and treatment decisions. This paper reviews the current application of artificial intelligence technology in orthodontic diagnosis and treatment in the hope that orthodontists can rationally treat and use artificial intelligence technology in the clinic, and make artificial intelligence better serve orthodontic clinical diagnosis and treatment, so as to promote the further development of intelligent orthodontic diagnosis and treatment processes.

Ectopic eruption of the first permanent molar is a common malocclusion in the early stage of mixed dentition. The incidence among children aged 6-10 years is 0.83%-8.7%, with an increasing trend. The main manifestation is mesial impaction of the first permanent molar during eruption, which is accompanied by the loss of root resorption and space loss of the second primary molar. Ectopic eruption of the first permanent molars can lead to underdevelopment of the dental arch and severe crowding of the posterior dentition. Prevention and early intervention are very important. The ectopic eruption of the first permanent molar is related to the disruption of the differential growth and developmental balance among the teeth, alveolar bone and jaw. In clinical practice, the diagnosis can be made according to the patient's medical history and clinical and imaging examinations, and the treatment can be performed by dividing the teeth, dividing the distal slices of the second primary molars, and distally moving the first permanent molars. This paper reviews the incidence, etiology, clinical manifestations, risks of ectopic eruption of the first permanent molar, diagnostic methods, and common treatment options to provide references for clinical treatment.

Root fracture is a kind of dental trauma involving dentin, cementum, pulp tissue, periodontal membrane ligament and even the surrounding alveolar bone. It occurs frequently between the ages of 10-20, mostly in the area of the maxillary anterior teeth with high aesthetic requirements. The treatment goal for root fracture in permanent teeth is to maintain the physiological and functional integrity of the tooth as much as possible and to reduce the incidence of complications. Clinicians usually classify the affected teeth according to the position of the root fracture, including the apical, mid-root, cervical-mid-root and cervical segments, since it determines the treatment plan and the prognosis of the affected teeth. CBCT examination can avoid misdiagnosis and missed diagnosis of root fracture to the greatest extent. The sequential treatment plan of root fracture after permanent anterior tooth trauma includes initial emergency treatment, pulp vitality monitoring and complication management during follow-up. Emergency treatment mainly includes local anesthesia and repositioning, if displaced, the coronal segment of the tooth as soon as possible. Then, after checking its position radiographically, adjustment occlusion and flexible splinting for 4 weeks (4 months for cervical root fracture). The process of root fracture repair includes many tissues and is affected by many clinical factors. Timely and standardized treatment and close follow-up according to the Dental Trauma Guideline guarantee a good prognosis of root fracture. The closer the root fracture line is to the apex, the higher the survival rate is. In addition to the location of the root fracture line, the prognosis is affected by many other clinical factors, such as the displacement of the coronal fragment of the root fracture, the pathological state of the dental pulp, patient age, developmental stage of the root, timely and good replacement of the root fracture, splinting method, and the presence of other dental trauma complications. Pulp vitality should be monitored regularly, and root canal therapy of the coronal segment should be carried out only when infection of the pulp is established. This article reviews the classification, diagnosis, emergency treatment, sequential follow-up treatment, and prognostic assessment of root fracture trauma to provide suggestions for clinicians to manage root fracture trauma in permanent teeth.

With the arrival of the era of big data, increasing attention has been drawn to the application of artificial intelligence (AI) in the medical field. AI has many advantages, such as objectivity, accuracy, minimal invasiveness, time savings and high efficiency. Therefore, the combination of AI with dental diagnosis and treatment can help dentists improve work efficiency and save medical resources, offering potential significant benefits for dental application. At present, AI has been gradually integrated into prosthodontics, oral and maxillofacial surgery, orthodontics, endodontics and periodontics. The AI system can realize automatic tooth preparation, automatic tooth arrangement and implantology. Deep learning can be used to assist in diagnosing maxillary sinus inflammation, predicting the complications of tooth extraction and improving the accuracy of osteotomy. The AI system can also provide significant clues for the diagnosis, treatment and prognosis of oral and maxillofacial tumors. The breakthrough brought by AI in cephalometric and the assessment of facial attractiveness of patients has promoted the development of intelligent and personalized orthodontic treatment. Deep learning and analysis of medical images also promote the accuracy of root canal therapy as well as the diagnosis and treatment of periodontal diseases. AI technology has realized the leap from digitalization to automation and intelligence in oral diagnosis and treatment, and its application potential in the oral field should not be underestimated. Based on the concepts of AI, this paper will focus on the application of artificial intelligence in various oral clinical fields and briefly introduce its advantages, problems and future.

Exosomes are phospholipid bilayer vesicles secreted by living cells that can carry a variety of signaling molecules, such as RNA, DNA, protein, and lipids. Exosomes play a role in the transmission of signaling molecules between cells, thus regulating many physiological and pathological processes. The methods of extracting exosomes include differential centrifugation, density gradient centrifugation, exclusion chromatography, ultrafiltration, coprecipitation, polymer immune affinity, microfluidic separation technology, etc. Each of these extraction technologies has advantages and disadvantages; however, there is no unified international standard. In addition, the expression of specific proteins and genetic material of exosomes from different cell sources are different; thus, their expression characteristics and functions are also distinctive. Based on this situation, research on exosomes is limited to preclinical studies, and difficulties and challenges still exist in clinical application. This paper summarizes the progress of research in the field of exosomes, to understand the characteristics, modification and application of exosomes from different cell sources, and to summarize their advantages and disadvantages as well as challenges, which can help researchers better understand and master the performance of exosomes. Furthermore, improvement of standard procedures in the extraction and manufacturing of exosomes is important, as it will provide a reference for researchers to carry out exosome-related translational clinical research.

As a new type of antibacterial material, copper-containing titanium alloys have good biological and mechanical properties and are expected to be widely used in clinical orthopedics and dental implants. Macrophages are the main cells that mediate the immune response after the alloy is implanted into the human body, and they directly affect the stability of the alloy in long-term service. Due to the addition of copper, the copper-containing titanium alloy gives the alloy antibacterial properties. On the one hand, this promotes the phagocytosis of macrophages and kills bacteria. On the other hand, copper promotes the polarization activation of macrophages, which then express a variety of cytokines and trigger inflammation in the body. However, at present, there is no definitive conclusion about the type of copper-containing titanium alloys that regulate the polarization of macrophages, and the mechanism of copper ions regulating the polarization of macrophages is still not fully clear. This article summarizes the published studies on the regulation of macrophage polarization by copper-containing titanium alloys and reviews the relevant literature in terms of material types, surface treatments, processing methods, cell culture methods, and culture density. The application of medical copper-containing titanium alloys has prospects. It is hoped that by changing the properties of copper-containing titanium alloys, such as the processing methods or surface treatments, the polarization direction of macrophages can be adjusted, with a view to the design and clinical application of medical copper-containing titanium alloys.

The most common periodontal biotype in the Chinese population is thin, which obviously limits orthodontic tooth movement. Periodontally accelerated osteogenic orthodontics (PAOO) can not only accelerate tooth movement through corticotomy but also expand the range of orthodontic tooth movement by alveolar bone augmentation, which could reduce the periodontal complications of orthodontic therapy. The development of PAOO has gone through a long and tortuous historical process over more than 100 years: from osteotomy based on "bony block movement" at the beginning to cortical osteotomy based on "the regional acceleratory phenomenon" and then to PAOO based on "bone tissue engineering". Throughout its development history, the understanding of the biological basis determines the development of the clinical technology. Therefore, PAOO should be based on basic research. Both the present clinical practice and future surgical improvements should be based on the fundamentals of bone repair and regeneration. According to the current evidence, it is suggested that piezocision and laser-assisted flapless corticotomy should be chosen only for simple cortical osteotomy, and surgical navigation technology or 3D-printed surgical guides are recommended. When a large amount of bone augmentation is needed, PAOO with an intact flap is still the first choice. A stable and infection-free healing environment is the key to wound healing; therefore, in addition to infection control, the surgical area should also be protected from external forces. At present, there are few high-quality clinical studies on PAOO. Multicenter, large-sample, randomized controlled clinical trials are needed to evaluate the clinical efficacy of different PAOO techniques in the future. The present article introduces the development history, fundamentals and operation precautions of PAOO, and a new perspective is also proposed, which may provide a reference for clinical practice.

Salivary exosomes are extracellular vesicles with a diameter of 30-50 nm in saliva. With the development of technology in recent years, many studies have revealed that salivary exosomes play an important role in the occurrence and development of various oral diseases. For example, salivary exosomal CD9 and CD81 promote tumor cell metastasis by regulating the cell adhesion and movement, salivary exosomal miR-24-3p promotes the tumor cell proliferation by acting on PER1, and salivary exosomal programmed cell death-ligand 1 (PD-L1) mRNA inhibits the destruction of inflammatory tissue, which can be biomarkers for the diagnosis of oral cancer, periodontitis and other oral diseases. Therefore, salivary exosomes can be used as potential prognostic and diagnostic markers for oral diseases. In addition to oral diseases, such as oral cancer, periodontitis, oral lichen planus, Sjogren’s syndrome, etc., salivary exosomes are closely related to distant tumors, such as pancreatic cancer, lung cancer, and systemic diseases, such as Parkinson’s disease, inflammatory bowel disease, etc. It is of great significance to study the role of salivary exosomes in the diagnosis and treatment of oral and systemic diseases and to develop the potential of salivary exosomes as biomarkers for disease diagnosis.

Objective To evaluate the clinical effect of endoscopic-assisted subgingival scaling and root planning (SRP) in the treatment of periodontitis. Methods PubMed, EMBASE, The Cochrane Library, Web of Science, CNKI, WanFang Data, and VIP databases were searched for randomized controlled trials (RCTs) related to endoscopy-assisted SRP. The search time limit was from the establishment of the database to September 15, 2021. The outcome indicators included in the study included the plaque index (PLI), probing depth (PD), attachment loss (AL), and bleeding index (BI). Review Manager 5.4 and Stata 12.0 software were used for the meta-analysis. Results A total of 111 studies were retrieved, and 5 quantitative studies were included after screening. Meta-analysis showed that for sites with 4 mm ≤ PD < 6 mm, 3 and 6 months after treatment, there was no significant difference in the PD value between the endoscope assisted group and the simple SRP group (P > 0.05); for sites with PD ≥ 6 mm, the PD value of the endoscope assisted group was smaller than that of the simple SRP group 3 and 6 months after treatment. The difference between the two groups was statistically significant (P < 0.05), but there was no significant difference in PLI, Al or BI between the two groups (P > 0.05). Conclusion Compared with simple SRP, the auxiliary use of endoscopy has a better effect on reducing PD in deep periodontal pockets (PD ≥ 6 mm). However, for clinical indicators such as PLI, AL, and BI, there was no difference between the therapeutic effects of the two methods.

With the improvement of computer computing capability and the accumulation of a large amount of medical data, artificial intelligence is gradually being applied in the diagnosis of oral and maxillofacial tumors. Artificial intelligence technology can assist doctors in clinical diagnosis and improve the efficiency of clinical work and the accuracy of diagnosis. In recent years, researchers have focused primarily on the recognition of medical images. The commonly used method is to annotate a large number of images by experts for learning image features by machines. The available literature has been able to utilize artificial intelligence technology to diagnose tumors by analyzing medical images, pathological sections, and tumor photos. The main issues in the current research are uneven labeling data quality, small data size, limited research problems, and single data modalities. These problems need to be solved through the continuous improvement of algorithms and the accumulation of high-quality data. The future direction of artificial intelligence applications should be to integrate medical data from multiple sources, assist doctors in diagnosis, and explore a variety of noninvasive and easy-to-use new methods for the early diagnosis of tumors. This may completely change the existing diagnosis and treatment model of oral and maxillofacial tumors.

Curcumin is a natural medicine with a wide range of sources and low toxicity. It has antibacterial, antifungal, anti-inflammatory and other pharmacological effects. In recent years, curcumin has attracted much attention in the field of prevention and treatment of oral infectious diseases. Single curcumin is easily degraded during application and has poor water solubility and low bioavailability, but it can be used as a natural photosensitizer to mediate photodynamic treatment of oral infections. Photodynamic therapy has high antibacterial efficiency and can better protect the appearance and function of the affected area. This article reviews the research on curcumin-mediated photodynamic therapy for oral infectious diseases. As a natural photosensitizer, curcumin mediates photodynamic therapy and has shown good therapeutic effects against dental caries, endodontics, periodontitis, oral candidiasis and other oral infectious diseases by enhancing antibacterial ability, increasing the production of reactive oxygen species, and inhibiting the formation of biofilms. In-depth exploration of the mechanism of action of curcumin-mediated photodynamic therapy in different oral infectious diseases can provide new strategies for the prevention and treatment of oral infectious diseases.

Objective To analyze the adverse drug reaction（ADR） reports of hydroxychloroquine for clinical medication safety. Methods The ADR reports of hydroxychloroquine between May 2019 and May 2021 were analyzed. Age, reasons for drug use, time of ADR, combined drug use, and ADR outcomes were statistically analyzed. Results No severe ADR was reported. Patients over 60 years old accounted for 53.85% of the total cases, and the time of ADR appearance was significantly earlier among those under 60 years old. A total of 61.54% of ADRs were involved in multiple organs, and optic neurotoxicity was reported in 46.15% of cases. Conclusion In the treatment of oral lichen planus with hydroxychloroquine, adverse drug reactions should be monitored, and increased attention should be given to patients over 60 years old to ensure the safety of this medication.

Objective To explore the value of an oral squamous cell carcinoma (OSCC) diagnostic model constructed by using principal component analysis (PCA) to analyze a database of differentially expressed genes in OSCC and to provide a reference for clinical diagnosis and treatment. Methods RNA-seq expression data of OSCC and normal control samples were obtained from The Cancer Genome Atlas (TCGA) database, and then, normalized and differentially expressed genes (DEGs) were identified by R software. DEGs were enriched by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis to identify their main biological characteristics. 70% of DEGs expression data in RNA-seq were randomly selected as the training set and 30% were selected as the test set. Then, the PCA method was applied to analyze the training set data and extract the principal components (PCs) related to the diagnosis of OSCC in order to construct a PCA model. Then, the receiver operating characteristic (ROC) curves of PCA models in the training set and the test set were respectively drawn, and the area under curve (AUC) was calculated to evaluate the accuracy of the PCA model in the diagnosis of OSCC. Results RNA-seq expression data of OSCC and normal control samples obtained from TCGA database included 330 samples and 32 samples, respectively. Using false discovery rate (FDR) <0.001 and |log2 fold change| (|log2FC|) >4 as the thresholds, a total of 159 downregulated and 248 upregulated DEGs were identified, which were mainly enriched in cellular components such as intermediate fiber and melanosomal membrane, pigment and salivation-related biological processes and mainly involved in salivary secretion and tyrosine metabolism pathways (P.adjust<0.05 and Q<0.05). The DEGs were proposed as tumor markers for OSCC, and PCA analysis of the training set showed that the cumulative ratio of variance of PC1, PC2 and PC3: [including submaxillary gland androgen regulated protein 3B (SMR3B), proline rich 27 (PRR27), histatin 3 (HTN3), statherin (STATH), cystatin D (CST5), BPI fold containing family A member 2 (BPIFA2), proline rich protein Hae Ⅲ subfamily 2 (PRH2), keratin 35(KRT35), histatin 1 (HTN1), amylase alpha 1B (AMY1B)] were 0.873, 0.100 and 0.023, respectively, and the total weight of the three was 0.996. The PCA diagnostic model of OSCC was further constructed by combining the eigenvectors of the above three components. The ROC curves of the training set and test set showed that the AUC values of the PCA model were 0.852 and 0.844, respectively, which were higher than those of other single genes. Conclusion The OSCC diagnostic model based on the expression levels of SMR3B, PRR27, HTN3, STATH, CST5, BPIFA2, PRH2, KRT35, HTN1 and AMY1B constructed with the PCA method and DEGs has a high diagnostic advantage. This study provides a theoretical basis for the early genetic diagnosis of OSCC and the application of the PCA model in clinical diagnosis.

Silicon nitride has high fracture toughness and compressive strength similar to human bone. It meets the basic mechanical requirements of implants and has good biocompatibility. The micrometer/nanometer morphology surface characteristics of silicon nitride give it good osteogenic activity and antibacterial properties, which are helpful to reduce the incidence of periimplant inflammation. Therefore, silicon nitride has good application potential in dental implants. In orthopedics, silicon nitride implants have been used in spine repair and joint implantation. However, there is a lack of research on silicon nitride as dental implant material. The evaluation of the osteogenic and antibacterial properties of silicon nitride bioceramics prepared using different sintering additives and sintering processes, the antibacterial properties of silicon nitride on different dominant oral pathogens, and the osteogenic activity and antibacterial properties of silicon nitride materials implanted into the jaw need to be further studied. Combined with the latest research results at home and abroad, this review discusses the application potential of silicon nitride materials in dentistry.

Dental anxiety refers to the unique tension, worry and even fear of dental treatment, which may lead to patients refusing to receive treatment and missing the best time for treatment. With the development of bio-psycho-social medical models, psychotherapy has gradually become the optimal treatment for dental anxiety. This article reviewed the etiology, evaluation and psychotherapy of dental anxiety. Research has shown that uncomfortable dental treatment experience is the main cause of dental anxiety, which is commonly assessed using questionnaires in clinical practice. Psychotherapy for dental anxiety is a noninvasive, widely applicable treatment without side effects, mainly including improving the treatment environment and service attitude, behavior therapy, and cognitive therapy, which has been shown to effectively alleviate dental anxiety in patients. However, psychotherapy for dental anxiety is highly demanding for dentists, which hinders its promotion and application. At the same time, the psychotherapeutic mechanism of dental anxiety is not clear and remains to be further elucidated by large-scale and high-quality randomized controlled studies.

Objective To evaluate the therapeutic effect of dental autotransplantation with the application of digital design combined with 3D printing of donor tooth models and recipient alveolar fossa model preoperatively. Methods Twelve cases that could not be retained due to tooth fracture or extensive absorption of alveolar bone were recruited in the study. Cone-beam computed tomography (CBCT) data were imported into Mimics software for digital design, and the best-matched third molar was selected as the donor tooth. Replicas of the donor teeth and the recipient socket were printed out with three-dimensional (3D) printing technologies as a simulation model for recipient tooth socket preparation. During tooth autotransplantation, preparation of the recipient tooth socket and the donor tooth were guided by the 3D-printed replicas sequentially. Then, the donor tooth was implanted into the recipient tooth pocket. Patients were followed up at 3, 6 and 12 months after the operation, with CBCT examination to evaluate the status of bone reconstruction and periodontal ligaments at each time point. Results Twelve patients were transplanted with an autogenous third molar with the apical foramen completely closed. Among them, 7 patients had alveolar fossa infection before the operation, of which 1 had extensive resorption of the alveolar bone due to the infection. All 12 patients recovered well after the operation and were followed up for at least 12 months. In total, 11 caseswere successful in tooth autotransplantation with normal mastication, and 1 case had root resorption 14 months postoperation. Conclusion Digital design combined with 3D printing technology can assistin the selection of thebest-matched donor tooth and preparation of the recipient socket before tooth transplantation proceduresand reduce the extra-alveolar exposure time of the donor tooth and number of trial placementsintothe alveolar fossa. Thus, this combined strategy can effectively improve the outcome of dental autotransplantation.

Corona Virus Disease 2019 (Corona Virus Disease 2019,COVID-19) has become a public health emergency that has attracted global attention because of its large-scale outbreak resulting in numerous human infections and deaths. COVID-19 is a highly contagious respiratory disease caused by novel coronavirus 2019-nCoV. Due to a large number of infections and fast transmission speed, it's significant to diagnose the infected people quickly and detect the asymptomatic infected people as soon as possible. At present, the preliminary screening is judged by the clinical manifestations of the patients, mainly involving the respiratory system, but recent studies have found that the patients infected with COVID-19 have unique oral manifestations, such as taste disturbance, xerostomia, halitosis, inflammation of salivary glands, necrotizing periodontal disease and some of them are earlier than typical symptoms such as dry cough, fever, etc. Paying attention to the oral manifestations of patients can further improve the COVID-19 screening procedure. At present, symptomatic treatment is mainly used for these oral symptoms.

Impacted teeth are a kind of complex malocclusion, and their incidence differs among different races, sexes and dental positions. The causes of impacted teeth include systemic factors and local factors, such as endocrine disorders, malnutrition, and acute and chronic infectious diseases. Local factors can cause abnormal tooth development or eruption during the process from tooth development to tooth eruption, such as damaged permanent tooth embryos caused by local inflammation or trauma, insufficient eruption space caused by premature loss of deciduous teeth, and eruption disorders caused by local lesions for example hyperplasia or odontoma. The clinical manifestation of impacted teeth is the absence of a permanent tooth in a normal position. We can use cone beam CT (CBCT) to locate the impacted teeth. Comprehensive orthodontic treatment includes surgical-assisted eruption, extraction of retained deciduous teeth or supernumerary teeth, removal of lesions such as odontomas and cysts, and expansion of the orthodontic space. When the dysfunctional local soft and hard tissues are removed during a surgical operation, the tooth still cannot sprout smoothly, and it needs to be assisted by orthodontic traction-guided eruption or extracted and autotransplantation. A clear diagnosis, evaluation of the difficulty of treatment and appropriate treatment are the keys to improving the success rate of treatment. In this paper, the epidemiology, etiology, diagnosis and corresponding treatment methods of impacted teeth will be reviewed, and the orthodontic treatment of impacted teeth will be comprehensively described to provide a reference for clinicians about the treatment of impacted teeth.

In recent years, the application of artificial intelligence (AI) in the medical field, especially in dental imaging diagnosis, has developed rapidly. This review introduces research on AI in detail from the aspects of identifying caries, periapical lesions, vertical root fracture, periodontitis, maxillary supernumerary teeth and impacted mandibular third molars, oral and maxillofacial cystic lesions and temporomandibular joint disorders. Studies have shown that the diagnostic accuracy of AI in the abovementioned oral diseases is equivalent to or even better than that of dentists, indicating that AI has potential in oral disease diagnosis. However, AI models are limited by manual annotation accuracy, poor interpretability, weak generalization ability and difficulty in incremental learning. Future investigations should focus on the development and training of algorithms to improve AI accuracy in oral disease diagnosis.

Regenerative endodontic procedures, based on dental pulp biology, use the basic principles of tissue engineering to promote the functional regeneration of dental pulp-dentin complexes. Good results have been achieved in the treatment of young permanent teeth with pulp necrosis or apical periodontitis. There have also been preliminary clinical explorations of the treatment of mature permanent teeth in recent years. The key to successful treatment is controlling infection as well as promoting tissue repair and regeneration. Moderate root canal mechanical preparation is allowed in the therapy of mature permanent teeth, while it is not recommended in the treatment of young permanent teeth. The choice of root canal irrigation and intracanal antisepsis requires a comprehensive consideration of the antibacterial effects, biological safety, and possible complications, such as crown discoloration and root canal calcification. The development of bioceramic materials provides more options for crown sealing materials, but further clinical evaluation is needed. In addition to traditional blood clot scaffolds, new types of tissue scaffolds represented by platelet-rich plasma, platelet-rich fibrin, concentrated growth factors and other platelet concentrates have been developed. Long-term and large-scale studies are needed to evaluate the actual clinical efficacy of these new scaffolds and the efficacy of their combined application with blood clots.

In orthodontic and orthognathic practice, cephalometric analysis is an integral tool throughout the clinical process. However, as landmark identification is still unautomated, both the conventional and semiautomated approaches are open to considerable subjectivity and could be time-consuming for inexperienced clinicians. Deep learning (DL), a state-of-the-art artificial intelligence (AI) technique, is highly effective in image recognition. In recent years, many studies have focused on the application of DL in cephalometric analysis, including automated landmark detection, automated diagnosis, cervical vertebral maturation stage determination, adenoid hypertrophy analysis and upper airway identification. Studies show that DL can effectively improve the efficiency of cephalometric analysis. In most studies, the accuracy of DL can reach more than 80%, and its difference from the gold standard is clinically acceptable, demonstrating good potential for future applications. However, most studies are limited to landmark detection, and the broadness and richness of the training dataset are limited. Future studies should broaden the research scope, improve the algorithm, elevate the richness of the datasets, and combine DL with other AI algorithms to improve its accuracy, stability and generalizability.

Objective To discuss and summarize the preventive measures and treatment methods for aspiration/ingestion during dental procedures. Methods One case of aspiration during an implant operation was reported, and the literature on aspiration/ingestion during oral procedures was reviewed. Results An implant screwdriver accidentally slipped into the mouth of the patient during implant surgery. The patient experienced no obvious discomfort except a few coughs. The surgeon and assistant paused the procedure immediately to search for the screwdriver, but it was not found. The patient declared that there was no special abnormality, such as breathing disorder or chest distress, so we considered that the foreign body was ingestion. After the implant surgery was completed, no foreign body was found in the stomach via gastroscopy. Chest X-ray and CT showed a dense metal shadow in the lower lobe of the left lung. Under local anesthesia, bronchoscopy and biopsy forceps were used by respiratory physicians to clip out the foreign body. After removal of the foreign body, the patient had no obvious discomfort but a slight cough. Cephalexin and metronidazole were given for three days to prevent infection. Three days later, the patient had no complaints of respiratory discomfort. After reviewing the literature, we found that the operation should be paused immediately after aspiration/ingestion occurs during dental procedures and that the dental chair should be laid down to prevent the foreign body from descending deeper, which may increase the difficulty of removal and cause gastrointestinal and respiratory tract injury. The position of the foreign body should be determined by imaging examination, and the corresponding means to remove the foreign body should be performed. Conclusion Patients may have no obvious symptoms after aspiration/ingestion during dental procedures, and the foreign body can be removed after imaging examination.

Objective To investigate the effect of elective neck dissection on the 5-year survival rate of patients with early oral squamous cell carcinoma. Methods The data of 100 patients with early oral squamous cell carcinoma (cT1-2N0M0) were retrospectively analyzed. In 61 cases, the primary tumor was subjected to elective neck dissection (END). Neck observation and follow-up (NOF) were performed in 39 cases with enlarged resection of primary lesions. Clinicopathological data such as pT staging, pathology classification,the rate of cervical lymph node metastasis and the 5-year survival rate of the patients were statistically analyzed. Results The 5-year survival rates of the END and NOF groups were 86.9% and 69.2%, respectively, and the difference was statistically significant (P=0.028). END treatment was significantly better than NOF in controlling cervical lymph node metastasis in early oral squamous cell carcinoma (P=0.009). After stratified analysis of histopathological features, the 5-year survival rate of patients with pathological T2 (pT2) stage OSCC in the END group was significantly higher than that in the NOF group (P=0.020). The 5-year survival rate of patients with moderate and poorly differentiated pathological grade OSCC in the END group was significantly higher than that in the NOF group (P=0.013). Conclusion END is effective for the management of the cervical lymph node metastasis rate in early OSCC patients. For patients with pT2 stage or low differentiation pathological grade, active END can significantly improve the 5-year survival rate.

Objective To explore the effects of long noncoding-RNA (lncRNA) taurine upregulated gene 1 (TUG1) on the proliferation and osteogenic/odontoblast differentiation of human dental pulp stem cells (hDPSCs). Methods hDPSCs were isolated and cultured. The surface antigens CD44, CD45, CD73, CD90, CD133 and STRO-1 were detected by flow cytometry. Alkaline phosphatase (ALP) staining and alizarin red staining were used to identify the ability of cells to differentiate. RNA was collected on Days 0, 7 and 14 of the osteogenic induction of hDPSCs, and qRT-PCR was used to detect the relative expression of TUG1. The hDPSCs were stably transfected with a lentiviral vector containing the TUG1-silenced pSLenti-U6-shRNA(TUG1)-CMV-EGFP-F2A-Puro-WPRE to silence TUG1. The ability of hDPSCs to proliferate was assessed with the CCK-8 method. ALP and alizarin red staining and quantitative detection were used to detect the ALP activity and formation of mineralized nodules of hDPSCs. The expression levels of dentin sialophosphoprotein (DSPP), dentin matrix protein-1 (DMP-1), Runt-associated transcription factor 2 (Runx2), osteocalcin (OCN) and osteopontin (OPN) genes and proteins were measured by qRT-PCR and Western blot. Results The hDPSCs were successfully isolated and cultured, and TUG1 expression was significantly increased during osteogenic differentiation (P<0.05). The hDPSCs proliferation was suppressed after silencing TUG1(P<0.05). After osteogenic induction, ALP and alizarin red staining showed that ALP activity and mineralized nodules were suppressed by silencing TUG1. The expression levels of the odontogenic differentiation gene DSPP and DMP-1 and the osteogenic differentiation gene Runx2, OCN and OPN were also significantly decreased (P<0.05). Conclusion Knocking down TUG1 can inhibit the proliferation and osteogenic/odontogenic differentiation of hDPSCs.

Benign tumors of the parotid gland are common tumors of the head and neck. Surgical resection is considered the main treatment. For the treatment of benign parotid tumors, different surgical approaches can be applied based on many factors, such as tumor type, size, location, depth of tumor and patient requirements, such as improved periauricular incision and improved facial wrinkle removal incision, to achieve the best therapeutic effect. In parotidectomy, the facial nerve, great auricular nerve and parotid duct should be protected as much as possible to preserve the function of the nerve and gland and reduce postoperative complications. In addition, complications after parotidectomy, such as facial nerve injury, salivary fistula, Frey syndrome, postoperative facial depression, abnormal ear sensation and recurrence, should be actively prevented and treated early after the operation, consequently minimizing the impact on patients' postoperative life and improving patients' satisfaction with the operation.

Objective To explore the effects of red LEDs on the proliferation and osteogenic differentiation of human stem cells from apical papilla (hSCAPs). Methods hSCAPs were obtained by isolation, culture and flow cytometry in vitro and irradiated with 1, 3, 5, and 7 J/cm² red LEDs. The proliferation of hSCAPs was detected using a CCK-8 assay. The osteogenic differentiation of hSCAPs was evaluated using alkaline phosphatase (ALP) staining, ALP activity assay and Alizarin red quantitative detection. The effect of 5 J/cm² red LEDs on the expression levels of the ALP, Runx2, OCN, OPN and BSP genes and proteins was detected by RT-PCR and western blot, respectively. Results Red LEDs at 1, 3, 5, and 7 J/cm² promoted the proliferation of hSCAPs (P < 0.05). The effects of red LEDs with different light energies on the proliferation of hSCAPs were different at different time points (P < 0.05). On the 7th and 14th days after irradiation, red LEDs promoted the osteogenic differentiation of hSCAPs, and the effect of 5 J/cm² red LEDs was the most obvious under osteogenic induction culture conditions (P<0.05). Red LEDs (5 J/cm²) promoted the expression of the ALP, Runx2, OCN, OPN and BSP genes and proteins (P < 0.05). Conclusion Red LEDs promoted the proliferation and osteogenic differentiation of hSCAPs.

Gingival pigmentation(GP) manifests as dark pigmentation spots, such as black or brown spots, in the gums. It is mostly caused by the deposition of melanin particles secreted by melanocytes on the gingival epithelium. The influencing factors may be divided into two categories, exogenous and endogenous. Exogenous factors include heavy metals, tattoos, smoking or drug use, and endogenous factors are related to certain diseases. The clinical grading of GP helps make a reasonable assessment of the necessity of treatment and prognosis. The Dummett-Gupta oral pigmentation index is a commonly used grading method, and the new grading method formed by combining the etiology and clinical manifestations described the patient’s situation more comprehensively. It is necessary to ask for a detailed medical history, complete examination, and correctly differentiate between physiological GP and GP caused by pathological state. Laser treatment is the currenttreatment with a better treatment effect and higher patient acceptance, and it is more comfortable and convenient, including diode laser, Er: YAG laser, and Nd: YAG laser, etc. This article summarizes the formation factors, clinical manifestations and treatment methods of GP to provide ideas for the clinical diagnosis and treatment of GP.

Objective Metagenomic sequencing was used to explore the species composition and internal functional metabolic pathway of saliva and supragingival plaque microbial communities in healthy adults to provide a theoretical reference for the biological prevention and treatment of oral diseases. Methods Saliva and supragingival plaque samples were collected from healthy adults, total DNA was extracted, and a metagenomic library was constructed. The qualified library was sequenced via metagenomics, and the sequencing data were analyzed using bioinformatics and statistics. Results The main bacterial phyla in healthy oral samples were Proteobacteria (32.51%), Bacteroidetes (30.81%), and Actinobacteria (16.23%), and the main bacterial species were Corynebacterium matruchotii (3.84%), Haemophilus parainfluenzae (2.91%), and Prevotella melaninogenica (2.76%). The alpha diversity of the supragingival plaque group was higher than that of the saliva group, and there was a significant difference in the composition of the microbial community between the two groups (P<0.05). At the species level, Prevotella melaninogenica, Fusobacterium periodonticum, and Prevotella intermedia were more abundant in saliva samples than in supragingival plaque samples, while Corynebacterium matruchotii, Propionibacterium acidifaciens, and Rothia dentocariosa were more abundant in supragingival plaque samples than in saliva samples (P<0.05). High-quality gene sets of saliva and supragingival plaque in healthy adults were constructed based on metagenomic sequencing. The results of KEGG pathway functional metabolic differences showed that starch and sucrose metabolism, leucine and isoleucine degradation, and arginine biosynthesis in salivary microorganisms were more abundant than in supragingival plaque, while glycolysis/gluconeogenesis and carbon metabolism in supragingival plaque were more abundant than in saliva. Conclusion There are significant differences in the species composition and functional gene metabolic pathways of saliva and supragingival plaque microecology in healthy adults. The sensitivity of dominant species in different microecological regions to the identification of oral diseases may be different. In the microbiological study of oral diseases, appropriate samples should be selected according to different diseases.

Vertical bone augmentation surgery still faces considerable challenges in clinical practice due to various problems, such as difficulty in restoring the ideal alveolar bone height and biological complications, and because it is highly technically sensitive. Plasmatrix is derived from patients’ own blood, and it can effectively promote the vascularization of the regenerated area, recruit stem cells, and reduce inflammation when used in vertical bone augmentation. Based on studies published worldwide, this article first divides vertical bone augmentation into 3 categories according to the height of the expected alveolar ridge, namely, type Ⅰ, the required vertical bone gain is less than 4 mm; type Ⅱ, the required vertical bone gain is between 4-8 mm; and type Ⅲ, the required vertical bone gain is greater than 8 mm. In the type Ⅰ vertical bone augmentation, the plasmatrix bone block is directly placed in the defect area and covered with the plasmatrix membrane before tension-free suturing; in the type Ⅱ vertical bone augmentation, the plasmatrix bone block should be placed in the defect area and fixed with titanium nails and then covered with an absorbable collagen membrane and plasmatrix membrane with a tension-free suture; in the type Ⅲ vertical bone augmentation, additional active ingredients (such as bone morphogenetic protein, autologous bone, etc.) should be added to the plasmatrix bone block and strong fixation (such as titanium nails) should be used. Absorbable collagen and plasmatrix membranes should be used to cover the surface of the bone block, and the flap should be sutured. According to different types of vertical bone augmentation categories, the above methods optimize the vertical bone augmentation effect. This article aims to provide a reference and guidelines for oral clinicians to fully understand plasmatrix and simplify the classification and operation of vertical bone augmentation.

Objective To investigate the mechanisms by which D-methionine (D-Met) eradicates Porphyromonas gingivalis biofilms by suppressing cyclic dimeric GMP (c-di-GMP) levels. Methods Cell viability, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were measured to determine the effective concentrations of D-Met, which were subsequently used in the following experiments. During the P. gingivalis biofilm formation inhibition experiment and the mature biofilm disassembly experiment, biofilm biomass, exopolysaccharide (EPS), biofilm morphology, integrity of the cell membrane, and the level of c-di-GMP were determined. Results D-Met < 40 mmol/L was biocompatible. During the biofilm formation inhibition and mature biofilm disassembly experiments, D-Met ≥ 20 mmol/L decreased the biofilm biomass and the production of EPS. SEM analysis showed that the extracellular matrix and bacterial density were drastically reduced by D-Met ≥ 20 mmol/L. TEM detection showed that 35 mmol/L D-Met ruptured the cell membrane during biofilm formation and increased the permeability of the cell membrane in the disassembly phase of mature biofilms. C-di-GMP levels decreased with increasing concentrations of D-Met in a concentration-dependent manner. Conclusion D-Met ≥ 20 mmol/L could eradicate P. gingivalis biofilms by suppressing c-di-GMP levels.

Condylar displacement can lead to temporomandibular joint (TMJ) symptoms and relapse after orthognathic surgery. To minimize condylar displacement, numerous condylar positioning techniques have been applied in clinical practice. To verify the effectiveness of condylar positioning techniques in preventing postoperative TMJ symptoms and relapse, we reviewed the literature related to all types of intraoperative condylar positioning techniques in the past 20 years. According to a literature review, positioning techniques aim to seat the condyles at a preoperative position during surgery and are divided into noncomputer-aided and computer-aided condyle positioning methods. At present, computer-aided design/computer-aided manufacturing condylar positioning devices (CAD/CAM CPDs) are the most superior positioning methods and are composed of teeth-supported and bone-supported guidance. The sequence of the remaining technology positioning effect from high to low is as follows: CAD/CAM titanium plate positioning > manual positioning > computer-aided navigation system > image positioning system. Different techniques reach considerable accuracy within 1-2 mm and 1°-2° in locating the preoperative condylar position and preventing TMJ symptoms or disorders and surgical relapse to provide a clinical reference for different levels of surgeons and cases. However, this study lacks randomized controlled trials with large samples and long-term follow-up. Future studies should upgrade the current methods, improve the clinical utility, and develop new positioning techniques.

The transpalatal arch (TPA) is widely used in clinical orthodontics for various purposes. This article reviews the versatile clinical uses and mechanics of TPAs for clinical reference. Traditionally, TPA is conceived as an anchorage reinforcement device. However, the literature does not support the sole use of TPA for anchorage control. TPA, combined with other conventional anchorage means, can only provide sufficient anchorage in certain cases. As an adjunct to fixed appliance treatment, TPA can be applied for arch width maintenance, tooth alignment and habit braking to improve treatment efficiency and reduce side effects. Meanwhile, TPA can be used to provide active orthodontic forces for maxillary molars to move or rotate bilaterally and unilaterally in all three planes of space, especially on occasions where molar rotation and transverse discrepancy exist. A two-couple system is formed with a TPA connecting bilateral maxillary first molars, the mechanical analysis of which can improve the understanding of treatment mechanics and make tooth movement more predictable. In recent years, TPA has also been used in combination with temporary anchorage devices for maxillary molar intrusion and full arch mesialization or distalization. The combined use of TPA with TADs and maxillary skeletal expanders could be further investigated in the future.

Ideal sutures can provide great fixation, wound closure and a stable environment for healing of the surgical site. Tension-free apposition sutures are important for tissue regeneration and could tackle insufficient amounts of soft and hard tissue, especially in missing tooth sites that require implantation. The internal horizontal mattress suture, similar to the conventional horizontal mattress suture, forms a rectangle that can be bisected by the incision with both intrusion and extrusion of the needle on each side. On the basis of the rectangle, the internal horizontal mattress suture emphasizes that the suture should be located below the incision, so the eversion of the wound margin is the highlight of this procedure. The internal horizontal mattress suture could stabilize the graft on the targeting tissue, realize the fixation of the collagen membrane, apically repositioned flap and soft tissue graft, reduce the tension on the incision, and further release the tension of the incision margin. Beyond the primary need for fixation and wound closure, internal horizontal mattress sutures can also achieve stress interruption that reduces the interference of the surrounding muscle and can better master wound tension with the assistance of interrupted sutures. Given the above advantages, horizontal internal mattress sutures have great potential in the application of implant-related regenerative surgery. In this review, according to our experience in clinical practice and the literature, we summarize the advantages of internal horizontal mattress sutures in tissue augmentation. In addition, the sites and sequence to insert the needle and the spatial relationship between the suture and incision are clarified with the rationale of the naming pattern, which is conducive to experience exchange and clinical practice.

Chronic periodontitis is a prevalent disease; if left untreated, it is a main indication for tooth extraction and can lead to tooth loss. The reactive soft tissue, formed as a result of the immune response to chronic inflammation, is left in the compromised socket. The major concern is how to deal with the residual reactive soft tissue. Conservative thought states that the reactive soft tissue should be completely debrided. In addition, novel practices concerning the reactive soft tissue were proposed in recent trials, which demonstrated that there might be merits for soft and hard tissue regeneration with preservation of the reactive soft tissue. Studies have shown that mesenchymal stem cells exist in inflammatory reactive soft tissue, stressing their potential in tissue regeneration. Although the therapeutic value is highly promising, the specific components of the reactive soft tissue and the standard on whether it should be preserved need further investigation.

Endodontic microsurgery is a vital treatment modality for teeth with persistent periradicular pathoses that have not responded to nonsurgical retreatment. The principle is to determine the reason for failure, completely eliminate the infection and promote periapical healing. Within recent years, endodontic microsurgery has evolved to become standardized and presents with a high success rate. However, its outcome is still influenced by many factors, including anatomy, periodontal condition, crown-to-root ratio, occlusion, the type of periradicular lesion, and prosthesis. Moreover, endodontists always concentrate on “the apex”, paying little attention to the general preoperative evaluation, accurate diagnosis, and comprehensive treatment plan. This article reviews the latest literature on these issues and the clinical experience of our research group and discusses the correlation between endodontic microsurgery and other oral disciplines, including periodontology, prosthodontics, oral implantology, oral and maxillofacial surgery and orthodontics. The oral interdisciplinary assessment should be made with comprehensive consideration of the root canal system, periradicular lesion, adjacent anatomical relationships, periodontal condition, occlusion, and esthetic rehabilitation. Based on these findings, the continuity of treatment will be optimized, and the best treatment plan will be proposed to provide clinical strategies for the diagnosis and treatment of complex periradicular diseases.

All-ceramic restorations are widely used in oral restoration because of their beauty and high strength. Glass ceramics and zirconia all-ceramic materials are the two most widely used all-ceramic materials in the clinic. However, when all-ceramic restorations need to be removed due to marginal microleakage and secondary caries, its high strength and high bonding strength greatly increase the difficulty of removal. In recent years, clinicians have tried to use Er: YAG lasers to remove all-ceramic restorations. The Er: YAG laser can be safely and efficiently applied to the removal of glass restorations, and it can also play a role in thinner zirconia restorations. Various factors, such as the material and thickness of the all-ceramic restoration, the type of cement, and the laser power, can affect the speed of removal of the Er: YAG laser. However, the current research is limited to case reports and in vitro studies, lacking systematic clinical research. The specific mechanism of Er: YAG laser removal of all-ceramic restorations and the influence of laser frequency, adhesive type, and abutment on the removal speed need to be further demonstrated by follow-up research.

Excellent mechanical properties and biocompatibility resulted in titanium and titanium alloys being widely used in the medical field. However, the biological activity of atitanium surface will gradually fade with increasing exposure time, which affects its final osseointegration. As an effective surface modification method, ultraviolet (UV) photofunctionalization does not change the surface morphology of implants and is a suitable surface treatment for many brands of implants. This article summarizes the research progress on the effect of UV photofunctionalization technology on the characteristics of titanium surfaces, biological activity and implant osseointegration, as well as its current clinical applications. Studies have shown that the superhydrophilicity of the titanium surface and improved biological activity endowed by UV photofunctionalization can accelerate and enhance bone formation, resulting in a higher success rate of implant surgery. Therefore, UV photofunctionalization has great potential for clinical chairside applications.

Objective To investigate the role of long non-coding RNA double homeobox A pseudogene 9 (DUXAP9) in head and neck squamous cell carcinoma (HNSCC) and to evaluate the expression level, molecular function and mechanism of DUXAP9 in HNSCC cells. Methods Differential expression of lncRNAs between normal and tumor tissues in HNSCC tissues were screened using lncRNA microarray, the expression level of DUXAP9 in HNSCC tissues and its relationship with prognosis were analyzed in the TCGA database. The expression levels of DUXAP9 in HNSCC tissues and cell lines were detected using qRT-PCR. The function in HNSCC cells after DUXAP9 silencing was evaluated using the CCK-8 assay, wound healing assay, Transwell migration assay and subcutaneous xenograft assay in nude mice. Changes in the transcription and translation of epithelial-mesenchymal transition (EMT)-related proteins in head and neck squamous cell carcinoma cells after DUXAP9 silencing were detected using qRT-PCR and Western blot. Results lncRNA microarray results showed that, compared to adjacent normal tissues, DUXAP9 was abnormally upregulated in HNSCC tissues. Analysis from TCGA database showed that, compared to HNSCC patients with low DUXAP9 expression, HNSCC patients with high DUXAP9 expression had poorer survival. The relative expression of DUXAP9 in HNSCC tissues and 4 HNSCC cell lines increased compared to paired adjacent normal tissues as detected using qRT-PCR. Silencing DUXAP9 significantly inhibited the proliferation, migration and expression of EMT-related genes in HNSCC cells. The silencing of DUXAP9 significantly inhibited subcutaneous tumorigenesis of the HNSCC cell line CAL27 in nude mice. Conclusion Silencing DUXAP9 significantly inhibited the proliferation of HNSCC cells and subcutaneous xenografts in nude mice. DUXAP9 may mediate the migration of head and neck squamous cell carcinoma cells via the EMT pathway.