OBJECTIVE: To establish a three-dimensional finite element model of a digital wire loop space maintainer for the mandible and primary tooth loss, in order to investigate the stress, deformation, and shear force experienced by patients with the loss of the second primary molar when wearing the wire loop space maintainer. METHODS: Cone beam computed tomography (CBCT) scans were performed on the patients to create a digital model of the mandible with the absence of the second primary molar using Mimics 21.0 software. A digital model integrating the crown's retention and the wire loop structure of the full crown and ring wire loop space maintainer was constructed using pediatric space maintainer design software, utilizing three different materials: cobalt-chromium alloy, polyether ether ketone (PEEK), and titanium alloy. In ANSYS Work Beach 2023 R2 software, vertical loads of 70 N, tilted 45° along the long axis of the tooth loads of 70 N, and a 10 N load on the surface of the wire loop were applied to the occlusal surfaces of models 46 and 84, simulating centric and lateral occlusions during chewing with the wire loop space maintainer in place. The stress states of the wire loop space maintainer and supporting teeth were analyzed. RESULTS: Under various loading conditions, the maximum principal stress of the ring wire loop space maintainer was significantly lower than that of the full crown. Stress contour maps indicated that the peak of the maximum principal stress occurred at the junction of the wire loop and crown structure, indicating that this area was more susceptible to fracture. The ring wire loop space maintainer made from PEEK material exhibited the lowest maximum shear stress on the internal organizational surfaces, with equivalent stresses of 23.18 MPa and 36.35 MPa for models 46 and 84, respectively. Stress contour maps demonstrated that the maximum stress on tooth 46 was located at its mesial, while the maximum stress on tooth 84 was situated near the root area on its distal, in contact with the wire loop space maintainer. CONCLUSION In cases of second primary molar loss, wearing the digital ring wire loop space maintainer can effectively distribute stress, and the ring wire loop space maintainer made from PEEK material reduces the stress experienced by supporting teeth to some extent, demonstrating its superiority in clinical application.
Finite Element Analysis ; Humans ; Tooth, Deciduous ; Cone-Beam Computed Tomography ; Space Maintenance, Orthodontic/methods* ; Imaging, Three-Dimensional ; Orthodontic Wires ; Dental Stress Analysis ; Mandible ; Stress, Mechanical

Enhancing transparency is an important means of reforming public health services in modern society， and its significance in the field of healthcare is self-evident （especially in terms of resource allocation）. In the construction and practice of an ethical review system， improving transparency is an important measure to solve problems such as low efficiency， formalism， inconsistent review decisions， and the lack of a complaint mechanism， and is also the key to ensuring the ethical compliance of research and promote the development of scientific research. Therefore， the international academic community and various countries have begun to emphasize the principle of transparency in ethical review， but its specific implementation still faces challenges. By analyzing the concept and content of transparency and arguing its ethical value and specific dimensions in ethical review work， this paper demonstrated that improving the transparency of ethical review can not only prevent violations and strengthen the accountability mechanism， but also balance information asymmetry， enhance public trust， and improve review efficiency. Finally， potential measures to enhance transparency in ethical review were explored， including formulating detailed transparency strategies， establishing an online information disclosure system， constructing a “precedent” system， setting up a supervisory appeal procedure， and other measures. These measures aim to optimize the ethical review system， providing solid ethical support for scientific research while enhancing public trust and understanding of ethical review work， with a view to further improving the practice of ethical review and promoting the interests of multiple stakeholders.

Objective: To explore the comorbidity and associated factors of dental caries and overweight/obesity among primary and secondary school students in Guangxi, so as to provide a scientific basis for the development of targeted prevention strategies. Methods: A stratified cluster random sampling method was used to survey 178 700 students from the fourth grade of primary school to the third year of high school in Guangxi Zhuang Autonomous Region from September to November 2023, including physical examination, oral screening, and questionnaire survey. Chisquare tests and binary Logistic regression analysis were employed to investigate the related factors of the cooccurrence of dental caries and overweight/obesity among students. Results: The comorbidity rate of dental caries and overweight/obesity was 9.55%, with urban areas (9.95%) higher than rural counties (9.24%), boys (10.54%) higher than girls (8.54%), primary school students (11.49%) higher than senior high school students (8.92%) and junior high school students (8.05%), and nonboarding students (11.44%) higher than boarding students (7.94%), and all differences were statistically significant (χ2=26.07, 207.91, 471.54, 629.14,P<0.01). Multivariate Logistic regression analysis showed that consuming cereal for breakfast (OR=0.91, 95%CI=0.88-0.94), drinking milk in the past week (OR=0.89, 95%CI=0.83-0.95), meeting sleep standards (OR=0.95, 95%CI=0.91-0.99), and brushing teeth at least once a day (OR=0.82, 95%CI=0.73-0.93) had a lower risk of the comorbidity of dental caries and overweight/obesity. In contrast, drinking beverages in the past week (OR=1.14, 95%CI=1.09-1.20), consuming fried foods in the past week (OR=1.11, 95%CI=1.06-1.17), eating fruit ≥1 time every day (OR=1.06, 95%CI=1.02-1.11), consuming fruit ≥1 type every day (OR=1.07, 95%CI=1.01-1.12), and having fish, poultry, meat, or eggbased breakfasts (OR=1.03, 95%CI=1.05-1.13) had a higher risk of the comorbidity of dental caries and overweight/obesity (P<0.05). Conclusions Dietary habits and lifestyle behaviors are associated with the comorbidity of dental caries and overweight/obesity among primary and secondary school students in Guangxi. Guiding students to form healthy living habits is helpful to preven dental caries and overweight/obesity.

Objective To evaluate the value of modified percutaneous endoscopic gastrostomy(PEG)for patients with amyotrophic lateral sclerosis(ALS)and dysphagia.Methods From January 2018 to December 2023,47 patients with ALS were treated with modified PEG in our hospital.The surgery was performed under local anesthesia.The patients were placed in a semi-seated position,and the surgeon performed surgery with an ultra-fine endoscope through oral entrance to the stomach.Results The modified PEG were successfully completed in all the 47 cases.The operation time was5-20 min[mean,(10.3±1.7)min].The postoperative hospitalization lasted for2-8 d(mean,2.8 d).Postoperative complications occurred in6 cases(12.8%),including aspiration pneumonia in4 cases(8.5%)and incision infection in2 cases(4.3%).The body mass index was17.06±0.89 before PEG and 18.15±0.81 at 3 months after PEG,with significant difference(t=-10.373,P=0.000).Conclusion For ALS patients with dysphagia,modified PEG is feasible,which significantly improves nutritional status of patients.

Objective:A retrospective study was conducted to investigate the safety of Percutaneous Endoscopic Gastrostomy(PEG)in elderly patients with Amyotrophic Lateral Sclerosis(ALS)and to identify the factors influencing major complications.The aim is to establish a more robust foundation for optimizing both the procedure and its timing, thereby enhancing the evidence base for refining the surgical approach.Methods:We retrospectively collected clinical data from elderly ALS patients(≥60 years old)who underwent PEG at Peking University Third Hospital between January 2006 and January 2024.This dataset includes information on general health conditions, the progression of ALS, comorbidities, surgical details, and related complications.Additionally, we analyzed the postoperative complications experienced by the included patients, focusing specifically on the risk factors associated with aspiration pneumonia.Results:A total of 140 patients were included in the study, with a mean age of 68.2±5.9 years.Among these, 69 were male(49.3%)with a mean age of 68.4±6.5 years, and 71 were female(50.7%)with a mean age of 67.7±6.0 years.Successful outcomes were observed in 139 cases(99.3%).One case was not completed due to respiratory arrest caused by intraoperative aspiration.Postoperative complications occurred in 36 cases(25.7%), which included 9 cases of wound infection(6.4%), 1 case of abdominal infection(0.7%), 21 cases of aspiration pneumonia(15.0%), 1 case of local fistula leakage(0.7%), 2 cases of transient fever(1.4%), and 2 cases of death during hospitalization(1.4%).Both univariate and multivariate analyses indicated that an onset duration of ≤1 year( P=0.020)and a half-sitting position( P=0.022)significantly influenced the occurrence of aspiration pneumonia, acting as protective factors( β<0, OR<1). Conclusions:PEG is a safe method for providing enteral nutrition to elderly patients with ALS.While most complications associated with the procedure are mild and can be managed, Aspiration pneumonia remains a common and serious complication.However, early surgical intervention and the use of a semi-seated position during the procedure can help reduce the incidence of aspiration pneumonia.

Objective: To investigate the prevalence and associated factors of spinal curvature abnormalities among primary and secondary school students in the Guangxi Zhuang Autonomous Region, so as to provide a scientific basis for the prevention and control of such abnormalities. Methods: From September to November 2023, adopting a stratified cluster random sampling method, spinal curvature screenings and questionnaire surveys were conducted among 168 931 students from grade 4 of primary school to grade 12 of high school in 111 districts and counties across 14 cities in Guangxi. Chi square tests and binary Logistic regression analysis were used to analyze influencing factors of spinal curvature abnormalities. Results: In 2023, the detection rate of poor posture among students above grade 4 in Guangxi was 4.24% , and the detection rate of spinal curvature abnormalities was 2.13%. The detection rate was higher among urban students (2.84%) than rural students (1.66%), boarding students (2.61%) than non-boarding students (1.60%), and high school students (3.16%) than junior high (2.45%) and primary school students (1.15%), and the differences were statistically significant ( χ 2=269.85, 221.44, 565.10, P <0.01). A trend of increasing detection rates with higher grade levels was observed ( χ 2 trend =617.63, P <0.01). Binary Logistic regression analysis indicated that students without boarding at school ( OR =0.82, 95% CI =0.75-0.90), engaging in high-intensity physical activity for over 60 min per day ≥5 days per week ( OR =0.90, 95% CI =0.82-0.98), and adequate sleep ( OR =0.87, 95% CI =0.81-0.94) had lower risks of detecting spinal curvature abnormalities ( P <0.05). Conclusions The prevalence of spinal curvature abnormalities increases with grade level among primary and secondary school students in Guangxi. Regular moderate-to-vigorous physical activity demonstrates protective effects against spinal abnormalities.

Objective:This study aims to investigate the feasibility and safety of implanting leadless pacemakers in the low septum and its impact on cardiac electrical synchronization.Methods:A total of 36 patients who received leadless pacemaker implantation at Fuwai Central China Cardiovascular Hospital from January 2021 to August 2023 were included in this study.According to implantation sites of leadless pacemakers,patients were divided into mid-septal group(n=16)and low-septal group(n=20).The clinical characteristics and cardiac electrical synchronization were compared between the two groups.Results:There were 21 male patients,mean age was(68±13)years old.There was no statistical difference in the type of brady-arrhythmia between the two groups(P=0.73).There were 61 implant attempts in these 36 patients,and there was no significant difference in the number of attempts,procedure time,and pacemaker parameters between the two groups,but the average procedure time tended to be shorter in the low-septal group([84±37]minutes vs.[105±35]minutes,P=0.09).In terms of electrical synchronization,there was no statistical difference in QRS duration between the low-septal group and the mid-septal group([162.0±21.1]ms vs.[174.0±14.8]ms,P=0.20).There were no vascular puncture complications,cardiac perforation,or pericardial tamponade during the procedure.There were no complications and readmissions related to the leadless pacemaker during follow-up period.Conclusions:Our results show that the implantation of a leadless pacemaker in the low ventricular septum is safe and effective,has a similar impact on cardiac electrical synchronization as mid-septal pacing.

Objectives:This study aims to explore the impact of new-onset heart conduction block post transcatheter aortic valve replacement(TAVR)on the cardiac conduction status during 1-year follow-up.Methods:A total of 130 patients who completed TAVR surgery at Fuwai Central-China Cardiovascular Hospital from July 2019 to October 2022 were screened.Among them,56 cases with postoperative heart conduction block were selected for analysis.According to the degree of heart block,patients were divided into mild block group(n=36),moderate block group(n=9),and severe block group(n=11).The clinical characteristics and cardiac conduction conditions at 1-year follow-up between different groups were compared.Results:During a mean(8.5±4.1)months follow-up period,10(17.9%)patients had long-term atrioventricular conduction block,and 46(82.1%)patients had partial or complete recovery of heart block,with 28(50.0%)patients with completely recovered cardiac conduction.In the mild block group,22(61.1%)cases were completely recovered,9(25.0%)patients partly recovered,and 5(13.9%)cases uncovered.In the moderate block group,2(22.2%)cases were completely recovered,5(55.6%)patients partly recovered,and 2(22.2%)cases uncovered.Difference in long-term atrioventricular conduction block among three groups was statistically significant(P<0.001).The Kaplan-Meier curve shows that patients with moderate to severe heart block have a higher rate of long-term atrioventricular conduction block(86.1%vs.77.8%vs.72.7%,log-rank P=0.03).Cox multivariate analysis exhibited that old age(≥75 years old,HR=1.204,95%CI:1.051-1.525,P=0.041)and severe heart conduction block(HR=1.106,95%CI:1.100-1.616,P=0.031)are the two independent risk factors for long-term atrioventricular conduction block post TAVR.Conclusions:The ratio of complete cardiac conduction recovery post TAVR is 50.0%.Older age(≥75 year)and new-onset severe heart conduction block are independent risk factors for long-term atrioventricular conduction block post TAVR procedure.

Objective:This study aims to investigate the feasibility and safety of implanting leadless pacemakers in the low septum and its impact on cardiac electrical synchronization.Methods:A total of 36 patients who received leadless pacemaker implantation at Fuwai Central China Cardiovascular Hospital from January 2021 to August 2023 were included in this study.According to implantation sites of leadless pacemakers,patients were divided into mid-septal group(n=16)and low-septal group(n=20).The clinical characteristics and cardiac electrical synchronization were compared between the two groups.Results:There were 21 male patients,mean age was(68±13)years old.There was no statistical difference in the type of brady-arrhythmia between the two groups(P=0.73).There were 61 implant attempts in these 36 patients,and there was no significant difference in the number of attempts,procedure time,and pacemaker parameters between the two groups,but the average procedure time tended to be shorter in the low-septal group([84±37]minutes vs.[105±35]minutes,P=0.09).In terms of electrical synchronization,there was no statistical difference in QRS duration between the low-septal group and the mid-septal group([162.0±21.1]ms vs.[174.0±14.8]ms,P=0.20).There were no vascular puncture complications,cardiac perforation,or pericardial tamponade during the procedure.There were no complications and readmissions related to the leadless pacemaker during follow-up period.Conclusions:Our results show that the implantation of a leadless pacemaker in the low ventricular septum is safe and effective,has a similar impact on cardiac electrical synchronization as mid-septal pacing.

Objective To evaluate the value of modified percutaneous endoscopic gastrostomy(PEG)for patients with amyotrophic lateral sclerosis(ALS)and dysphagia.Methods From January 2018 to December 2023,47 patients with ALS were treated with modified PEG in our hospital.The surgery was performed under local anesthesia.The patients were placed in a semi-seated position,and the surgeon performed surgery with an ultra-fine endoscope through oral entrance to the stomach.Results The modified PEG were successfully completed in all the 47 cases.The operation time was5-20 min[mean,(10.3±1.7)min].The postoperative hospitalization lasted for2-8 d(mean,2.8 d).Postoperative complications occurred in6 cases(12.8%),including aspiration pneumonia in4 cases(8.5%)and incision infection in2 cases(4.3%).The body mass index was17.06±0.89 before PEG and 18.15±0.81 at 3 months after PEG,with significant difference(t=-10.373,P=0.000).Conclusion For ALS patients with dysphagia,modified PEG is feasible,which significantly improves nutritional status of patients.