Objective To construct a molecular classification system for head and neck squamous cell carcinoma (HNSCC) utilizing hypoxia-related gene (HAG) expression profiles, and to comprehensively examine the clinicopathological significance and biological functions of the hypoxia gene stanniocalcin 2 (STC2) in HNSCC. Methods Transcriptomic data and clinical information of 546 HNSCC samples were obtained from The Cancer Genome Atlas (TCGA) database, and based on the expression profiles of 200 HRGs, HNSCC was classified subclasses using non-negative matrix factorization (NMF). HNSCC was classified into three subclasses (C1, C2, and C3), and the molecular characteristics and prognostic differences of the subclasses were assessed by comparing the tumor mutation load, functional enrichment analysis, drug sensitivity, and clinical features among the subclasses. LASSO-Cox regression was used to screen prognosis-related genes and construct prognostic models. Using oral squamous cell carcinoma (OSCC)-related data in the TCGA database, we analyzed the expression differences of STC2 in OSCC and control samples, and detected the mRNA and protein expression of STC2 in oral squamous carcinoma samples using qRT-PCR and immunohistochemistry. We knocked down STC2 in CAL-27 cells and verified the knockdown efficiency by qRT-PCR and Western blot. CCK-8 assay and cell scratch assay were used to assess the effect of STC2 on cell proliferation and migration ability. Results Based on HRGs expression profiles, HNSCC was categorized into three subclasses (C1, C2, and C3). Subclass C1 had moderate hypoxic activity and good prognosis; subclass C2 had the highest hypoxic activity, poor prognosis, and poor sensitivity to CTLA-4 inhibitors (P<0.05); subclass C3 had the lowest hypoxic activity and moderate prognosis, and STC2 belonged to subclass C3. The frequency of cyclin-dependent kinase inhibitor 2A (CDKN2A), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), and tumor protein p53 (TP 53) mutations was higher in HNSCC. C1 genomic gain and deletion burden were significantly higher than C3 subclass (P<0.05) and C2 genomic gain than C3 subclass (P<0.05). The C2 subclass was significantly enriched in hypoxia-associated pathways, such as glycine metabolism and base excision repair (P<0.05). The C1, C2, and C3 subclasses were significantly positively correlated in terms of sex (male) (Cramer’s V=0.15), radiation exposure (Cramer’s V=0.12), medication (Cramer’s V=0.18), and pathological grading (G1/G2) (Cramer’s V=0.25) (P<0.05). Nine prognosis-related genes were screened by LASSO-Cox regression, among which high expression of STC2 was positively correlated with poorer overall survival (OS) in HNSCC patients (P<0.01). Bioinformatics analysis showed that STC2 mRNA expression was higher in OSCC than in normal controls (P<0.05). qRT-PCR and immunohistochemistry confirmed that both mRNA and protein expression of STC2 were significantly upregulated in OSCC tissues and cells (P<0.01). In vitro experiments showed that STC2 expression was knocked down to approximately 80% in CAL-27 cells (P<0.001), and the STC2 knockdown group had a reduced value-added rate (P<0.001) and a reduced percentage of scratch closure (P<0.05) compared with the control group. Conclusion We successfully constructed a molecular typing system for HNSCC based on the expression profiles of HRGs and categorized HNSCC into three subclasses with significant prognostic differences, among which the C2 subclass had the highest hypoxic activity and the poorest prognosis. STC2 was highly expressed in HNSCC and suggested a poor prognosis, demonstrating that it may be a potential target for HNSCC treatment.

Objective To screen and analyze mutations in two families with non-syndromic tooth agenesis, providing a theoretical basis for the diagnosis and treatment of tooth agenesis. Methods This study was reviewed and approved by the Medical Ethics Committee, and informed consent was obtained from patients. Information and blood samples from two core families with non-syndromic congenital tooth agenesis were collected, along with blood samples from 100 normal controls. Pathogenic gene mutations were explored through whole exome sequencing and Sanger sequencing. The pathogenicity of the identified mutations was analyzed using prediction software Polyphen-2, CADD, and FAMMTH. The impact of the mutations on protein stability was predicted using Mupro, DUET, and I-Mutant software. Conservation analysis and protein 2D/3D structure analysis were used to predict the impact of mutations on protein function. The impact of the mutant proteins on subcellular localization was predicted using DeepLoc 2.1 software. Results We identified two novel mutations in the muscle segment homeobox 1 (MSX1) gene: c.547C>A (p.Gln183Lys) and c.854T>C(p.Val285Ala) in the two families. Polyphen-2, CADD, and FATHMM predicted these mutations to be pathogenic, and ACMG classified these mutations as likely pathogenic. Conservation analysis showed that the two mutation sites (Gln183 and Val285) are located in highly conserved regions during evolution. Protein stability predictions indicated that these mutations influence protein stability. Protein 2D structure analysis indicated that these two mutations affect the 2D structure of the protein. 3D structure analysis showed that these two mutations can cause changes in the 3D structure. Software predictions indicated that these mutations do not affect the subcellular localization of the protein. Conclusion This study is the first to report two novel mutations in the MSX1 gene (c.547C>A and c.854T>C) associated with tooth agenesis, providing a basis for clinical diagnosis and treatment of congenital tooth loss.

Objective To investigate the effect of periodontal inflammation of maxillary molars on the mucosal thickening of the maxillary sinus and to provide references for the prevention and treatment of odontogenic maxillary sinusitis. Methods This study was approved by the hospital’s Medical Ethics committee. A retrospective analysis was conducted on the cone beam CT (CBCT) images of the maxillary sinuses of 246 patients with periodontitis. Based on the inclusion and exclusion criteria, a total of 331 maxillary sinus images were finally included. The molars with the most severe periodontal inflammation were selected for statistical analysis, including 270 first molars and 61 second molars. CBCT images of these patients were collected. Periodontal indices of maxillary molars [minimum remaining alveolar bone height (minRABH), degree of alveolar bone absorption, furcation involvement, and vertical bone loss] were measured. The correlation between these periodontal indices and maxillary sinus mucosal thickening (defined as normal when the maximum thickness of the maxillary sinus mucosa ≤ 2 mm and thickening when>2 mm) was analyzed. Results Among the 331 maxillary molars and their corresponding maxillary sinuses, 264 cases showed thickening of the maxillary sinus mucosa, with an average thickness of (5.9 ± 5.1) mm, accounting for 79.8%. The thickening of the maxillary sinus mucosa was significantly correlated with periodontal indices, including minRABH, degree of alveolar bone absorption, furcation involvement, and vertical bone loss (P<0.05), as well as with tooth position (P<0.05). Further binary logistic regression analysis revealed that the possibility of maxillary sinus mucosal thickening in the minRABH<4 mm group was 5.6 times that of the group with minRABH ≥ 10 mm. The possibility of maxillary sinus mucosal thickening in the group with minRABH of 4-10 mm was 2.2 times that of the group with minRABH ≥ 10 mm. The possibility of maxillary sinus mucosal thickening caused by periodontitis in the second maxillary molar was 2.8 times that of the first maxillary molar. minRABH and tooth position of the maxillary molar had a more significant impact on the thickening of the maxillary sinus mucosa compared to other factors (P<0.05). Conclusion When the minRABH of maxillary molars is less than 4 mm or when the tooth position is the second maxillary molar, the possibility of thickening of the maxillary sinus mucosa increases. This suggests that thorough periodontal treatment is an important factor in preventing odontogenic maxillary sinusitis.

Objective To investigate the sleep quality in patients with burning mouth syndrome (BMS) and its influencing factors, providing a basis for developing sleep intervention measures to reduce the impact of BMS symptoms. Methods This study was reviewed and approved by the Medical Ethics Committee, and informed consent was obtained from patients. A total of 150 patients with BMS and 150 healthy volunteers were enrolled as subjects in this study. The Pittsburgh sleep quality index (PSQI) was used to assess the sleep quality of patients with BMS. Visual analog scale (VAS) was used to assess the degree of oral mucosal pain, generalized anxiety disorder 7-item scale (GAD-7) was used to assess the frequency of anxiety symptoms, and the patient health questionnaire depression questionnaire (PHQ-9) was used to assess the frequency of depression symptoms. Univariate analysis was performed to identify potential influencing factors affecting sleep quality in patients with BMS, and multiple linear regression analysis was employed to determine independent risk factors. Results The PSQI score for patients with BMS was 7.61 ± 4.29, which was significantly higher than that of healthy controls (P = 0.016). In the PSQI subscale analysis, patients with BMS exhibited increased sleep latency, decreased sleep duration, and lower sleep efficiency compared to healthy controls (P<0.05). Patients with BMS and comorbid sleep difficulties had significantly higher scores on GAD-7 and PHQ-9 compared to the patients with BMS without sleep difficulties (P<0.001), but there was no significant difference in pain VAS scores between the two (P = 0.068). Multiple linear regression analysis revealed that longer disease duration (>6 months), the presence of systemic concomitant symptoms (such as headache and mental stress), and higher depression scores were identified as independent risk factors affecting sleep quality in patients with BMS. Conclusion For patients with BMS, long course of illness, presence of headaches, high mental stress, and depressive symptoms may be independent factors affecting their sleep quality.

Objective To investigate the effect of a free pit and fissure sealing program for caries prevention on first permanent molars (six-year molars) in Haizhu District, Guangzhou, three years after its implementation in 2019. The study aims to provide a reference for the future development of pit and fissure sealing programs for children’s first permanent molars and the effective prevention and treatment of permanent tooth caries in children. Methods A random sampling method was used. In 2022 October, 270 sixth-grade primary-school students in Haizhu District, Guangzhou, who had participated in the free pit and fissure sealing program for their first permanent molars in 2019, were placed in the sealant group. Another 223 age-matched students from the same schools who met the criteria for the pit and fissure sealing but did not participate in the program were placed in the control group. The first permanent molars of students in both groups were examined. The retention status of the sealant and the caries status of the first permanent molars were recorded for the sealant group, and the caries status of the first permanent molars was recorded for the control group. The 2022 results were compared with the results of a prior pit and fissure sealing program implemented in Haizhu District in 2011, three years after its implementation. Results Compared with the control group, the caries rate in the sealant group decreased (15.56% vs. 21.52%, P>0.05), the caries detection rate was significantly lower (6.12% vs. 9.00%, P<0.001), and the mean number of decayed teeth was significantly reduced (0.19 vs. 0.37, P<0.001). Compared with the results of the pit and fissure sealing program in Haizhu District in 2011 (in 2014, the retention rate of the first permanent molar sealant was 65.56%, the intact rate was 42.25%, and the protection rate was 38.34%), the results of the pit and fissure sealing program in Haizhu District in 2019 [in 2022, the retention rate of the first permanent molar sealant was 86.09% (P<0.001), the intact rate was 47.00% (P<0.001), and the protection rate was 51.97%] were improved. Conclusion The quality of the pit and fissure sealing program for the first permanent molars in Haizhu District, Guangzhou in 2019 was good. It reduced the caries detection rate, and the retention rate of the sealant was maintained at a high level. However, the intact rate was less than 50%; therefore, it is necessary to vigorously promote oral-health education and examinations in all age groups, and to be attentive to the re-examination and re-sealing of fissure sealants.

Objective This study aims to explore the influencing factors, formation mechanisms, and treatment methods of labial protuberance in the anterior maxilla during orthodontic treatment, providing a reference for clinical practice. Method This study reports a case where the absence of upper anterior teeth 11 and 21, and the retraction tilting movement of teeth 12 and 22, resulted in labial protuberance and gingival hyperplasia. Alveolar osteoplasty and gingivoplasty were performed. The specific changes in the alveolar bone during the retraction of the anterior teeth and the characteristics of its remodeling were analyzed. Combined with relevant literature, the factors influencing the formation of labial protuberance in orthodontic patients, mechanisms, and methods for prevention and treatment were summarized. Results After periodental surgery follow-up for 6 months, the gingival color and shape of teeth 12 and 22 were good, the labial alveolar bone was normal, and the overall condition was stable. A review of the literature showed that labial protuberance is more common in adult orthodontic patients, and the distance (>4 mm) and speed of retraction of anterior teeth are related to its formation, with the main mechanism likely being differential remodeling of the alveolar bone. In adult patients, the number of active osteoblasts and osteoclasts in the alveolar bone decreases, along with a reduction in metabolic activity and overall cellular activity, which diminishes the reactivity of the alveolar bone. After treatment of anterior teeth retraction, there is insufficient labial bone resorption. Moreover, the lack of mechanical stress-mediated periodontal ligament in the interdental space leads to reduced bone remodeling stimulation in this area, resulting in thickening of the labial alveolar bone of the upper anterior teeth. The remodeling rates of cortical and trabecular bone differ, with active trabecular bone proliferation near the tooth root surface and slow cortical bone resorption near the outer surface, which ultimately results in increased bone thickness at the labial cervical region. Specific case analysis indicates that the retraction distance of the upper anterior teeth in this case was about 6 mm. The alveolar bone at the missing sites of teeth 11 and 21, lacking periodontal ligament stimulation, showed less remodeling and absorption, likely appearing as hyperplasia. The prevention of labial bone protrusion mainly involves controlling the speed and distance of retraction of anterior teeth. Smaller labial protuberances generally do not require treatment, but those affecting function and aesthetics can be addressed with periodontal alveolar osteoplasty. Conclusion After the retraction of anterior teeth in orthodontics, a prominent, hard bone protuberance on the labial side can sometimes occur, which may be due to differential remodeling efficiency in different regions of the alveolar bone. For bone protuberance that influences aesthetics or function, periodontal alveolar osteoplasty can be a reliable option.

The human oral microbiota includes over 700 microorganisms such as fungi, bacteria, archaebacteria, and viruses. The interaction between fungi and bacteria, as well as their impact on the host immune system, is currently a popular topic in the field of oral disease research. Porphyromonas gingivalis (P.g) is the key pathogenic bacterium of chronic periodontitis, while Candida albicans (C.a) is a common opportunistic pathogen. P.g and C.a are associated with various oral diseases. A review of the literature suggests that P.g and C.a synergistically increase the amount of biofilm. They adhere to each other, promoting the formation of mixed biofilms. At the same time, C.a can utilize its dense hyphae and metabolic activities to consume oxygen, providing a low-oxygen microenvironment for P.g, thereby enhancing its vitality and virulence. C.a and P.g can also enhance their virulence through heme competition mechanisms and maintain the normal morphology of P.g by extracellular polysaccharides. In addition, P.g and C.a can synergistically invade the host and escape from the host’s immune system, ultimately leading to a state of chronic infection in the host. Based on the interactions of P.g and C.a, numerous studies on prevention and treatment strategies have been conducted, including those of various composite materials and natural plants. However, such drugs are mostly limited to phenotypes and suffer from poor selectivity, thus resulting in a lack of specific drugs and research on their mechanisms. This review aims to explore the latest advances in the bacterial-fungal interactions, highlighting the roles of P.g and C.a in oral diseases, emphasizing the importance of developing treatment strategies for co-infection of P.g and C.a, and providing new ideas for the prevention and treatment of related diseases.

T helper cells (Th cells) play an important role in periodontitis. During the progression of periodontitis, the levels of pro-inflammatory cytokines such as INF-γ and IL-17, which are produced by Th1 and Th17 cells, are elevated, while the levels of anti-inflammatory cytokines such as IL-4 and TGF-β, which are secreted by Th2 cells and regulatory T cells (Tregs), are diminished. Interventions using mesenchymal stem cells (MSCs) or their exosomes can alter the dynamics of helper T cell populations and their associated cytokine profiles, thereby mitigating the bone loss associated with periodontitis or even promoting bone regeneration. Mesenchymal stem cell-derived exosomes (MSC-exos) have been shown to directly modulate Th cell activity through the proteins and microRNAs they transport. Recent studies indicate that MSC-exos carry immune-suppressive protein molecules: PD-L1 and IDO contribute to regulating the balance between Th17 and Tregs; TGF-β inhibits the proliferation of T lymphocytes while facilitating differentiation into Tregs by sustaining forkhead box protein O3 (FOXP3) and Smad expression; and CD73 catalyzes the conversion of monophosphate adenosine into adenosine, which interacts with A2A receptors on Th1 cells to induce apoptosis in Th1 cells. In addition, microRNAs exhibit immunoregulatory functions: periodontal ligament stem cell-derived exosomes contain miRNA-155-5p, which targets sirtuin-1 to suppress Th17 cell differentiation. Furthermore, evidence in rat models of periodontitis suggests that these exosomes may also carry miR-205-5p targeting XBP1 to restore the balance between Th17 and Tregs. Dental pulp stem cell-derived exosomes reestablish this balance via the miR-1246/Nfat5 axis. Bone marrow mesenchymal stem cell-derived exosomes harbor miR-1246, which targets ACE2 to promote differentiation towards Tregs. Moreover, MSC-exos can indirectly enhance the differentiation of Tregs through interactions with other immune entities, such as antigen-presenting cells or macrophages. This article reviews the changes and roles of helper T cells in periodontitis, as well as the regulatory role of exosomes on helper T cells, hoping to provide new ideas for immunotherapy in the treatment of periodontitis.

How to effectively promote osseointegration of dental implants remains a pressing clinical challenge. Low-intensity pulsed ultrasound (LIPUS) has demonstrated remarkable efficacy in accelerating the healing of various bodily tissues, including bone tissue. In recent years, there has been extensive research on its application in promoting osseointegration in the field of dental implantology. Animal studies have shown that LIPUS exhibits significant potential in facilitating osseointegration of dental implants. In vitro experiments have further revealed that LIPUS can enhance the expression of key osteogenic factors, extracellular matrix mineralization, and induce local neurons to secrete αCGRP. Through the regulation of signaling pathways such as bone morphogenetic protein/Smad (Bmp/Smad), mitogen-activated protein kinase (MAPK), and phosphatidylinositol 3-kinase/protein kinase B (PI3k/Akt), LIPUS promotes the proliferation, migration, and osteogenic differentiation of osteogenic-related cells, thereby enhancing osseointegration of dental implants. Additionally, clinical studies have shown that bone mass increases around the implants after LIPUS treatment, with more pronounced growth observed on the buccal bone plate than on the palatal side. Furthermore, there is a lack of research that systematically summarizes the clinical evidence, in vitro and in vivo studies, and mechanisms of action regarding the role of LIPUS in promoting osseointegration of implants. Therefore, the aim of this study is to discuss the mechanisms of effect of LIPUS on osseointegration of implants, with the goal of further enhancing the outcome of implant-supported prosthodontic treatment.

Oral cancer is one of the most common malignancies in the head and neck regions. few patients benefit from current clinical therapy. Zinc finger proteins (ZNFs) are one of the largest transcription factor family proteins in the human genome. ZNFs bind to DNA, RNA, and proteins through their unique three-dimensional structure created by zinc ions to regulate gene transcription, RNA packaging, and protein folding. In recent years, the number of studies focused on the functional mechanism of ZNFs in regulating the progression of oral cancer has been increasing, with focuses on: ① ZNF677, ZNF460, ZNF154, ZNF132, ZNF281, Kaiso, and ZNF582, which regulate the invasion and metastasis of tumor cells; ② ZNF750 and PEST-containing nuclear protein (PCNP), which regulate the cell cycle; ③ ZNFs, which are involved in forming the tumor immune microenvironment, such as ZNF71 and myeloid zinc finger 1 (MZF1). For example, methylation modification modulates the reduction of ZNF677 in oral cancer and reduces the proliferation, migration, and invasion of oral cancer cells by inhibiting the protein kinase B/forkhead box O3a (AKT/FOXO3a) pathway; and ZNF460 promotes the proliferation, migration, and invasion of oral cancer cells by regulating microRNA-320a/alpha thalassemia/mental retardation, X-linked (ATRX) axis. In addition, ZNF750 inhibits the growth and metastasis of oral cancer by suppressing cell cycle transcription factor activity. Further, ZNF71 promotes the progression of oral cancer by reducing the infiltration of tumor immune cells. In this review, we will summarize the molecular mechanism, regulatory meshwork, and pro-tumor and anti-tumor roles of ZNFs in the pathogenesis of oral cancer. Our study may provide a new strategy for the diagnosis and treatment of oral cancer.