Objective:To develop a risk prediction model for moderate to severe orthodontic-induced inflammatory root resorption (OIIRR) of maxillary incisors based on cone beam CT (CBCT) radiomics features and clinical characteristics of the orthodontic patients.Methods:Clinical and CBCT data from 101 orthodontic patients treated by the same attending orthodontist in the Department of Orthodontics, Stomatology Hospital of Tianjin Medical University from January 2019 to January 2024 were retrospectively collected. The sample included 42 class Ⅰ patients, 52 class Ⅱ patients and 7 class Ⅲ patients [age: (19.7±6.3) years], and a total of 394 maxillary incisors were analyzed. Potential influencing factors for moderate to severe OIIRR (root volume resorption rate≥10%) were collected from the patients′ CBCT and medical records, including initial age, gender, treatment duration, Angle′s classification, extraction or not, type of orthodontic appliance (fixed or clear aligner), changes in root inclination, root movement distance and direction, pre-treatment cephalometric measurements, pre-treatment root-bone relationship, pre-treatment root length, and pre-treatment radiomics features of the teeth. Univariate analysis was initially performed to screen for factors influencing moderate to severe OIIRR. Subsequently, least absolute shrinkage and selection operator (LASSO) regression, best subset regression, and random forest were used for feature selection to construct the OIIRR risk prediction model. The discrimination, calibration, and net benefit of the three risk prediction models were evaluated, and the optimal model was displayed using a nomogram.Results:LASSO regression identified clinical features including initial age (LASSO coefficient 0.052), treatment duration (LASSO coefficient 0.024), pre-treatment root length (LASSO coefficient -0.023), and vertical root movement distance (LASSO coefficient -0.029). Initial age and treatment duration were positively correlated with the severity of OIIRR, while root length and vertical root movement distance were negatively correlated. A total of 14 radiomics features were identified, including 2 original image features and 12 wavelet features. Best subset regression identified vertical root movement distance as the clinical feature and 7 radiomics features, including 1 original image feature and 6 wavelet features. The random forest model identified 8 wavelet features as important predictors, and all of which were radiomics features. Model performance evaluation showed that the random forest model had the highest discrimination, calibration, and net benefit, making it the optimal model, with radiomics features being the most important predictors.Conclusions:Based on the data from this study, radiomics features were identified as the most important predictors by the optimal model for OIIRR risk prediction. Predicting the occurrence of moderate to severe OIIRR before orthodontic treatment held potential clinical application value.

Objective:To develop a risk prediction model for moderate to severe orthodontic-induced inflammatory root resorption (OIIRR) of maxillary incisors based on cone beam CT (CBCT) radiomics features and clinical characteristics of the orthodontic patients.Methods:Clinical and CBCT data from 101 orthodontic patients treated by the same attending orthodontist in the Department of Orthodontics, Stomatology Hospital of Tianjin Medical University from January 2019 to January 2024 were retrospectively collected. The sample included 42 class Ⅰ patients, 52 class Ⅱ patients and 7 class Ⅲ patients [age: (19.7±6.3) years], and a total of 394 maxillary incisors were analyzed. Potential influencing factors for moderate to severe OIIRR (root volume resorption rate≥10%) were collected from the patients′ CBCT and medical records, including initial age, gender, treatment duration, Angle′s classification, extraction or not, type of orthodontic appliance (fixed or clear aligner), changes in root inclination, root movement distance and direction, pre-treatment cephalometric measurements, pre-treatment root-bone relationship, pre-treatment root length, and pre-treatment radiomics features of the teeth. Univariate analysis was initially performed to screen for factors influencing moderate to severe OIIRR. Subsequently, least absolute shrinkage and selection operator (LASSO) regression, best subset regression, and random forest were used for feature selection to construct the OIIRR risk prediction model. The discrimination, calibration, and net benefit of the three risk prediction models were evaluated, and the optimal model was displayed using a nomogram.Results:LASSO regression identified clinical features including initial age (LASSO coefficient 0.052), treatment duration (LASSO coefficient 0.024), pre-treatment root length (LASSO coefficient -0.023), and vertical root movement distance (LASSO coefficient -0.029). Initial age and treatment duration were positively correlated with the severity of OIIRR, while root length and vertical root movement distance were negatively correlated. A total of 14 radiomics features were identified, including 2 original image features and 12 wavelet features. Best subset regression identified vertical root movement distance as the clinical feature and 7 radiomics features, including 1 original image feature and 6 wavelet features. The random forest model identified 8 wavelet features as important predictors, and all of which were radiomics features. Model performance evaluation showed that the random forest model had the highest discrimination, calibration, and net benefit, making it the optimal model, with radiomics features being the most important predictors.Conclusions:Based on the data from this study, radiomics features were identified as the most important predictors by the optimal model for OIIRR risk prediction. Predicting the occurrence of moderate to severe OIIRR before orthodontic treatment held potential clinical application value.

BACKGROUND:The traditional fixation method for femoral neck fractures is three hollow screws inverted triangle fixation,and the optimal fixation method for femoral neck fractures that have not achieved anatomical reduction is inconclusive. OBJECTIVE:To compare the biomechanical properties of cannulated screws internal fixation for sub-capitated femoral neck fracture with different reduction qualities based on finite element analysis. METHODS:The three-dimensional digital model was reconstructed using CT data of the proximal femur from a healthy male volunteer.The femur was modeled to sub-capitated femoral neck fractures.Fracture models were divided into anatomical reduction group,coxa vara group,and coxa valgus group.All fracture model groups were transferred using the standard group,screw depression group,and screw elevation group.A vertical downward stress of 1 400 N was applied to the femoral head at the top of the acetabulum.The displacement and stress distribution of the femur and internal fixator under different fixation methods were observed,and the maximum stress and displacement of the femur and fixator were compared. RESULTS AND CONCLUSION:(1)For anatomical reduction femoral neck fracture,the peak stress of fixation in the standard group,screw depression group and screw elevation group was 41.35,31.27 and 43.32 MPa,respectively.The maximum peak stress of the femur was found on the screw elevation group(28.58 MPa),and the standard group had the maximum peak displacement.(2)During hip varus,the stresses in the three subgroups were relatively dispersed and even.The peak stress of the femur in the standard group was the smallest,but the peak displacement was the largest.The stability of fixation might be poor.The peak displacement of the femur in the screw depression group was the smallest.(3)In the hip valgus,obvious screw stress concentration appeared in the screw depression group,and the peak displacement was the largest among the three subgroups,and an in-out-in phenomenon appeared.The peak stress of the screws in the screw elevation group was the largest among the three subgroups,but the peak displacement was the smallest.(4)It is concluded that for sub-capitated femoral neck fractures that are completely anatomically reduced,it is recommended to use standard inverted triangular nails for fixation.When the hip varus and hip valgus occur within the allowable range of the reduction standard,it is recommended to use the inverted triangle screw to fix it by rotating the corresponding angle in the same direction as the hip varus or valgus.

Objective:To explore the teaching effect and novel ideas of online teaching applied in skill operation course.Methods:One hundred and fifty-one students studying in Sichuan University taking the First Aid in the Life: Basic Knowledge and Skills as an elective course in the autumn semester of 2019 and spring semester of 2020 were included as the research subjects in this study. Among them, 77 students in the spring semester of 2020 were selected as the experimental group and 74 students in the autumn semester of 2019 were selected as the control group. The students in the experimental group studied the first aid course by online platform, and the others in the control group studied through traditional teaching mode. The teaching effect of the two groups was compared and the teaching satisfaction of the two groups weas analyzed. SPSS 23.0 was used for Chi-square test and t-test. Results:There was no significant difference between the control group and the experimental group in the assessment scores of cardiopulmonary resuscitation, hemostatic bandaging, and fracture fixation [(8.65±0.81 vs 8.69±0.90, P=0.750); (8.10±0.50 vs 8.12±0.61, P=0.880); (8.21±0.89 vs 8.16±0.78, P=0.710)]. Among the students participating in the questionnaire survey in the experimental group, 59 (95.16%) students thought that this course was helpful in dealing with first aid in daily life, and 38 (61.29%) students did not want to change the traditional teaching method to online teaching. Conclusion:The application of online teaching in first-aid skill operation course is feasible and can achieve the similar teaching effect, which provides a novel idea for exploring the online teaching of first aid skills.

OBJECTIVES: This study aims to predict the risk of deep caries exposure in radiographic images based on the convolutional neural network model, compare the prediction results of the network model with those of senior dentists, evaluate the performance of the model for teaching and training stomatological students and young dentists, and assist dentists to clarify treatment plans and conduct good doctor-patient communication before surgery. METHODS: A total of 206 cases of pulpitis caused by deep caries were selected from the Department of Stomatological Hospital of Tianjin Medical University from 2019 to 2022. According to the inclusion and exclusion criteria, 104 cases of pulpitis were exposed during the decaying preparation period and 102 cases of pulpitis were not exposed. The 206 radiographic images collected were randomly divided into three groups according to the proportion: 126 radiographic images in the training set, 40 radiographic images in the validation set, and 40 radiographic images in the test set. Three convolutional neural networks, visual geometry group network (VGG), residual network (ResNet), and dense convolutional network (DenseNet) were selected to analyze the rules of the radiographic images in the training set. The radiographic images of the validation set were used to adjust the super parameters of the network. Finally, 40 radiographic images of the test set were used to evaluate the performance of the three network models. A senior dentist specializing in dental pulp was selected to predict whether the deep caries of 40 radiographic images in the test set were exposed. The gold standard is whether the pulp is exposed after decaying the prepared hole during the clinical operation. The prediction effect of the three network models (VGG, ResNet, and DenseNet) and the senior dentist on the pulp exposure of 40 radiographic images in the test set were compared using receiver operating characteristic (ROC) curve, area under the ROC curve (AUC), accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and F1 score to select the best network model. RESULTS: The best network model was DenseNet model, with AUC of 0.97. The AUC values of the ResNet model, VGG model, and the senior dentist were 0.89, 0.78, and 0.87, respectively. Accuracy was not statistically different between the senior dentist (0.850) and the DenseNet model (0.850)(P>0.05). Kappa consistency test showed moderate reliability (Kappa=0.6>0.4, P<0.05). CONCLUSIONS Among the three convolutional neural network models, the DenseNet model has the best predictive effect on whether deep caries are exposed in imaging. The predictive effect of this model is equivalent to the level of senior dentists specializing in dental pulp.
Humans ; Deep Learning ; Neural Networks, Computer ; Pulpitis/diagnostic imaging* ; Reproducibility of Results ; ROC Curve ; Random Allocation

Objective To analyze the clinical efficacy and safety off emoral head replacement(FHR)assisting by the traction table in direct anterior approach(DAA)for the treatment of femur neck fractures in gerontal patients.Methods A retrospective analysis was conducted on 79 elderly patients who under went FHR for femoral neck fractures from March 2019 to July 2020.A total of 42 patients underwent FHR through DAA by using traction table were assigned to the observation group and 37 patients receiving FHR through the PLA to the control group.The perioperative data,follow-up results and complications were compared between the two groups.Results The observation group was significantly superior to the control group in intraoperative blood loss(P<0.05),where as the former was inferior to the latter in preoperative preparation time(P<0.05).There was no significant difference in anesthesia time and operation time between the two groups(P>0.05).The observation group resumed first postoperative standing time,partial-weight bearing walking time and full-weight bearing walk-ing time significantly earlier than control group(P<0.05).Harris score at 1 month after the operation in the observation group were significantly higher than that of the control group(P<0.05),whereas which became not statistical significant between the two groups in 6 months and 1 year(P>0.05).No significant difference was found between the two groups for the incidence of complications(P>0.05).Conclusion DAA-FHR assisting by the traction table for the treatment of femur neck fractures in the elderly was effective and safe,but the preoperative preparation time was longer.

Objective: To study the influence of environmental factors on the two-species biofilm formed by the combinations of Streptococcus oligofermentans (So) with Streptococcus mutans (Sm) and Streptococcus sanguinis (Ss) with Sm so as to evaluate the role of So in maintaining the microecological balance of the oral cavity. Methods: Single-and two-species biofilms were grown on saliva-coated surfaces (glass tube and 96-well plate). Colony-counting method and safranin staining method were used to measure the biofilms formed under various oxygen conditions (aerobic and anaerobic), sucrose conditions (0%, 1% and 5% sucrose concentrations) and pH conditions (5.5, 6.0, 6.5, 7.0, 7.5 and 8.0). Results: Comparing the numbers of Sm in two co-cultures under various conditions, Sm counts in So+Sm group [(7.70±2.46)×10⁸ CFU/ml] were significantly lower than those in Ss+Sm group [(9.00±1.13)×10⁸ CFU/ml] in aerobic environment (P<0.05). Sm counts in So+Sm group [(2.80±0.52)×10⁸ CFU/ml] were also significantly lower than those in the Ss+Sm group [(4.00±1.25)×10⁸ CFU/ml] in anaerobic environment (P<0.05). The Sm counts in So+Sm group [(8.90±0.82)×10⁸ CFU/ml] were significantly higher than those in Ss+Sm group [(7.50±1.73)×10⁸ CFU/ml] in 0% sucrose environment (P<0.05). The Sm counts in So+Sm group [(5.70±2.94)×10⁸ CFU/ml] were significantly lower than those in Ss+Sm group [(10.30±3.21) ×10⁸ CFU/ml] in 1% sucrose environment (P<0.05). The Sm counts in So+Sm group [(6.10±1.71)×10⁸ CFU/ml] were also significantly lower than those in Ss+Sm group [(7.40±1.20)×10⁸ CFU/ml] in 5% sucrose environment (P<0.05). The Sm counts in So+Sm group [(3.50±1.50)×10⁸ CFU/ml] were significantly lower than those in Ss+Sm group [(10.70±2.80)×10⁸ CFU/ml] in pH7.0 environment (P<0.05). Comparing the formation of biofilm after 24 h cultivation, the Sm counts in So+Sm group were significantly lower than those in Ss+Sm group both in aerobic and anaerobic environments (P<0.05). The Sm counts in So+Sm group were significantly higher than those in Ss+Sm group in 0% sucrose environment (P<0.05). The Sm counts in So+Sm group were significantly lower than those in Ss+Sm group in 1% and 5% sucrose and pH 7.0 environments (P<0.05). Both So and Ss had no inhibitory effect on Sm in pH5.5 and pH8.0 environments. Conclusions In the in vitro two-species co-culture systems, So showed stronger inhibitory effects than Ss on Sm and its inhibitory ability might influenced by various environmental factors.

Objective To study the influence of environmental factors on the two?species biofilm formed by the combinations of Streptococcus oligofermentans (So) with Streptococcus mutans (Sm) and Streptococcus sanguinis (Ss) with Sm so as to evaluate the role of So in maintaining the microecological balance of the oral cavity. Methods Single?and two?species biofilms were grown on saliva?coated surfaces (glass tube and 96?well plate). Colony?counting method and safranin staining method were used to measure the biofilms formed under various oxygen conditions (aerobic and anaerobic), sucrose conditions (0%, 1% and 5% sucrose concentrations) and pH conditions (5.5, 6.0, 6.5, 7.0, 7.5 and 8.0). Results Comparing the numbers of Sm in two co?cultures under various conditions, Sm counts in So+Sm group [(7.70 ± 2.46)× 108 CFU/ml] were significantly lower than those in Ss+Sm group [(9.00 ± 1.13)×108 CFU/ml] in aerobic environment (P<0.05). Sm counts in So+Sm group [(2.80±0.52)×108 CFU/ml] were also significantly lower than those in the Ss+Sm group [(4.00±1.25)×108 CFU/ml] in anaerobic environment (P<0.05). The Sm counts in So+Sm group [(8.90±0.82)×108 CFU/ml] were significantly higher than those in Ss+Sm group [(7.50± 1.73)×108 CFU/ml] in 0% sucrose environment (P<0.05). The Sm counts in So+Sm group [(5.70 ± 2.94)× 108 CFU/ml] were significantly lower than those in Ss+Sm group [(10.30±3.21)×108 CFU/ml] in 1% sucrose environment (P<0.05). The Sm counts in So+Sm group [(6.10±1.71)×108 CFU/ml] were also significantly lower than those in Ss+Sm group [(7.40±1.20)×108 CFU/ml] in 5% sucrose environment (P<0.05). The Sm counts in So+Sm group [(3.50 ± 1.50)×108 CFU/ml] were significantly lower than those in Ss+Sm group [(10.70±2.80)×108 CFU/ml] in pH7.0 environment (P<0.05). Comparing the formation of biofilm after 24 h cultivation, the Sm counts in So+Sm group were significantly lower than those in Ss+Sm group both in aerobic and anaerobic environments (P<0.05). The Sm counts in So+Sm group were significantly higher than those in Ss+Sm group in 0% sucrose environment (P<0.05). The Sm counts in So+Sm group were significantly lower than those in Ss+Sm group in 1% and 5% sucrose and pH 7.0 environments (P<0.05). Both So and Ss had no inhibitory effect on Sm in pH5.5 and pH8.0 environments. Conclusions In the in vitro two?species co?culture systems, So showed stronger inhibitory effects than Ss on Sm and its inhibitory ability might influenced by various environmental factors.

Objective: To investigate the status of abnormal menstruation in female nurses in a comprehensive hospital in Beijing, China and related influencing factors. Methods: In July 2016, a cross-sectional survey was performed, and a self-administered questionnaire was used to investigate the status of menstruation and occupation in female nurses in a comprehensive hospital in Beijing. The chi-square test and a multivariate logistic regression analysis were used for statistical analysis. Results: A total of 892 female nurses were investigated, and among them, 485 experienced abnormal menstruation within the past three months, resulting in an abnormal menstruation rate of 54.37%. The female nurses who were exposed to harmful factors during work, negative life events, or high workload had a significantly higher abnormal menstruation rate than those who were not exposed to such factors (χ²=5.199, 16.186, and 10.227, P<0.05 or P<0.01) . Negative life events (odds ratio [OR]=1.813, 95% confidence interval[CI]: 1.317-2.496) and high workload (OR=1.461, 95%CI: 1.112-1.918) were risk factors for abnormal menstruation. Conclusion Nurses have an abnormal menstruation rate as high as 54.37%, and high workload and negative life events were risk factors for abnormal menstruation in nurses.

Objective: To evaluate the mental health of female doctors and nurses. Methods: Investigat the psychologic status of female doctors and nurses using symptom checklist 90. And statistical software was applied to analyze results of symptom checklist 90. Results: There were differences in the score of SCL-90 between doctor and nurse groups, the difference was statistically significant (P<0.05) . Negative life events (OR=2.940) , relative suffer from mental illness (OR=3.683) , shift work (OR=1.611) and heavy workload (OR=2.265) were found to risk factors for the positive of SCL-90. Conclusion There were differences in the score of SCL-90 between doctor and nurse groups. Negative life events, relative suffer from mental illness, shift workand heavy workload are risk factors for SCL-90 positive of female doctors and nurses.