Characteristics of alveolar bone loss in severe periodontitis and consideration of rehabilitation with implant / 中华口腔医学杂志

Severe periodontitis is the main cause of tooth loss in adults, with varying degrees of horizontal and vertical alveolar bone loss. In view of the complex alveolar bone defect, a suitable surgery planning should be made on the basis of fully nuderstanding the characteristics of alveolar bone defect in severe periodontitis and the key points of bone augmentation technique, so as to choose an appropriate method for reconstruction of alveolar bone and complete the implantation and restoration to ensure the integrity of dentition, which are important for the long-term stability of periodontal health. Based on clinical experiences and literature review, we summarizes the characteristics of alveolar bone loss in patients with severe periodontitis and the timing of implant placement after bone augmentation surgery, in order to provide reference for implant treatment of severe periodontitis.

Preliminary evaluation of the trueness of 5 chairside 3D facial scanning techniques / 北京大学学报(医学版)

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.

Study on the method of automatically determining maxillary complex landmarks based on non-rigid registration algorithms / 中华口腔医学杂志

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.

Advances in algorithms for three-dimensional craniomaxillofacial features construction based on point clouds / 中华口腔医学杂志

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.

The design method of the digital sequential tooth-sectioning guide for the extraction of mandibular impacted third molars / 中华口腔医学杂志

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.

Preliminary study on three-dimensional morphological reconstruction method for external nose defect based on three-dimensional face template / 中华口腔医学杂志

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.

Primary adrenal NK/T cell lymphoma: a clinicopathologic analysis of six cases / 中华病理学杂志

Objective: To investigate the clinicopathologic features of primary adrenal NK/T cell lymphoma (PANKL). Methods: Six cases of PANKL were collected at Henan Provincial People's Hospital from January 2000 to December 2021. The clinicopathologic features including morphology, immunophenotype, treatment and prognosis were retrospectively analyzed, and relevant literature was reviewed. Results: There were two males and four females. The median age was 63 years (ranged from 57 to 68 years). The tumors involved bilateral adrenal glands in 4 cases and unilateral adrenal gland in 2 cases. The main clinical symptom was low back pain without obvious cause. Serum lactate dehydrogenase (LDH) is elevated in five cases. The imaging feature was rapidly enlarging mass initially confined to unilateral/bilateral adrenal glands. Morphologically, the lymphoid cells were mainly medium-sized with a diffuse growth pattern. Coagulative necrosis and nuclear fragmentation were common. Angioinvasion was seen. Immunophenotypically, the neoplastic cells were positive for CD3, CD56 and TIA-1 while CD5 was negative in 5 cases. All cases were positive for EBER by in situ hybridization with more than 80% proliferative activity by Ki-67. Four cases received chemotherapy, one case underwent surgery, and one case underwent surgery with chemotherapy. Follow-up was done in 5 cases; one case was lost to follow-up. Three patients died with a median survival of 11.6 months (3-42 months). Conclusions: PANKL is rare with highly aggressive clinical presentation and poor prognosis. Accurate diagnosis entails correlation of histomorphology, immunohistochemistry, EBER in situ hybridization and clinical history.

Automatic determination of mandibular landmarks based on three-dimensional mandibular average model / 北京大学学报(医学版)

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.

Effect and Mechanism of Yishen Tongluo Prescription on miR-514a-5p/TNFSF15 Signaling Pathway in MN Rats / 中国实验方剂学杂志

ObjectiveTo explore the molecular mechanism of Yishen Tongluo prescription in inhibiting the apoptosis of glomerular podocytes in rats with membranous nephropathy （MN） based on the miR-514a-5p/tumor necrosis factor superfamily member 15 （TNFSF15） signaling pathway. MethodEighty SD rats were pre-immunized and injected with cationized bovine serum albumin （C-BSA） into the tail vein for inducing MN， and the successfully modeled MN rats were randomly divided into the model group， high-， middle-， and low-dose （26.44， 13.22， 6.61 g·kg-1） Yishen Tongluo prescription groups， and benazepril （10 mg·kg-1） group， with 10 rats in each group， and another 20 healthy rats were classified into the normal group. Rats in each group were gavaged with the corresponding drugs， once a day， for four successive weeks. After the administration， the 24-hour urine total protein （UTP） level， serum total cholesterol （TC）， triglyceride （TG）， albumin （ALB）， creatinine （SCr）， and urea nitrogen （BUN） levels were measured. The miR-514a-5p and TNFSF15 mRNA expression levels in the rat kidney tissue were detected by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， and the expression levels of podocyte marker proteins Nephrin， Podocin， Podocalyxin， Synaptopodin， TNFSF15， and podocyte apoptosis-related proteins B lymphocytoma-2 （Bcl-2）-related X protein （Bax）， Bcl-2-associated death promoter （BAD） protein， and B-cell lymphoma-extra large （Bcl-XL） by immunohistochemistry （IHC）. Western blot was used to detect the expression levels of TNFSF15， Bax， BAD， Bcl-2， and BCL-XL in the rat kidney tissue. The apoptosis rate of rat kidney tissue was measured using the in situ end labeling method （Tunnel）. ResultCompared with the normal group， the level of miR-514a-5p in the kidney tissue was significantly reduced （P<0.05）， and the TNFSF15 mRNA expression was significantly increased （P<0.05）. The expression levels of podocyte marker proteins Nephrin， Podocin， Podocalyxin， and Synaptopodin were down-regulated （P<0.05）. The protein expression levels of TNFSF15， Bax， and BAD were increased （P<0.05）， whereas the Bcl-2 and Bcl-XL protein expression levels were decreased （P<0.05）. The number of apoptotic cells diminished significantly （P<0.05）. Compared with the model group， the level of miR-514a-5p in the kidney tissue was significantly increased （P<0.05）， while the level of TNFSF15 mRNA was significantly decreased （P<0.05）. The expression levels of podocyte marker proteins Nephrin， Podocin， podocalyxin， and Synaptopodin were up-regulated （P<0.05）， whereas the TNFSF15， Bax， and BAD protein expression levels were down-regulated （P<0.05）. Bcl-2 and Bcl-XL protein expression levels rose （P<0.05）. The number of apoptotic cells significantly decreased （P<0.05）. ConclusionYishen Tongluo prescription reduces the apoptosis of rat kidney podocytes and alleviates the kidney injury of MN rats through the miR-514a-5p/TNFSF15 signaling pathway.

Initial establishment of digital reference standardized crown models of the primary teeth / 北京大学学报(医学版)

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.

Preliminary clinical application verification of complete digital workflow of design lips symmetry reference plane based on posed smile / 北京大学学报(医学版)

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.

In vitro evaluation of positioning accuracy of trephine bur at different depths by dynamic navigation / 北京大学学报(医学版)

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.

Deep learning-assisted construction of three-demensional facial midsagittal plane / 北京大学学报(医学版)

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.

Preliminary study on the method of automatically determining facial landmarks based on three-dimensional face template / 中华口腔医学杂志

Objective: To explore the establishment of an efficient and automatic method to determine anatomical landmarks in three-dimensional (3D) facial data, and to evaluate the effectiveness of this method in determining landmarks. Methods: A total of 30 male patients with tooth defect or dentition defect (with good facial symmetry) who visited the Department of Prosthodontics, Peking University School and Hospital of Stomatology from June to August 2021 were selected, and these participants' age was between 18-45 years. 3D facial data of patients was collected and the size normalization and overlap alignment were performed based on the Procrustes analysis algorithm. A 3D face average model was built in Geomagic Studio 2013 software, and a 3D face template was built through parametric processing. MeshLab 2020 software was used to determine the serial number information of 32 facial anatomical landmarks (10 midline landmarks and 22 bilateral landmarks). Five male patients with no mandibular deviation and 5 with mild mandibular deviation were selected from the Department of Orthodontics or Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from June to August 2021. 3D facial data of patients was collected as test data. Based on the 3D face template and the serial number information of the facial anatomical landmarks, the coordinates of 32 facial anatomical landmarks on the test data were automatically determined with the help of the MeshMonk non-rigid registration algorithm program, as the data for the template method to determine the landmarks. The positions of 32 facial anatomical landmarks on the test data were manually determined by the same attending physician, and the coordinates of the landmarks were recorded as the data for determining landmarks by the expert method. Calculated the distance value of the coordinates of facial anatomical landmarks between the template method and the expert method, as the landmark localization error, and evaluated the effect of the template method in determining the landmarks. Results: For 5 patients with no mandibular deviation, the landmark localization error of all facial anatomical landmarks by template method was (1.65±1.19) mm, the landmark localization error of the midline facial anatomical landmarks was (1.19±0.45) mm, the landmark localization error of bilateral facial anatomical landmarks was (1.85±1.33) mm. For 5 patients with mild mandibular deviation, the landmark localization error of all facial anatomical landmarks by template method was (2.55±2.22) mm, the landmark localization error of the midline facial anatomical landmarks was (1.85±1.13) mm, the landmark localization error of bilateral facial anatomical landmarks was (2.87±2.45) mm. Conclusions: The automatic determination method of facial anatomical landmarks proposed in this study has certain feasibility, and the determination effect of midline facial anatomical landmarks is better than that of bilateral facial anatomical landmarks. The effect of determining facial anatomical landmarks in patients without mandibular deviation is better than that in patients with mild mandibular deviation.

Design of non-metallic crown for primary molars and analyzation of stress distribution: a finite element study / 中华口腔医学杂志

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.

Yishen Tonglong Decoction inhibits the epithelial-mesenchymal transition and Ras/ERK signaling pathway in human prostate cancer DU-145 cells / 中华男科学杂志

Objective@#To observe the effect of Yishen Tonglong Decoction (YTD) on the epithelial-mesenchymal transition (EMT) and Ras/ERK signaling pathway in human PCa DU-145 cells and explore its action mechanism.@*METHODS@#We treated human PCa DU-145 cells with normal plasma (the blank control) or plasma containing 5% (low-dose), 10% (medium-dose) and 15% (high-dose) YTD. After intervention, we examined the proliferation of the DU-145 cells in different groups with CCK-8 and their apoptosis by Annexin V/PI double staining. We detected the cell cycle by PI assay, the invasion and migration of the cells using the Transwell chamber and scratch test, and the expressions of the proteins and genes related to the EMT and Ras/ERK signaling pathways in the cells by Western blot and RT-PCR.@*RESULTS@#Compared with the blank control group, high-, medium- and low-dose YTD significantly inhibited the proliferation of the PCa DU-145 cells, decreased their adherence and growth (P < 0.05, P < 0.01), promoted their apoptosis (P < 0.01), regulated their cell cycles (P < 0.05, P < 0.01), and reduced their in vitro invasion and migration abilities (P < 0.05), all in a dose-dependent manner. The results of Western blot and RT-PCR revealed down-regulated protein and mRNA expressions of N-cadherin, zinc finger transcription factor (Snail), Ras, p-ERK1/2 and ERK1/2, but up-regulated protein and mRNA expressions of E-cadherin in the PCa DU-145 cells treated with YTD (P < 0.05, P < 0.01).@*CONCLUSIONS@#Yishen Tonglong Decoction can effectively inhibit the proliferation, promote the apoptosis, regulate the cell cycle and suppress the invasion and migration abilities and EMT process of human PCa DU-145 cells. The mechanism of Yishen Tonglong Decoction acting on PCa may be associated with its inhibitory effect on the EMT process and expression of the Ras/ERK signaling pathway in PCa cells./.

Effect of moxibustion on renal function and hypercoagulable state in patients with idiopathic membranous nephropathy of low to medium risk with spleen-kidney deficiency and blood stasis / 中国针灸

OBJECTIVE@#To compare the effect of moxibustion combined with basic treatment and simple basic treatment on the clinical symptoms, renal function and hypercoagulable state in patients with idiopathic membranous nephropathy (IMN) of low to medium risk with spleen-kidney deficiency and blood stasis.@*METHODS@#A total of 60 patients with IMN of low to medium risk with spleen-kidney deficiency and blood stasis were randomized into an observation group (30 cases, 2 cases dropped off) and a control group (30 cases, 1 case dropped off). In the control group, the conventional basic treatment of anti-hypertension, regulating blood lipid and anti-coagulation was adopted. On the basis of the control group, moxibustion was applied at Shenshu (BL 23), Pishu (BL 20), Guanyuan (CV 4), Zusanli (ST 36) and Sanyinjiao (SP 6) in the observation group, once a day, 5 days a week continuously with 2 day interval. The treatment of 6 months was required in the both groups. Before treatment and 3 and 6 months into treatment, the total TCM syndrome score, the renal function indexes (24-hour urinary protein quantity [UTP], albumin [ALB], urea nitrogen [BUN] and creatinine [Scr]), the blood coagulation indexes (fibrinogen [FIB], D-Dimer [D-D], p-selection and von Willebrand factor [vWF]), total cholesterol (TC) and triacylglycerol (TG) levels were observed, and the therapeutic efficacy was evaluated on 3 and 6 months into treatment in the two groups.@*RESULTS@#The effective rates of 3 and 6 months into treatment were 78.6% (22/28) and 89.3% (25/28) in the observation group, which were higher than 62.1% (18/29) and 75.9% (22/29) in the control group respectively (@*CONCLUSION@#Moxibustion combined with basic treatment can effectively improve the clinical symptoms, renal function and renal microcirculation in patients with idiopathic membranous nephropathy of low to medium risk with spleen-kidney deficiency and blood stasis, the therapeutic effect is superior to the simple basic treatment.

Performance of loop-mediated isothermal amplification (LAMP) assay for detection of Schistosoma japonicum infection in Oncomelania snails in schistosomiasis transmission-interrupted regions / 中国血吸虫病防治杂志

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.

Application of double plasma molecular adsorption system in children with acute liver failure / 中国当代儿科杂志

OBJECTIVE@#To study the efficacy and safety of double plasma molecular absorption system (DPMAS) in the treatment of pediatric acute liver failure (PALF).@*METHODS@#A prospective analysis was performed on the medical data of children with PALF who were hospitalized in the Intensive Care Unit (ICU), Hunan Children's Hospital, from March 2018 to June 2020. The children were randomly divided into two groups:plasma exchange group (PE group) and DPMAS group (@*RESULTS@#Compared with the PE group, the DPMAS group had a significantly lower number of times of artificial liver support therapy and a significantly shorter duration of ICU stay (@*CONCLUSIONS@#DPMAS is safe and effective in the treatment of PALF and can thus be used as an alternative to artificial liver support therapy.

Textual Research on Illustrations of Medicinal Materials Named After Geographical Names of Jiangsu Province in Illustrated Classic of Materia Medica / 中国实验方剂学杂志

Illustrated Classic of Materia Medica （Ben Cao Tu Jing）， compiled in 1061， is regarded as the crystallization of the second national survey of Chinese medicinal resources in the history of China after the Newly Revised Materia Medica （Xin Xiu Ben Cao）， which serves as a precious source for exploring the Chinese medicinal resources in the Song Dynasty. The Illustrated Classic of Materia Medica （Ben Cao Tu Jing） covers 50 illustrations for Chinese medicinal materials named after geographical names of Jiangsu Province， 39 of which have been verified in today's Jiangsu Province. To be specific， Chinese medicinal materials in 32 illustrations can be traced back to their species， those in four illustrations to genera， and those in three illustrations to family. The remaining 12 illustrations remain to be further verified. The origins of most Chinese medicinal materials in the illustrations can be traced， which is attributed to their exquisiteness and lifelikeness as well as the detailed descriptions of the characters of the original plants and animals. In the textual research of these illustrations， we have noticed that there are inconsistencies between pictures and texts， and different illustrations may be derived from the same origin. This is believed to be related to SU Song's principle of collation that "for all Chinese medicinal materials presented as examples， if their shapes and categories recorded are not consistent with those in the literature， they will be retained. If there is any connection with the literature， they will be annotated according to literature to make their origins clear". As revealed by the distribution of Chinese medical materials in Jiangsu Province reported in the Illustrated Classic of Materia Medica （Ben Cao Tu Jing）， the utilization and development of Jiangsu medicinal materials during the Northern Song Dynasty were mainly concentrated in the low-altitude valleys and coastal areas. It could be seen from the illustrations of Chinese medicinal materials named after geographical names of today's Jiangsu Province that the production areas with a large number of illustrations were relatively developed in politics， economy， and transportation at that time， which enabled the medicinal resources to be fully utilized.