Pemphigus vulgaris (PV) is a group of autoimmune bullous diseases characterized by life-threatening intradermal blisters. Hashimoto thyroiditis (HT) is a kind of autoimmune disease with abnormal increase of thyroid peroxidase autoantibody (TPOAb), which is the thyroid specific antibody, leading to hypothyroidism. In recent years, the probability of HT in patients with PV is increasing, and the co-disease may be related to the effect of TPOAb autoantibody on oral keratinocytes. This article reviews the epidemiological relationship between PV and HT and the mechanism of TPOAb in their co-disease, in order to provide ideas for the diagnosis and treatment of both.

Periodontitis constitutes the primary cause of tooth loss among adults in China. The disease is characterized by the high morbidity, which significantly impairs both oral and systemic health. As the key insights of initial periodontal therapy, subgingival scaling and root planing (SRP) have been considered as simple, effective, and cost-efficient treatment approaches for managing periodontal inflammation. Substantial published evidences indicated that the majority of patients diagnosed with periodontitis could achieve lifelong retention of their natural teeth through standardized initial periodontal therapy, rigorous plaque control, and long-term supportive periodontal treatment. However, the proficiency in periodontal diagnosis and treatment among general dental practitioners in China is heterogeneous, with a notable scarcity of periodontists and a suboptimal level of SRP standardization. Drawing upon over four decades of clinical expertise from Peking University School and Hospital of Stomatology as well as comprehensive literature reviews, this paper meticulously outlines the standardized procedures for SRP, aiming at guiding clinicians to perform standardized SRP step by step, and thereby enhancing clinical efficacy of periodontal treatment, promoting periodontal health, and ultimately improving patients′ quality of life.

Insufficient keratinized mucosa is a common clinical problem. Although there is no consistent data on the long-term success of implant restorations relative to the presence or absence of peri-implant keratinized mucosa, it is widely accepted that the presence of keratinized mucosa width<2 mm is associated with increased biofilm accumulation, soft-tissue inflammation, and mucosal recession. Free gingival graft (FGG) is the standard surgical intervention for augmenting the width of keratinized gingiva. However, the clinical application of FGG is technique-sensitive. Therefore, this article describes the significance and efficacy, surgical timing, conventional procedures and techniques, common complications, as well as some modified approaches of the FGG, aiming to provide guidelines for its clinical application.

To better reflect the current status and key research trends in oral medicine research of China and to enhance the overall research abilities in this field, this special issue on oral medicine research integrates the work of several young academic leaders from oral medicine research centers nationwide. Their work focuses on key areas such as artificial intelligence-assisted diagnosis, the pathogenic mechanisms of intracellular bacteria, the relations between oral mucosal diseases and systemic diseases, as well as the study and reporting of rare and unique cases, aligning with the forefront of biomedical research. Although it does not encompass all the high-level researches conducted in China, it presents a rich and diverse array of academic achievements. Those achievements of researches reflect that it is important to further advance interdisciplinary and cross-disciplinary research collaborations, particularly by strengthening cooperation with engineering and technological disciplines in the future. We also need to set sights on driving researches in novel pathogenesis mechanisms of oral mucosal diseases, exploring innovative diagnostic technologies, enhancing diagnostic accuracy and treatment efficacy, and developing new effective intervention strategies. Additionally, greater emphases will be placed on ensuring the accuracy, comprehensiveness, readability, and scientific rigor of case studies and reports to promote sustained progress in this field.

Objective:Comprehensive characterization of B-cell phenotypes and spatial distribution in oral lichen planus (OLP) and related oral lichenoid lesions (OLL)(OLP/OLL), with an emphasis on transcriptomic profiling and functional analysis, to uncover the epigenetic mechanisms underlying B cell-mediated immune regulation within the oral mucosal microenvironment.Methods:Single-cell RNA sequencing raw data were sourced from the GSE211630 database, encompassing samples from 2 cases of erosive OLP (EOLP), 3 cases of non-erosive OLP (NEOLP) and 1 healthy control (NORMAL). Following stringent quality control, the data underwent normalization, selection of highly variable genes and batch effect correction. Subsequent analyses included dimensionality reduction and unsupervised clustering to identify distinct cell populations. This study collected pathological specimens from 3 OLP/OLL patients and 3 healthy controls who were treated at the Department of Oral Medicine, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine from January 2021 to December 2023. Using 10X Genomics Visium HD spatial transcriptomics technology, tissue sections were processed through dewaxing, staining and histological imaging, enabling the reconstruction of nucleic acid structures and the capture of gene expression profiles. Data analysis included quality assessment, gene quantification, normalization, dimensionality reduction and clustering. Furthermore, cell type deconvolution was performed using the robust cell type decomposition algorithm, integrating single-cell transcriptomic data to accurately predict and spatially resolve cell type distributions within the tissue microenvironment.Results:After integrating single-cell data from EOLP, NEOLP and NORMAL, cells were classified into seven major categories: B/plasma cells, endothelial cells, epithelial cells, fibroblasts, myeloid cells, smooth muscle cells and T/natural killer cells. The proportion of B/plasma cells varied significantly among the three groups, accounting for 10.7% (1 693/15 815), 3.8% (833/21 653) and 0.4% (47/11 556) of the total cells respectively. Further clustering analysis of B/plasma cells identified four distinct subpopulations: naive B cells, activated B cells, memory B cells and plasma cells. In the EOLP group, these subpopulations constituted 25.9% (348/1 344), 45.9% (617/1 344), 3.3% (45/1 344) and 24.9% (334/1 344) of the B/plasma cells respectively. In the NEOLP group, they represented 31.6% (195/617), 59.6% (368/617), 0.2% (1/617) and 8.6% (53/617). Howerer, only plasma cells were detected in the NORMAL group. Spatial analysis revealed that B cells were actively involved in the formation of tertiary lymphoid structures (TLS) at various stages in OLP/OLL samples, with a prominent structural organization observed in secondary follicle-like TLS. Within these structures, the expressions of T cells marker gene CD3E and B cells marker gene MS4A1 were significantly elevated. Additionally, in secondary follicle-like TLS, the gene encoding follicular dendritic cell secreted protein, germinal center marker gene B cell lymphoma 6 and the gene for activation induced cytidine deaminase also showed strong expression. In OLP/OLL samples, plasma cell marker gene CD38, immunoglobulin (IGH) G3, IGHG1, IGHM, IGHD, IGHE, imunoglobulin Kappa constant, immunoglobulin alpha 1, immunoglobulin Lambda constant 1 and complement gene C3 all exhibited high levels of expression.Conclusions:Compared to normal mucosa, extensive B-cell infiltration is observed in both OLP and OLL, accompanied by significant differences in B-cell phenotypes and proportions. B cells appear to play a central role in local immune responses, primarily through the formation of TLS. However, the precise functional mechanisms underlying their involvement require further investigation.

Objective:To explore the differences in bacterial communities within tissues during the process of oral mucosal carcinogenesis, and analyze the relationship between the high-abundance species Prevotella intermedia (Pi) and the occurrence and development of oral mucosal carcinogenesis. Methods:Fresh tissue samples were collected from patients diagnosed with oral leukoplakia (OLK), oral squamous cell carcinoma (OSCC), and healthy controls (HC) at Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University, from January 2022 to November 2024, following strict inclusion criteria. Bacterial DNA was extracted from these specimens, and the 2bRAD sequencing for microbiome (2bRAD-M) was employed to analyze and compare the α and β diversity, as well as the community composition of bacteria within tissues, aiming to identify specifically expressed bacteria. Subsequently, paraffin-embedded clinical specimens were collected: 15 cases in the OLK group (including 4 cases of simple hyperplasia, 6 cases of mild dysplasia, and 5 cases of moderate to severe dysplasia), 12 cases in the OSCC group, and 5 cases in the HC group. A 4-nitroquinoline N-oxide (4NQO)-induced OLK progression mouse model was also constructed. Mice were randomly divided into three groups using a random number table, with six in each group. The negative control group was given distilled water to drink; Group 1 was given distilled water containing 4NQO to drink until week 12, while Group 2 was given distilled water containing 4NQO to drink until week 22. After the mice were sacrificed, their tongue tissue were collected and fixed. Fluorescence in situ hybridization (FISH) with specific probes was used to validate the presence of Pi in human and mouse tissue sections, analyzing the correlation between histopathological grading and the invasion depth of Pi.Results:The 2bRAD-M microbial analysis revealed that the relative abundance of Pi in OSCC tissues (10.80%) was significantly higher than in the HC group (0.50%) ( P=0.001) and OLK group (0.70%) ( P=0.002). FISH probe detection showed that the fluorescence intensity of Pi in human OSCC tissues [123.50 (101.00, 142.30)] was higher than in the HC group [0.00 (0.00, 28.50)], simple hyperplasia OLK [0.00 (0.00, 35.25)], and mild dysplasia OLK [24.50 (0.00, 55.50)] groups, with statistically significant differences respectively ( P=0.002, P=0.003, P=0.005). However, there was no significant difference compared to moderate to severe dysplasia OLK [56.00 (28.00, 62.50)] ( P=0.210). The fluorescence area of Pi in human OSCC tissues [8 615.00 (7 439.00, 11 084.00)] was significantly larger than in the HC group [0.00 (0. 00, 45.00)], simple hyperplasia OLK group [0.00 (0.00, 81.00)], mild dysplasia [49.00 (0.00, 151.00)], and moderate to severe dysplasia groups [1 450.00 (454.00, 2 892.00)], with highly significant differences ( P<0.001). There was a significant correlation between the invasive depth of Pi and the degree of histopathological grading ( P<0.001). In mice, the fluorescence intensity of Pi in OSCC tissues [120.00 (110.00, 127.00)] was significantly higher than in the HC group [0.00 (0.00, 12.25)] ( P<0.01), but showed no significant difference compared with the OLK group [50.00 (0.00, 58.00)] ( P>0.05). The fluorescence area of Pi in mice OSCC tissues [11 020.00 (6 790.00, 12 102.00)] was significantly larger than in the HC group [0.00 (0.00, 56.75)] and the OLK group [0.00 (0.00, 751.50)] ( P=0.006, P=0.043). There is a significant correlation between the depth of invasion of Pi and the degree of histopathological grading ( P<0.01). Conclusions:This study suggests that Pi in oral mucosal tissue may be a potential biomarker for early detection of OSCC and play an important role in the carcinogenesis process of oral mucosa.

Bone marrow edema (BME) of the temporomandibular joint is an abnormal change within the bone marrow that appears as low signal intensity on T1-weighted images and high signal intensity on T2-weighted images in MRI. It is commonly seen in patients with temporomandibular joint osteoarthritis. Studies have shown that BME is closely related to joint pain, disc displacement and bony degeneration, but its specific mechanism is not yet fully understood, potentially involving abnormal mechanical loading, inflammatory responses and imbalances in bone metabolism. Although BME is considered an early sign of osteoarthritis, BME persists in approximately 71.4% of patients after pain resolution , suggesting the complexity of its association with clinical symptoms. In recent years, advanced MRI techniques (such as T2 mapping and fat suppression sequences) have improved the detection rate of BME and facilitated the assessment of its dynamic changes. However, the exact role of BME in temporomandibular disorders remains controversial. This article reviews the etiology and mechanism, pathology, imaging characteristics, and correlation with clinical symptoms of BME in the temporomandibular joint, and proposing future research directions to to elucidate its significance in disease progression and to provide guidance for clinical diagnosis and treatment.

Temporomandibular disorders (TMD), a common condition in oral and maxillofacial surgery, significantly impairs patients' quality of life. Early prediction and appropriate treatment of TMD are therefore critically important. Research on TMD prediction models has evolved from traditional statistical methods to machine learning and subsequently to deep learning, each offering unique advantages and limitations. Traditional statistical methods can effectively identify independent risk factors influencing treatment outcomes but generally rely on substantial prior knowledge and assumptions. Machine learning techniques can process large-scale, high-dimensional data and autonomously learning patterns and regularities within datasets. However, they exhibit strong dependence on data quality and limited model generalization capabilities. Deep learning approaches excel at automatically extracting temporal patterns and trends from time-series data while effectively capturing complex nonlinear relationships, yet they require extensive training datasets and suffer from interpretability challenges due to their inherent black-box testing. This review comprehensively evaluates the implementation and performance of these computational approaches in TMD prediction, critically analyzes their respective strengths and constraints, and discusses promising future research directions.

Tooth development is a complex process of the orderly interaction between epithelium originating from the ectoderm and mesenchyme derived from cranial neural crest cells, which not only depends on cell genes regulatory network but also involves crosstalk between cells and their surrounding environment. Even within the same type of cellular populations, obvious heterogeneity may be observed. Single-cell RNA sequencing is a novel technology aimed at sequencing the transcriptome of individual cell. As a critical bridge linking genetic information from the genome to the functional proteome, transcriptome analysis at the single-cell level enables a deeper understanding of cellular heterogeneity and organ developmental trajectories. This approach provides a powerful tool for elucidating complex biological processes and identifying potential therapeutic targets. Here, we summarize the latest advances in employing single-cell RNA sequencing analysis to the process of tooth development, which will help provide insights into a better understanding of prosthodontics and regeneration.

Objective:To investigate whether there is mitochondrial transfer in dental mesenchymal stem cells (MSCs) and its significance for the odontogenic differentiation.Methods:Flow cytometry and immunohistochemical staining were used to isolate dental mesenchymal stem cells. Immunofluorescence staining and live cell imaging were applied to determine whether there is mitochondrial transfer in dental MSCs. Transcriptome sequencing data re-analysis of human dental pulp stem cells (DPSCs) and bone marrow mesenchymal stem cells (BMSCs) from gene expression omnibus (GEO) data base demonstrated the importance of mitochondrial transfer in dental MSCs. Cells were managed with mitochondrial transfer inhibitor ML141 with dimethyl sulfoxide as the control. Immunofluorescence staining, senescence-associated β-galactosidase (SA-β-gal) staining, reactive oxygen species (ROS) assay, 5-ethynyl-2'-deoxyuridine(EdU) labelling, cell counting kit-8 (CCK-8) assay, Western blotting, live cell imaging and transmission electron microscope were used to investigate cell morphology, ROS level, cellular senescence, cell proliferation, MSCs marker paired related homeobox 1 (Prrx1) and Sp7 transcription factor (Sp7) expression, mitochondrial transfer and mitochondrial morphology, respectively. Further, after using ML141 during the induction of odontogenic differentiation, alkaline phosphatase (ALP) chromogenic kit was used to detect ALP activity and real-time fluorescence quantitative PCR (RT-qPCR) was used to detect the expression of odontogenic differentiation-related genes Alp, Sp7, dentin matrix protein 1 (Dmp1), and dentin salivary phosphoprotein (Dspp), which were applied to investigate the effect of mitochondrial transfer on odontogenic differentiation.Results:An ultrafine tunneling nanotubes (TNTs) structure labelled with F-actin existed between dental MSCs, and the presence of transferring mitochondria in this structure was also confirmed. Transcriptome sequencing data suggested that the gene expression profiles were significantly different between DPSCs and BMSCs. Genes related to mitochondrial transfer and mitochondrial dynamic were significantly increased in DPSCs compared to BMSCs. Compared with the control group, treatment with 1, 5, 10 μmol/L ML141, the mitochondrial transfer inhibitor, had little significant effects on the cell morphology, cytoskeleton and ROS level. SA-β-gal activity and the proportion of SA-β-gal positive cells in the ML141-treated groups [(3.93±0.21)%, (3.23±0.42)%, (4.06±0.84)%] had no significant differences with the control group [(3.83±0.28)%] (all P>0.05). In the cell proliferation assay, the proportion of EdU positive cells in the ML141-treated groups [(20.00±3.82)%, (19.48±1.96)%, (12.55±2.86)%] had no significant differences (all P>0.05) with the control group [(18.57±0.87)%], whereas the CCK-8 assay showed similar results in ML141-treated group of 1, 5 μmol/L (all P>0.05). Western blotting results showed that the protein expression levels of PRRX1 and SP7 in the ML141-treated group had no significant differences with the control group. Live cell imaging showed that compared with the control group [(31.42±4.01)%], the proportion of TNTs and mitochondrial transfer in the ML141-treated groups [(13.45±1.46)%, (10.36±3.47)%, (9.32±1.11)%] were significantly decreased in dental MSCs (all P<0.001). Scanning electron microscope showed that the mitochondrial morphology of dental MSCs in the ML141-treated group was similar to the control group, with globular and short-rod shape. After 7 days of odontogenic differentiation, the ALP staining intensity of the ML141-treated group was significantly lower than the control group. After 21 days of induction, RT-qPCR results showed that compared with control group, the relative mRNA expressions of Alp, Sp7, Dmp1 and Dspp were significantly decreased in the ML141-treated group (all P<0.05), indicating that the suppression of mitochondrial transfer in dental MSCs inhibited the odontogenic differentiation. Conclusions:Mitochondrial transfer exists between dental MSCs, and inhibition of mitochondrial transfer impairs the odontogenic differentiation.