Objective: To understand the current status and related factors of oral health behavior in preschool children, so as to provide scientific basis for improving parents oral health care abilities. Methods: From March 5 to 12, 2024, using a stratified cluster sampling method, an online questionnaire survey was conducted among parents of 1 381 preschool children aged 3-6 from 6 selected kindergartens of a district in Beijing. A structural equation model (SEM) was constructed based on the Theory of Planned Behavior framework to analyze the factors associated with preschool children s oral health behaviors. Results: The rates of parental assistance in brushing teeth, regular oral examination, and postprandial rinsing were 44.4%, 18.6% and 23.6%, respectively. Attitude, subjective norms were positively correlated with oral health behavior intention ( r =0.61, 0.55); attitude, perceived behavioral control, and behavioral intention were positively correlated with oral health behavior ( r =0.14, 0.13, 0.16) (all P < 0.01 ). The results of the SEM showed that attitude and subjective norms had a significant direct effect on oral health behavior intention ( β = 0.42 , 0.40), and the direct effect of perceived behavioral control on oral health behavior was statistically significant ( β =0.42) (all P <0.01). Conclusions The overall level of oral health behavior among preschool children needs to be improved. Perceived behavioral control is the most direct positive related factor of oral health behavior. In the future, intervention measures should focus on perceived behavioral control as the entry point and provide systematic intervention guidance in combination with planned behavior theory.

Salivary gland tumor is one of the most common tumors in oral and maxillofacial regions.The diagnosis and treatment of salivary gland tumors had been a clinical characteristic project in Peking University School and Hospital of Stomatology since long time ago.Here we introduced the research pro-gress in diagnosis and treatment of salivary gland tumors during the past 10 years.Among 7 190 cases of salivary gland tumors treated in this institution,4 654 cases(64.7％)were benign,and 2 536(35.3％)were malignant,with benign:malignant ratio of 1.84∶1.Parotid was the most common loca-tion,followed by minor salivary gland and submandibular gland,while sublingular gland tumor was sel-dom seen.The proportion of minor salivary gland tumor was relatively high.Among 1 874 cases with pri-mary malignant tumors,the cases with T3 and stage Ⅲ accounted for only 9.6％and 10.3％,respec-tively,which indicated that there was shortcoming in the T classification and clinical stage formulated by Union for International Cancer Control(UICC),and further revision was required.The 5,10,and 15 year survival rates of 1 637 cases with postoperative follow-up were 93.1％,87.2％and 79.3％,respec-tively,which were much higher than those we reported 30 years ago.The improvement of treatment re-sults was related to more widely used combined treatment with surgery and postoperative radiotherapy,and the increase in patients with early stage.Adenoid cystic carcinoma was the malignant tumor with high rate of distant metastasis.The 5 and 10 year survival rates of the patients with pulmonary metastasis were 76.2％and 51.8％,respectively,which indicated that the pulmonary metastatic carcinomas developed slowly.Recurrent rate of carcinoma ex pleomorphic adenoma was 46.7％after single treatment of sur-gery,while it decreased to 27.5％after combined theraphy with surgery and radiotherapy,indicating that postoperative radiotheraphy could reduce the recurrent rate effectively.The normal myoepithelial cells had the inhibiting role in the invasion and metastasis of carcinoma ex pleomorphic adenoma.The evaluation of integrity of myoepithelial cells surrounding the tumor mass is helpful to understand the invasiveness of the tumors.The new surgical modalities such as extracapsular resection and partial sialoadenectomy were used in treatment of benign tumors of parotid gland and submandibular gland with advantages of decreased tissue damage and preservation of glandular function.Application of digital surgical techniques such as mixed reality combined with surgical navigation and real-time three-dimensional holograms in the surgical treatment of parotid gland tumors showed the benefits of more safety and precision,and less tissue da-mage.

Objective:To study the impact of fluoride exposure through drinking water on the risk of hypertension among residents in Jishan County, Shanxi Province.Methods:From March to April 2023, a cluster sampling method was used to select permanent residents aged ≥18 years and residing for ≥10 years in 12 villages in drinking water-borne endemic fluorosis areas of Jishan County, Shanxi Province as the survey subjects. A questionnaire survey, physical examination, and morning urinary fluoride level testing were conducted. The least absolute shrinkage and selection operator (Lasso) regression were used to analyze the key influencing factors of hypertension. Restricted cubic spline was used to evaluate the linear relationship between urinary fluoride and hypertension. Logistic regression was used to analyze the impact of urinary fluoride on hypertension.Results:Finally, 2 453 survey subjects were included, aged (62 ± 10) years, including 1 565 patients (63.80%) with hypertension. There were significant differences in the distribution of age, gender, education level, annual household income, body mass index (BMI), and the level and distribution of urinary fluoride between hypertension group and normal blood pressure group ( P < 0.05). The Lasso regression results showed that age, education level, BMI, and urinary fluoride were the key influencing factors of hypertension, with coefficients of 1.04, - 0.12, 0.24 and 0.01, respectively. The results of the restricted cubic spline showed that there was a linear relationship between urinary fluoride and hypertension after adjusting for age, education level, and BMI ( Poverall = 0.018, Pnonlinear = 0.482). The logistic regression results showed that after adjusting for age, education level, and BMI, urinary fluoride > 4.68 mg/L was a risk factor for hypertension ( OR = 1.42, 95% CI: 1.10 - 1.84, P = 0.007). Conclusion:High urinary fluoride is a risk factor for hypertension in drinking water-borne endemic fluorosis areas of Jishan County, Shanxi Province.

Objective:To study the impact of fluoride exposure through drinking water on the risk of hypertension among residents in Jishan County, Shanxi Province.Methods:From March to April 2023, a cluster sampling method was used to select permanent residents aged ≥18 years and residing for ≥10 years in 12 villages in drinking water-borne endemic fluorosis areas of Jishan County, Shanxi Province as the survey subjects. A questionnaire survey, physical examination, and morning urinary fluoride level testing were conducted. The least absolute shrinkage and selection operator (Lasso) regression were used to analyze the key influencing factors of hypertension. Restricted cubic spline was used to evaluate the linear relationship between urinary fluoride and hypertension. Logistic regression was used to analyze the impact of urinary fluoride on hypertension.Results:Finally, 2 453 survey subjects were included, aged (62 ± 10) years, including 1 565 patients (63.80%) with hypertension. There were significant differences in the distribution of age, gender, education level, annual household income, body mass index (BMI), and the level and distribution of urinary fluoride between hypertension group and normal blood pressure group ( P < 0.05). The Lasso regression results showed that age, education level, BMI, and urinary fluoride were the key influencing factors of hypertension, with coefficients of 1.04, - 0.12, 0.24 and 0.01, respectively. The results of the restricted cubic spline showed that there was a linear relationship between urinary fluoride and hypertension after adjusting for age, education level, and BMI ( Poverall = 0.018, Pnonlinear = 0.482). The logistic regression results showed that after adjusting for age, education level, and BMI, urinary fluoride > 4.68 mg/L was a risk factor for hypertension ( OR = 1.42, 95% CI: 1.10 - 1.84, P = 0.007). Conclusion:High urinary fluoride is a risk factor for hypertension in drinking water-borne endemic fluorosis areas of Jishan County, Shanxi Province.

Objective To investigate the correlation between different grade glioma and MRI image texture parameters and the guiding value of texture analysis for postoperative prognosis.Methods A total of 107 glioma patients were selected,and the texture parameters of MRI images were recorded.The correlation between the grade of glioma and the texture parameters of MRI images was analyzed.The risk factors affecting postoperative adverse effects of glioma patients were analyzed,and the diagnostic efficacy of each texture parameter in predicting glioma grade and postoperative good condition was evaluated.Results Comparison of MRI image tex-ture parameters between patients with low-grade glioma and patients with high-grade glioma showed no significant differences in kur-tosis,skewness,standard deviation,contrast and uniformity,but significant differences in correlation,entropy,consistency and gap distance.Correlation,entropy,consistency and gap distance were significantly correlated with glioma grade.The diagostic efficiency of entropy in predicting glioma grade was significantly higher than that of correlation,consistency and gap distance.The combination of the four predicted glioma patients with good postoperative diagnostic efficacy was the highest.Conclusion The correlation,entropy,consistency and gap distance of MRI image texture parameters can effectively diagnose the grade of glioma,and the combination of the four parameters is more beneficial to the postoperative evaluation of glioma patients.

Objective:To assess the feasibility and application of mixed reality combined with surgical navigation technology in parapharyngeal space tumor surgery, and to provide a reference for the development and promotion of this technology.Methods:In this study, retrospective data collection was conducted on 16 patients with parapharyngeal space tumors who were treated at the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from June 2020 to June 2023. The patient′s age was (39.6±17.8) years, with 4 males and 12 females. Mixed reality combined with surgical navigation technology was utilized to assist physicians in the treatment of these patients. Mixed reality combined with surgical navigation technology was used to assist physicians in treatment of these patients. The application steps included acquisition of image data, processing of image data [three-dimensional (3D) reconstruction, image fusion, and virtual surgical design], development of surgical navigation plan, connection of mixed reality and navigation system, automatic registration and intraoperative guidance and validation. In the preoperative plan, landmark points were placed on the virtual tumor and surrounding important structures reconstructed using digital software, serving to guide the localization of crucial anatomical structures. Intraoperative positioning deviation, surgical time, intraoperative blood loss, and postoperative complications were recorded and analyzed to evaluate the clinical application effectiveness of mixed reality combined with surgical navigation technology.Results:With the assistance of mixed reality combined with surgical navigation technology, 16 patients successfully underwent tumor resection. All patients were accurately diagnosed preoperatively by 3D reconstruction and image fusion technology, and a comprehensive preoperative plan was formulated; intraoperatively, mixed reality combined with surgical navigation technology was utilized for the localization of important structures. The average localization deviation of 38 landmark points during the operation were (4.43±1.96) mm, with 62% (26/42) of the points having a deviation of ≥0 and<5 mm. The average duration of the operation was (149.6±53.9) min and the blood loss was 70 (45, 150) ml. The average postoperative follow-up was 16 months, and five patients experienced postoperative complications involving facial paralysis, hoarseness, and choking.Conclusions:Mixed reality combined with surgical navigation technology can achieve the three-dimensional visualization of oral and maxillofacial anatomical structures to achieve precise preoperative diagnosis. During surgery, the technology can real-time display the relationship between soft tissue tumors and the surrounding important anatomical structures, guide surgical operation, and enhance the safety of surgery.

Objective:To analyze the influence of type 2 diabetes mellitus(DM)on the prognosis of oral squamous cell carcinoma(OSCC)patients with surgical treatment.Methods:The clinical data of 309 patients,who were diagnosed with OSCC and admitted to the same ward of Peking University Hospi-tal of Stomatology from January 2014 to December 2017 were retrospectively reviewed,of whom,104 were classified into DM group and 205 into non-DM group.The basic clinical data and follow-up results of the patients were analyzed and compared.Propensity score matching(PSM)was used to reduce con-founding bias between the DM group and the non-DM group.Kaplan-Meier was used to calculate the sur-vival rate of the two groups.Proportional hazards model was used to analyze the independent prognostic factors.The effect of glucose level on survival was analyzed.Results:After PSM,77 patients in each group were matched and the variables were balanced.There were statistically significant differences in postoperative oral dysplasia and local recurrence between the two groups(P＜0.05).There was no sig-nificant difference in survival analysis between the two groups,but the survival rate of the DM group had the tendency to be lower than that of the non-DM group after matching.Univariate analysis and multiva-riate analysis both revealed that the tumor stage was an independent factor influencing the overall survival rate and tumor-specific survival rate of the OSCC patients(P＜0.05),while diabetes had no significant influence on the survival of the OSCC patients(P＞0.05).Multivariate analysis showed that tumor stage,triglyceride level,preoperative mean capillary fasting blood glucose,postoperative mean postpran-dial blood glucose were indepen-dent prognostic factors for overall survival in the DM group.Tumor stage and mean postoperative postprandial blood glucose were independent prognostic factors for tumor-specific survival in the DM group.The risk of postoperative complications and distant metastasis in the DM group with poor glycemic control was higher than that in the good glycemic controls.Conclusion:There is no significant difference in overall survival and tumor-specific survival of the patients with or without DM.However,the possibility of mucosal dysplasia or local recurrence in the DM group is higher than that in the non-DM group.The tumor stage,triglyceride level and glycemic control of the patients with DM may affect their prognosis.

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 di-agnosis 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 per-sonalize 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 sur-gery.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 ap-plication 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 ex-perience of the author group.

Objective:To evaluate the postoperative denture restoration and denture function in pa-tients with mandibular defect reconstructed with vascularized free fibula flap.Methods:In the study,154 patients who underwent mandibular segment resection and used vascularized free fibula flap to repair mandibular defects due to inflammation,trauma and tumor from January 2015 to December 2020 were collected.These patients had common inclusion criteria which were stable occlusal relationship before operation,segmental defects of mandibular bone caused by lesions of mandible and adjacent parts(such as floor of mouth,tongue,cheek),free fibula flap used for repair and surviving after operation.Relevant data were reviewed and situation of denture restoration was followed up.A questionnaire related to den-ture functional evaluation had been proposed for those who had completed the denture rehabilitation.The evaluation index of denture restoration function was assigned by expert authority to obtain the denture function score.SPSS 18.0 software was used for statistical analysis of the basic information of the patients included in the study and the denture restoration of the patients.Results:The rate of postoperative den-ture restoration in the patients with mandibular defects repaired by free fibula flap was 17.5％,and the rate of postoperative denture restoration in the patients with benign mandibular tumors was 25.0％(18/72),which was significantly greater than that in the patients with malignant tumors 11.0％(9/82,P＜0.05).There was no significant difference in denture function score between the patients with condylar defect and those without condylar defect in denture repair rate and denture function score(P＞0.05).The functional score of implant denture was significantly greater than that of removable denture(P＜0.05).According to Brown classification,the denture function score of the patients with the defect invo-lving the anterior mandibular region was significantly greater than that of the patients without the anterior mandibular region involved(P＜0.05).The poor oral conditions,such as less amount of remaining teeth,insufficient retention strength,large mobility of soft tissue in the surgical area,poor oral vestibular groove condition became the main reason of not receiving denture restoration(37.86％).Conclusion:The denture rehabilitation of mandibular defect reconstructed with vascularized free fibula flap is closely rela-ted to pathological properties and oral conditions.The clinical outcome of implant denture has been con-firmed effectively and it is a better choice for future denture restoration after mandibular reconstruction.

Objective:To evaluate the outcome of Augmented reality technology in the recognizing of oral and maxillofacial anatomy.Methods:This study was conducted on the undergraduate students in Peking University School of Stomatology who were learning oral and maxillofacial anatomy.The image da-ta were selected according to the experiment content,and the important blood vessels and bone tissue structures,such as upper and lower jaws,neck arteries and veins were reconstructed in 3D(3-dimension-al)by digital software to generate experiment models,and the reconstructed models were encrypted and stored in the cloud.The QR(quick response)code corresponding to the 3D model was scanned by a net-worked mobile device to obtain augmented reality images to assist experimenters in teaching and subjects in recognizing.Augmented reality technology was applied in both the theoretical explanation and cadaveric dissection respectively.Subjects'feedback was collected in the form of a post-class question-naire to evaluate the effectiveness of augmented reality technology-assisted recognizing.Results:In the study,83 undergraduate students were included as subjects in this study.Augmented reality technology could be successfully applied in the recognizing of oral and maxillofacial anatomy.All the subjects could scan the QR code through a connected mobile device to get the 3D anatomy model from the cloud,and zoom in/out/rotate the model on the mobile.Augmented reality technology could provide personalized 3D model,based on learners'needs and abilities.The results of likert scale showed that augmented reality technology was highly recognized by the students(9.19 points),and got high scores in terms of forming a three-dimensional sense and stimulating the enthusiasm for learning(9.01 and 8.85 points respective-ly).Conclusion:Augmented reality technology can realize the three-dimensional visualization of impor-tant structures of oral and maxillofacial anatomy and stimulate students'enthusiasm for learning.Be-sides,it can assist students in building three-dimensional space imagination of the anatomy of oral and maxillofacial area.The application of augmented reality technology achieves favorable effect in the recog-nizing of oral and maxillofacial anatomy.