Oral and maxillofacial tumors are common oral and maxillofacial surgery-related diseases. Digital surgical technology, represented by virtual surgical design and surgical navigation, is the main auxiliary means of the surgical diagnosis and treatment of oral and maxillofacial tumors. However, the existing digital technology still has some problems and room for improvement in terms of 3D visualization imaging and intraoperative hand-eye coordination. At present, the application of 3D visualization technology represented by mixed-reality technology has been rapidly developing in the medical field. It assists in realizing the real-time stereoscopic presentation of medical images by superimposing 3D virtual images onto the real surgical environment. Mixed-reality technology has been gradually applied to the diagnosis and treatment of oral and maxillofacial tumors. Preoperatively, mixed-reality technology can be used to construct a 3D model of the tumor and its surrounding vital structures based on imaging data, at which point the medical team can personalize the preoperative assessment and design the surgical plan in the mixed-reality environment. Intraoperatively, the combination of mixed-reality technology and surgical navigation technology can be used to display the 3D virtual model in real time in the actual environment of the operation area, overcoming the hand-eye coordination problem associated with using navigation technology alone and further improving the accuracy and safety of oral and maxillofacial tumor surgery. The combination of mixed-reality technology and internet medical technology can provide a high-quality teaching platform to promote the development of regional oral and maxillofacial surgery practices. The limitations of mixed-reality technology include image occlusion, lack of accuracy when used alone, and long alignment times. In this review, the application of mixed-reality technology to the diagnosis and treatment of oral and maxillofacial tumors will be summarized and assessed by combining information from domestic and international literature reports with the practical clinical experience of the author group.

Free tissue flap transplantation is the preferred option for repairing and reconstructing postoperative defects in oral and maxillofacial-head malignant tumors. However, challenges remain for oral and maxillofacial-head and neck oncology surgeons in terms of ischemia-reperfusion (I/R) injury, airway management, quality of life and prognosis. I/R injury is an inevitable complication of free-flap transplantation surgery. In addition to shortening the vascular anastomosis time as much as possible during the surgical process, many studies have attempted to further prevent and treat free-flap I/R injury using physical intervention therapy, antioxidant and reactive oxygen species (ROS) scavenger therapy, hyperbaric oxygen therapy, etc. However, there is a lack of large-scale clinical randomized controlled trial evidence to further support these methods. Postoperative tracheal management of patients receiving free tissue flap transplantation is very important. In recent years, delayed extubation has been proposed as an alternative to traditional tracheostomy. This method can facilitate wound care for patients, reduce infections, speed up patient recovery, and reduce the incidence of vascular crises. In the future, such management is expected to improve the practicality and safety of delayed extubation by formulating more appropriate patient selection criteria and intensive care plans. Preoperative selection of suitable free tissue flaps according to the defect for repair and reconstruction is beneficial for improving the quality of life and survival rate of patients. At the same time, for patients who require postoperative radiotherapy, reducing the complications of postoperative radiotherapy and improving the quality of life of patients can be achieved through intraoperative nerve anastomosis, preradiation oral hygiene maintenance, early speech training, and other methods.

The functional reconstruction of large maxillofacial defects is a major issue in oral and maxillofacial surgery, and autologous bone transplantation is the main method. However, bone is readily absorbed following an autologous bone transplant. Even with vascular anastomosis, spontaneous osteoporosis of transplanted bone is still serious, which affects dental implantation and functional recovery. Therefore, osteoporosis of the grafted bone has become one of the main complications of jaw reconstruction, and there is no preventive measure. The problem that autologous bone with sufficient blood supply cannot avoid osteoporosis suggests that systemic factors such as nerves, which have been neglected in traditional methods, may regulate the internal environment of the transplanted bone. Based on previous studies on the regulation of mesenchymal stem cells by the neural microenvironment, we initiated a new surgical procedure for innervated and vascularized iliac bone flaps based on animal model and cadaver studies. In the innervated and vascularized iliac bone flap, vascular microanastomosis was performed in conjunction with microneuronal anastomosis between the simultaneously harvested ilioinguinal nerve (which innervates the iliac bone and is usually sacrificed and neglected in the conventional vascularized iliac bone flap) and the inferior alveolar nerve proximally and with the mental nerve distally. By conducting clinical retrospective studies and prospective randomized controlled trials, we proved that the novel method of simultaneous innervated iliac bone transplantation can not only prevent bone resorption but also restore the sensation of adjacent soft tissues such as the lip. This may solve the key problems of sensory loss and osteoporosis after mandibular reconstruction, ensure the success of dental implant dentures, and put forward the new concept of "blood supply + innervation" bi-system bone transplantation.

With the development of computer-aided surgery and rapid prototyping via 3D printing technology, digital surgery has rapidly advanced in clinical practice, especially in the field of oral and maxillofacial surgery. 3D printing technology has been applied to the functional restoration and reconstruction of the jawbone. Before surgery, a 3D digital model is constructed through software to plan the scope of the osteotomy, shape the bone graft and plan the placement of the implant. Additionally, 3D models of personalized surgical instrument guides are printed prior to surgery. With these 3D-printed models and guides, accurate excision of the jaw tumor, accurate placement of the grafted bone and precise placement of implants can be achieved during surgery. Postoperative evaluation of accuracy and function shows that 3D printing technology can aid in achieving the biomechanical goals of simultaneous implant placement in jaw reconstruction, and in combination with dental implant restoration, the technology can improve patients' postoperative occlusal and masticatory functions. Nevertheless, 3D printing technology still has limitations, such as time-consuming preparation before surgery. In the future, further development of 3D printing technology, optimization of surgical plans, and alternative biological materials are needed. Based on domestic and foreign literature and our research results, we have reviewed the process and clinical application prospects of jaw reconstruction via 3D printing technology to provide a reference for oral and maxillofacial surgeons.

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

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.

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.

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.

Traumatic temporomandibular joint ankylosis refers to fibrous or bony fusion between the condyle and the glenoid fossa. It can cause problems with mouth-opening limitations, mastication difficulties, obstructive sleep apnea and hypopnea syndrome. When traumatic temporomandibular joint ankylosis occurs during childhood, it can cause facial asymmetry, micrognathia, and malocclusion, which significantly affect the physical and mental health. Once temporomandibular joint ankylosis occurs, it will be refractory and recurrent. The pathogenesis of temporomandibular joint ankylosis has not been completely elucidated and has always been a research hotspot in the oral and maxillofacial fields. In this paper, worldwide research was conducted, and the pathogenesis of traumatic temporomandibular joint ankylosis was clarified, such as “damage of condyle”,“disc displacement or rupture”,“damage to the glenoid fossa” and “lateral pterygoid muscle distraction”. The relative pathogenesis hypotheses were summarized, such as “hematoma organization” and “lateral pterygoid muscle distraction osteogenesis”. The related pathogenesis of traumatic temporomandibular joint ankylosis was discussed based on the latest cytology and molecular biology research.

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.

Chronic obstructive diseases of the parotid gland are common clinically, with repeated swelling and a prolonged course and poor treatment outcomes. Based on the summarization of clinical practice and related literature, from the viewpoint of etiology, parotid obstructive diseases can be classified as mechanical obstructions, specific obstructions and non-specific obstructions. The principles of fluid mechanics are introduced to explain the formation of parotid obstructions. According to the different causes, the methods of changing the flow pattern of saliva in the parotid to reduce the resistance and relieve the obstruction, are proposed, such as mechanical factors removals, application of drugs that promote saliva secretion and lower saliva viscosity, ductal expansion under endoscopy and stent placement, and embolization of collateral ducts. These managements can effectively increase the salivary flow rate, reduce the occurrence of the saliva stranded and parotid gland obstructions.

Benign condylar hyperplasia is one of the causes of mandibular lateral deformity, it is easily to be misdiagnosed clinically and leads to the treatment failure. This article will elaborate the etiology and clinical features of benign condylar hyperplasia, as well as the diagnostic points and treatment progress, based on the literature and the clinical experience of our research group, to provide evidence-based medical evidence for the standardized clinical treatment of benign condylar hyperplasia. The etiology of benign condylar hypertrophy includes neurotrophic disorders, local circulatory disorders, traumatic injuries (especially condylar injuries that occur in childhood), unilateral mastication, temporomandibular arthritis, endocrine disorders, condylar osteoma, and heredity. Benign condylar hypertrophy is insidious, and occurs most frequently in individuals 10-30 years old, and the course of disease can last for many years. Its clinical characteristics are slow progressive facial asymmetry. Radionuclide bone scans have become the basis for the diagnosis and differential diagnosis of and treatment planning for benign condylar hypertrophy. Different treatment plans for active and inactive periods need to be developed, including close observation, proportional condylar resection and orthognathic surgery.

Most salivary gland stones involve the submandibular gland, which often cause recurrent swelling and pain of the glands after meals, and used to be the main reasons for the gland removals. With the trend of minimally invasive treatment, gland preservation and functional recovery in the diagnosis and the treatment of submandibular lithiasis have been paid more and more attention. New equipment and technologies such as CBCT and sialendoscopy, which are widely used in clinical practice, have contributed a lot to the accurate orientation and minimally invasive treatment of stones, and enriched the managements of submandibular lithiasis. Based on our experience and the review of relevant literature, this paper attempts to summarize the treatment strategies for submandibular stones distributed in different parts of the duct: ① emphasizing on the integrity and functions of the organ; ② endoscopy and minimal invasiveness come first; ③ scientific classifications and personal managements. Appropriate treatment options should be selected according to the features of the stones: endoscopic lithotomy helps a lot in removing those located in the anterior or middle part of the duct; endoscopic lithotomy or/and sialolithotomy are needed according to the features of hilar stones; the regular follow-up is required for the intraglandular stones. Meanwhile, the evaluation of the gland function is also important. After the removals of sunmandibular stones, the functions of the glands should be promoted to restore as far as possible.

The evaluation of immune function plays an important role in the diagnosis, treatment and prognosis of many diseases. To date, immune function detection includes cellular immunity, humoral immunity, and inflammatory markers. In this paper, the application of immune function detection in the diagnosis, differential diagnosis and treatment monitoring of various diseases was discussed; then, the application value of immune function detection in the diagnosis and treatment of three common oral mucosa-related diseases, including recurrent aphthous ulcer (RAU), oral lichen planus (OLP), and oral squamous cell carcinoma (OSCC), were reviewed combined with the literature and our research. Our research found that RAU patients present abnormal humoral immune function and obvious inflammatory reactions, whereas OLP and OSCC patients present mild inflammatory reactions and more serious abnormal cellular and humoral immune function, so the combined detection of immune function has a certain guiding value for the diagnosis and treatment of these diseases. Moreover, in the future, it is necessary to carry out a study on large sample, multicenter and multiindex joint detection to better clarify the role of immune dysfunction in the pathogenesis of various diseases and its mechanism, to establish the corresponding diagnostic model and prognostic prediction model, to find more effective treatment methods.

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.

Marsupialization is effective in the treatment of cystic lesions of the jaw. It is a simple operation that can result in minimal trauma, the reduction of postoperative recurrence, and maximum preservation of the surrounding tissue structure and function. However, there is a certain failure rate in clinical treatment due to the improper grasp of indications and nonstandard operation. The highest failure rate reported in the literature is 32.6%. To further standardize the clinical application of marsupialization and improve the success rate of treatment, we put forward an expert consensus of marsupialization in the treatment of jaw cystic lesions by reviewing the domestic and foreign literature and summarizing the experience in marsupialization from some famous domestic experts. In this consensus, we propose three elements of marsupialization: the establishment of the opening, the maintenance of cyst plugs and regular washing. The scope of application of marsupialization includes jaw cysts and cystic ameloblastomas. It is necessary to standardize the position of the opening, the size of the opening and the manufacture of the cyst plug, and a panoramic film or cone beam computed tomography(CBCT) should be used to observe the changes in the cystic cavity before and after operation. A second-stage operation should be performed when the lesion is significantly reduced by more than 50% or at least 5 mm from important structures; furthermore, the teeth of focus should be treated according to the relationship between the lesion and tooth and the type of tooth.

Stem cells are a class of undifferentiated cells with high self-renewal and rapid proliferative capabilities. Undercertain conditions, stem cells can induce differentiation into other tissue cells of the human body, such as skeletal muscle cells, cardiomyocytes, osteoblasts, and nerve-like cells. In recent years, with the development of tissue engineering and regenerative medicine, stem cells have been extensively used in various fields of regenerative medicine as optimal seeded cells; however, there are still some problems, such as the decreased cell survival rate and regenerative capacity after transplantation, immune rejection, and ethical supervision. Therefore, it is difficult to universally and safely use stem cell banks for regeneration applications. The paracrine effect of stem cells has been extensively studied since its discovery. Increasing evidence supports the view that stem cells act in paracrine manner, and the secretion of exosomes plays a vital role in their biological functions. Exosomes are nanoscale extracellular vesicles containing biologically active molecules such as RNA and proteins; they possess similar functions to stem cells and play important roles in cell communication, immune response, and repair of tissue damage. At present, clinical studies on stem cell exosomes in tissue engineering and regenerative medicine have also been carried out in the fields of bone and cartilage repair, nerve tissue regeneration, liver tissue regeneration, skeletal muscle tissue engineering, vascular regeneration, taste bud repair, tooth regeneration, etc. In this paper, the composition, formation, release and identification of exosomes are introduced in detail. The research status of exosomes from different stem cell sources in tissue engineering and regenerative medicine is described, and their broad application prospects are discussed.

Temporomandibular joint disorder (TMD) is a common clinical disease in stomatology that occurs frequently in young people, mostly in women, with an incidence of approximately 30%; its clinical manifestations include mandibular dysfunction, regional pain, and clicking noises around the temporomandibular joint (TMJ). Some patients have tinnitus, headache and other symptoms. With regard to the treatment procedures of TMD, a gradient sequential treatment model is currently preferred, each of which has strict indications. Generally, conservative treatment or noninvasive treatment is preferred and is suitable for patients with dysfunction or mild organic disease. The second-choice minimally invasive treatment is suitable for patients who have failed conservative treatment or patients with mild organic disease. Finally, open surgery, which is suitable for patients who are not responsive to the first two treatments and show severe organic lesions, can be considered. The formulation of an open surgery treatment diagnosis and treatment plan should be personalized, led by doctors, and completed with the cooperation of patients. This article describes the “gradient sequential treatment” of temporomandibular joint disorders.

The etiology and pathogenesis of hemangiomas and vascular malformations are still unclear and face many challenges in terms of treatment. This article focuses on the etiology and genetic mechanism of common vascular tumors (such as infantile hemangiomas, congenital hemangioma and pyogenic granuloma) and vascular abnormalities (such as sporadic venous malformations, blue rubber bleb nevus syndrome, hereditary cutaneomucosal venous malformations, glomuvenous malformations, verrucous venous malformations, lymphatic malformations, and arteriovenous malformations). Some gene mutations have been identified and established. Several mutations in key proteins in the signaling pathways of endothelial cells (ECs) have been shown to play a major role in the pathogenesis of vascular abnormalities. Mutations in PIK3CA and G-protein coupled receptors were most frequently identified. The detection of genetic or somatic gene mutations is important for elucidating the underlying molecular mechanisms and developing effective therapeutic approaches.

Parotid obstructions can cause repeated swelling of the glands. Previously, duct stones were thought to be the main cause of obstructions, but salivary gland endoscopy examinations have revealed the absence of stones or foreign bodies in the duct system of the parotid glands with obstructive symptoms. Diseases of the parotid gland with obstructive symptoms include chronic recurrent parotitis, non-stone chronic obstructive parotitis, Sj?gren′s syndrome, IgG4-related parotitis and radiation-induced parotitis. The mechanism of obstructions is unknown, and the disease course is prolonged. In this paper, based on a brief analysis of duct stenosis, distortion and mucus emboli, which may lead to parotid obstructions, a new perspective is emphasized: the duct system of the parotid and flowing saliva constitute a microflow field. Based on the principle of fluid mechanics, the flow of saliva in the flow field can be affected by the confluence, diameter changes, and twist of the ducts. This outcome results in changes in the low velocity zone, backflow, counterflow and turbulence; affects saliva flow and normal discharge; and causes symptoms of parotid obstruction. An analysis of the possible mechanisms of parotid obstruction using two variables, duct anatomy and saliva traits, helps explain the causes of nonstone parotid obstructions.

Osteosarcoma is the most common osteogenic malignancy of the head and neck, and its incidence in the upper mandible is predominant. Osteosarcoma of the head and neck has various causes and rich pathological subtypes. Diagnosis of osteosarcoma requires the synthesis of symptoms and imaging data and pathological characteristics (including cell characteristics, immunohistochemical characteristics and molecular markers). Surgery is the core treatment for osteosarcoma of the head and neck. Compartment resection based on the Enneking staging system has high practicability in the surgical treatment of osteosarcoma of the head and neck. Osteosarcoma can be treated by combined craniomandibular surgery to achieve complete resection of the tumor. The combination of adjuvant radiotherapy, adjuvant chemotherapy and surgery can further reduce the risk of local recurrence and distant tumor metastasis. The emergence of targeted therapy and immunotherapy provides more options for the treatment of head and neck osteosarcoma. This article reviews the diagnosis and treatment of osteosarcoma of the head and neck.

Sialorrhea is a group of symptoms characterized by excessive accumulation of saliva in the mouth and unconscious overflow from the mouth. It can be divided into physiological sialorrhea and pathological sialorrhea. The etiology of sialorrhea is complex. Local oral factors, systemic diseases, drug induction or psycho-physiological factors can lead to excessive saliva secretion or excessive saliva storage in the mouth, which can lead to sialorrhea. Physiological sialorrhea generally does not require treatment, while different treatment strategies are needed in cases of pathological sialorrhea. There are many treatments for sialorrhea, including oral and maxillofacial system training, drugs, botulinum toxin injection, surgical treatment, and less commonly, traditional Chinese medicines, radiotherapy and neuromuscular electrical stimulation therapy. For different patients, different treatment methods should be adopted, and the treatment should be gradual. To correct the abnormalities in the oral and maxillofacial regions, the primary disease should be treated, contact with/the use of substances inducing salivation should be stopped, or psychological treatment should be administered, combined with oral and maxillofacial system training; if the effect is not good, invasive treatment, such as surgery, should be considered. At present, there are no unified, clear diagnostic criteria or simple and effective treatments in the clinic. In this paper, the etiology, diagnosis and treatment of sialorrhea, combined with our group′s many years of experience in the diagnosis and treatment of sialorrhea, are reviewed to provide a useful reference for the clinical diagnosis and treatment of sialorrhea.

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.

Sj?gren′s syndrome lacks a single and objective diagnostic index, and its diagnosis often requires comprehensive analysis according to classification criteria. With increasing research and a deepening understanding of the disease, the classification criteria are constantly being adjusted and revised. The sensitivity and specificity of the diagnosis have gradually improved, which has the value of diagnostic criteria largely. Since 1965, more than ten diagnostic criterias for Sj?gren′s syndrome have been published. After debate and experience, international criteria with wide applicability have gradually replaced regional criteria. In the evolution of the diagnostic criteria, the diagnostic rules and evaluation methods have become more concise and unified. Techniques with poor specificity and operative difficulty, which are not easy to popularize or apply in the clinic, have gradually been eliminated. A diagnostic system based on an objective examination and subjective symptoms has gradually formed, and lip gland biopsy and serum autoantibody sampling have demonstrated great diagnostic value. The optimization of diagnostic rules makes the diagnosis of this disease more efficient and scientific. This paper reviews the characteristics of and differences in diagnostic criteria for Sj?gren′s syndrome and analyzes the internal logic of the evolution of different diagnostic criteria in light of development in research on the disease with the hope of benefitting the diagnosis, treatment and related research of Sj?gren′s syndrome.

Epidemiological studies have shown that abnormal glucose and lipid metabolism is associated with a variety of malignant tumors, including oral squamous cell carcinoma. In this paper, the role of abnormal glucose and lipid metabolism, especially diabetes mellitus and obesity, in the occurrence and development of oral squamous cell carcinoma and its pathogenesis are reviewed based on the research results of our group and the literature. Hyperglycemia and insulinemia in diabetes mellitus are the main mechanisms that increase the risk of cancer. Our research shows that hyperglycemia can promote the proliferation, invasion and metastasis of tongue squamous cell carcinoma through the glycolytic enzyme M2 pyruvate kinase (PKM2) and hexokinase 2 (HK2). Hyperinsulinemia can promote the proliferation, invasion and metastasis of tongue squamous cell carcinoma by activating the insulin-like growth factor signal transduction system. Obese patients are often accompanied by increased serum adipokine Chemerin (Chem). Our study shows that serum Chem concentrations in obese patients with tongue cancer are significantly higher compared with nonobese patients. Chem can regulate the proliferation, invasion and migration of tongue squamous cell carcinoma cells through the SOD2-H₂O₂ signaling pathway. These results provide a basis for the prevention of oral squamous cell carcinoma, provide a new iqdea for the precise treatment of oral squamous cell carcinoma, and suggest that the treatment of oral squamous cell carcinoma should also actively treat patients with diabetes and obesity.

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.

Dento-maxillofacial deformity refers to an abnormal relationship of the volume or shape of the upper and lower jaw bones with the other bones of the craniofacial area. Its correction mainly involves hard tissues, such as the jaws and teeth. In recent years, digital techniques based on virtual surgery, real-time navigation, and 3D printing have developed rapidly in the area of craniomaxillofacial surgery. Digital technology has advantages for preoperative diagnosis, surgical plan formulation, surgical simulation, intraoperative navigation, effect prediction, doctor-patient communication, and young physician training. The Department of Orthognathic and TMJ Surgery of West China Hospital of Stomatology, Sichuan University, has conducted digitized diagnosis and treatment of dento-facial deformities since 2008 and has established a digital center for the treatment of dentofacial deformities based on equipment such as spiral CT, dental arch laser scanners, facial 3D cameras, virtual surgery software, 3D printers, and sleep-breathing monitoring. The result is a diagnostic and treatment protocol for dentofacial deformity specific to the characteristics of the population of West China. This article combines the latest domestic and foreign literature and comprehensively introduces the application of digital technology for the diagnosis and treatment of dental and maxillofacial deformities.

Decompression is an effective and widely used treatment for jawbone cystic lesions that can, to a great extent, preserve the function and appearance of the jawbone. However, some problems exist with its clinical application, such as the inappropriate determination of indication and the lack of standardized operational guidelines, resulting in treatment ineffectiveness or even failure. This paper aimed to summarize the clinical value of decompression for jawbone cystic lesions in terms of mechanism, scientific evidence, advancement, indications and effective evaluation by reviewing relevant literature and our clinical experience.

The success of orthognathic surgery depends not only on surgical techniques but also on accurate and scientific surgical design and planning. The adoption of digital surgery has created a paradigm shift in surgical planning. However, compared with traditional methods, digital surgery-assisted planning of an orthognathic operation differs fundamentally from planning using traditional methods, including the elimination of plaster dental model surgery and of the increase in splint design accuracy. This article focuses on the application of digital virtual tools for pre-operative design of orthognathic surgery to provide a virtual surgical procedure reference for surgeons who need to incorporate digital surgery into orthognathic surgery.

A biomarker is defined as a biological molecule found in the blood, other body fluids, or tissues that is a sign of normal or abnormal processes or a condition or disease. In cancer research, biomarkers are classified as diagnostic, prognostic, or predictive. The identification and application of biomarkers in clinical practice are important for evaluating their usefulness for clinical diagnosis, treatment and prognostic warning and for determining the biological effects of anti-cancer drugs, and they are currently one of the hottest topics in oncological translational research. Currently, translational research on biomarkers mostly focus on oncological diagnosis and molecular typing, targeted therapy, treatment protocol selection and optimization, prognostic prediction, etc. Here, we review the progress of translational research on treatments based on biomarkers in oral squamous cell carcinoma as well as the clinical application of inhibitors targeting EGFR, PD1, PI3K, WEE1, the Wnt/β-catenin pathway, the SHH pathway, and the ERK pathway. The prospect of research strategies for personalized treatments based on biomarkers in oral squamous cell carcinoma is also discussed.

First-aid medicine is indispensable in emergency treatments, and the rational use of first-aid medicine is directly related to efficacy. Oral treatment seems to be simple, but there are still many potential risks with different levels. Therefore, the rational use of first-aid medicine is related to the patient’s life. First-aid drugs that are commonly used in oral practice include anti-shock vasoactive drugs, anti-heart failure drugs, anti-arrhythmia drugs, anti-angina drugs, glucocorticoids, anti-allergy drugs, electrolytes and acid-base balance regulators. This article summarizes the indications, usages, common adverse reactions and cautions of emergency medicine in the oral clinic. Additionally, the rational usage of first-aid medicine in the dental clinic is discussed. This work is expected to provide some suggestions for the reasonable use of emergency medicine in domestic dental clinics.

Deglutition is one of the basic physiological functions of humans. The surgical treatment of oral cancer can cause impairment in swallowing functions and even dysphagia in serious cases. Currently, there are many types of methods for assessing dysphagia, including bedside evaluation, scale evaluation, radiographic assessment, and stress or electromyographic evaluation during swallowing. However, each of these methods has advantages and disadvantages, and there is no uniform standard. This article briefly introduces the current status of methods for assessing dysphagia related to oral cancer.

Tongue squamous cell carcinoma (TSCC) is the most common oral cancer, with early lymph node metastasis and poor prognosis. Surgery is the primary treatment based on sequential therapy for TSCC. The treatment of TSCC has evolved gradually in the past few years and has exhibited a trend of standardization and personalization. Several aspects of TSCC treatment are discussed in this article, such as surgery, radiotherapy, chemotherapy, biotherapy, functional rehabilitation, psychological rehabilitative treatment, prognosis and follow-up systems. This article comments on the types of treatments and research progress for TSCC in China and abroad with the aim of providing a better understanding and references for clinical treatment.

Saliva is rich in DNA, RNA, proteins, microorganisms and metabolites, containing large amounts of bio?information, similar to blood, and reflecting the physiological or pathological state of the whole body. Additionally, with its advantages of non?invasive collection methods, safe transport and low transportation cost, saliva has attracted extensive attention of scholars recently as a potential substitute for blood. With the rapid development of high?throughput techniques such as microarray technology, whole genome sequencing and whole transcriptome sequencing, a variety of disease-specific salivary biomarkers have been discovered. Salivary transcriptomics, a bridge connecting genomics and proteomics, provides a comprehensive understanding of gene transcription, RNA composition and interactions. This methodology not only allows the investigation of salivary components with temporal and spatial specificity but also reveals regulatory networks during disease development, with high potential for the early screening and assessment of diseases. Here, we outline the development of salivary transcriptomics, highlight its current research status in oral cancer from two aspects of technological and clinical applications, and further address prospects and challenges of the near future.

Severe tissue defects in the oral and maxillofacial region are commonly caused by tumor resection and trauma and can impair physiological function and aesthetics in patients. Applying a soft-tissue free flap transfer may avoid exposing important blood vessels and nerves and restore basic anatomical structures and facial features. However, the outcomes of soft-tissue free flap transfer have tended to be unsatisfactory because of the exquisite anatomical structure and complicated functions of the oral and maxillofacial region. Therefore, it is clinically important to choose a proper reconstructive method based on specific tissue defects and to optimize the processes involved in the designing and harvesting of soft-tissue free flaps. In this review, we summarize the application of soft-tissue free flaps in oral and maxillofacial defects and strategies for optimizing the quality of tissue reconstruction.

Temporomandibular joint is the pivot joint system in oral and maxillofacial chewing system, bearing the intricate function such as speaking and chewing movement. During the process of derangement or functional impairment of temporomandibular joint, there are some changes in radiograph or the synovial fluid physical and chemical properties. Besides, the variation of intra-articular pressure also reflects the pathological mechanism and course of temporomandibular joint disorders. This article will review our related researches on intra-articular pressure of temporomandibular joint in the last 30 years, including the fluctuating rule, its significance of intra-articular pressure in TMJ and the effect of that on the joint physiopathology and biomechanics, to provide new ideas for clinical diagnosis and treatment of temporomandibular disorders.

Oral and maxillofacial area constitute an important part of the human appearances, the means of treatment, the size of surgical incision become the concern of patients. With the continuous improvement of minimally invasive surgical instruments and imaging technology, minimal invasive surgery has been rapidly developed in various surgical fields that including oral and maxillofacial surgery. The purpose of minimally invasive surgery is to seek the smallest surgical incision path and the minimal tissue damage to complete the diagnosis and treatment for the patients. In recent years, with broader development and application of minimal invasive surgical techniques in the field of oral and maxillofacial surgery, such as dento-alveolar surgery, maxillofacial tumor, maxillofacial trauma, the operative approach and surgical procedures of these diseases have been changed greatly. This article intends to synthesize the literatures and the author's clinical experiences, describing the application and development of minimally invasive surgery in oral and maxillofacial surgery.

Derived from the neural crest, dental stem cells (DSCs) are a population of cells with the characteristics of mesenchymal stem-ness, which under certain appropriate conditions can differentiate into multiple cells such as osteocytes, chondrocytes, hepatocyte and neuronal-like cells. DSCs are consist of odontogenic stem cells mainly include dental pulp stem cells, periodontal ligament stem cells, stem cells from deciduous teeth, stem cells from apical papilla, as well as dental follicle progenitor cells. DSCs have been widely used in the field of regenerative medicine research and preclinical research, including nervous system diseases, oral diseases, immune diseases, heart and lung diseases, etc. This review will focus on the storage of DSCs and current translational and clinical studies regarding DSCs in tissue regeneration.

The 4th edition of WHO Classification of Head and Neck Tumours has been published in Jan. 2017. In Chapter 8 ‘Odontogenic and maxillofacial bone tumours’, the classification of odontogenic tumors was recomposed from the previous edition in 2005. In this paper, we introduced the modification of odontogenic tumors classification between 2017 and 2005 in a comprehensive discussion.

The mandible is the most important bony support in the lower 1/3 skeleton of the face which is critical for both esthetics and function. Mandibular defects, resulting from tumor resection, can cause severe functional and cosmetic deformities. Nowadays, vascularized bony tissue transfer such as free fibula flap has been widely used for mandibular reconstruction. However, traditional mandibular reconstruction based on clinical experience may hawe some problems in accuracy and efficiency because of lacking individualized design. In recent years, digital surgical techniques such as computer-aided design, rapid prototyping and surgical navigation have been used for mandibular reconstruction surgery. Accurate design for tumor resection as well as individualized design for mandibular reconstruction can be performed with computer preoperatively which help to turn the virtual plan into reality by using surgical guide or navigation. Many studies suggested that digital surgical techniques could significantly improve the clinical outcome of mandibular reconstruction. In this article, we summarized the application of digital surgical techniques for mandibular reconstruction based on our own experience and literatures review.