Oral squamous cell carcinoma (OSCC) is a common head and neck malignancy. Approximately 50% to 60% of patients with OSCC are diagnosed at a locally advanced stage (clinical staging III-IVa). Even with systemic and sequential treatment primarily based on surgery, the 5-year overall survival rate remains below 50%, and patients often suffer from postoperative functional impairments such as difficulties with speaking and swallowing. Programmed death receptor-1 (PD-1) inhibitors are increasingly used in the neoadjuvant treatment of locally advanced OSCC and have shown encouraging efficacy. However, clinical practice still faces key challenges, including the definition of indications, optimization of combination regimens, and standards for efficacy evaluation. Based on the latest research advances worldwide and the clinical experience of the expert group, this expert consensus systematically evaluates the application of PD-1 inhibitors in the neoadjuvant treatment of locally advanced OSCC, covering combination strategies, treatment cycles and surgical timing, efficacy assessment, use of biomarkers, management of special populations and immune related adverse events, principles for immunotherapy rechallenge, and function preservation strategies. After multiple rounds of panel discussion and through anonymous voting using the Delphi method, the following consensus statements have been formulated: 1) Neoadjuvant therapy with PD-1 inhibitors can be used preoperatively in patients with locally advanced OSCC. The preferred regimen is a PD-1 inhibitor combined with platinum based chemotherapy, administered for 2-3 cycles. 2) During the efficacy evaluation of neoadjuvant therapy, radiographic assessment should follow the dual criteria of Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 and immune RECIST (iRECIST). After surgery, systematic pathological evaluation of both the primary lesion and regional lymph nodes is required. For combination chemotherapy regimens, PD-L1 expression and combined positive score need not be used as mandatory inclusion or exclusion criteria. 3) For special populations such as the elderly (≥ 70 years), individuals with stable HIV viral load, and carriers of chronic HBV/HCV, PD-1 inhibitors may be used cautiously under the guidance of a multidisciplinary team (MDT), with close monitoring for adverse events. 4) For patients with a poor response to neoadjuvant therapy, continuation of the original treatment regimen is not recommended; the subsequent treatment plan should be adjusted promptly after MDT assessment. Organ transplant recipients and patients with active autoimmune diseases are not recommended to receive neoadjuvant PD-1 inhibitor therapy due to the high risk of immune related activation. Rechallenge is generally not advised for patients who have experienced high risk immune related adverse events such as immune mediated myocarditis, neurotoxicity, or pneumonitis. 5) For patients with a good pathological response, individualized de-escalation surgery and function preservation strategies can be explored. This consensus aims to promote the standardized, safe, and precise application of neoadjuvant PD-1 inhibitor strategies in the management of locally advanced OSCC patients.

Objective To investigate whether membrane vesicles (MVs) of Streptococcus mutans （S.mutans） contain autoinducer-2 (AI-2) and to preliminarily explore the effects of these MVs on the growth and biofilm formation of S. mutans. Methods MVs were isolated from the S. mutans UA159 strain using differential centrifugation. The isolated MVs were characterized by nanoparticle tracking analysis for particle size and concentration and observed by transmission electron microscopy. The presence of AI-2 was identified using the Vibrio harveyi BB170 bioluminescence assay: the BB170 diluent was supplemented with AB medium (control group), MV extract (MVs group), pre-ultrafiltration supernatant (Sup group), or post-ultrafiltration supernatant (Sup-af group). The effects of MVs on growth and biofilm formation were assessed using the S.mutans UA159 strain or a luxS deletion mutant as the control group, compared with experimental groups stimulated with gradient concentrations of MVs (MVs-2.0E+7, MVs-2.0E+8, and MVs-2.0E+9 groups). Growth curves, MTT assay, and colony-forming unit (CFU) counts were used to determine changes in growth capacity. Biofilm formation was evaluated using crystal violet staining, confocal laser scanning microscopy, and the anthrone method for polysaccharide quantification. Results Enriched S. mutans MVs were successfully obtained, with an average particle size of approximately 94.19 nm and a concentration of 1.87E+11 particles/mL. The bioluminescence assay showed that the luminescence intensity of the Sup group was higher than that of the Sup-af group, and the MVs group exhibited higher intensity than the control group. Assessments via growth curves, MTT assay, and CFU counts indicated no significant differences in the growth capacity of the various S. mutans strains after treatment with different concentrations of MVs. Crystal violet staining quantification and confocal laser scanning microscopy observations revealed that high-concentration MV treatment (2.0E+9 particles/mL group) resulted in lower biofilm mass compared to the control. The anthrone method showed that the production of both water-soluble and water-insoluble polysaccharides was significantly lower in the high-concentration MV group than in the control. Conclusion S. mutans MVs contain the quorum sensing signal molecule AI-2. These MVs do not significantly affect the growth of S. mutans, but they can regulate biofilm formation and exhibit an inhibitory effect at high concentrations.

Objective To assess the causal association between specific oral microbiota and the risk of oral leukoplakia (OLK) using a Mendelian randomization (MR) approach, and to elucidate the potential mediating role of immune cells. Methods Summary statistics from genome-wide association studies (GWAS) of the oral microbiome, GWAS data for immune cell phenotypes, and GWAS summary statistics for OLK from FinnGen were used. The inverse variance weighted (IVW) method was adopted as the primary approach, and it was supplemented by MR Egger regression, simple mode, weighted median, and weighted mode methods for additional analyses, to investigate the causal relationship between 3 117 types of tongue coating and salivary microbiota, as well as 731 immune cell traits, and OLK. Furthermore, a two-step MR approach was applied to explore the potential mediating role of immune cells in the association between oral microbiota and OLK. Results IVW analysis revealed causal associations between 15 oral microbial genera and OLK. Among these, Streptococcus, Neisseria, and Catonella were associated with a reduced risk of OLK, with Fusobacterium showing the most significant protective effect (OR = 0.41, P = 0.023). In contrast, genera, including Microbacterium, Campylobacter, and Haemophilus_A, were linked to an increased risk of OLK, with Lancefieldella exhibiting the strongest risk effect (OR = 2.66, P = 0.006). Eleven immune cell phenotypes with potential causal associations with OLK were identified, including four protective and seven risk-increasing factors. Mediation analysis further identified four key mediating pathways: pathogenic genera, particularly Campylobacter_A and Lancefieldella, may promote the development and progression of OLK by upregulating highly activated pro-inflammatory immune subsets such as activated monocytes, B cells, and myeloid cells. Conversely, the potentially protective genus Catonella appeared to exert inhibitory effects on OLK by significantly downregulating dendritic cell subsets. Conclusion This study is the first to reveal, at the genetic level, causal pathways through which specific oral microbial genera influence the risk of OLK by mediating immune cell responses. These findings provide novel insights into the immunopathological mechanisms underlying OLK and offer potential targets for intervention strategies aimed at modulating specific microbial genera or immune cell subsets.

Objective To evaluate the performance of 5T magnetic resonance imaging (MRI) in visualizing dental pulp and periodontal ligament (PDL) tissues in vivo in the young adult population, thereby providing a basis for the application of high-field MRI technology in clinical oral examinations. Methods The study was approved by the Ethics Committee of the hospital. A total of 15 healthy volunteers (413 permanent teeth altogether) were recruited and underwent full-mouth 5T MRI scans. Among them, six volunteers (168 permanent teeth) also received both 3T MRI and cone-beam computed tomography (CBCT) scans. Two dental specialists independently evaluated the imaging quality of the dental pulp and PDL on the images using a 5-point Likert scale and recorded the number of detectable root canals for each tooth. Inter-rater agreement was assessed using weighted kappa statistics and intraclass correlation coefficient (ICC). Non-parametric tests were employed to compare differences in imaging performance among different tissue structures, tooth positions, and imaging modalities. Results 5T MRI can achieve in vivo imaging for most dental pulp tissues and partial periodontal membrane structures. There was a high level of agreement between the two raters in their imaging scores for the dental pulp and PDL (dental pulp κ = 0.934, PDL κ = 0.737). The imaging scores for dental pulp were significantly higher than those for PDL (P < 0.001), and the scores for molar dental pulp were lower than those for premolars and anterior teeth. In the multimodal comparison involving six volunteers, the raters showed good consistency in scoring dental pulp and PDL imaging across 5T MRI, 3T MRI, and CBCT, as well as in root canal counts (5T MRI for dental pulp κ = 0.971, 3T MRI for dental pulp κ = 0.933, CBCT for dental pulp κ = 0.964; 5T MRI for PDL κ = 0.625, 3T MRI for PDL κ = 0.667, CBCT for PDL κ = 0.571; ICC for root canal counts all ≥ 0.990). The imaging scores for dental pulp and PDL using 5T MRI were significantly higher than those using 3T MRI (dental pulp: P < 0.001; PDL: P = 0.022), but there was no statistically significant difference in the detection rate of the number of root canals between the two (P > 0.05). Although the imaging scores for dental pulp and PDL as well as the detection rate of the number of root canals with 5T MRI were inferior to those with CBCT (dental pulp: P < 0.001; PDL: P = 0.02; number of root canals: P < 0.05), 5T MRI can truly achieve "direct imaging" of these two soft tissues. Conclusion 5T MRI enables effective in vivo direct imaging of dental pulp and PDL tissues in the young adult population, indicating its potential clinical application value in the diagnosis and treatment of pulp and periodontal diseases.

Objective To study the association between ankyloglossia and sagittal mandibular development impairment as well as lower anterior dental crowding, providing a reference for clinical practice. Methods This study was approved by the hospital's Medical Ethics Committee. A total of 100 patients aged 7-13 years were enrolled from January 2024 to January 2025, comprising 50 patients with ankyloglossia (case group) and 50 individuals with a healthy lingual frenulum (normal group). Clinical examination was performed to assess lingual frenulum length, Kotlow classification, and the simplified Hazelbaker assessment tool for lingual frenulum function (HATLFF) score. Cephalometric radiographs were used to measure the A-point-nasion-B-point (ANB) angle, sella-nasion-B-point (SNB) angle, and mandibular total length (condylion-gnathion [Co-Gn]). Dental cast analysis was conducted to evaluate lower anterior teeth crowding. Data were compared between the two groups. Pearson correlation analysis was used to examine the relationships between the lingual frenulum length, simplified HATLFF score, and cephalometric/dental cast parameters (ANB, SNB, Co-Gn, lower anterior crowding). The diagnostic value of ankyloglossia for mandibular development and lower anterior crowding was analyzed using receiver operating characteristic (ROC) curves. Results Ankyloglossia was significantly associated with mandibular development and lower anterior crowding (P<0.05). The case group showed significantly lower values for the lingual frenulum length, simplified HATLFF score, SNB angle, and Co-Gn, while the ANB angle and lower anterior crowding index were significantly higher compared to the normal group (P<0.05). The lingual frenulum length and simplified HATLFF score were negatively correlated with the ANB angle and lower anterior crowding index, and positively correlated with the SNB angle and Co-Gn (P<0.05). ROC curve analysis indicated that the area under the curve (AUC) for the simplified HATLFF score, and ankyloglossia in predicting mandibular development deficiency and lower anterior crowding was greater than 0.700, demonstrating good diagnostic value. Conclusion A significant correlation exists between ankyloglossia and both mandibular development deficiency and lower anterior crowding.

Objective To explore the characteristics of the diversity and composition of oral microbial flora with age, and to provide a reference for understanding the succession of oral microecology at different ages. Methods Oral rinse 16S rRNA (V4 region) sequencing data from 9 021 participants 14-69 years of age in the 2009-2012 National Health and Nutrition Examination Survey (NHANES) were analyzed. Alpha diversity (Observed OTUs, Faith’s PD, Shannon Index), beta diversity (Bray-Curtis and UniFrac), and genus-level composition were examined using weighted generalized linear models (GLMs), including quadratic terms for age and adjusting for key covariates (gender, race/ethnicity, BMI, smoking status, and periodontitis severity). Results Alpha diversity demonstrated a clear inverted U-shaped trajectory across age, peaking at 25-30 years old and declining thereafter. This trend remained consistent across sex, race, smoking, and periodontal health strata. Beta diversity analyses revealed a modest but steady age-related shift in community structure. Genus-level analyses revealed that Rothia, Prevotella_6, and Lactobacillus increased steadily with age, while Haemophilus, Porphyromonas, and Corynebacterium declined significantly. Notably, potential periodontopathogens, such as Fusobacterium and Treponema_2, peaked in early adulthood before declining with age. Conclusion Age is an important driver of oral microbial succession, and the oral microbiome exhibits dynamic changes across different life stages. Future longitudinal and multi-omic studies are warranted to elucidate the mechanisms underlying these age-related trajectories.

The homeostasis of the oral microbiome is essential for maintaining host health, and its disruption can contribute to the development of both oral and systemic diseases. The oral microbiome influences the initiation and progression of oral squamous cell carcinoma (OSCC) through multiple mechanisms. ① Oral microbes can directly act on epithelial cells, inducing cell-cycle dysregulation, DNA damage, and epigenetic reprogramming, thereby promoting cell proliferation and epithelial-mesenchymal transition (EMT). For example, Fusobacterium nucleatum binds to E-cadherin via its adhesin FadA, activating the β-catenin pathway and directly driving tumor-cell proliferation and EMT, while Porphyromonas gingivalis reprograms lipid synthesis to enhance the stemness of OSCC cells. ② Oral microbes and their metabolites reshape the tumor immune-suppressive microenvironment by altering the density, composition, and function of infiltrating immune cells. Periodontal pathogens induce a chronic inflammatory state in the oral cavity and activate signaling cascades such as MAPK/ERK and NF-κB, thereby indirectly accelerating OSCC progression. ③ Bacteria and viruses in the oral cavity exhibit synergistic interactions. Bacterial biofilms and proteases facilitate viral activation and infection, and microbial metabolites such as butyrate can enhance histone acetylation to promote the lytic reactivation of latent viruses. ④ At the ecological level, the depletion of commensals and expansion of anaerobic pathogens disrupt the metabolic network of the community, and complex interspecies interactions collectively shape a pro-carcinogenic niche that drives OSCC progression on multiple fronts. Future studies should integrate multi-omics analyses with longitudinal clinical cohorts to explore functional causal networks of key microbial communities and develop individualized targeted intervention strategies for microecology.

Periodontitis is a chronic inflammatory disease. The heterotopic colonization of periodontal pathogens results in the development of several systemic diseases. Porphyromonas gingivalis (P. gingivalis), a key pathogen for periodontitis, has been linked to the development of various cancers, such as oral squamous cell carcinoma (OSCC), lung cancer, esophageal cancer, pancreatic cancer, colorectal cancer, cervical cancer, and prostate cancer. P. gingivalis promote the progression of tumor through various mechanisms, P. gingivalis regulates proteins targeting cell cycle and apoptosis to promote proliferation of tumor cells directly, enhances tumor stemness by upregulating the expression of cluster of differentiation 44 (CD44) and cluster of differentiation 133 (CD133), activates inflammasome and p38/c-Jun N-terminal kinase 1(JNK) pathways, regulates tumor-associated neutrophil (TAN) polarization to remodel the tumor microenvironment, regulates epithelial-mesenchymal transition (EMT) to promote tumor metastasis, remodel macrophage function to evade host immune response, and regulates multi-communicating with symbiotic bacteria. In addition, P. gingivalis accelerates the progression of esophageal cancer, pancreatic cancer, colorectal cancer, and prostate cancer by promoting cell proliferation, inhibiting apoptosis, inducing chronic inflammation, and escaping immunity. However, the oral microbiome is a complex system, whether the interactions between oral bacteria affect tumor progression needs to be further investigated.

Chronic mucocutaneous candidiasis (CMC) is an infectious phenotype characterized by recurrent or persistent infections caused by Candida species that affect the skin, nails, oral, and genital mucosae for a duration exceeding six months. Current research suggests that CMC is an immunodeficiency disease with a complex pathogenesis. Patients with CMC have various defects in nonspecific and/or specific immunity against Candida infection, resulting in the inability of patients to defend themselves against Candida infection. CMC can be stratified into primary CMC and secondary CMC based on etiology. Primary CMC is often associated with genetic mutations leading to immunodeficiencies in T helper cell 17 and interleukin-17, whereas secondary CMC is frequently linked to factors such as human immunodeficiency virus infection, diabetes mellitus, and immunosuppressive therapy. Primary CMC typically manifests as Candida infections, with distinct genetic mutations often correlating to varied concomitant symptoms. Secondary CMC may present with not only superficial mucosal Candida infections and manifestations of the underlying primary disease but also with invasive fungal infections. Diagnosing CMC requires an integration of medical history and clinical presentation, supplemented by the outcomes of auxiliary diagnostic procedures, including microscopic examination of fungal smear, fungal culture, immunological testing, and genetic sequencing and analysis. Furthermore, confirming primary CMC requires exclusion of the aforementioned secondary factors. At present, antifungal drugs such as triazoles, echinocandins, and polyenes are the main treatment for CMC. Moreover, immunotherapy with biologics such as Janus kinase (JAK) inhibitors provides more options for the clinical treatment of patients with CMC. Gene therapy also has potential clinical application value. In this review, we discuss the etiologies, pathogenesis, clinical manifestations, diagnosis, and treatments of CMC, aiming to provide a reference for the clinical diagnosis and treatment of CMC.

Nifedipine-induced gingival overgrowth (NIGO) refers to gingival hyperplasia caused by long-term use of the hypertensive drug nifedipine (NIF), and it is a drug adverse reaction. NIGO is characterized by a high incidence rate and a large patient base, and it is one of the most common types of gingival hyperplasia in clinical practice. Previous studies on the etiology of NIGO mainly focused on the pharmacological effects of NIF, while in recent years, it has been proposed that inflammation may also be a major risk factor for NIGO. Plaque is the initiating factor of periodontal inflammation. However, the role and mechanism of bacteria in the pathogenesis of NIGO remain unclear at present. Therefore, this article reviews relevant research and finds that bacteria may be involved in the pathogenesis of NIGO through the following pathways: ① Hypertensive drugs represented by NIF can cause dysbiosis of the oral flora, increasing the relative abundance of periodontal pathogenic bacteria. The inflammatory chemokines released by fibroblasts in the immune response to bacteria can work in synergy with NIF to promote excessive collagen production or recruit immune cells to participate in tissue fibrosis. ② Transforming growth factor-β (TGF-β) plays a significant role in fibrotic diseases. Bacterial infections can significantly increase the level of TGF-β, promoting epithelial-mesenchymal transition or allowing TGF-β and its downstream substances to directly participate in gingival fibrosis. ③ Bacteria can also cause massive proliferation of gingival fibroblasts, increased collagen synthesis and reduced degradation by activating the Wnt/β-catenin pathway, interfering with integrin α2β1 expression, and inhibiting miR-200 to alter the cell cycle, ultimately exacerbating NIGO. In conclusion, bacteria may be an important factor in aggravating NIGO, and oral health management for patients with hypertension should be given due attention. Future research can focus on the interaction between the oral microbiota and immune cells in NIGO patients, providing new strategies for their prevention and treatment.