Periodontitis is the most common oral disease and has a high incidence in humans. Periodontitis seriously affects the function of the oral and maxillofacial systems and is the most important cause of tooth loss in adults. In addition, as a long-term and persistent source of infection, periodontitis can not only trigger chronic inflammation and immune responses but also has an important impact on systemic health. Traditional periodontitis treatment focuses on inflammation control, and although this can prevent or delay the progression of the disease, satisfactory periodontal lesion tissue regeneration is difficult to obtain. With the introduction of new technologies and new materials such as guided tissue regeneration, bone grafting, growth factors and biological materials for the treatment of periodontitis, the method of periodontal tissue regeneration is more abundant, and the clinical effect has been greatly improved. In the future, stem cell transplantation and endogenous regeneration strategies are expected to become important methods for physiological and functional regeneration of periodontal lesions. This article briefly reviews the basic research and clinical application of periodontal tissue regeneration and forecasts the future development prospects and opportunities in this field.

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.

Ferroptosis is a newly discovered method of programmed cell death. Current studies have shown that activation of ferroptosis-related pathways can inhibit the growth and proliferation of tumor cells and reverse their drug resistance. Oral cancer is a common malignant tumor with a high recurrence rate and high drug resistance. Inducing ferroptosis is a potential treatment strategy. There are still many uncertainties in the application of ferroptosis in the treatment of oral cancer, which need to be further explored. This article systematically introduces the mechanism of ferroptosis and its recent progress in oral cancer treatment to provide new mechanisms and methods for the clinical treatment of oral cancer. Current research shows that the mechanism of ferroptosis is mainly related to amino acid metabolism, Fe²⁺ metabolism, and lipid metabolism. Ferroptosis in oral cancer cells can reverse drug resistance in cancer cells and improve the activity of immune cells. New drugs, such as curcumin analogs and triptolide, can induce ferroptosis in oral cancer, and the development of nanomaterials has improved the utilization rate of drugs. Inhibiting the expression of the ferroptosis-related factors SLC7A11, NF-E2-related factor 2 (Nrf2), and ferritin heavy chain 1 (FTH1) can promote ferroptosis in oral cancer cells. It is a potential target for the clinical treatment of oral cancer, but its translation into clinical practice still needs further research.

Temporomandibular joint (TMJ) ankylosis is a joint disorder which refers to bone or fibrous adhesion of the anatomic joint components and the ensuing loss of function. When it occurs in children, it can cause secondary dentofacial deformities with physical and psychological disability. Correction of TMJ ankylosis and secondary deformities remains a great challenge for oral and maxillofacial surgeons. Distraction osteogenesis (DO) has been used for the treatment of TMJ ankylosis and secondary deformities with satisfactory outcomes. An average of 50-60 patients with TMJ ankylosis is referred to our department annually.In this review, we summarized the characteristics of DO and discussed some factors involved in the treatment of TMJ ankylosis with dentofacial deformities.

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.

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.

In recent years, due to precise control of the amorphous mineral precursor in the demineralization of dentine collagen fibers in orderly deposition, forming apatite crystals similar to the natural mineralized dentin, the bottom-up remineralization approach which does not depend on the existence of seed crystallites, dentin biomimetic mineralization techniques gradually become a hotspot in the research field of restoration of demineralized dentin caused by dental caries. This paper reviews the changing concepts and practices of the remineralization of demineralized dentin, emphasizing biomimetic remineralization studies. The results of the literature review show that the traditional dentin remineralization method is usually a disordered mixture of demineralized dentin and minerals, so mineralized dentin is not comparable to natural mineralized dentin in terms of the morphological characteristics and mechanical properties. With its gradual increase in recent years, dentine biomimetic mineralization technology perfectly resembles the minerals in the dentin overlapping sequence arranged with the dentine collagen fiber structure characteristics, leading to greatly improved microstructural, physical and chemical properties. As a result, dentine biomimetic mineralization technology is expected to achieve new breakthroughs in the fields of resin-dentin bonding mixing layers and the decay of dentin. At present, the technical obstacles that need to be overcome in the clinical application of the biomimetic remineralization of dentin are how to continuously supplement all the active ingredients needed for mineralization in the process of remineralization and how to keep the mechanical properties of the parent material unchanged while slowly releasing all ingredients. Researchers have successively proposed three-step transportation of the biomimetic remineralization of raw materials, as well as the preparation of mineralization precursors stabilized by polymers in advance and the reuse of mesoporous silicon nanomaterials for the transportation of the mineralized ingredient system. The concept described above provides the preliminary in vitro experimental basis for the transformation of the biomimetic remineralization strategy of dentin in clinical applications.

Objective This study aims to compare the incidence of dentinal microcracks produced by ProTaper Universal (PTU) and ProTaper Gold (PTG) file systems during root canal procedures in different curved canals using a dyeing technique. Methods Sixty extracted human molars were divided into 3 groups of 20 samples each in terms of root curvature (mild bending group, 10 °-19 °; moderate bending group, 20 °-29 °; severe bending group, 30 °-39 °). Ten samples of each group were then randomly allocated to the PTU and PTG file systems. After preparation, all roots were stained using a dyeing method and sectioned at the most curved plane and 2 mm below and above the most curved plane with a low-speed saw under cold water. A stereomicroscope was used to inspect dentinal microcracks at 60 × magnification, and differences between these three instrument groups were analyzed using the chi-square test. Results The PTG file system induced significantly fewer dentinal microcracks for total, incomplete and complete cracks (P < 0.05), and the effect was more obvious with increasing canal curvature. Conclusion With the limitations of this in vitro study, it can be concluded that ProTaper Gold can result in fewer dentinal microcracks than ProTaper Universal.

The traditional biological principle for developing bone biomaterials is to directly stimulate the osteogenic differentiation of osteoblastic lineage cells, the direct effector cells for osteogenesis. This strategy has been successful for the development of bone biomaterials. However, recent progress in bone biology has revealed the vital role of the local bone microenvironment, especially the immune environment, in controlling osteogenesis. Interdisciplinary osteoimmunology has found that the osteoimmune and skeletal systems are closely related, sharing numerous cytokines and regulators. In addition, immune cells play an important role in the physiological and pathological processes of the skeletal system, suggesting that neglecting the importance of the immune response is a major shortcoming of the traditional strategy. Based on this principle, we propose a novel “osteoimmunomodulation”-based strategy to meet the strict requirements of new-generation bone biomaterials: instead of directly regulating the osteogenic differentiation of osteoblastic lineage cells, we should focus more on manipulating the responses of immune cells and developing biomaterials to induce an immune environment that provides conditions that balance osteogenesis and osteoclastogenesis for optimal osseointegration. This article reviews the recent progress on osteoimmunology and immunomodulatory biomaterials for the generation of the “osteoimmunomodulation” concept. Additionally, the outcomes of “osteoimmunomodulation”-related studies have been summarized to guide the development of advanced “osteoimmune-smart” bone substitute materials.

Transverse maxillary deficiency is a common malocclusion in the clinic. Palatal expansion techniques are commonly used in the treatment of maxillary transverse deficiency. Traditional palatal expansion techniques have good effects on the treatment of children and adolescents whose palatal suture has not yet closed, but the effects on adult patients are unsatisfied. New palatal expansion techniques, such as miniscrew-assisted rapid palatal expansion and surgical-assisted maxillary expansion, have increased the age-related indications for palatal expansion, and their bone expansion effect has been strengthened. With the development of CAD/CAM technology and 3D printing technology, techniques such as Invisalign and personalized appliances have been developed and have promising application prospects. To provide references for the clinical treatment of maxillary transverse deficiency, palatal expansion techniques are reviewed from the following aspects: mechanism and indications, expansion pattern, traditional and new palatal expansion appliances, stability and retention of palatal expansion, outlook of future expanders, etc.

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.

Objective To summarize the clinical manifestations of IgG4-related diseases in the head and neck, explore treatment methods. Methods The clinical data of 21 patients diagnosed with IgG4-related diseases were retrospectively analyzed. The clinical data and the results of glucocorticoid and immunosuppressive therapy were studied retrospectively. Results All patients had swollen sclerotic masses, and CT showed irregular high-density masses with uniform enhancement in the enlarged glands. Some patients had mucosal thickening and mass-like changes in theoral cavity, nose, sinuses, throat and other tissues, and most of the patients had cervical lymphadenopathy and elevated serum IgG4 levels (≥ 1.35 g/L). Histopathological examination of affected exosine glands and affected mucosa and lymph nodes in all patients showed infiltration of lymphocytes, plasma cells and IgG4⁺ plasma cells. In 21 patients, the mass in the affected glands and mucosa (including head, neck and other tissues) disappeared, and the clinical symptoms were relieved after the application of glucocorticoids. However, with a reduction in glucocorticoids, the mass recurred or even worsened. Conclusion For patients with a single mass in the submandibular gland, parotid gland and other salivary glands, as well as lymph node enlargement, CT is the first choice to identify the nature of gland neoplasms. Combined with pathological examination, related auxiliary examination and peripheral blood examination are also needed to obtain a definitive diagnosis. Glucocorticoid therapy is used to achieve a good prognosis, and long-term follow-up and timely adjustment of medication regimens are required.

In the process of enamel development, premature senescence and apoptosis of ameloblasts are important causes of hereditary enamel hypoplasia. Silence information regulator 2-related enzyme 1 (Sirt1) is a nicotinamide adenosine dinucleotide (NAD⁺)-dependent deacetylase that has been widely reported to be involved in the regulation of cell senescence. This paper reviews the research progress of Sirt1 regulating epithelial cell senescence, starting with the structural characteristics of Sirt1, and further expounds on the relationship between Sirt1 and senescence. When epithelial cells are stimulated, Sirt1 affects the senescence of epithelial cells in many ways, such as mitochondrial dysfunction. Sirt1 participates in regulating mitochondrial function and metabolic homeostasis, and telomere length is negatively related to senescence. Sirt1 regulates the expression of telomere reverse transcriptase needed for telomere extension, thus positively regulating telomere homeostasis. DNA damage will undergo damage repair, unrepaired DNA damage will cause cell senescence, and the Sirt1/p53 pathway can inhibit epithelial cell senescence by reducing DNA damage. Senescent cells are the source of chronic inflammation, and chronic inflammation can also promote aging in many ways. Sirt1 inhibits epithelial cell senescence by relieving inflammatory symptoms. In future research, we can focus on the effect of Sirt1 on ameloblast senescence and explore its specific mechanism of action on ameloblasts to find a breakthrough in the etiology and treatment of enamel hypoplasia.

Objective Oxygen-glucose deprivation (OGD) is used to mimic ischemia in vitro to observe whether endoplasmic reticulum (ER) stress is involved in human dental pulp cells (hDPCs) after OGD and to better understand the regulatory mechanism of hDPCs in ischemia. Methods hDPCs were cultured in glucose-free DMEM and hypoxia (volume fraction 2% O₂) to establish an hDPCs OGD model in vitro, which mimics hDPCs ischemia in vitro. hDPCs were divided into a control group (normal culture) and an experimental group (OGD 0 h, 2 h, 4 h and 8 h groups). After pretreatment with OGD for 0, 2, 4 and 8 h, hDPC viability was measured by methylthiazol tetrazolium (MTT) assay. qRT-PCR was used to detect the mRNA expression of ER stress markers [splicing x-box binding protein1 (sXBP1), activating transcription Factor 4 (ATF4) and C/EBP homologous protein (chop)]. Western blot was used to detect the protein expression of ER stress markers [phosphorylated RNA-activated protein kinase-like ER-resident kinase (p-perk) and phosphorylated eukaryotic initiation factor-2α (p-eIF2α)]. Results Compared with OGD 0 h group, cell viability of hDPCs decreased when exposed to OGD treatment for 2 h, 4 h and 8 h. Compared with the control group, mRNA expressions of ER stress makers (sXBP1, ATF4 and chop) and the protein expressions of ER stress protein markers (p-perk andp-eIF2α) increased in OGD treatment cells after 4 h were higher in OGD cells. The differences were statistically significant (P<0.05). Conclusion The results indicate that ER stress response is involved in hDPCs in OGD treatment.

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.

Increasing numbers of adult patients are seeking orthodontic treatment, which increases the need for orthodontists to treat malocclusion in periodontally compromised teeth affected by periodontitis. It is essential to control active inflammation prior to initiating an orthodontic protocol to avoid further breakdown of alveolar bone caused by periodontitis. However, whether the condition of periodontal ligaments can completely recover to a normal condition after controlling inflammation and tolerate orthodontic tooth movement remains controversial. The present review elaborates, from clinical trials (macroscopic) to biological tests (microscopic), the characteristics of periodontal tissue and periodontal ligament cells with a history of periodontitis that are submitted to orthodontic force loading. The following conclusions are made: 1. Orthodontic treatment in periodontally compromised patients is unusual because of changes in periodontal condition. 2. The combination of orthodontic force loading and uncontrolled periodontal inflammation aggravates pathological bone resorption; therefore, it is crucial to perform periodontal therapy prior to orthodontic treatment. 3. The periodontal ligament can withstand proper mechanical force loading after periodontal treatment. 4. Orthodontic treatment, as an adjunctive therapy, can improve periodontally compromised tissue and pathological tooth movement.

Optical illusion refers to the phenomenon in which the scene observed by the human eye is not completely consistent with the objectively presented scene. Optical illusions in stomatology, as well as their clinical application, are demonstrated in this paper in terms of shade, shape and aesthetic design. Shade is not only affected by the optical illusions with which it is associated, such as color metamerism, color constancy and the Chevreul illusion, but also influenced by the surroundings. It is suggested that the surrounding lighting during veneering should be the same as that during color matching in the clinic. As indicated by the Poggendorf illusion and the Leaning Tower illusion, the practice should be conducted and checked from multiple perspectives to compensate for the limitation of human eyes, such as intraoral scanning. Other digital technologies, including digital facial scanning and cephalometric measurement, could be used to reduce the subjective influence of observation. In terms of esthetic design, the interaction of the part and the whole, suggested by Ebbinghaus illusion, should be considered: an individual harmony smile should be designed considering the characteristics of the personality and the features of the face, lips, teeth and gingiva of the patient. Furthermore, personal information, such as gender and age, should be taken into consideration in beautification presentation. Further research should be focused on the influence of optical illusions in stomatology in more details. More communication among doctors, technicians and patients is needed. Clinicians should be aware of the impact of optical illusions to reduce subjective bias in clinical standardized operations and further take advantage of optical illusions to create beautification presentations of dental restorations and smiles.

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.

The nature, significance, parameters, influencing factors and testing of implant primary stability were studied by a literature review. Primary stability is a kind of anchorage force at the interface between the implant and bone, and it is merely mechanical. The significance of primary stability is to keep the implant unmovable so that the new bone can grow undisturbed on the surface of the implant without interference from fibrous tissue. The implant is finally bound to the bone by osseointegration. The most common assessments of primary stability are insertion torque (IT), the implant stability quotient (ISQ) of the resonance frequency analysis (RFA) and Periotest. IT is more commonly used to directly imply initial stability. At present, no consensus has been reached regarding the concrete parameters of primary stability to predict osseointegration. Implant osseointegration could be developed through all phases of primary stability. However, the excessive primary stability would cause mini-bone fractures, followed by bone necrosis at the interface and the final failure of implantation. Primary stability is influenced by three factors: implant design, bone condition of alveolar bone, and surgical technique. Under the condition of a lack of primary stability and immediate implantation, there may be the possibility of successful osseointegration. Therefore, it is necessary to re-examine the accuracy of the current elaboration on the primary stability. It is related directly to whether the clinic can choose the appropriate implant treatment path.

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.

Objective To explore the clinical effect of simultaneous distraction osteogenesis of the maxilla and affected mandible combined with second-stage orthognathic surgery for the treatment of adult hemifacial microsomia to provide a reference for clinical practice.Methods Twelve adult patients with hemifacial microsomia who underwent simultaneous distraction osteogenesis and second-stage orthognathic surgery from 2006 to 2013 were enrolled. Distraction osteogenesis of the maxilla and malformed lateral mandible and second-stage orthognathic surgery were performed according to each patient’s specific conditions. The height ratio of the mandibular ramus of the affected side to the contralateral side, the shift distance of the chin point and the inclination angle of the screw plane were measured before and after the operation, and the therapeutic effect was evaluated with clinical photographs.Results No patients had obvious complications after the operation, the postoperative aesthetic effect was good, and the relationship between the facial shape and occlusion was significantly improved. The cephalometric measurement showed that the height ratio of the mandibular ramus of the affected side to the contralateral side was increased by 23.83% (t=11.658, P<0.001), the deviation distance of the chin was corrected, and the chin point moved back to the midline by 6.63 mm (t=13.042, P<0.001) on average, and the inclination angle of the occlusal plane was improved and returned to the horizontal plane by 8.83° (t=15.358, P<0.001) on average.Conclusion The application of simultaneous distraction osteogenesis of the maxilla and mandible combined with secondary orthognathic surgery for the treatment of adult hemifacial microsomia can obtain satisfactory clinical and aesthetic results and has clinical value.

Osteoradionecrosis of the jaw (ORNJ) is a common complication after radiotherapy for head and neck malignant tumors. Surgery is the main treatment method for ORNJ with large lesions. In the case of serious maxillofacial and cervical soft and hard tissue damage caused by radiation, surgical treatment may have some difficulties and risks. In this paper, we discuss the main points for indication selection and treatment as well as surgical difficulties and their causes, including local inflammation and radiation injury during the operation, timing of bone defect reconstruction, condylar preservation, selection of recipient vessels, implant bed treatment, common complications of ORNJ operations (i.e., wound healing and nerve injury), severe complications (i.e., vascular crisis and tissue flap necrosis), pulmonary infection, cerebral pulmonary embolism, important vascular rupture, and severe psychological trauma, including its prevention and treatment. This information will enable clinicians to fully understand the various difficulties and risks that may be encountered during the ORNJ operation and will minimize serious complications, ensure the life, health and safety of the patients, and provide a reference for improvement of the clinical efficacy of ORNJ treatment.

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.

The pulpal or periapical diseases of immature permanent teeth often lead to incomplete root development. It is a challenge for us to figure out how to ensure the continuous growth of the teeth and the formation of roots. There are many cases about pulp regeneration reported recently. With the regeneration and differentiation ability of stem cells, which exist in residual pulp tissue, periapical and periodontal tissues, the regeneration of new vital pulp tissue was induced under proper conditions, which is highly vascularized and rich in connective tissue, thus prompting continuous root growth and development, increasing root length, thickening root canal walls, and facilitating the coarctation of the apical foramen. Besides, clinical and radiographic examinations shows successful results about the regenerative treatment, which is of milestone significance. The pulp regeneration treatment is designed to replace the pathological dental pulp tissue with new regenerated pulp tissue, based on biological tissue engineering process. This process includes two key parts: one is pulp revascularization, regenerating new vital pulp tissue in the root canal to achieve the continuous root growth and development; the other is tissue engineering, new pulp dentin complex is regenerated by the stem cells under the induction of suitable biological active scaffolds and growth factors. This article reviews about the research progress and clinical characteristics of aforementioned two key parts.

Chloroquine and hydroxychloroquine are both classic 4-aminoquinoline antimalarial drugs with similar chemical structures and mechanisms of action. As the toxicity and side effects of hydroxychloroquine are lower than those of chloroquine, hydroxychloroquine is the main clinical application at present, with good efficacy and safety. Chloroquine and hydroxychloroquine are widely used in the clinic because of their immunosuppressive, anti-inflammatory, antiviral, antitumor and photoprotective effects. The main mechanisms by which chloroquine/hydroxychloroquine inhibits immunity include inhibiting lysosome activity, autophagy, immune response signaling pathways production of proinflammatory cytokines. Chloroquine stabilizes the lysosomal membrane and reduces the release of lysosomal enzymes. As a prostaglandin antagonist, chloroquine can reduce the production of prostaglandins and leukotrienes, thus playing an anti-inflammatory role. Chloroquine/hydroxychloroquine can inhibit virus proliferation in the early stage of virus replication by inhibiting the glycosylation of the angiotensin converting enzyme 2 receptor. At present, hydroxychloroquine has been found to have significant efficacy in discoid lupus erythematosus, oral lichen planus, chronic cheilitis, pemphigus foliaceus, Sj?gren’s syndrome and other stomatological diseases. However, eye damage is the most important adverse reaction of hydroxychloroquine, and its occurrence is related to the cumulative dose of drugs.

Hemangioma is the most common vascular benign tumor in infants and young children, 60% of which occur in the oral maxillo-facial region. One characteristic of oral and maxillofacial hemangioma is spontaneous regression, which generally does not require treatment; however, a few hemangiomas can produce complications including ulceration, functional disorders and dis?gurement, which require active treatments. Currently, the treatment of oral and maxillofacial hemangioma include drug treatment, laser treatment and surgical treatment. The drugs used to treat hemangioma mainly include beta blockers, glucocorticoids, alpha-interferon, imiquimod and antitumor drugs. Drug therapy is suitable for multiple, rapidly proliferating hemangiomas and hemangiomas that affect vital organ function or endanger life. Laser therapy can be applied to the early treatment of rapidly growing hemangiomas at exposed sites. Surgical treatment is suitable for proliferative hemangioma with serious complications, the reconstruction of any external deformity and the repair of a scar after an ulcer. Combined therapy and the development of new technologies provide new directions for the treatment of hemangioma but the efficacy remains to be proven by large sample prospective studies. Clinicians should appropriately evaluate the patients with hemangioma and develop individualized treatment programs for patients with treatment indications. This article reviews the efficacy, mechanism, clinical application and adverse reactions of different treatment methods and provides references for clinical treatment.

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.

Gingival recession (GR) is characterized by exposure of the root surface into oral environment due to apical migration of the marginal gingiva to the cementoenamel junction (CEJ). A high prevalence of GR has been reported in several representative population samples. GR may result in a certain degree of functional and aesthetic alterations if left untreated for long periods. In severe cases, root-dentin hypersensitivity, abrasion, abfraction and root caries may also be involved in GR, which increases the challenge of plaque control. The etiology of GR is multifactorial, including periodontal disease, local anatomical variation, tooth malposition, improper tooth brushing, mechanical trauma and iatrogenic factors, of which periodontal disease is the most common cause. The treatments of GR consist of nonsurgical and surgical therapy, and the latter generally involves mucogingival surgery to restore the aesthetics and function of the local gingival recession. However, over the past 50 years, the periodontal plastic surgical technique has evolved from the traditional free gingival graft method into a more advanced, minimally invasive tunnel technique. For this technique, sulcular incisions instead of vertical relieving incisions are provided through each recession area, and full thickness mucoperiosteal flaps are created and extended beyond the mucogingival junction to facilitate coronal displacement. Each pedicle adjacent to the recession is gently undermined to create a tunnel at recipient site, where either autograft or allograft can be used. A minimally invasive tunnel technique is a better method for root coverage and reduced postoperative patient discomfort. This technique is characterized by both practical and aesthetic features.

In recent decades, although great progress has been made on the diagnosis and treatment of oral squamous cell carcinoma (OSCC), its 5-year survival rate has not been significantly improved. The basic reason is the unclear pathogenesis, lack of effective molecular markers for assessing invasion, metastasis, and recurrence as well as therapeutic targets. The present view is that genetic and epigenetic abnormalities are related to the occurrence and development of OSCC. Epigenetic inheritance is a biological behavior that can be regulated and reversed, and it plays an important role in the occurrence and development of malignant tumors. First, this review will describe the role of epigenetic modifications in the development of OSCC in combination with our research and the latest research progress of epigenetics, including DNA methylation, RNA methylation, short noncoding RNAs (miRNAs, etc.), long noncoding RNAs, circular RNAs, histone modifications (acetylation and methylation), chromatin remodeling and genomic imprinting. Then, we will analyze the value of epigenetic studies in the prevention, diagnosis, and targeted therapy of OSCC.

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.

Radioactive jaw necrosis is a serious complication of head and neck radiotherapy. This complication's main characteristics are chronic necrosis and infection, and its clinical manifestations are local pain, mouth opening re'striction, speech disorder, dysphagia, exposure of dead bone, prolonged healing of facial and neck soft tissue fistula, and even pathological fracture, which brings great pain to the patient's body and mind. Radioactive jaw necrosis has become a clinical problem in the field of medicine, specifically for maxillofacial surgery of the external head and neck. The pathogenesis of radiation-induced jaw necrosis is still unclear, but high radiotherapy dose, extraction of teeth after radio-therapy and surgical trauma are recognized as high-risk factors. The diagnosis of radiation-induced jaw necrosis needs to be combined with the patient's radiotherapy history, clinical symptoms and imaging examination. Conservative or sur-gical treatment should be selected according to its clinical classification and stages, and the prevention of radiation-in- duced jaw necrosis should be emphasized. The key points are to remove dental caries, residual roots and crowns before radiotherapy; improve radiotherapy technology; and take preventive measures against high-risk factors. In recent years, the diagnosis and treatment of radiation-induced jaw necrosis has gradually become standardized and individualized.This article reviews the progress of treatment and research on radiation-induced jaw necrosis at home and abroad in terms of its definition, etiology, risk factors, diagnosis, treatment and prevention to provide reference for clinical treat-ment.

Hemangiomas and vascular malformations are common clinical diseases. According to their clinical and imaging characterizations, the International Society for the Study of Vascular Anomalies (ISSVA) has systematically classified infantile hemangioma and vascular malformations, and the classification has been widely recognized and applied. To date, most vascular malformations involve the following important signaling pathways: PI3K/Akt/mTOR and RAS/MAPK/ERK. This discovery has major impacts on the diagnosis and treatment of vascular malformations including the following: the understanding of the biology of vascular malformations has been increased; the understanding of vascular malformations based on genotype has been refined; and the development of targeted drugs for the treatment of vascular malformations has been promoted. Despite facing many challenges, with the development of gene sequencing, molecular biology and imaging technology, the relevance of vascular malformation classification and the accuracy of diagnosis are improving, and this is accompanied by innovations in surgical treatment and sclerotherapy, interventional embolization, and continuous progress in targeted therapy. At present, investigations on vascular malformations are mostly retrospective clinical studies or low-level clinical trials. The purpose of this paper is to review the literature on the treatment of infantile hemangioma, lymphatic malformation, venous malformation and arteriovenous malformation and to review the research progress in evidence-based treatment of infantile hemangioma and vascular malformation.

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.

The facial submental artery island flap (FSAIF) is a fasciocutaneous flap supplied by the facial submental artery. It is in close proximity with many oral and maxillofacial regions, and its tex ture and color are similar to those of the head and face. The flap has a constant and sufficient blood supply, and it is easy to prepare and has high survival rates and few complications. According to the tissue carried, FSAIF can be divided into fasciocutaneous flaps, myocutaneous flaps and simple flaps. The flap can also be made into an osteofasciocutaneous (myocutaneous) flap with a mandible to repair maxillary defects. Because this flap is a pedicled flap, it can greatly shorten the operation time, bed rest time and hospitalization time and has been widely used in repairing medium-sized defects of the oral and maxillofacial region. The indications for FSAIF in repairing maxillofacial defects should be strictly controlled. It can be safely used for benign or malignant tumors without cervical lymph node metastasis. For malignant tumors with cervical lymph node metastasis but without extranodal extension, the flap can be used on the premise of thorough neck dissection. The contraindication is cervical lymph node metastasis and extranodal extension of malignant tumors; therefore, other flaps should be selected for repair.

The loss of jaw position relationship will seriously affect the face and masticatory function of patients, and accurate restoration of vertical dimension of occlusion (OVD) is the key to occlusal reconstruction in edentulous patients. There are many methods to measure OVD in edentulous patients. In this paper, the working principle, scope of application, advantages and disadvantages, measurement methods and operation points of OVD recording method are reviewed in order to provide some reference for clinical treatment. The results show that the pre- extraction recording method is more objective and accurate, but the diagnosis model before extraction is required to accurately reflect the patients′ original OVD; the rest and stop jaw reference method is easily affected by subjective factors, and the edentulous patients with unstable jaw relationship are forbidden; the swallowing method is more subjective, especially suitable for patients with emotional tension and poor coordination; The facial landmark measurement method is more objective, but it is also affected by some subjective measurement factors. The patients with maxillofacial malformation are forbidden; the subjectivity of speech method is strong, and the accuracy of measurement results is closely related to the clinical experience of doctors, and the patients with aphasia and deafness are forbidden. X-ray cephalometric method and finger measurement method have strong objectivity. They are new measurement methods in recent years and have a bright future. Among them, finger measurement method is especially suitable for patients with maxillofacial deformity or postoperative deformity of tumor.

TNM（tumor node metastasis）classification is a common way to evaluate the prognosis of patients with oral cancer; however, many years of application have proven this method to be confined merely in clinical and pathological data and it cannot be adapted to the development of modern medicine. Deep learning (DL) has been widely used in various aspects of human life, has advantages for conducting efficient and intelligent searches and can explore and analyze substantial medical information well. Additionally, the application of DL to medical practice is quickly increasing. In the field of oral cancer prognosis, DL can efficiently process and analyze the pathological, radiographic and molecular data of oral cancer patients represented by lymphocytes, gray level cooccurrence matrix (GLCM) and gene maps and make accurate prognostic judgments accordingly. By assisting physicians in optimizing treatment plans, DL can effectively improve patients’ survival. Although DL lacks sufficient data and practical clinical application in prognostic studies, it has shown good clinical application prospects.

Three-dimensional tooth segmentation is the segmentation of single-tooth models from a digital dental model. It is an important foundation for diagnosis, planning, treatment and customized appliance manufacturing in digital orthodontics. With the deep integration of artificial intelligence technology and big data from stomatology, the use of deep learning algorithms to assist 3D tooth segmentation has gradually become mainstream. This review summarizes the current situation of deep learning algorithms that assist 3D tooth segmentation from the aspects of dataset establishment, algorithm architecture, algorithm performance, innovation and advantages, deficiencies of current research and prospects. The results of the literature review showed that deep learning tooth segmentation methods could obtain an accuracy of more than 95% and had good robustness. However, the segmentation of complex dental models, operation time and richness of the training database still need to be improved. Research and development of the "consumption reduction and strong core" algorithm, establishment of an authoritative data sample base with multiple centers, and expansion of data application depth and breadth will lead to further development in this field.

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.

Short implants can be used as an alternative in cases of insufficient vertical bone volume after dentition defect or absence of dentition to simplify or avoid bone augmentation procedures. Short implants (≤ 6 mm) are reported to have a mean survival rate of 96% after a period of 1-5 years in function and have been widely used in cases of dentition defects or absence of dentition. Compared with conventional implants (≥ 10 mm) combined with bone augmentation procedures, short implants have fewer surgery-related complications, less marginal bone loss, shortened treatment times and reduced costs, and are preferred by patients. Due to a lack of evidence, a high crown-implant ratio should not be an obstacle for the use of short implants. In addition, most of the current literature has not enough follow-up time, the long-term implant survival data of short implants remain unclear. To improve the clinical outcomes of short implants, attention should be paid to the implant site, bone quality, and occlusal force as well as to the presence of oral health maintenance, periodontal diseases and habits through a careful intraoral and radiographic examination. The choices of wider implant use and splint restoration are recommended, occlusal force should be paid attention during implant maintenance. Inappropriate stress on restorations should be avoided. Future studies should be focused on the long-term clinical outcomes of short implants.