Objective To investigate the effect of tension on donor site recovery of modified forearm flaps (closed forearm donor site skin flaps). Methods From October 2018 to April 2021, 12 patients with oral cancer underwent forearm flap repair at Xuzhou Central Hospital. Handgrip strength and wrist motion were recorded before surgery. During the surgical incision at the donor site of the forearm, the triangular full-thickness skin of the donor site was used to close part of the surgical incision, and the other part of the surgical incision was directly closed and sutured. Tension was measured with a tension meter during the surgical incision at the donor site. Patients were followed up after surgery to observe whether there were postoperative complications such as necrosis and poor healing of donor site wounds, as well as forearm grip strength, wrist range of motion and appearance satisfaction. Results Among the 12 patients, there was only one elderly patient with postoperative necrosis near the wrist in the donor site skin, and the average tension of the patient was 0.65 kg; the lesion healed after dressing changes. All of the other patients recovered well without postoperative complications. The mean tension of 12 patients was (0.51 ± 0.05) kg. The preoperative and postoperative grip strength of 12 patients was (23.7 ± 10.3) kg and (22.3 ± 10.7) kg, respectively, and the difference was not statistically significant (t=5.872, P<0.001). The mean range of motion of the wrist was (47.6 ± 8.3)°, (45.8 ± 5.8)°; dorsiflexion (54.6 ± 3.2)°, (53.9 ± 2.3)°; radial deviation (37.0 ± 2.3)°, (36.1 ± 2.2)°; ruler deviation (27.1 ± 1.9)°, (26.4 ± 1.3)°, respectively. The t values were 1.64, 1.636, 2.116 and 1.412, and the P values were 0.129, 0.130, 0.058 and 0.186, respectively. All 12 patients were satisfied with the appearance of the donor site of the forearm. Conclusion When the average tension during suturing is less than 0.5 kg, there is a lower risk of complications at the donor site of the forearm one month after surgery, a lower risk of impaired donor site function, and a greater possibility of patient satisfaction with the appearance of the donor site.

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.

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.

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.

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.

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.

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.

Plaque pH detection technology can detect the risk of caries and assist in the prevention of caries, with a mature theory and a relatively simple operation. With the increasing demand for clinical caries risk detection technology and the rapid development of microelectrode techniques, there is an increasing variety of types of microelectrodes that can detect the pH of dental plaque, including glass microelectrodes, metal oxide microelectrodes and ion-sensitive field effect transistors. The glass microelectrode was the first microelectrode to be applied in this field, but its structure is weak. Among the various options, the iridium oxide microelectrode has become the most promising caries risk detection electrode in recent years because of its high strength and excellent response. Metal oxide microelectrodes can also effectively compensate for the insufficient strength of glass microelectrodes. With advances in electrode technology, miniaturized, sensitive ion-sensitive field effect transistors have attracted the attention of researchers. Scientists have also recently developed a way to detect the pH of dental plaque with an optical no-contact technique. Optical contactless detection technology will not damage the dental plaque structure, so it has great research and clinical prospects. Future research will further improve the strength and performance of these electrodes on the premise of ensuring miniaturization and achieving noncontact detection.

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.

Objective To evaluate the caries preventive effect and economic outcome of an oral health promotion model in rural primary schools in Guangxi Zhuang Autonomous Region. Methods In November 2015, a baseline survey was conducted on the caries prevalence of rural first graders in program areas, and then a program intervention was carried out on the first graders of target primary schools. The intervention methods included the distribution of oral health care products, oral health education, teacher training, etc. In 2020, the method of cluster random sampling was adopted to include the sixth graders who received the program intervention as first graders and were still available in 2020 as the intervention group. During this period, the sixth graders transferred from foreign schools who failed to receive the program intervention as first graders were included in the non-intervention group. The caries preventive effect was evaluated by analyzing the caries epidemiological data of 2 652 children aged 11-13 years, comparing the intervention and non-intervention group. The cost of the program was estimated by the structural analysis method. A decision tree model was established by TreeAge pro2019 and incorporated into the effect parameters and cost parameters for cost-effectiveness analysis and sensitivity analysis. Results The prevalence of caries in the intervention group was 54.8%, and the mean DMFT was 1.36 ± 1.64, both of which were lower than those in the non-intervention group. The difference in prevalence and mean DMFT between the two groups was statistically significant (P < 0.05). It costs CNY 319.83 per child to reduce suffering from caries. The number of patients with caries in the intervention group was the most sensitive indicator of an economic effect. The probability of a cost-effectiveness advantage for the program was 92.2%. Conclusion This oral health promotion model used in rural schools demonstrated a caries preventive effect that was very likely economically advantageous. It is of practical significance to improve and promote this model in the Guangxi Zhuang Autonomous Region.

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.

Objective To determine the clinical problems and outcome indicators that need to be included in the expert consensus of 5-aminolevulinic acid (ALA) photodynamic therapy in the treatment of oral potential malignant diseases. Methods Based on the relevant literature, the clinical problems and outcome indicators were drafted during the meeting. The Delphi method was used for expert consultation and expert opinion collection. The average and standard deviation of the voting results were calculated to determine the importance of the indicators, and the positive coefficient, variation coefficient and coordination coefficient were calculated for quality control. Results In the first round of the Delphi method, 12 outcome indicators (the main reference elements include photon integral flux, power density, illumination time, and spot diameter were identified; the specific parameters are photon integral flux of 100 J/cm² and power density of 100-600 mW/cm². A diode laser of (630 ± 5) nm wavelength should be chosen. The analgesic regimen is local anesthesia supplemented by hypothermia and intermittent laser irradiation before treatment. Lesions with hyperkeratotic require pretreatment. The concentration of ALA administered was set at 20%. Eight clinical problems (main reference elements of photodynamic irradiation dose, specific parameters, choice of light source, evaluation criteria of efficacy, prevention of adverse effects, dosing concentration, whether oral potentially malignant diseases with hyperkeratosis should be pretreated, administration of photosensitizers) were included according to the literature and expert discussion. In the second round, 89 experts completed the questionnaire and gave very important evaluations of 9 outcome indicators (the main reference elements included photon integral flux, power density and illumination time; the specific parameters were a photon integral flux of 100 J/cm ² and a power density of 100-600 mW/cm²). A diode laser of (630 ± 5)nm wavelength should be chosen. The concentration of ALA administered was set at 20%. Six clinical problems (main reference elements of photodynamic irradiation dose, specific parameters, choice of light source, evaluation criteria of efficacy, dosing concentration, administration of photosensitizers), and the remaining 3 were given important evaluations, with good consistency. Conclusion In this study, the irradiation dose, mode of administration and concentration, evaluation criteria of efficacy, prevention of adverse effects and pretreatment regimen of ALA photodynamic therapy for oral potentially malignant diseases determined by the Delphi method had good agreement among experts.

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.

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.

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.

Root position plays an important role in healthy, stable, and aesthetic orthodontic treatment. In the past, two-dimensional radiographic images were used to assess the accuracy and precision of tooth root positions. In recent years, the use of cone beam CT (CBCT) and its reconstructed images to measure the three-dimensional spatial position and angle of root position has become mainstream. The root position is mainly described by measuring the relationship between the root and adjacent structures in the buccolingual, vertical, and mesiodistal directions as well as the root angle. The thickness of the alveolar bone on the buccolingual side of the root represents the buccolingual position, the vertical height in the alveolar bone and the relationship between apex and maxillary sinus represents the vertical position, the interroot alveolar bone thickness represents the mesiodistal position of the root, and the root angle is mostly based on incisal mandibular plane angle, angulation, torque, and other angles in the traditional two-dimensional measurement. Fitting CBCT and digital model data can be used to monitor the relationship between root and alveolar bone during orthodontic treatment, but a more comprehensive, standardized three-dimensional tooth root position measurement method is required to make full use of the root data provided by CBCT to study the relative optimal position of the tooth root at different anatomical levels, which combines with computer technology to optimize the digital design of orthodontic diagnosis and treatment.

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.

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.

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.

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.

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 To investigate the antibacterial effect of a new photosensitizer, indocyanine green (ICG)-mediated photodynamic therapy, on a biofilm of Fusobacterium nucleatum (F. nucleatum) in vitro. Methods The biocompatibility of the photosensitizer ICG was detected by CCK8. F. nucleatum (10⁸ CFU/mL) was cultured in anaerobic conditions (80% N₂, 10% H₂ and 10% CO₂) mixed with the photosensitizer ICG at concentrations of 0, 10, 20, 30, and 40 μg/mL and then treated with antibacterial photodynamic therapy (808 nm near infrared light with an intensity of 0.1 W/cm² for 3 min), and a mature biofilm was formed after 2 days. The bacteriostatic effects of different concentrations of ICG on F. nucleatum biofilms were compared by colony formation unit count (CFU). The effect of ICG on the formation of F. nucleatum biofilms and biofilm metabolic activity was determined by crystal violet quantification and MTT assays. The effect of ICG on the formation of extracellular polysaccharides in F. nucleatum biofilms was determined by the phenol-sulfuric acid method. The change in the number of bacteria was observed by confocal microscopy. Results CFU and biomass of the biofilm gradually decreased with increasing ICG concentration, and there were significant differences compared with the control group. Meanwhile, the metabolic activity of the biofilm and the production of extracellular polysaccharides also showed a significant difference between the ICG groups and the control group (P<0.01). At the same time, laser confocal microscopy showed that the number of living bacteria decreased gradually. Conclusion Antibacterial photodynamic therapy with photosensitizer ICG can effectively inhibit the formation of F. nucleatum biofilms.

The properties of adhesives and light-cured resin composites are closely related to the repair of dental defects. Therefore, improving the properties of adhesives and resins composite to increase the success rate of filling has been the focus of research in the field of prosthodontics in recent years. Current studies have confirmed that temperature can change the properties of adhesives and light-cured resin composites, affecting their repair effect. A proper storage temperature ensures the good performance of materials: the self-etching adhesive system should be refrigerated, and the light-cured resin composite should be refrigerated or stored at room temperature according to its composition, proportion and other properties; however, the appropriate storage temperature for the etch-and-rinse adhesive system is not clear. The appropriate application temperature could improve the fluidity, monomer conversion, bonding strength, compressive strength and other properties of the materials to improve the quality of filling restoration. However, there is a wide variety of adhesives and resin composites, and the effect of temperature on each material is different. Thus, it is still necessary to explore the temperature range for material storage, precooling and preheating. Few studies have been performed in vivo, and the clinical restorative effects of adhesives and resin composites stored and used at different temperatures need to be further studied.

With the advances in understanding the relationships among biomaterials, the immune system and the skeletal system, the host responses elicited by implanted biomaterials can be balanced by properly designing material characteristics from the perspective of osteoimmunology. The immunoregulatory properties of bone tissue engineering scaffolds provide advantages for inducing macrophages from the proinflammatory M1 phenotype to the anti-inflammatory M2 phenotype and promoting osseointegration. Hydrogels are increasingly a focus in bone tissue engineering, and the immune response can be affected by different compositions of hydrogels, such as the sources, concentration, molecular weight, coupling with fibronectin, and the addition of cross-linking agents. Different physicochemical properties of modified hydrogels can trigger different host immune responses, modified by using soft photolithography to fabricate micropatterned hydrogels, adding enzyme-sensitive sequences, ester bonds and dynamic covalent chemistry to prevent rapid or slow degradation of the hydrogels, and adding porogens and 3D printing to modify the hydrogels with macroporous interconnective pore structures, soft and injectable hydrogels, etc. These optimized hydrogels can reduce proinflammatory factors, promote M2 macrophage polarization, and minimize foreign body reactions to evoke bone regeneration. However, the mechanism underlying the bone immune response is still poorly understood, and further study of the effects of hydrogels with different physicochemical properties on immune regulation is needed.

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.

Objective To compare the disinfection effects of 500 mg/L chlorine-containing disinfectant and 3% hydrogen peroxide disinfectant applied to the threaded plastic hose at the fixed end of the saliva suction pipe of the oral comprehensive treatment table after diagnosis and treatment of patients in stomatology to provide a basis for clinical cleaning and disinfection. Methods The fixed ends of saliva suction pipes of 12 comprehensive treatment tables in the dental pulp department and maxillofacial surgery were selected as the research objects. The absorption was randomly divided into two groups and a control group: experimental group 1 with 500 mg/L chlorine disinfectants and experiment 2 group with 3% hydrogen peroxide disinfectant rinse disinfection and the control group with 0.9% sterile saline flushing pipe once a week for four weeks. Before and after washing and disinfection, samples from the inner wall of the threaded plastic hose interface were collected for bacterial culture and colony count, and colony counts within and between groups were compared before and after disinfection. Statistical analysis was conducted using SPSS 24.0 software. Results The baseline number of bacterial colonies in the first three groups was balanced, with no statistically significant difference (χ² = 0.538, P = 0.764). The number of bacterial colonies after washing and disinfection was lower than that before washing and disinfection. The difference between 500 mg/L chlorine-containing disinfectant and 3% hydrogen peroxide disinfectant before and after disinfection was highly significant (Z = -4.801, P<0.001; Z = -4.429, P<0.001). There was no significant difference between the disinfection effect of 500 mg/L chlorine-containing disinfectant and 3% hydrogen peroxide disinfectant, but they were both better than the control group (χ² = 18.070, P<0.001). Conclusion Disinfecting the saliva suction pipe with disinfectant between diagnosis and treatment can effectively reduce the bacterial contamination at the fixed end threaded plastic hose interface of the saliva suction pipe. The disinfection method is simple and convenient, and it is worth applying in the oral clinic.

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.

Objective To explore the feasibility of applying the Malocclusion Impact Questionnaire (MIQ) of Chinese version among Chinese teenagers, through the verification and evaluation of the Chinese version. Methods According to the standard procedures of the international quality of life assessment program, the MIQ was translated, back translated, adapted and updated culturally, and the Chinese version was established. The 161 teenagers with the first orthodontic treatment were included. This patient group was assessed for oral health-related quality of life by the Chinese version of the MIQ and Children's Perception Questionnaire (11-14 years old). The reliability and validity of the Chinese version of the MIQ were evaluated statistically by Spearman and factor analysis. Results A total of 161 valid questionnaires were collected. The internal consistency Cronbach's α of the Chinese scale was 0.887. The correlation coefficient between items and the scale ranged from 0.000 1 to 0.824. A significant positive correlation of the scores was noted between the translated scale and the Children's Perception Questionnaire (11-14 years old), and the correlation coefficient was 0.444 (P<0.001). Conclusion The reliability and validity of the Chinese version of the MIQ are reliable and can be applied for clinical orthodontic treatment.

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.

Tissue engineering provides a new possibility for pulp regeneration. As one of the three elements of tissue engineering, scaffolds have attracted increasing attention. Because the root canal system is limited by the unique anatomical structure of the long and narrow lumen, the preformed scaffold cannot be completely covered with the whole root canal space, although it is convenient to apply, so the injectable scaffold may be an ideal choice for pulp tissue engineering. Hydrogels are hydrophilic polymer networks with physical properties similar to soft tissues. They can provide a porous hydrophilic microenvironment, which facilitates the diffusion of oxygen and nutrients. In recent years, researchers have used injectable hydrogels with different mechanical properties and/or loaded biologically active ingredients as scaffolds to promote revascularization and the regeneration of pulp. The results show that natural polymer hydrogels, synthetic polymer hydrogels, and composite hydrogels combining natural and synthetic polymers all have excellent biocompatibility. The types and mechanical properties of hydrogels and the addition of bioactive ingredients can influence the behavior of stem cells, and gelatin-based hydrogels and fibrin-based hydrogels can also achieve rapid vascularization, which creates the conditions for the formation of pulp-like tissues. Among them, photocrosslinked methacrylated gelatin/hyaluronic acid hydrogels, two/multicomponent hydrogels combined with chitosan with antibacterial and temperature-sensitive properties and new self-assembled peptides have become major research topics in recent years due to their excellent properties. To develop suitable hydrogel scaffolds and promote their application in pulp regeneration, this article reviews the research progress in the types, preparation, and application of injectable hydrogels used for dental pulp regeneration.

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.

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.

Polyetheretherketone (PEEK) is known as a high-grade engineering plastic with good mechanical properties, chemical stability and biocompatibility. Currently, PEEK materials have been widely used in prosthodontics, such as complete dentures and removable partial dentures. The relevant research shows that PEEK posts are superior to glass fiber posts, which have high tensile bond strength and bending strength. At present, few case reports of PEEK postcores have been published, and clinical case reports suggest that PEEK postcores have good oral prosthetic aesthetics and are ideal and reliable postcore crown materials. However, the preparation and surface treatment methods of PEEK require further refinement. A review of the related properties of PEEK and the prospects of its application in the field of postcore crown restoration will be presented in this paper.

With the deepening of research in oral microbiomics, an important relationship between changes in the oral microbiome and orthodontic treatment has been found. Orthodontic treatment will have an impact on the oral and systemic microbiome. The presence of oral appliances can change the quantity and quality of the oral microbiometo and increase the risk of oral and even systemic diseases in patients undergoing orthodontic treatment. Compared with fixed orthodontic treatment, clear aligners will not have a harmful impact on the structure of the oral microbiome, which is more conducive to maintain oral health during the orthodontic treatment process. In addition, different bracket types and materials can lead to different changes in the oral microbiome, and the occurrence and development of orthodontic-related diseases, such as white spot lesions, dental caries, gingivitis and periodontitis, are also related to changes in the oral microbiome. At present, the role of the oral microbiome in the process of orthodontic treatment needs to be further studied. Whether a change in the oral microbiome caused by orthodontic treatment can be restored after orthodontic treatment is still uncertain and needs more research. This paper reviews the research progress on the application of microbiomics in orthodontics, including the impact of fixed appliances and clear aligners on the microbiome and the relationship between orthodontic-related diseases and the oral microbiome.

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.

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 establish a three-dimensional coordinate system that can accurately measure the recurrence rate after orthognathic surgery, and evaluate and analyze the degree of recurrence. Methods Data from patients who underwent orthognathic surgery in a hospital were selected to reconstruct three-dimensional images with spiral CT. The two researchers used the multiplane assisted positioning method to fix the points three times and screened them using intra-andintreclass correlation coefficients (ICC). Reproducible and accurate landmark points were drawn to establish different coordinate systems and calculate the facial asymmetry index (AI) to determine the coordinate system with the best mid-sagittal plane symmetry. This coordinate system and lateral radiographs were used to separately measure the recurrence rate, and evaluate and analyze the three-dimensional recurrence degree of orthognathic surgery. Results Ten landmark points that may be repeatedly fixed were obtained, including N (nasion), K (K point), ANS(anterior nasal spine), PNS (posterior nasal spine), Ptm(pterygomaxillary fissure), Gn (gnathion), IZ(IZ point), MZ (MZ point), Ms (mastoideale), Cor (coronion) and and Go (gonion). Three coordinate systems were established, and the most suitable coordinate system was the upper edge point of the left infraorbital foramen. The inner upper edge of the right infraorbital foramen and both sides of the midpoint of the ear points constituted the horizontal plane (HP), which passed through the outermost point of the left zygomatic frontal suture and the outermost point of the right zygomatic frontal suture and was perpendicular to the horizontal plane to constitute the coronal plane (CP). It was perpendicular to the two planes to form a sagittal plane (SP). Two-dimensional and three-dimensional measurements of recurrence were performed on 112 patients, and new three-dimensional recurrence evaluation results were obtained. Less than 40% had low recurrence, 40% to 61% had moderate recurrence, and greater than 61% had high recurrence. Conclusion This study established a three-dimensional coordinate system suitable for measuring the recurrence rate after orthognathic surgery, obtained a new three-dimensional recurrence evaluation result, and provided a clinical experimental basis for evaluating the effect of orthognathic surgery and improving stability.

Objective To explore the medication law and mechanism of traditional Chinese medicine compounds in the treatment of periodontal disease through data mining, network pharmacology, and molecular docking. Methods First, data mining was used to search single medicinal materials for the treatment of periodontal disease, and the active components and their action targets were screened. Second, the disease target database was employed to download the targets related to the pathogenesis of periodontal disease, map them with the action targets of traditional Chinese medicine, and obtain the targets that are considered potential targets of traditional Chinese medicine in the treatment of periodontal disease. Potential targets were analyzed for gene ontology function and signaling pathway. They were then screened to obtain the key targets for the treatment of periodontal disease. Finally, the active components were docked with key targets. Results Among the traditional Chinese medicine prescriptions for the treatment of periodontal disease, Shudihuang, Mudanpi, Danggui, Fuling, Jinyinhua, Shanyao and Zhimu had the highest frequencies. Forty-three active components and 118 action targets were screened, and 52 potential targets were obtained by intersection with 856 disease targets. The molecular functions and biological processes in which potential targets may participate mainly focus on vitamin D biosynthesis and RNA polymerase Ⅱ regulation and involve 96 signaling pathways. Through the analysis of network topology parameters, 11 key targets were obtained. The results of molecular docking showed that the active components and RAC-alpha serine/threonine-protein kinase (AKT1), cellular tumor antigen p53 (TP53), and mitogen-activated protein kinase-1 (MAPK-1) have good binding activity. Conclusion Traditional Chinese medicine compounds may play a role in the treatment of periodontal disease by inhibiting alveolar bone absorption, have antibacterial and anti-inflammatory properties, and promote tissue repair. The effective treatment of periodontal disease by traditional Chinese medicine compounds provides a more scientific reference to the sustainable development of traditional Chinese medicine.

Enamel demineralization is one of the most common adverse reactions to orthodontic treatment. The existence of orthodontic appliances affects oral hygiene maintenance, which easily leads to plaque accumulation and oral flora dysbiosis, and cariogenic bacteria produce acid to cause enamel demineralization. It not only affects aesthetics but may develop into caries and endanger oral health. Therefore, enamel demineralization has become an urgent problem. Nanoparticles generally refer to solid particles with diameters of 1 to 100 nm and have unique physicochemical properties that provide a new strategy for preventing enamel demineralization during orthodontics. Reviewing the relevant literature, nanoparticles used for the prevention of enamel demineralization in orthodontics may be classified into antibacterial, remineralization and carrier-type nanoparticles according to their functions. Most research was performed on the application of nanoparticles to modify orthodontic adhesives for enhancement of antibacterial or remineralization properties, but some studies also focused on the modification of orthodontic appliances with nanoparticles for surface coating or overall doping to provide antimicrobial properties. The advantage of these two approaches is that they are not dependent on patient compliance. Nanoparticle-modified fluoride varnishes and nanocarriers loaded with antimicrobial or remineralization agents may be used to promote oral health care in orthodontic patients, which have a sustained preventive effect but depend on the cooperation of the patient. It was indicated that the small size effect of nanoparticles provides better performance, but there may be certain safety issues, and there is still some influence on the physicochemical properties of the modified materials themselves. These issues must be further explored. Although there are some limitations in the current studies, nanoparticles are expected to play an important role in the prevention of enamel demineralization during orthodontics in the future.