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Objective: To explore the digital design and fabrication technology of personalized restorative matrix for dental filling, and to explore the feasibility of direct resin restoration for deep caries lesions in distal neck of mandibular second molar. Methods: For patients with deep caries lesions in the distal neck of the mandibular second molar who visited the Department of Cariology and Endodontology of Peking University School and Hospital of Stomatology from September 2023 to April 2024, after preparing the cavity and gingival retractor, a three-dimensional intraoral scanner was used to obtain three-dimensional data of the patient's dentition. In the dental restoration computer-aided design software, the inlay function was used to generate the restored tooth morphology. The edge range of the personalized restorative matrix was drawn on the restored model by three-dimensional reverse engineering software to achieve edge sealing effect. The selected edge range data was processed with distal shelling to generate a digital model of a personalized restorative matrix with a thickness of 0.5 mm. A metal three-dimensional printer was used to fabricate the titanium alloy restorative matrix, and its application was completed in 10 clinical cases. The marginal adaptation and retention stability of the personalized restorative matrix were evaluated under a dental microscope, and forming effect evaluation was performed through immediate postoperative periapical radiographs. Results: The preliminary clinical application of the personalized restorative matrix fabricated using digital technology revealed that, in the treatment of 10 affected teeth, rubber dam isolation was successfully ensured, resulting in clinically effective direct resin composite restorations with optimal marginal adaptation and reasonable contours. Immediate postoperative periapical radiographs showed good convexity of the filling body, with no overhangs found. Both marginal adaptation and retention stability met the requirements of clinical treatment. Conclusions: The personalized restorative matrix designed in this study can solve the clinical problems of moisture separation and resin forming in the treatment of deep caries lesions in distal neck of the mandibular second molar, and can achieve stable and reliable adhesive restoration effects.

Pediatric dentistry treats patients aged 0-18 years, encompassing the characteristics of general dentistry. The clinical techniques are closely related to restorative dentistry, endodontics, orthodontics, and maxillofacial surgery, while also possessing unique aspects. It particularly focuses on the growth and development patterns of children's dentition and maxillofacial structures. Currently, digital technology has deeply integrated with various clinical disciplines of dentistry, and pediatric dentistry has made significant progress with pediatric-specific digital applications. On one hand, the introduction of mature digital technologies is enabling the digital transformation of pediatric dental treatment models; on the other hand, there is innovative development of new digital technologies tailored to the specific needs of pediatric dental care, filling gaps in the field. Based on years of research in digital technology for pediatric dentistry, our team details the current innovative applications and scientific explorations in this area from these two perspectives. Additionally, we anticipate the potential expansion of digital technologies not yet applied in pediatric dentistry, providing a reference for clinical scholars in the field to conduct exploratory research.

Objective: To establish an intelligent registration algorithm under the framework of original-mirror alignment algorithm to construct three-dimensional(3D) facial midsagittal plane automatically. Dynamic Graph Registration Network (DGRNet) was established to realize the intelligent registration, in order to provide a reference for clinical digital design and analysis. Methods: Two hundred clinical patients without significant facial deformities were collected from October 2020 to October 2022 at Peking University School and Hospital of Stomatology. The DGRNet consists of constructing the feature vectors of key points in point original and mirror point clouds (X, Y), obtaining the correspondence of key points, and calculating the rotation and translation by singular value decomposition. Original and mirror point clouds were registrated and united. The principal component analysis (PCA) algorithm was used to obtain the DGRNet alignment midsagittal plane. The model was evaluated based on the coefficient of determination (R 2 ) index for the translation and rotation matrix of test set. The angle error was evaluated on the 3D facial midsagittal plane constructed by the DGRNet alignment midsagittal plane and the iterative closet point(ICP) alignment midsagittal plane for 50 cases of clinical facial data. Results: The average angle error of the DGRNet alignment midsagittal plane and ICP alignment midsagittal plane was 1.05°±0.56°, and the minimum angle error was only 0.13°. The successful detection rate was 78%(39/50) within 1.50° and 90% (45/50)within 2.00°. Conclusions: This study proposes a new solution for the construction of 3D facial midsagittal plane based on the DGRNet alignment method with intelligent registration, which can improve the efficiency and effectiveness of treatment to some extent.

Objective: To explore the predictive value of cerebrospinal fluid melanin-concentrating hormone (MCH) combined with other related biomarkers in preoperative cognitive dysfunction of elderly patients. Methods: A total of 80 patients who underwent elective hip or knee replacement under intravertebral anesthesia in Chifeng Municipal Hospital, Inner Mongolia, from March to November 2022 were prospectively included, with 32 males and 48 females, and aged 65-85 (70.7±5.2) years old. According to the evaluation results of the Montreal Cognitive Assessment (MoCA), patients were divided into the preoperative cognitive dysfunction ( n =23) and control ( n =57) groups. The levels of MCH, amyloid-β 40 (Aβ 40 ), amyloid-β 42 (Aβ 42 ), and phosphorylated tau protein (p-tau) in cerebrospinal fluid were determined by enzyme-linked immunosorbent assay (ELISA). The receiver operating characteristic (ROC) curve was drawn to evaluate the predictive value of each biomarker separately or in combination for preoperative cognitive dysfunction. Spearman's rank correlation analysis was utilized to test the correlation between the level of each biomarker and MoCA scores. Results: The levels of MCH, Aβ 40 , Aβ 42 , p-tau, and Aβ 42 /p-tau in the preoperative cognitive dysfunction group were (35.53±5.94) μg/L, (39.21±9.18) ng/L, (221.83±43.17) ng/L, (42.64±9.74) ng/L, and 5.53±1.92, and the levels of these biomarkers in the control group were (28.74±4.90) μg/L, (36.37±7.87) ng/L, (280.23±45.67) ng/L, (35.00±9.27) ng/L, and 8.62±2.78, respectively. Compared with the control group, the levels of cerebrospinal fluid MCH and p-tau in the preoperative cognitive dysfunction group were significantly increased (all P <0.01), and the levels of Aβ 42 and Aβ 42 /p-tau were significantly decreased (all P <0.001). MCH and Aβ 42 /p-tau provided higher predictive values. The area under the curve (AUC) of MCH and Aβ 42 /p-tau were 0.807 (95% CI : 0.703-0.911) and 0.842 (95% CI : 0.741-0.943), the sensitivity were 78.3% and 87.0%, and the specificity were 75.4% and 94.7%. MCH combined with Aβ 42 /p-tau have the higher AUC of 0.915 (95% CI : 0.837-0.992), the sensitivity (87.0%) and specificity (86.0%) were both high, which had a higher predictive value. The levels of cerebrospinal fluid MCH and p-tau were negatively correlated with MoCA score ( r =-0.467, -0.321, all P <0.01), and the levels of Aβ 42 and Aβ 42 /p-tau were positively correlated with MoCA score ( r =0.480, 0.520, all P <0.001). Conclusion: The increase in cerebrospinal fluid MCH levels is associated with preoperative cognitive dysfunction in elderly patients. MCH combined with Aβ 42 /p-tau has the greatest predictive value.

Objective: To analyze the mortality trend and characteristics of chronic obstructive pulmonary disease (COPD) among residents in China from 2004 to 2020. Methods: From the area, gender, region, and age dimensions, the Joinpoint regression model was used to analyze the trend of COPD mortality rate from 2004 to 2020, extracted from the China Death Surveillance Dataset. Results: From 2004 to 2020, the mortality rate and age-adjusted mortality rate of COPD showed a downward trend (AAPC=-3.68%, P <0.001; AAPC=-7.27%, P <0.001), which were consistent with urban and rural subpopulations (mortality rate: AAPC=-3.62%, P =0.009, AAPC=-3.23%, P =0.014; age-adjusted mortality rate: AAPC=-7.26%, P <0.001, AAPC=-6.78%, P <0.001). The mortality rate of COPD in rural was higher than that of urban subpopulations ( P <0.001). Also, the mortality rate and age-adjusted mortality rate of COPD showed a downward trend in males and females (mortality rate: AAPC=-3.00%, P <0.001, AAPC=-4.37%, P <0.001; age-adjusted mortality rate: AAPC=-6.73%, P <0.001, AAPC=-8.11%, P <0.001), and the COPD mortality rate for male was generally higher than female ( P <0.001). Meanwhile, the mortality rate of COPD in eastern, central and western regions also showed a downward trend (AAPC=-3.87%, P <0.001; AAPC=-3.12%, P <0.001; AAPC=-1.37%, P =0.001), and western regions were significantly higher than that in central ( P <0.001) and eastern ( P <0.001) regions. The mortality rate of COPD in the age group of Chinese people showed a downward trend in<45, 45-59, and≥60 years groups (AAPC=-9.48%, P <0.001; AAPC=-9.03%, P <0.001; AAPC=-5.91%, P <0.001). Among them,≥60 years groups was significantly higher than that in<45 ( P <0.001) and 45-59 ( P <0.001) years groups, and the decline rate was slowest. Conclusion: In China, the mortality rate of COPD decreases from 2004 to 2020, and more efforts are needed to reduce COPD mortality, especially in western regions, rural populations, males and the elderly.

Objective: To explore an automatic landmarking method for anatomical landmarks in the three-dimensional (3D) data of the maxillary complex and preliminarily evaluate its reproducibility and accuracy. Methods: From June 2021 to December 2022, spiral CT data of 31 patients with relatively normal craniofacial morphology were selected from those who visited the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology. The sample included 15 males and 16 females, with the age of (33.3±8.3) years. The maxillary complex was reconstructed in 3D using Mimics software, and the resulting 3D data of the maxillary complex was mesh-refined using Geomagic software. Two attending physicians and one associate chief physician manually landmarked the 31 maxillary complex datasets, determining 24 anatomical landmarks. The average values of the three expert landmarking results were used as the expert-defined landmarks. One case that conformed to the average 3D morphological characteristics of healthy individuals' craniofacial bones was selected as the template data, while the remaining 30 cases were used as target data. The open-source MeshMonk program (a non-rigid registration algorithm) was used to perform an initial alignment of the template and target data based on 4 landmarks (nasion, left and right zygomatic arch prominence, and anterior nasal spine). The template data was then deformed to the shape of the target data using a non-rigid registration algorithm, resulting in the deformed template data. Based on the unchanged index property of homonymous landmarks before and after deformation of the template data, the coordinates of each landmark in the deformed template data were automatically retrieved as the automatic landmarking coordinates of the homonymous landmarks in the target data, thus completing the automatic landmarking process. The automatic landmarking process for the 30 target data was repeated three times. The root-mean-square distance (RMSD) of the dense corresponding point pairs (approximately 25 000 pairs) between the deformed template data and the target data was calculated as the deformation error of the non-rigid registration algorithm, and the intra-class correlation coefficient ( ICC ) of the deformation error in the three repetitions was analyzed. The linear distances between the automatic landmarking results and the expert-defined landmarks for the 24 anatomical landmarks were calculated as the automatic landmarking errors, and the ICC values of the 3D coordinates in the three automatic landmarking repetitions were analyzed. Results: The average three-dimensional deviation (RMSD) between the deformed template data and the corresponding target data for the 30 cases was (0.70±0.09) mm, with an ICC value of 1.00 for the deformation error in the three repetitions of the non-rigid registration algorithm. The average automatic landmarking error for the 24 anatomical landmarks was (1.86±0.30) mm, with the smallest error at the anterior nasal spine (0.65±0.24) mm and the largest error at the left oribital (3.27±2.28) mm. The ICC values for the 3D coordinates in the three automatic landmarking repetitions were all 1.00. Conclusions: This study established an automatic landmarking method for three-dimensional data of the maxillary complex based on a non-rigid registration algorithm. The accuracy and repeatability of this method for landmarking normal maxillary complex 3D data were relatively good.

In light of the increasing digitalization of dentistry, the automatic determination of three-dimensional (3D) craniomaxillofacial features has become a development trend. 3D craniomaxillofacial landmarks and symmetry reference plane determination algorithm based on point clouds has attracted a lot of attention, for point clouds are the basis for virtual surgery design and facial asymmetry analysis, which play a key role in craniomaxillofacial surgery and orthodontic treatment design. Based on the studies of our team and national and international literatures, this article presented the deep geometry learning algorithm to determine landmarks and symmetry reference plane based on 3D craniomaxillofacial point clouds. In order to provide reference for future clinical application, we describe the development and latest research in this field, and analyze and discuss the advantages and limitations of various methods.

Objective: To provide a new solution for the digital design of nasal prostheses, this study explores the three-dimensional (3D) facial morphology completion method for external nasal defects based on the non-rigid registration process of 3D face template. Methods: A total of 20 male patients with tooth defect and dentition defect who visited the Department of Prosthodontics, Peking University School and Hospital of Stomatology from June to December 2022 were selected, age 18-45 years old. The original 3D facial data of patients were collected, and the 3D facial data of the external nose defect was constructed in Geomagic Wrap 2021 software. Using the structured 3D face template data constructed in the previous research of the research group, the 3D face template was deformed and registered to the 3D facial data of external nose defect (based on the morphology of non-defective area) by non-rigid registration algorithm (MeshMonk program), and the personalized deformed data of the 3D face template was obtained, as the complemented facial 3D data. Based on the defect boundary of the 3D facial data of the external nose defect, the complemented external nose 3D data can be cut out from the complemented facial 3D data. Then the nasofacial angle and nasolabial angle of the complemented facial 3D data and the original 3D facial data was compared and analyzed, the ratio between the nose length and mid-face height, nose width and medial canthal distance of the complemented facial 3D data was measured, the edge fit between the edge curve of the complemented external nose 3D data and the defect edge curve of the 3D facial data of external nose defect was evaluated, and the morphological difference of the nose between the complemented external nose 3D data and the original 3D facial data was analyzed. Results: There was no significant statistically difference ( t= -0.23, P= 0.823; Z= -1.72, P= 0.086) in the nasofacial angle (28.2°±2.9°, 28.4°±3.5° respectively) and nasolabial angle [95.4°(19.2°), 99.9°(9.5°) respectively] between the 20 original 3D facial data and the complemented facial 3D data. The value of the ratio of nose length to mid-face height in the complemented facial 3D data was 0.63±0.03, and the value of the ratio of nose width to medial canthal distance was 1.07±0.08. The curve deviation (root mean square value) between the edge curve of the complemented external nose 3D data and the defect edge curve of the 3D facial data of external nose defect was (0.37±0.09) mm, the maximum deviation was (1.14±0.32) mm, and the proportion of the curve deviation value within±1 mm was (97±3)%. The distance of corresponding nose landmarks between the complemented facial 3D data and the original 3D facial data were respectively, Nasion: [1.52(1.92)] mm; Pronasale: (3.27±1.21) mm; Subnasale: (1.99±1.09) mm; Right Alare: (2.64±1.34) mm; Left Alare: (2.42± 1.38) mm. Conclusions: The method of 3D facial morphology completion of external nose defect proposed in this study has good feasibility. The constructed complemented external nose 3D data has good facial coordination and edge fit, and the morphology is close to the nose morphology of the original 3D facial data.

Objective: To explore a method for digitally designing and fabricating a sequential tooth-sectioning guide that can assist in the extraction of mandibular horizontal impacted third molars, preliminarily evaluate its feasibility and provide a reference for clinical application. Methods: Twenty patients with mandibular low level impacted third molars who visited the Department of General Dentistry, Peking University School and Hospital of Stomatology from March 2021 to January 2022 were selected. Cone-beam CT showed direct contact between the roots and mandibular canal, and full range impressions of the patients' intraoral teeth were taken and optical scans of the dental model were performed. The patients' cone-beam CT data and optical scan data were reconstructed in three dimensions, anatomical structure extraction, registration fusion, and the design of the structure of the guide (including crown-sectioning guide and root-sectioning guide) by Mimics 24.0, Geomagic Wrap 2021, and Magics 21.0 software, and then the titanium guide was three dimension printed, and the guide was tried on the dental model. After confirmation, the guide was used to assist the dentist in the operation. We observed whether the guide was in place, the number of tooth splitting, the matching of tooth splitting with the preoperative design, the operation time, and whether there were any complications. Results: In this study, 20 sectioning guides were successfully printed, all of them were well fitted in the patients' mouth, the average number of section was 3.4 times, the tooth parts was better matched with the preoperative design, and the average operative time of the guides was (29.2±9.8) minutes without complications such as perforation of the bone cortex. Conclusions: The use of sequential sectioning guides to assist in the extraction of mandibular impacted third molars was initially validated to accurately replicate the preoperative sectioning design, and is expected to provide a digital solution to improve surgical precision and ensure safety. Further studies with larger sample sizes are needed to evaluate its accuracy and safety.

Objective: To investigate the clinical phenotype and genetic characteristics of disorders of sex development (DSD) caused by Y chromosome copy number variant (CNV). Methods: A retrospective analysis was performed on 3 patients diagnosed with DSD caused by Y chromosome CNV admitted to the First Affiliated Hospital of Zhengzhou University from January, 2018 to September, 2022. Clinical data were collected. Clinical study and genetic test were performed by karyotyping, whole exome sequencing (WES), low coverage whole genome copy number variant sequencing (CNV-seq), fluorescence in situ hybridization (FISH) and gonadal biopsy. Results: The 3 children, aged 12, 9, 9 years, the social gender were all female, presented with short stature, gonadal dysplasia and normal female external genital. No other phenotypic abnormality was found except for case 1 with scoliosis. The karyotype of all cases were identified as 46, XY. No pathogenic vraiants were found by WES. CNV-seq determined that case 1 was 47, XYY,+Y(2.12) and case 2 was 46, XY,+Y(1.6). FISH concluded that the long arm of Y chromosome was broken and recombined near Yq11.2, and then produced a pseudodicentric chromosome idic(Y). The karyotype was reinterpreted as mos 47, X, idic(Y)(q11.23)×2(10)/46, X, idic(Y)(q11.23)(50) in case 1. The karyotype was redefined as 45, XO(6)/46, X, idic(Y)(q11.22)(23)/46, X, del(Y)(q11.22)(1) in case 2. 46, XY, -Y(mos) was found by CNV-seq in case 3, and the karyotype of 45, XO/46, XY was speculated. Conclusions: The clinical manifestations of children with DSD caused by Y chromosome CNV are short stature and gonadal dysgenesis. If there is an increase of Y chromosome CNV detected by CNV-seq, FISH is recommended to classify the structural variation of Y chromosome.

Objective: To quantitatively evaluate the trueness of five chairside three-dimensional facial scanning techniques, and to provide reference for the application of oral clinical diagnosis and treatment., Methods: The three-dimensional facial data of the subjects were collected by the traditional professional three-dimensional facial scanner Face Scan, which was used as the reference data of this study. Four kinds of portable three-dimensional facial scanners (including Space Spider, LEO, EVA and DS-FScan) and iPhone Ⅹ mobile phone (Bellus3D facial scanning APP) were used to collect three-dimensional facial data from the subjects. In Geomagic Studio 2013 software, through data registration, deviation analysis and other functions, the overall three-dimensional deviation and facial partition three-dimensional deviation of the above five chairside three-dimensional facial scanning technologies were calculated, and their trueness performance evaluated. Scanning time was recorded during the scanning process, and the subject's comfort was scored by visual analogue scale(VAS). The scanning efficiency and patient acceptance of the five three-dimensional facial scanning techniques were evaluated., Results: DS-FScan had the smallest mean overall and mean partition three-dimensional deviation between the test data and the reference data, which were 0.334 mm and 0.329 mm, respectively. The iPhone Ⅹ mobile phone had the largest mean overall and mean partition three-dimensional deviation between the test data and the reference data, which were 0.483 mm and 0.497 mm, respectively. The detailed features of the three-dimensional facial data obtained by Space Spider were the best. The iPhone Ⅹ mobile phone had the highest scanning efficiency and the highest acceptance by the subject. The average scanning time of the iPhone Ⅹ mobile phone was 14 s, and the VAS score of the subjects' scanning comfort was 9 points., Conclusion: Among the five chairside three-dimensional face scanning technologies, the trueness of the scan data of the four portable devices had no significant difference, and they were all better than the iPhone Ⅹ mobile phone scan. The subject with the iPhone Ⅹ scanning technology had the best expe-rience.

Objective: To explore an efficient and automatic method for determining the anatomical landmarks of three-dimensional(3D) mandibular data, and to preliminarily evaluate the performance of the method., Methods: The CT data of 40 patients with normal craniofacial morphology were collected (among them, 30 cases were used to establish the 3D mandibular average model, and 10 cases were used as test datasets to validate the performance of this method in determining the mandibular landmarks), and the 3D mandibular data were reconstructed in Mimics software. Among the 40 cases of mandibular data after the 3D reconstruction, 30 cases that were more similar to the mean value of Chinese mandibular features were selected, and the size of the mandibular data of 30 cases was normalized based on the Procrustes analysis algorithm in MATLAB software. Then, in the Geomagic Wrap software, the 3D mandibular average shape model of the above 30 mandibular data was constructed. Through symmetry processing, curvature sampling, index marking and other processing procedures, a 3D mandible structured template with 18 996 semi-landmarks and 19 indexed mandibular anatomical landmarks were constructed. The open source non-rigid registration algorithm program Meshmonk was used to match the 3D mandible template constructed above with the tested patient's 3D mandible data through non-rigid deformation, and 19 anatomical landmark positions of the patient's 3D mandible data were obtained. The accuracy of the research method was evaluated by comparing the distance error of the landmarks manually marked by stomatological experts with the landmarks marked by the method of this research., Results: The method of this study was applied to the data of 10 patients with normal mandibular morphology. The average distance error of 19 landmarks was 1.42 mm, of which the minimum errors were the apex of the coracoid process [right: (1.01±0.44) mm; left: (0.56±0.14) mm] and maximum errors were the anterior edge of the lowest point of anterior ramus [right: (2.52±0.95) mm; left: (2.57±1.10) mm], the average distance error of the midline landmarks was (1.15±0.60) mm, and the average distance error of the bilateral landmarks was (1.51±0.67) mm., Conclusion: The automatic determination method of 3D mandibular anatomical landmarks based on 3D mandibular average shape model and non-rigid registration algorithm established in this study can effectively improve the efficiency of automatic labeling of 3D mandibular data features. The automatic determination of anatomical landmarks can basically meet the needs of oral clinical applications, and the labeling effect of deformed mandible data needs to be further tested.

Objective: To explore the method of measuring root volume with cone-beam computed tomography (CBCT) three-dimensional reconstruction technology, and to study root length and root volume of upper and lower central incisors in patients with skeletal Class Ⅲ malocclusion treated by surgical orthodontic treatment., Methods: Twenty patients with skeletal Class Ⅲ malocclusion undergoing surgical orthodontic treatment were selected. CBCT data at three time points, before decompensation treatment (T0), after decompensation treatment (before orthognathic surgery, T1), and the end of post-operative orthodontic treatment (T2) were collected. Three-dimensional reconstruction technology was used to measure the root length and root volume of the upper and lower central incisors (including total root volume, cervical root and apical root), calculate the percentage of reduction volume, and measure the distance of tooth movement after orthodontic treatment. Data were statistically analyzed by SPSS 20.0 software. Least significant difference (LSD) method was used for pair comparison between the groups subject to normal distribution, and non-parametric test was used for comparison between the groups not subject to normal distribution. The differences of root length and root volume of upper and lower incisors were compared, and the characteristics of root absorption were analyzed., Results: Root length and root volume of the upper and lower central incisors were reduced during the surgical orthodontic treatment ( P < 0.05) in cases. Both the root volume of cervical root and apical root were significantly reduced ( P < 0.05), the reduction of apical root was more significant. The percentage of root volume reduction of the upper central incisor was (30.51±23.23)%, and lower central incisor (23.24±11.96)%. Compared with the upper central incisor, the root volume reduction amount and percentage of the lower central incisor were smaller, and apical root volume reduction of the upper central incisor was greater than that of the lower central incisor, which was statistically significant ( P < 0.05). During pre-surgical orthodontic treatment, maxillary central incisor palatal moving was in a controlled tipping manner, and the mandibular central incisor tipped labially., Conclusion: In patients with skeletal Class Ⅲ malocclusion, root length and total root volume of upper and lower central incisors decreased during surgical orthodontic treatment. Root volume measurement indicated that the cervical root also had root resorption. The difference in root resorption of the upper and lower central incisors might be related to the distance and direction of teeth movement. CBCT three-dimensional reconstruction will compensate for the limitation of root length measurement in evaluating root resorption.

Ben Cao Tu Jing had 38 materia medica illustrations related to the regional names in Zhejiang province. It was found that 30 of them were identified as being named after regional names in Zhejiang province, involving 20 families and 29 genera. One of the 38 materia medica illustrations was mineral medicine and seven of them were unverified. The twenty-five of these materia medica illustrations with regional names were found to be consistent with their names used today. Five of them came from similar names in Zhejiang province in the Northern Song Dynasty, another five of the 25 names were known with the names but not entity for the lack of full descriptions and drawings. It was found that the drawing and the text of "Ming Zhou Huang Yao" and "Qin Zhou Hong Yao" in Ben Cao Tu Jing were reversed. By comparing the materia medica illustrations related to regional names in Da Guan Ben Cao by Liu Jia and Zheng He Ben Cao by Zhang Huicun, the name and the illustration of "Jin Zhou Bei Mu" in Zheng He Ben Cao by Zhang Huicun was more believable than "Yue Zhou Bei Mu" in Da Guan Ben Cao by Liu Jia. "Tai Zhou Wu Yao" and "Zhe Ba Wei", as genuine medicinal materials in Zhejiang, can be traced back to the illustrations of "Tai Zhou Wu Yao", "Yue Zhou Bai Zhu", "Mu Zhou Mai Dong", "Wen Zhou Peng 'e Shu", "Yue Zhou Bei Mu" and "Tian Tai Wu Yao" in Ben Cao Tu Jing. These findings provided text and drawing literature of herbs in the Song Dynasty for the research of genuine medicinal materials and their characteristics in Zhejiang province. They also showed that the utilization and development of the resources of traditional Chinese medicine in Zhejiang in the Northern Song Dynasty mainly focused on the coastal areas.

Objective: To explore the construction process of the digital reference crown models, and to initially establish the digital reference crown models of the primary teeth to lay the foundation for the establishment of the standardized crown models and the future related applications of computer-aided design/computer-aided manufacture (CAD/CAM) technology to pediatric dentistry., Methods: This study randomly selected children who were caries free, aged from 4 to 5 years in several kindergartens of Haidian District of Beijing.Plaster dental models were made for the children after taking complete impressions.The digital dental models were reconstructed by using the three-dimensional (3D) dental model scanner.And then, Geomagic Studio, a 3D reverse engineering software, was employed to extract the single dental crown data, the mesiodistal and buccolingual diameters and the height of the crowns were measured.The object was reduced or enlarged by a numerical factor, and then the size of each dental crown was standardized.A total of 3-5 points features on the crown were created, and all the objects were aligned through the functions of feature-based alignment.Finally, through average-based object creation and smoothing, the digital models of reference crowns of the primary teeth were established., Results: A total of 40 plaster dental models from 16 boys and 26 girls were selected out for our further study.The digital dental models were reconstructed, and the mesiodistal and buccolingual diameters and the height of the crowns were measured by using reverse engineering technology.Comparing the results of using mesiodistal diameter, buccolingual diameter and height as the standards, we chose the mesiodistal diameters of crowns to do the standardization, and successfully established the digital reference models of 20 primary teeth crowns with detailed surface characteristics., Conclusion: In this study, the digital reference crown models of the primary teeth were established by reverse engineering technology, providing reference value for the standardized crown models and application for clinical practice, scientific research and teaching.Furthermore, this study also contributes to the extensive application of CAD/CAM technology in pediatric dentistry and the development of CAD/CAM dental systems with independent intellectual property rights.

Objectives: To study the design of nonmetallic crowns for deciduous molars by means of computer aided design and to analyze the key parameters of the nonmetallic crowns of deciduous molars using finite element method. Methods: The three-dimensional model of a mandibular second primary molar was constructed by using a micro-CT system. The thickness of the crown was limited to 0.5 mm and four different crown shapes (chamfer+anatomic, chamfer+non-anatomic, knife edge+anatomic and knife edge+non-anatomic) were designed. Then, the crown shape was limited as chamfer+non-anatomic and five different thicknesses of the crown (0.50, 0.75, 1.00, 1.25, 1.50 mm) were designed, and three different materials, including polyetherketoneketone (PEKK), polymethylmethacrylate (PMMA) resin and resin-infiltrated ceramic, were applied to make the crown. Stress distribution and fatigue of each component of the model under vertical and oblique loadings were analyzed by using finite element method. Non-axial retention analysis was performed on chamfer+non-anatomic crowns, made of PMMA resin, with thicknesses of 0.50, 0.75, 1.00, 1.25 and 1.50 mm. Results: Among the four crown shape designs, the chamfer+non-anatomic type crown showed the lowest von Mises stress and the highest safety factor. By comparing three different materials, the resin-infiltrated ceramic group showed obvious stress concentration on the buccal edge of the crown and the PEKK group showed stress concentration in the adhesive layer. Results of non-axial retention analysis showed that the torques required by the crowns with five thicknesses at the same rotation angle were as follows: 4 856.1, 4 038.1, 3 497.3, 3 256.3 and 3 074.3 N⋅m, respectively. The comparison of areas of the adhesives fracture among groups were as follows: 0.5 mm group < 0.75 mm group < 1.00 mm group < 1.25 mm group < 1.50 mm group. Conclusions: In the design of nonmetallic crowns for primary molars, the edge of the crown should be designed as chamfer, the shape of the inner crown should be non-anatomical and the minimum preparation amount of the occlusal surface should be 1.00 mm. Among the three materials, PMMA resin, of which elastic modulus is similar to the dentin and the dental adhesive, might be the most suitable material for the crowns of primary molars.

Objective: To evaluate the accuracy of trephine bur drilling at different depths guided by dynamic navigation system in 3D printing in vitro model., Methods: A model at the depth of 5 mm, 10 mm, and 15 mm from the outer surface of which hemispherical cavities was reserved and the 3D printing technology was used to make the standardized model with Veroclear resin. The cone beam CT (CBCT) was taken and the data were imported into the dynamic navigation software (DCARER, China) to establish navigation path programming. Under the guidance of dynamic navigation, a trephine bur with a diameter of 4.5 mm was used to complete the access operation. At each depth, 10 approaches were completed. The postoperative model CBCT was taken. The approach trajectory under navigation was reconstructed and compared with the designed path. The two-dimensional distance deviation, depth deviation, three-dimensional distance deviation, and angle deviation between the actually prepared path and the designed path were calculated., Results: At the depth of 5 mm, the two-dimensional distance deviation between the end position of the prepared path and the designed path was (0.37±0.06) mm, the depth deviation was (0.06±0.05) mm, the three-dimensional distance deviation was (0.38±0.07) mm, and the angle deviation was 2.46°±0.54°; At the depth of 10 mm, the four deviations between the end position of prepared path and the designed path were (0.44±0.05) mm, (0.16±0.06) mm, (0.47±0.05) mm, and 2.45°±1.21°, respectively; At the depth of 15 mm, the four deviations were (0.52±0.14) mm, (0.16±0.07) mm, (0.55±0.15) mm, and 3.25°±1.22°, respectively. With the increase of entry depth, the three-dimensional and depth accuracy of dynamic navigation system decreased ( P < 0.01), and the positioning angle deviation had no relation with the entry depth ( P >0.01)., Conclusion: Dynamic navigation technology can achieve high positioning accuracy in the depth range of 15 mm, but its deviation increases with the increase of entry depth.

Objective: To establish a deep learning algorithm that can accurately determine three-dimensional facial anatomical landmarks, multi-view stacked hourglass convolutional neural networks (MSH-CNN) and to construct three-dimensional facial midsagittal plane automatically based on MSH-CNN and weighted Procrustes analysis algorithm., Methods: One hundred subjects with no obvious facial deformity were collected in our oral clinic. Three-dimensional facial data were scanned by three-dimensional facial scanner. Experts annotated twenty-one facial landmarks and midsagittal plane of each data. Eighty three-dimensional facial data were used as training set, to train the MSH-CNN in this study. The overview of MSH-CNN network architecture contained multi-view rendering and training the MSH-CNN network. The three-dimensional facial data were rendered from ninety-six views that were fed to MSH-CNN and the output was one heatmap per landmark. The result of the twenty-one landmarks was accurately placed on the three-dimensional facial data after a three-dimensional view ray voting process. The remaining twenty three-dimensional facial data were used as test set. The trained MSH-CNN automatically determined twenty-one three-dimensional facial anatomical landmarks of each case of data, and calculated the distance between each MSH-CNN landmark and the expert landmark, which was defined as position error. The midsagittal plane of the twenty subjects' could be automatically constructed, using the MSH-CNN and Procrustes analysis algorithm. To evaluate the effect of midsagittal plane by automatic method, the angle between the midsagittal plane constructed by the automatic method and the expert annotated plane was calculated, which was defined as angle error., Results: For twenty subjects with no obvious facial deformity, the average angle error of the midsagittal plane constructed by MSH-CNN and weighted Procrustes analysis algorithm was 0.73°±0.50°, in which the average position error of the twenty-one facial landmarks automatically determined by MSH-CNN was (1.13±0.24) mm, the maximum position error of the orbital area was (1.31±0.54) mm, and the minimum position error of the nasal area was (0.79±0.36) mm., Conclusion: This research combines deep learning algorithms and Procrustes analysis algorithms to realize the fully automated construction of the three-dimensional midsagittal plane, which initially achieves the construction effect of clinical experts. The obtained results constituted the basis for the independent intellectual property software development.

Objective: To automatically construct lips symmetry reference plane (SRP) based on posed smile, and to evaluate its advantages over conventional digital aesthetic design., Methods: Eighteen subjects' three-dimensional facial and dentition data were gathered in this study. The lips SRP of experimental groups were used with the standard weighted Procrustes analysis (WPA) algorithm and iterative closest point (ICP), respectively. A reference plane defined by experts based on regional ICP algorithm, served as the truth plane. The angle error values between the lips SRP of WPA algorithm in the experimental groups and the truth plane were evaluated in this study, and the lips SRP of ICP algorithm of the experimental groups was calculated in the same way. The lips SRP based on posed smile as a reference for aesthetic design and evaluate preliminary clinical application., Results: The average angle error between the lips SRP of WPA algorithm and the truth plane was 1.78°±1.24°, which was smaller than that between the lips SRP of ICP and the truth plane 7.41°±4.31°. There were significant differences in the angle errors among the groups ( P < 0.05). In the aesthetic design of anterior teeth, automatically constructing the lips SRP of WPA algorithm based on posed smile and the original symmetry plane by re-ference compared with the prosthetic design, the subjects' scores on the lips SRP of WPA algorithm based on posed smile (8.48±0.57) were higher than those on the original symmetry plane (5.20±1.31)., Conclusion: Automatically constructing the lips SRP of WPA algorithm based on posed smile was more accurate than ICP algorithm, which was consistent with the truth plane. Moreover, it can provide an important reference for oral aesthetic diagnosis and aesthetic analysis of the restoration effect. In the aesthetic design of anterior teeth, automatically constructing the lips SRP of WPA algorithm based on posed smile can improve the patients' satisfaction in esthetic rehabilitation.

A total of 568 paintings of herbaceous plants and woody plants as medicine were involved in Ben Cao Tu Jing , accounting for 60% of the total drug illustrations and 76% of the botanical medicine paintings. These medicinal paintings can be classified into four types: original plant paintings, medicinal material paintings, plant and medicinal material paintings, and plant and their habitat paintings. The original plant paintings can be specifically divided into five sections: the whole plant paintings with roots, partial aerial part paintings with roots, plant paintings with ground lines, rootless plant paintings, and broken branch paintings. Among them, the drawings of " the broken branch paintings " and " the whole plant paintings with roots " are consistent with the basic principles of collecting plant specimens. Additionally, "the plant and medicinal material paintings " and "the medicinal material paintings "reflect that they were drawn based on the market survey of medicinal materials or collected medicinal materials specimens. These medicine painting demonstrate rich characteristics of medicinal plants and medicinal materials and a high artistic quality with realistic details.These paintings in Ben Cao Tu Jing echoes Tu Jing , combine the art of painting with the cognition ofnatural science, as the rudiment of early paintings of plant science.

Objective: To compare the effectiveness of loop-mediated isothermal amplification (LAMP) assay and microscopic examinations for detection of Schistosoma japonicum infections in Oncomelania hupensis in transmission-interrupted regions, so as to provide insights into the optimization of snail surveillance tools in these regions., Methods: Four hilly schistosomiasis-endemic villages where transmission interruption was achieved were selected in Heqing County of Yunnan Province as the study villages, including Xinzhuang and Gule villages in hilly regions and Lianyi and Yitou villages in dam regions. Snail survey was performed by means of systematic sampling combined with environmental sampling in July 2018. All captured snails were identified for S. japonicum infections using microscopy. In addition, 10 to 20 snails were randomly sampled from each snail habitat following microscopy, numbered according to environments and subjected to LAMP assay. The positive rate of settings with S. japonicum -infected snails was compared among villages., Results: A total of 7 949 living snails were captured from 83 snail habitats in 4 villages, and no S. japonicum infection was detected in snails. There were 226 mixed samples containing 1 786 snails subjected to LAMP assay, and positive LAMP assay was found in 3 mixed samples from 3 snail habitats in 2 dam villages. The positive rates of settings with S. japonicum -infected snails were comparable between Lianyi Village (one setting) and Yitou Village (2 set tings) (5.89% vs. 14.29%, P = 0.344). However, the overall positive rate of settings with S. japonicum -infected snails was significantly higher in dam villages (9.67%, 3/31) than in hilly villages (0) ( P = 0.048)., Conclusions: LAMP assay is more sensitive to detect S. japonicum infections in O. hupensis than conventional microcopy method, which may serve as a supplementary method for detection of S. japonicum infections in O. hupensis in high-risk snail habitats in hilly transmission-interrupted regions.

Objective: To analyze the clinical characteristics of chronic total coronary occlusion (CTO) combined with bifurcation lesions and the features of coronary intervention and perioperative complications. Methods: This study adopted retrospective cross-sectional research methods and included 673 patients who underwent interventional therapy for chronic total occlusion in Beijing Anzhen Hospital. According to whether there were side branches (diameter ≥2 mm) within 5 mm before and after the CTO occlusion segment, patients were divided into bifurcation group (337 cases) and non-bifurcation group (336 cases). The measurement data did not conform to the normal distribution and were represented as M ( Q 1 , Q 3 ). The clinical risk factors, coronary angiography characteristics, interventional treatment strategies and perioperative complications were compared between the two groups. Results: The patients in the bifurcation group were 60 (51, 65) years old, and 86.6% (292 cases) were male; the patients in the non-bifurcation group were 60 (52, 66) years old, and 83.0% (279 cases) were male.Coronary artery disease in all patients was mainly multivessel disease, of which three-vessel disease accounted for 59.9% (403 cases) and double-vessel disease accounted for 25.4% (171 cases).The target vessel in the bifurcation group was predominantly left anterior descending artery (62.3%, 210 cases), and the target vessel in the non-bifurcation group was more common in the right coronary artery (56%, 188 cases). The target vessel diameter was larger in the bifurcation group (2.91(2.71, 3.24) mm vs 2.80(2.55, 3.13) mm, P <0.001). Most patients used the antegrade technique (88%, 592 cases), and the use of antegrade technique in the bifurcation group (91.9%, 307 cases) was higher than that in the non-bifurcation group (84.8%, 285 cases) ( P =0.012). After CTO-PCI, 72.8% (490 cases) of patients achieved successful angiography. A total of 73 patients (10.8%) had perioperative complications, and there was no statistical difference between the two groups. However, the incidence of perioperative myocardial infarction was higher in the bifurcation group (5.9%, 20 cases) than non-bifurcation group (2.7%, 9 cases) ( P =0.038). Conclusions: CTO complicated with bifurcation lesions are very common in clinical practice. Most patients with CTO have multiple coronary artery disease at the same time. The target vessel is more common in the left anterior descending artery, and the diameter of the vessel is larger. It is more common to use antergrade technique, accompanied by more perioperative myocardial infarctions.

To explore the technical process and the therapeutic effect of using sequential surgical guide with independent intellectual property rights assisting immediate implantation and restoration of the full arch, with the support from the periodontal splint for mobile supporting teeth, patients with severe periodontitis who planned to undergo immediate full arch implantation were recruited from August 2019 to December 2020 at the Department of Prosthodontics, Department of Periodontology, Department of Implantology and First Clinical Division, Peking University School and Hospital of Stomatology. Through the procedure of collecting preoperative maxillofacial data, making systematic diagnostic design, making periodontal splints fixation, producing surgical guide, and carrying out guided surgery for full arch immediate implantation, eight cases were included. By registering the postoperative cone-beam CT (CBCT) with the preoperative data, the difference between the actual three-dimensional position of the implants and the virtual design was observed, and the accuracy of the implant placement position guided by the sequential guide was statistically analyzed using SPSS 25.0 software. Analysis indicators include coronal and apical global displacement, coronal horizontal and vertical displacement, apical horizontal and vertical displacement, and angular deviation. Results revealed that the 8 patients [2 males and 6 females, aged (49.0±9.3) years (38-65 years)] of recruited cases included 7 cases of maxilla and 1 cases of mandible. A total of 48 implants, of which 44 implants were placed upright and 4 were placed tilted, 16 implants in the anterior region and 32 implants in the posterior region. No guide plate fracture or damage to important anatomical structures were reported. The overall displacement at the coronal point [(0.83±0.48) mm] and the global displacement at the apical point [(1.36±0.57) mm] were within the clinically acceptable safety range, and the horizontal displacement and vertical displacement at the coronal point, horizontal displacement and vertical displacement at the apical point, and the angle deviation of implants axial have no statistic significant difference in the anterior and posterior region ( P >0.05). Periodontal splints combined with sequential surgical guides to assist patients with severe periodontitis for immediate full arch implantation and immediate restoration can expand the indications of guide assisted implant surgery. It meets the safety requirements in clinical applications.

Objective: To investigate the change of endo-sinus bone height and bone volume in osteotome sinus floor elevation (OSFE) without bone graft but placing implants simultaneously by using cone beam computed tomography (CBCT) and three dimensional analysis, and to find the impacting factors on endo-sinus bone augmentation., Methods: OSFE was performed in 38 edentulous patients with missing teeth at posterior maxillary region, and 44 implants were placed and referred for OSFE using no graft materials. CBCT was performed pre-surgery and 9－68 months post-surgery when the patients encountered another implant surgery. The gained bone height at mesial, distal, buccal and palatal sites around the implant in sinus were measured, volumetric measurements of the endo-sinus gained bone volume (ESGBV) in the elevated region were calculated by Mimics software. Univariate analysis and multiple linear regression were performed to investigate the impacting factors on the gained bone height and ESGBV. Marginal bone loss was recorded according to the periapical radiography after implant restoration., Results: The mean residual bone height (RBH) pre-surgery was (3.41±1.23) mm, the mean protruded length (PL) into sinus of implant post-surgery was (3.41±1.28) mm, the mean endo-sinus gained bone height was (2.44±1.23) mm at distal sites, (2.88±1.20) mm at mesial sites, (2.83±1.22) mm at buccal sites and (2.96±1.16) mm at palatal sites, the mean endo-sinus gained bone height at distal sites was significantly lower than the other three sites ( P < 0.05). The average endo-sinus gained bone height was (2.78±1.13) mm. The mean ESGBV was (122.15± 73.27) mm 3 . Univariate analysis showed the more RBH, the less bone height gained in sinus, which existed at buccal, lingual, mesial and distal sites ( P < 0.001), and the more RBH, the smaller ESGBV gained ( P =0.012). The ESGBV was significantly higher in the subjects whose bone generation period was more than 24 months than those whose bone generation period less than 24 months ( P =0.034). The more PL, the more bone height and ESGBV gained ( P =0.008). Multivariate analysis showed after adjusting factors of gender, age, smoking, width of sinus floor, thickness of sinus membrane pre-surgery, diameter and length of the implant, PL and bone generation period was positively correlated with mean endo-sinus gained bone height and ESGBV, while RBH negatively correlated with mean endo-sinus gained bone height. During the follow-up, the mean marginal bone loss was 0 (0－1.41) mm and all the implants loaded successfully., Conclusion: OSFE without bone graft but with placed implant simultaneously can increase endo-sinus gained bone height and ESGBV. RBH, PL and bone generation period are the significant factors impacting endo-sinus bone augmentation.

Objective: To establish a novel method based on three-dimensional (3D) shape analysis and weighted Procrustes analysis (WPA) algorithm to construct a 3D facial symmetry reference plane (SRP), automatically assigning weight to facial anatomical landmarks. The WPA algorithm suitability for commonly observed clinical cases of mandibular deviation were analysed and evaluated., Methods: Thirty patients with mandibular deviation were recruited for this study. The 3D facial SRPs were extracted independently based on original-mirror alignment method. Thirty-two anatomical landmarks were selected from the overall region by three times to obtain the mean coordinate. The SRP of experimental groups 1 and 2 were using the standard Procrustes analysis (PA) algorithm and WPA algorithm, respectively. A reference plane defined by experts based on regional iterative closest point (ICP) algorithm, served as the ground truth. Three experts manually selecting facial regions with good symmetry for original model, and common region was included in the study. The angle error values between the SRP of WPA algorithm in the experimental group 1 and the truth plane were evaluated in this study, and the SRP of PA algorithm of experimental group 2 was calculated in the same way. Statistics and measurement analysis were used to comprehensively evaluate the clinical suitability of the WPA algorithm to calculate the SRP. A paired t -test analysis (two-tailed) was conducted to compare the angles., Results: The average angle error between the SRP of WPA algorithm and the ground truth was 1.53°±0.84°, which was smaller than that between the SRP of PA and the ground truth (2.06°±0.86°). There were significant differences in the angle errors among the groups ( P < 0.05). For the patients with severe mandibular deviation that the distance between pogonion and facial midline greater than 12 mm, the average angle error of the WPA algorithm was 0.86° smaller than that of the PA algorithm., Conclusion: The WPA algorithm, based on weighted shape analysis, can provide a more adaptable SRP than the standard PA algorithm when applied to mandibular deviation patients and preliminarily simulate the diagnosis strategies of clinical experts.

Objective: To establish a method for the production of digital individual tooth tray based on three-dimensional (3D) scan, computer-aided design (CAD) and 3D printing, and to evaluate the effect of impression taking of full-arch crown abutments by digital individual tooth tray technique and conventional method through in vitro study., Methods: The full crown preparation was performed on all the fourteen resin teeth in a standard model of mandibular dentition. The surface data of prepared abutments was collected by 3D scanning. A new project was created in a dental CAD software including all the fourteen teeth in the mandibular dentition. The design modules of anatomy crown and coping were selected for each tooth. The dentition was divided for three sections: right posterior teeth, anterior teeth, and left posterior teeth areas. The connector design was added between the abutments within the same section. The scanned data of the abutments were imported. The occlusal plane and insertion path were determined. The position of margin line, as well as the shape of anatomy crown and connector as the main body of the individual tooth tray were designed for each abutment. The shape of coping was generated as the space for holding the impression material. The finalized data of the main body was imported into Geomagic software. The retentive attachment was added at the external surface and the tissue stop was formed at the internal surface. The completed individual tooth tray was manufactured by 3D printing with resin material. The data of full-arch crown abutments were modified and printed. The conventional dentition trays A and B, as well as digital individual tooth tray were designed and printed for four copies each. The polyether impressions of the full-arch abutments were made by conventional one-step method using dentition tray A, and by sectional-impression technique using digital individual tooth tray and dentition tray B for four times each. The time spent for each impression taking and the numbers of defects at the shoulder and axial/occlusal surface in each impression were recorded. The impression quality of each abutment was evaluated. The overall quality distribution and the pass rate of abutments between the two methods were analyzed., Results: The impressions made by conventional method had more defects at shoulder than those made by digital individual tooth tray technique. No difference of the number of defects at axial/occlusal surface between the two methods was observed. The digital individual tooth tray technique for the full-arch abutment impression exhibited higher pass rate of abutments and better quality of impression, compared with conventional methods., Conclusion: A new method for the production of digital individual tooth tray based on digital scanning, CAD and 3D printing was established. Compared with conventional method, using digital individual tooth tray technique for impression taking of full-arch abutments can achieve better effect.

Objective: To explore the effect and mechanism of peroxiredoxin1 (PRDX1) in epithelial mesenchymal transformation (EMT) of gastric cancer cells. Methods: The expression of PRDX1 protein was detected by immunohistochemistry (IHC) in 70 paraffin specimens of cancer and normal mucosa adjacent to gastric cancer, and the relationship between PRDX1 protein and clinicopathological characteristics was analyzed. Then PRDX1-small interfering RNA (siRNA) was synthetized and transfected into human gastric cancer cell line AGS, and 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) assay was used to test cell proliferation. Transwell chamber assay was employed to test invasion of cells. Real-time quantitative polymerase chain reaction (RT-qPCR) and western blot were utilized to test the expressions of PRDX1, E-cadherin, N-cadherin, vimentin, and claudin-1. Results: The positive rate of PRDX1 protein expression in gastric cancer was 81.4%, higher than that in normal mucosa (27.1%, P <0.05). The expression of PRDX1 protein was related to invasive depth and lymph node metastasis of gastric cancer ( P <0.05). The expressions of PRDX1 mRNA and protein in AGS cells (2.216±0.445, 1.212±0.136), were higher than those in GES-1 cells (0.342±0.041, 0.328±0.038) ( P <0.05). When PRDX1-siRNA was transfected into AGS cells, the proliferation of AGS cells was significantly inhibited (all P <0.05). The invasion and migration rate of AGS cells in the transfection group [(112.00±17.98), (50.87±9.79)%] were significantly lower than those of the negative control group [(192.50±22.02), (83.03±8.67)%] and blank control group [(193.83±22.40), (82.40±7.21)%] (all P <0.05). The expressions of mRNA and protein of N-cadherin, vimentin and claudin-1 decreased, while the expression of E-cadherin increased when PRDX1-siRNA was transfected into AGS cells ( P <0.05). Conclusion: PRDX1 may promote the development of gastric cancer by regulating the EMT of gastric cancer cells.

Objective: To investigate the therapeutic effect of simple tunica albugineaincision and ventral penile lengthening surgery on the correction of penile curvature due to asymmetry of the cavernous bodies in hypospadias. Methods: A retrospective analysis was performed in 39 children with hypospadias who underwent simple tunica albuginea incision and ventral penile lengthening surgery for correcting asymmetry of the cavernous bodies from January 2016 to December 2018(36 of them were from Department of Pediatric Urology surgery, The Children's Hospital, Zhejiang University School of Medicine, and 3 from Department of Urology surgery, Affiliated Hospital ofJiaxing University), all of whom aged from 0.5 to 5, with a median age of 1.1 years. During the first stage of the operation, firstly penile skin and sarcoma was released by completely degloving the skin and fascia of penis, secondly the factor of short urethral plate was solved by transection of urethral plate, and then the dorsal length of penis (A), the ventral length of the penis before and after straightening by incision of tunica albuginea (B and C) were measured and recorded; onto the second stage of the operation, an artificial erection test was performed to observe the curvature of the penis, the dorsal and ventral length of the penis (D and E) were measured. The dorsal and ventral length of the penis before and after straightening were compared. Results: The dorsal length of penis (A) was 33-39(35.6±3.2) mm, the length of ventral length of penis before straightening (B) was 28-35 (29.8±2.8) mm and the length of ventral length of penis after straightening (C) was 32-38 (34.3±2.1) mm, which were measured during the first stage of operation, and the difference between B and C was statistically significant ( P <0.05), while the difference between A and C was not statistically significant ( P >0.05). The dorsal length of penis (D) was34-41 (36.4±2.5) mm and the ventral length of penis (E) was 33-40 (35.7±3.6) mm, which were measured during the second stage of operation, and there was no significant difference between D and E ( P >0.05). The degree of penile curvature at the time of erection was less than 15° by measuring with the side photos in all patients during 0.5 to 2.5 years of follow-ups with an average of 1.7 years. Conclusions: Penile curvature due to the asymmetry of the cavernous bodies could be effectively corrected by simple incision of ventral tunica albuginea, which showed a good result of early follow-up. The effect of this surgery on ventral penile straightening could be verified by measuring and comparing the ventral and dorsal length of penis during surgery.

Fabrication of conventional complete dentures involves a complex restoration method, requiring significant time and typically involving primary impressions, definitive impressions, jaw relation records, clinic try-in, and complete denture placement, which has been used for nearly a century without change. A novel digital system named Functionally Suitable Denture (FSD) was researched and developed so as to reduce clinical steps, operation difficulties and errors of complete denture restoration. It pioneered a unique diagnostic complete denture aided by computer aided design (CAD) & 3D printing, by which, the functional impression, jaw relation, and try-in (3 steps) were simplified to 1 step, thus the number of visits to the dentist was reduced by 2 times. Moreover, for the first time, it put forward a CAD software of template matching based on the expert design, which was an efficient and intelligent design scheme, and the excellent denture experts' experience and skills could be inherited and iterated. The system included the 3D scanner with appropriate accuracy and high efficiency, the CAD software, the special 3D printer and process software, and the innovative clinical operation process. The Patent Cooperation Treaty (PCT) patent international search report showed that all the 15 claims of the technology were of novelty, creativity and industrial utility. All the digital products were independently developed and made by Peking University School and Hospital of Stomatology, China. The design and manufacture process of denture prosthesis was fast, simple and accurate. At the same time, personalized functional and aesthetic matching of the patients after wearing prosthesis was realized. It effectively solved the global problems of "slow, difficult and inaccurate" of the traditional manual technology of complete denture, and brought good news to edentulous patients. Compared with the traditional complete denture treatment, FSD system has a wide range of applications for different types of edentulous patients, including those with severe resorption of the alveolar ridge or a high occlusal force. Furthermore, the low-cost of 3D printers, compared with expensive milling machines, may make the approach more accessible. This review describes that our research is related to the development of the FSD system, including multi-source data acquisition technology, three generations of complete denture design software, 3D printing systems of individual tray and complete denture pattern, the clinical and laboratory operation process of the FSD system.

Objective: To measure the dimensional data of complete dentures and to design a novel tray for recording maxillomandibular relationship of edentulous patients., Methods: For the measurement, 100 pairs of complete dentures from the clinic were surveyed for the following parameters: a1, the distance between the middle fossa of the upper left and right first molars; a2, the anterior-posterior distance between the middle fossa of the upper first molars and the incisal edge; a3, the width of the upper denture; a4, the anterior-posterior length of the upper denture; a5 1 , the height from the mesio-lingual cusp of the right upper first molar to the saddle surface; a5 2 , the height from the central fossa of the right lower first molar to the saddle surface; a6, the height from the notch of the upper lip frenulum to the upper central incisor edge; a7, the least thickness of the labial saddle base in the upper central incisor region. Based on the data, the trays with different sizes were designed and fabricated, and the key parameters were: b1, the distance between the foramina of screw posts, b2, the anterior-posterior distance between the foramina of the screw posts and the incisal edge; b3, the width of the tray; b4, the anterior-posterior length of the tray; b5 1 , the height of the posterior platform with the screw nut; b5 2 , the height of the screw post; b6, the height of the anterior tray handle; b7, the thickness of the anterior tray handle., Results: The minimum, average and maximum data for each parameter were (in millimeter): a1: 37.1, 44.5, and 59.6; a2: 22.6, 29.0, and 38.1; a3: 48.5, 58.2, and 76.6; a4: 37.4, 50.8, and 61.0; a51: 5.6, 9.5, and 14.7; a52: 3.8, 9.9, and 18.8; a6: 8.9, 16.6, and 24.7; a7: 1.2, 2.8, and 5.9. Based on the data, the trays in small, medium and large sizes were designed and fabricated. In clinical application, the putty silicone rubber impression material was used to reline the tray, meanwhile the posterior platform and anterior tray handle were set as the occlusal plane, then the screw posts were added and adjusted till the proper vertical dimension, after that, the putty silicone rubber impression material was added around the screw posts to record the horizontal maxillomandibular relationship, finally, the anterior surface of the tray handle was used to record the midline of the face and lower edge of the upper lip at rest and with smile., Conclusion: The dimensional data offered reference for the analysis of restoration space in edentulous patients. The tray designed and fabricated in this study may serve as a new tool for recording the maxillomandibular relationship.

With the wide application of digital technology in the field of stomatology, the acquisition of three-dimensional tooth and dentition information through three-dimensional (3D) image data and optical scan data has become an indispensable process in clinical diagnosis and analysis. Cone-beam CT images and optical scanning images have their own characteristics in terms of data acquisition range and the accuracy of data. Single data source is not accurate enough or complete in the delivery of tooth and dental information. At present, two data sources are used to construct a 3D crown root model with high-precision crown and complete root information to meet the requirement of clinical orthodontic functional setup and implant surgical guide design. The integration of tooth crown and root is one of the focused topics of clinical research. This review will summarize the research progress of 3D crown root model construction method, introduce the application of various algorithms, and analyze the characteristics of these approaches, in order to provide reference for clinical application and scientific research.

Intraoral three-dimensional scanning technology has been adopted in stomatology field and developed rapidly with improved accuracy. At present, the scanning accuracy of the intraoral three-dimensional scanners used in restoration of single crown, three unit fixed partial bridge and single implant crown satisfies the clinical requirements. While for restoration of multi-unit fixed, the scanning accuracy is not enough. There are still technical bottlenecks for scanning functional motion boundary of soft tissue, especially for direct acquisition of edentulous functional impressions. Through literature review and analysis, we summarize the intraoral scanning accuracy of oral hard and soft tissues, and analyze the clinical applicability and limitations of intraoral scanning technology, providing reference for clinical application.

Objective: To provide a reference for using intraoral scanners for making clinical diagnostic dentures of edentulous jaws by comparing the accuracy of three intraoral scanners for primary impression and jaw relation record of edentulous jaws., Methods: This study contained 6 primary impressions of the edentulous patients. Each of the impressions consisted of the maxillary primary impression, the mandibular primary impression and the jaw relation record. For each of them, a dental cast scanner (Dentscan Y500) was used to obtain stereolithography (STL) data as reference scan, and then three intraoral scanners including i500, Trios 3 and CEREC Primescan were used for three times to obtain STL data as experiment groups. In Geomagic Studio 2013 software, trueness was obtained by comparing experiment groups with the reference scan, and the precision was obtained from intragroup comparisons. Registered maxillary data of the intraoral scan with reference scan, the morphological error of jaw relation record was obtained by comparing jaw relation record of the intraoral scan with the reference scan. Registered mandibular data with jaw relation record of intraoral scan and the displacement of the jaw position were evaluated. Independent samples t test and Mann-Whitney U test in the SPSS 20.0 statistical software were used to statistically analyze the trueness, precision and morphological error of jaw relation record of three intraoral scanners. The Bland-Altman diagram was used to evaluate the consistency of the jaw relationship measured by the three intraoral scanners., Results: The trueness of i500, Trios 3 and CEREC Primescan scanners was (182.34±101.21) μm, (145.21±71.73) μm, and (78.34±34.79) μm for maxilla; (106.42±21.63) μm, and 95.08 (63.08) μm, (78.45±42.77) μm for mandible. There was no significant difference in trueness of the three scanners when scanning the maxilla and mandible(P>0.05). The precision of the three scanners was 147.65 (156.30) μm, (147.54±83.33) μm, and 40.30 (32.80) μm for maxilla; (90.96±30.77) μm, (53.73±23.56) μm, and 37.60 (93.93) μm for mandible. The precision of CEREC Primescan scanner was significantly better than that of the other two scanners for maxilla (P<0.05). Trios 3 and CEREC Primescan scanners were significantly better than i500 scanner for mandible (P<0.05). The precision of the i500 and Trios 3 scanners for mandible was superior to maxilla (P<0.05). The upper limit of 95% confidence intervals of trueness and precision of three scanners for both maxilla and mandible were within ±300 μm which was clinically accepted. The morphological error of jaw relation record of the three scanners was (337.68±128.54) μm, (342.89±195.41) μm, and (168.62±88.35) μm. The 95% confidence intervals of i500 and Trios 3 scanners were over 300 μm. CEREC Primescan scanner was significantly superior to i500 scanner(P<0.05).The displacement of the jaw position of the three scanners was (0.83±0.56) mm, (0.80±0.45) mm, and (0.91±0.75) mm for vertical dimension; (0.79±0.58) mm, (0.62±0.18) mm, and (0.53±0.53) mm for anterior and posterior directions; (0.95±0.59) mm, (0.69±0.45) mm, and (0.60±0.22) mm for left and right directions. The displacement of the jaw position of the three scanners in vertical dimension, anterior and posterior directions and the left and right directions were within the 95% consistency limit., Conclusion: Three intraoral scanners showed good trueness and precision. The i500 and Trios 3 scanners had more errors in jaw relation record, but they were used as primary jaw relation record. It is suggested that three intraoral scanners can be used for obtaining digital data to make diagnostic dentures and individual trays, reducing possible deforming or crack when sending impressions from clinic to laboratory.

Objective: To explore the possibility of the Smile Lite MDP (Smile Lite Mobile Dental Photograph) portable dental photography system applying in anterior teeth aesthetic photography, and to provide the chance to simplify aesthetic photography process and facilitate communication among patients, dentists and dental technitians., Methods: The Smile Lite MDP photography system combined with the smartphone were used to photograph the front occlusal phase photos of anterior teeth. The photographic conditions including the color temperature parameter, the Smile Lite MDP light position and the intensity settings were explored. The best photographic conditions were chosen by blind evaluation within experienced dentists and technicians through the method of the visual analogue scale/score (VAS) evaluation, which went through statistical analysis to figure out the optimum photograghic conditions. Smile Lite MDP photography system was used to photograph the front occlusal phase photos of anterior teeth under the optimum parameter by different magnifications. The width/height ratio of the central incisor and the front width ratio of the upper anterior teeth in those photos were measured and calculated respectively. The accuracy of the anterior teeth photos taken by Smile Lite MDP photography system was analyzed based on the photographs taken by digital single lens reflex (DSLR) camera., Results: The optimum color temperature parameter of Smile Lite MDP portable camera system was 5 000 K, the optimum magnification was 4 times, the best light position was the side lights of Smile Lite MDP, the optimum intensity of lights was 2 grades. Photos taken by the optimum parameters won the highest score during the VAS evaluation and the result of statistical analysis had significant difference compared with other groups (P<0.05). When comparing the photos of the upper anterior teeth taken by the Smile Lite MDP portable photography system using 4 times magnification or by DSLR using the standard parameters, there was no significant difference neither in the width/hieght ratio of the central incisor nor in the front width ratio of the upper anterior teeth (P>0.05)., Conclusion: The Smile Lite MDP portable dental photography system applying in anterior teeth aesthetic analysis photography was capable to show the color and shape of anterior teeth in an accurate way by using the right photography parameters. Therefore, Smile Lite MDP portable dental photography system was considered to be a simple and easy photographic tool in clinical work.

Objective: To analyze the distribution and area of occlusal contacts of clinical dental model using three kinds of digital analysis methods, to compare the results of these methods and traditional occlusal analysis method, and to further analyze the characteristics of each digital analysis method., Methods: A set of plaster models of normal subjects was selected. The models were scanned by lab scanner 3shape E4 and the files were exported in a stereolithography file format. In 3D analysis software Geomagic Studio 2013 and Geomagic Qualify 2013, the corresponding results of 3D occlusal contact distribution and occlusal contact area were obtained through three digital analysis methods: "3D color difference map method", "point cloud analysis method", and "virtual articulating paper method". The occlusal contact distribution and occlusal contact area were also obtained by two traditional occlusal analysis methods: "silicone interocclusal recording material method" and "scanned articulating paper mark method". A threshold of 100 μm was used to analyze the occlusal contacts and 100 μm was also the thickness of articulating paper used in this study. The results of these five different occlusal analysis methods were evaluated qualitatively and quantitatively., Results: The results of 3D occlusal contact distribution obtained by the above five methods were basically consistent. The total occlusal contact area obtained by 3D color difference map method, point cloud analysis method, virtual articulating paper method, silicone interocclusal recording material method and scanned articulating paper mark method were 133.10 mm², 142.08 mm², 128.95 mm², 163.31 mm², and 100.55 mm² respectively. There was little difference between the results of three digital analysis methods. The results of occlusal contact area obtained by the digital methods and the traditional methods were different., Conclusion: The three digital analysis methods can provide reliable and accurate analysis results of occlusal contact distribution and occlusal contact area of dental model. The results obtained by these methods can serve as references for the digital occlusal surface design of dental prosthesis and clinical occlusal analysis.

Objective: To evaluate the three-dimensional (3D) reconstruction accuracy of the intercuspal occlusion (ICO) of the dental casts, by the dental articulator position method, and provide a reference for clinical application., Methods: The standard dental casts in ICO were mounted on average values articulator, and five pairs of milling resin cylinders were respectively attached to the base of both the casts. 100 μm articulating paper and occlusal record silicone rubber were used to detect the occlusal contact number between the posterior teeth of casts mounted on articulator in ICO. The occlusal contact numbers NA detected by the two methods were calculated simultaneously, as the reference. After the upper and lower casts were scanned separately, and the buccal data of casts in ICO were scanned with the aid of the dental articulator position, registration was carried out utilizing the registration software. Then the digital casts mounted in ICO as well as the buccal occlusal data were saved in standard tessellation language (STL) format. Geomagic Studio 2013 software was used to analyze the contact number NS between digital upper and lower casts by the "deviation analysis" function. The differences were compared between N S and N A , to evaluate the sensitivity and positive predict value (PPV) of the model scanner to reproduce the occlusal contact with the aid of dental articulator position. The distance D R between the centers of the circles at the top surface of the upper and lower corresponding cylinders was obtained by the three-coordinate measuring system Faro Edge, as the reference value. The Geomagic Studio 2013 software was used to construct the cylinders of digital casts and the distance D M between the centers of the circles at the top surface of the corresponding cylinders were measured, as the test value. The one-sample T test was used to analyze the variable differences between D M and D R ., Results: The PPV of reproducing the occlusal contact point was 0.76 and sensitivity was 0.81. The distance error of the opposite cylinder was (0.232±0.089) mm. There was no statistical difference between the feature points 5-5', while there were statistical differences between the other feature points., Conclusion: By the dental articulator position method, the model scanner reproduces the occlusal contact point with high sensitivity and PPV, and that meets clinical needs. Meanwhile, the distance between the feature points is greater than the reference value, which will lead to occlusal disturbance, and require clinical grinding.

Objective: To study the visual sensitivity threshold of physician's naked eye to the difference of nasolabial angle in edentulous jaw patients, and to provide a reference value for the study of aesthetic evaluation of soft tissue profile for the difference of nasolabial angle that can be recognized by human eyes., Methods: Three-dimensional facial images of three edentulous patients with different diagnostic dentures introoral were obtained. Lateral screenshots of each patient's three-dimensional facial image with the same scale were obtained by using reverse engineering software (Geomagic studio 2014).The screenshot of the patient's three-dimensional facial image with suitable lip support (The suitable lip support was confirmed by both patients and prosthodontists who had clinical experience for more than 20 years) was taken as the reference picture, and the remaining pictures were grouped with it respectively. All the pictures were observed in random order by the subjects. Fifteen dentists were asked to judge the difference of nasolabial angle between the two pictures of each group on the computer screen. The difference of nasolabial angle between the two pictures in each group was measured and calculated. The ROC curve was drawn, and the best cut-off value was calculated as the visual sensitivity threshold., Results: The data of the 15 subjects were used to draw ROC curves separately. The maximum and minimum best cut-off values were 5.55 degrees and 3.12 degrees respectively. The ROC curve of the whole 15 subjects was drawn after data aggregation, and the best cut-off value was 5.36 degrees (AUC=0.84>0.5, P=0.000<0.05). When the difference of nasolabial angle was above 5.36 degrees, the subjects could recognize it effectively., Conclusion: There is a visual limit in the observation of the nasolabial angle with the naked eye. In this study, a visual sensitivity threshold of 5.36 degrees for the difference of the nasolabial angle was obtained. The difference of nasolabial angle below this value can be regarded as no clinical significance. This result provides a reference value for human eyes to recognize the difference of nasolabial angle in soft tissue profile aesthetic evaluation. It can be applied to the aesthetic evaluation of soft tissue profile and can be used as the error level of related research with nasolabial angle as an index for accuracy evaluation.

Objective: To establish a quantitative three-dimensional method based on intraoral scan to evaluate the changes of soft tissue, and to evaluate the changes of supracrestal gingival thickness (SGT) in skeletal class Ⅲ patients induced by periodontal regenerative and corticotomy surgery (PRCS). Methods: Twenty-two systematically and periodontally healthy skeletal class Ⅲ patients (4 males and 18 females, aged between 19 and 35 years), who were in need of combined orthodontic-orthognathic treatment and referred to the Department of Periodontology from the Department of Orthodontics and the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from January, 2018 to March, 2019, were collected in the study. The teeth involved were 112 anterior teeth (46 maxillary anterior teeth and 66 mandibular anterior teeth). PRCS in anterior tooth area was conducted before orthodontic decompensation. Probing depth (PD), bleeding index (BI) and keratinized gingiva width (KGW) were recorded before surgery and 6 months post-surgery. The intraoral digital impressions of maxillary and mandibular anterior teeth were obtained by 3-shape intraoral scanner before surgery and 6 months after surgery. The Standard Tessellation Language (STL) files were processed using Geomagic qualify 12.2 software to establish the soft tissue morphological measurement model, and to quantitatively analyze the changes of gingival thickness situated 1 to 2 mm apical to the free gingival margin on the median sagittal measurement plane. Results: Probing depth and bleeding index had no significant difference before and 6 months after operation ( P >0.05). KGW in 6-month post-operation group [(5.18±2.32) mm] was significantly higher than that in pre-operation group [(4.22±1.43) mm] ( P< 0.05). Supracrestal gingival thickness situated 1 to 2 mm apical to the free gingival margin also significantly increased 6 months after surgery ( P< 0.05). The changes of gingival thickness situated 1 to 2 mm apical to the free gingival margin in the upper anterior area were (0.68±0.56) and (1.00±0.69) mm, respectively. The changes in the lower anterior area were (0.38±0.42) and (0.58±0.45) mm, respectively. The gingival changes of the upper anterior teeth were also significantly higher than those of the lower anterior teeth ( P< 0.01). Conclusions: The described quantitative measurement based on intraoral scan could be an effective method for quantitative evaluation of the changes of soft tissue. PRCS could safely increase the supracrestal gingival thickness as well as KGW in skeletal class Ⅲ patients who were in need of combined orthodontic-orthognathic treatment.

Objective: To evaluate the risk factors of coloanal anastomotic stricture after laparoscopic intersphincteric resection (Lap-ISR) for patients with low rectal cancer. Methods: A retrospective case-control study was performed to collect clinicopathological data from a prospective database (registration number: ChiCTR-ONC-15007506) at the Department of Colorectal Surgery, the Characteristic Medical center of PLA Rocket Force. From June 2011 to August 2018, a total of 144 consecutive patients with low rectal cancer who underwent Lap-ISR were enrolled in the study. Inclusion criteria: (1) reconstruction of digestive tract by end-to-end hand-made coloanal anastomosis (HCAA); (2) distance from lower tumor margin to anorected sphincter ring < 1 cm and distance from lower tumor margin to intersphincteric groove ≥ 1 cm; (3) T1-3 stage tumor with expected negative circumferential resection margin evaluated by preoperative MRI or 3D endoanal ultrasound; (4) rectal cancer confirmed as well- or moderately-differentiated adenocarcinoma; (5) preoperative Wexner incontinence score >10 points. Exclusion criteria: (1) follow-up period less than 3 months; (2) multiple primary cancers; (3) undergoing colonic J-pouch, coloplasty or reconstruction of end-to-side coloanal anastomosis; (4) death within perioperative period (within 3 months after surgery). Coloanal anastomotic stricture was diagnosed if the index finger or 12 mm electronic colonoscope had obvious resistance through the anastomosis or new rectum, or could not pass, accompanied by clinical symptoms such as difficult defecation and anal incontinence. Degree of anastomotic stricture was divided into 3 grades: grade A required anal enlargement, laxative or enema to assist defecation without active surgical treatment; grade B required surgery or endoscopic intervention; grade C required definitive ostomy, including unreducible preventive ileostomy or permanent colostomy. Univariate and multivariate analysis were used to evaluate the effects of 28 variables, including baseline data (age, gender, body mass index, neoadjuvant therapy, etc.), tumor-related factors (distance between tumor low margin and anal edge, maximum diameter of tumor, TNM staging, etc.), surgery-related factors (operation time, intraoperative blood loss, ISR procedure, anastomotic height, etc.) and anastomotic leakage, on the postoperative coloanal anastomotic stricture. Univariate analysis used χ(2) test or Fisher's exact test, then factors with P <0.05 were further included in multivariate analysis using logistic regression. Results: A total of 144 patients were enrolled in the study, including 90 males and 54 females with a median age of 59 years and median BMI of 24.88 kg/m(2). R0 resection rate was 96.5% (139/144). Median tumor distal resection margin was 1.5 (0.5 to 3.0) cm. Median follow-up was 31.5 (4 to 86) months. Coloanal anastomotic stricture was observed in 19 patients (13.2%), including 3 cases (2.1%) of grade A, 9 cases (6.2%) of grade B, and 7 cases (4.9%) of grade C. The median interval from the initial surgery to diagnosis of anastomotic stricture was 7 (1 to 31) months. Univariate analysis showed that male (χ(2)=6.795, P =0.009), radiotherapy (χ(2)=13.330, P =0.001), operation type of ISR (χ(2)=7.996, P =0.013), and anastomotic leakage (χ(2)=10.198, P =0.004) were associated with the postoperative coloanal anastomotic stricture. Multivariate analysis further indicated that male (OR=5.975, 95% CI: 1.209-29.534, P =0.028), postoperative radiotherapy (OR=8.748, 95% CI: 2.397-31.929, P =0.001), and anastomotic leakage (OR=6.313, 95% CI: 1.834-21.734, P =0.003) were independent risk factor of postoperative coloanal anastomotic stricture. Conclusion: For male patients, or patients with postoperative radiotherapy or anastomotic leakage, close follow-up should be carried out to prevent postoperative coloanal anastomotic stricture following Lap-ISR.

Objective: This study explored the prognostic factors of patients with supratentorial anaplastic gliomas and tried to propose a prognostic scoring scale with aim to provide theoretical reference for clinical treatment. Methods: The clinical data of 198 patients surgically treated for primary anaplastic glioma in Henan Provincial People's Hospital between Jan 2009 and Jan 2018 were reviewed. Univariate and multivariate analyses were used to identify prognostic factors with methods of Kaplan-Meier plot and Cox proportional hazard model, respectively. Based on the prognostic factors, a scoring scale was thereby proposed. Results: Univariate analysis results showed age, tumor location, tumor diameter, preoperative KPS, extent of resection, radiotherapy, chemotherapy, pathology with oligodendroglial components, 1p/19q, IDH, MGMT were significantly correlated with survival ( P< 0.05). Multivariate analysis results showed age ≥45 years old, tumor diameter ≥6 cm, preoperative KPS<70, without radiotherapy, 1p/19q intact, MGMT promoter unmethylation were independent prognostic risk factors ( P< 0.05). Patients were scored with 0-6 points based on the formulation that each independent prognostic risk factor was assigned with 1 point. Then patients were further grouped according to the score. Those with less than 2 points were low-risk group, equal to 2 points were medium-risk group, equal to 3 points were high-risk group, more than or equal to 4 points were extremely high-risk group. There were significant differences in survival between the different groups ( P< 0.000 1). Conclusions: The higher score, the shorter survival time. This prognostic scoring scale can provide a theoretical basis for the prognosis estimation of patients with anaplastic glioma and help to carry out personalized clinical treatment.

Objective: To establish a reference dental model used for trueness evaluation of photo-curing 3D printing technologies, and to establish a multidimensional trueness evaluation method based on the reference dental model, which can yield a comprehensive objective evaluating result., Methods: A reference dental model was designed in 3ds Max 2018 software based on the statistical analysis results of dental crown and dental arch of Chinese population in previous studies in order to simulate a real dental model. This model was made up of several simple geometrical configurations, which could minimize the manual measurement error. Physical models were fabricated using three types of photo-curing three-dimensional printers using different techniques: Objet30 Pro (PJ), Projet 3510 HD Plus (MJP), and Perfactory DDP (DLP). The models were scanned by a laser-scanning device and the files were exported in a stereolithography file format. In Geomagic Studio 2012, 3D shape deviations (including overall 3D deviation, flatness error, parallelism error and perpendicularity error) were measured by several commands using the data obtained from the scanning. With regard to the feature size of the simulated dental crown and dental arch, linear measurements (including mesiodistal diameter, buccolingual diameter, crown height of each simulated dental crown and feature size of dental arch) were recorded for selected landmarks using a digital caliper. The measurement results of feature sizes were used to analyze the occlusal plane percentage error and the occlusogingival direction percentage error., Results: For the 3D shape deviation, the results showed that the printed model made by the Objet30 Pro had the lowest overall 3D deviation, the model made by Projet 3510 HD Plus had the best perpendicularity accuracy and the model made by Perfactory DDP had the best flatness accuracy. In terms of the accuracy of the feature size, the model made by the Objet30 Pro was the most accurate in consideration of the results of the occlusal plane percentage error and the occlusogingival direction percentage error., Conclusion: The reference dental model and the trueness evaluation method using this model is universally applicable in evaluating the trueness of photo-curing three-dimensional printed dental model and can provide a comprehensive objective evaluating result, which can serve as a reference for the clinical use of photo-curing 3D printing technology.

Objective: To explore the clinical value of static and dynamic magnetic resonance imaging (MRI) in evaluating the effect of electrical stimulation combined with biofeedback in the treatment of pelvic organ prolapse postpartum. Methods: A total of 50 primiparas diagnosed as pelvic organ prolapse postpartum from February 2016 to November 2017 were randomly divided into treatment group (24 cases) and control group (26 cases). The control group recovered spontaneously, and the treatment group received electric stimulation combined with biofeedback therapy (6 weeks). All subjects underwent static and dynamic MRI before and after treatment. The thickness of bilateral puborectal muscles, levator ani hiatus area (LHA), H line, M line and levator ani plate angle (LPA) were respectively measured in rest state and strain state at 42 days and 12 weeks postpartum, and the differences of parameters were compared between two groups. Results: (1) Compared with 42 days postpartum, the effective rate of pelvic organ prolapse was 15.4% (4/26) in the control group and 62.5% (15/24) in the treatment group, which was significantly higher than that of the control group ( P< 0.01). (2) Compared with 42 days postpartum, the thickness of bilateral puborectal muscles in the treatment group increased at 12 weeks postpartum, while that of the H line, LHA, M line and LPA in strain state decreased. (3) At 12 weeks postpartum, the thickness of the bilateral puborectal muscle in the treatment group was greater, and LHA, M line, and LPA in strain state were less than that in the control group (all P< 0.05). Conclusion: Electrical stimulation combined with biofeedback therapy can improve pelvic organ prolapse due to vaginal delivery, and the static and dynamic MRI can objectively evaluate the effect of pelvic floor rehabilitation therapy on improving the pelvic floor supporting structure and function, providing an important support and guidance for restoration of postpartum pelvic organ prolapse.

Objective: To establish a quantitative three-dimensional method based on intraoral scan and apply it to evaluation of the facial soft tissue contour alterations following single immediate implant and immediate provisionalization (IIPP) in central incisor via intraoral scanning. Methods: This study was a prospective clinical study. The trial was conducted at Department of Implantology, Peking University School and Hospital of Stomatology, from January 2016 to September 2017. Twenty-nine eligible consecutive patients (15 women, 14 men) with a mean age of (34.3±12.0) were included and received immediate replacement of the failure maxillary single central incisor. A screw-retained immediate restoration was delivered for each patient. At 6-month follow-up, impression was taken and a screw-retained permanent restoration was performed for each patient. The anterior maxillary region was scanned by an intraoral scanning system at pre-surgery and 1-year follow-up. The Standard Tessellation Language (STL) files were output to a dedicated software and superimposed. Mid-facial recession and gingival zenith symmetry at 1-year follow-up were measured in the digital models. Three-dimensional configurations of the contour change volume were calculated and reconstructed for visual analysis. Furthermore, the following parameters were used to analyze the reconstructed volume: mean contour change in thickness (△d), mesio-distal width (D(W)), coronal-apical height (D(H)), contour change at 0, 1, 2, 3, 4, 5 mm apical to the free gingival margin on the implant site. Results: Twenty-seven out of twenty-nine enrolled patients were finally available for analysis. At 1-year follow-up, the mid-facial mucosa level at implant site was (0.23±0.39) mm apical to the gingival zenith of the contralateral tooth. In general, a contour collapse was found in every patient. △d, D(W) and D(H) of the collapsed volume were (0.62±0.22), (11.03±1.74) and (6.82±1.52) mm, respectively. Contour change at 0, 1, 2, 3, 4, 5 mm apical to the free gingival margin on the implant site were (0.54±0.48), (0.87±0.62), (1.03±0.46), (0.96±0.52), (0.90±0.52), (0.89±0.57) mm. Conclusions: The described quantitative measurement based on intraoral scan can be an effective method for assessment of soft tissue contour changes. At 1 year following single IIPP treatment in maxillary incisor, free gingival margin is stable, with only mild recession. The mean level of the facial soft tissue contour collapse is 0.62 mm.

Facial symmetry is a crucial component of human facial esthetics. Along with the increasing pursuit of aesthetic, in recent years, more and more researchers have focused on facial asymmetry assessment, of which determining the facial median sagittal plane is the first and most important step, and it will directly affect the accuracy of asymmetry evaluation and clinical treatment outcome. Limited by technical means, the earlier studies of facial soft tissue asymmetry assessment were mainly based on midline from two-dimensional (2D) images. Along with the development of three-dimensional (3D) measurement and data analysis techniques, new methods such as 3D landmark-based method and mirror-original alignment method have become main trend nowadays. This article systematically reviews the methods of determination of median sagittal plane of facial soft tissue, elaborates the developments and the latest research progress in this field, and discusses the advantages and limitations of each method in order to provide reference for clinical application.

Objective: To investigate effects of benzo(a)pyrene (BaP) on expressions of insulin-degrading enzyme (IDE) and neprilysin (NEP) which have the ability to degrade β-amyloid (Aβ) in neuroglia cells., Methods: Primary mix-neuroglia cells were cultured from newborn SD rats. After exposure to BaP, Aβ 1-42 oligomer or Aβ 1-42 fiber individually or jointly for 24 h, the cell survival rate was measured by cell counting kit-8 (CCK-8). Afterwards, the primary mix-neuroglia cells were divided randomly into six groups: Control group, BaP group (2.00 μmol/L), Aβ 1-42 oligomer group (20.00 mg/L), BaP plus Aβ 1-42 oligomer group, Aβ 1-42 fiber group (20.00 mg/L) and BaP plus Aβ 1-42 fiber group, of which BaP was pretreated for 12 h followed by cotreatment with different aggregated Aβ 1-42 . The expressions of IDE and NEP were measured by quantitative real-time polymerase chain reaction (qRT-PCR) for mRNA level and Western blotting for protein level., Results: The cell survival rate showed no significant differences after treatment with BaP (≤20.00 μmol/L), Aβ 1-42 oligomer (20.00, 40.00 mg/L), Aβ 1-42 fiber (20.00, 40.00 mg/L) or cotreatment with BaP and Aβ 1-42 oligomer or BaP and Aβ 1-42 fiber. Compared with the control group, expressions of IDE and NEP in BaP-treated alone group had no obvious change; however, exposure to Aβ 1-42 oligomer alone significantly increased the mRNA and protein level of IDE (P<0.05), and the BaP pretreatment could significantly inhibit the up-regulated expressions of IDE by Aβ 1-42 oligomer (P<0.05); on the other hand, exposure either to Aβ 1-42 fiber alone or under the BaP pretreatment did not change the mRNA and protein level of IDE and NEP obviously., Conclusion: On the premise of no significant change of cell survival rate, BaP pretreatment inhibited the up-regulated expressions of IDE in primary mixed neuroglia cells under cotreatment with Aβ oligomer, indicating that BaP may disturb degradation of Aβ oligomer and cause deposition of β-amyloid and further induce cognitive decline and acceleration of Alzheimer.

Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose.

Objective: To know the incidence of heat stroke and explore it's prediction model in Pudong New Area of Shanghai. Methods: An epidemiological investigation was conducted on heat stroke cases in Pudong New Area of Shanghai from 2013 to 2017. Daily temperature data during this period were collected to explore it's influence. Results: 246 heat stroke cases were reported and investigated, 70.3% (173/246) of them were male. 170 cases are severe heat stroke, accounting for 69.1%. 28 patients died, accounting for 11.4% of all cases of heat stroke, and 16.5% (28/170) of severe heat stroke cases. Thermoplegia (56.5%, 96/170) was the most popular type among severe heat stroke cases. Heat prostration, heat cramps and mixed type account for 17.1% (29/170) , 12.4% (21/170) and 14.0% (24/170) respectively. Scatter plot and linear regression demonstrated that there was a significant linear relation between number of high temperature days and number of heat stroke cases ( P <0.01) . And the prediction model is: Predictive number of annual heat stroke cases=β×Number of annual high temperature days+Intercept. Leave-one-out cross validation result shows that the predictive number of annual heat stroke cases from 2013 to 2017 were 85.7%, 90.9%, 83.3%, 91.9 and 84.3% respectively. Conclusion: There was a significant linear relation between number of high temperature days and number of heat stroke cases in Pudong New Area. The related work arrangement for heat stroke prevention could be well planed according to the prediction model.

In recent years with the rapid development of digital technology for stomatology, the application field, application model, technical features and technical connotation of the chair-side digital technology has got development and change. The open modular system has gradually replaced the traditional closed system, and the application field of digital technology is no longer limited to chair-side dental restoration, it also has been extend to various kinds of chair-side digital treatment-assisted technology. In this paper, from the engineering point of view, the up to date general connotation of chair-side digital technology was explained, the characteristics and the development of each unit in chair-side digital technology were analyzed, and the application pattern and the localization status were also discussed in this paper. The aim of this paper was to introduce the trend of chair-side digital technological to readers and to better guide clinical application.