北京大学学报（医学版）最新文献

{"title":"[Evaluation of micro crestal flap-alveolar ridge preservation following extraction of mandibular molars with severe periodontitis].","authors":"Yutong Shi, Yiping Wei, Wenjie Hu, Tao Xu, Haoyun Zhang","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Objective: </strong>To evaluate the clinical and radiographic efficacy of micro crestal flap-alveolar ridge preservation following extraction of mandibular molars with severe periodontitis compared with natural healing, and to preliminarily propose the surgical indication.</p><p><strong>Methods: </strong>A retrospective analysis was conducted on clinical data from patients with mandibular molars with severe periodontitis either receiving micro crestal flap-alveolar ridge preservation (MCF-ARP group) or undergoing natural healing in department of periodontology, Peking University School and Hospital of Stomatology from September 2013 to June 2021. Cone-beam computed tomography scannings performed before/immediately after extraction (as baseline) and repeated before implantation (after the extraction socket healing) were used to measure the ridge width, height and volumetric changes of the sockets, and the proportion of guided bone regeneration (GBR) during implant therapy were compared between the two groups.</p><p><strong>Results: </strong>Between baseline and healing, significant differences in changes of MCF-ARP group [(8.34±2.81) mm] and natural healing group [(3.82±3.58) mm] in the distances from mandibular canal to center of the tooth socket were recorded (<i>P</i> < 0.001). The ridge width at 1 mm below the most coronal aspect of the crest increased by (3.50±4.88) mm in the MCF-ARP group but decreased by (0.16±5.70) mm in the natural healing group, respectively (<i>P</i>=0.019). After healing, the MCF-ARP group showed the distances from mandibular canal to center of the tooth socket >8 mm in all the cases, with 97.1% exceeding 10 mm. Natural healing group displayed 23.1% of the cases with center bone height < 8 mm and 61.5% exceeding 10 mm. Volume changes at the buccal and lingual aspect as well as the total socket were significantly greater in the MCF-ARP group compared with natural healing group (<i>P</i> < 0.001).At the time of implantation, GBR was performed in 5 out of 68 subjects (8.3%) in the MCF-ARP group, whereas 8 out of 26 subjects (30.8%) in the natural healing group required GBR, reflecting significant difference (<i>P</i>=0.003).</p><p><strong>Conclusion: </strong>In the sites of mandibular molars with severe periodontitis, when the distances from mandibular canal to center of the tooth socket was not enough (less than 7 mm), clinicians could consider performing the micro crestal flap-alveolar ridge preservation to achieve augmentation for alveolar ridge and reduce the proportion of guided bone regeneration during implant therapy to reduce the difficulty and risk of injuries during implant therapy.</p>","PeriodicalId":8790,"journal":{"name":"北京大学学报（医学版）","volume":"57 1","pages":"33-41"},"PeriodicalIF":0.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11759800/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143036327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Analysis of soft tissue healing after keratinized tissue augmentation in reconstructed jaws].","authors":"Junnan Nie, Jiayun Dong, Ruifang Lu","doi":"","DOIUrl":"","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Objective: &lt;/strong&gt;To evaluate the wound healing of recipient and donor sites following keratinized mucosa augmentation (KMA) around implants in reconstructed jaw areas and to compare these outcomes with gingival grafts in native jawbone, so as to provide clinical guidance for postoperative maintenance, and to investigate the impact of clinical experience on the evaluation of KMA postoperative healing through subgroup comparisons.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;This study included patients who underwent resection of maxillofacial tumors, fibular or iliac flap reconstruction, and implant placement at Peking University Dental Hospital from October 2020 to April 2023. Three months post-implant placement, the patients were referred for KMA procedures. Clinical photographs of the reconstructed area were taken preoperatively, immediately postoperatively, and 3 weeks and 3 months post-surgery. Additionally, photographs of the palatal donor site were obtained preoperatively and 3 weeks later. Wound healing was assessed by four junior and three senior clinicians utilizing the early healing index (EHI), early wound healing score (EHS), and pink esthetic score (PES).And senior clinicians evaluated the healing effect compared with gingival transplantation on natural jawbone using a 10-point scale.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;A total of 26 patients with jawbone reconstruction were included, with an average age of (34.2±10.2) years, 11 males (42.3%) and 15 females (57.7%). Among them, 13 cases (50.0%) underwent fibula flap reconstruction, and 13 cases (50.0%) underwent iliac flap reconstruction. The average number of implants per patient was 3.2±0.7. In the recipient area, 3 weeks postoperatively, the EHS was 7.0 (4.0, 9.0), with sub-item scores as follows: Clinical signs of re-epithelialization (CSR) 6.0 (3.0, 6.0), clinical signs of haemostasis (CSH) 1.5 (1.0, 2.0), and clinical signs of inflammation (CSI) 1.0 (0.0, 1.0), indicating that the average appearance of the wound in the recipient area was characterized by generally well-approximated wound edges with minimal fibrin lines and mild erythema and swelling. The EHI for the recipient area was 2.0 (1.5, 2.5), suggesting that the incision was mostly closed with some fibrin lines 3 weeks postoperatively. The long-term healing evaluation system, PES, was 2.5 (2.0, 3.0), with sub-scores for color [1.0 (1.0, 1.5)] and texture [1.5 (1.0, 2.0)], which were slightly different from the reference values.In the palatal donor area, 3 weeks postoperatively, the EHI score was lower at 1.3 (1.0, 2.5), while the EHS score was higher at 8.5 (6.0, 10.0), indicating better soft tissue healing in the donor area compared with the recipient area. Among the clinicians with different levels of experience, the assessment of wound healing revealed that except for the CSI sub-item, where the junior group scored higher than the senior group, all other sub-items showed significantly higher scores in the senior group c","PeriodicalId":8790,"journal":{"name":"北京大学学报（医学版）","volume":"57 1","pages":"57-64"},"PeriodicalIF":0.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11759810/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143036207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Deep learning algorithms for intelligent construction of a three-dimensional maxillofacial symmetry reference plane].","authors":"Yujia Zhu, Hua Shen, Aonan Wen, Zixiang Gao, Qingzhao Qin, Shenyao Shan, Wenbo Li, Xiangling Fu, Yijiao Zhao, Yong Wang","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Objective: </strong>To develop an original-mirror alignment associated deep learning algorithm for intelligent registration of three-dimensional maxillofacial point cloud data, by utilizing a dynamic graph-based registration network model (maxillofacial dynamic graph registration network, MDGR-Net), and to provide a valuable reference for digital design and analysis in clinical dental applications.</p><p><strong>Methods: </strong>Four hundred clinical patients without significant deformities were recruited from Peking University School of Stomatology from October 2018 to October 2022. Through data augmentation, a total of 2 000 three-dimensional maxillofacial datasets were generated for training and testing the MDGR-Net algorithm. These were divided into a training set (1 400 cases), a validation set (200 cases), and an internal test set (200 cases). The MDGR-Net model constructed feature vectors for key points in both original and mirror point clouds (X, Y), established correspondences between key points in the X and Y point clouds based on these feature vectors, and calculated rotation and translation matrices using singular value decomposition (SVD). Utilizing the MDGR-Net model, intelligent registration of the original and mirror point clouds were achieved, resulting in a combined point cloud. The principal component analysis (PCA) algorithm was applied to this combined point cloud to obtain the symmetry reference plane associated with the MDGR-Net methodology. Model evaluation for the translation and rotation matrices on the test set was performed using the coefficient of determination (<i>R</i>²). Angle error evaluations for the three-dimensional maxillofacial symmetry reference planes were constructed using the MDGR-Net-associated method and the \"ground truth\" iterative closest point (ICP)-associated method were conducted on 200 cases in the internal test set and 40 cases in an external test set.</p><p><strong>Results: </strong>Based on testing with the three-dimensional maxillofacial data from the 200-case internal test set, the MDGR-Net model achieved an <i>R</i>² value of 0.91 for the rotation matrix and 0.98 for the translation matrix. The average angle error on the internal and external test sets were 0.84°±0.55° and 0.58°±0.43°, respectively. The construction of the three-dimensional maxillofacial symmetry reference plane for 40 clinical cases took only 3 seconds, with the model performing optimally in the patients with skeletal Class Ⅲ malocclusion, high angle cases, and Angle Class Ⅲ orthodontic patients.</p><p><strong>Conclusion: </strong>This study proposed the MDGR-Net association method based on intelligent point cloud registration as a novel solution for constructing three-dimensional maxillofacial symmetry reference planes in clinical dental applications, which can significantly enhance diagnostic and therapeutic efficiency and outcomes, while reduce expert dependence.</p>","PeriodicalId":8790,"journal":{"name":"北京大学学报（医学版）","volume":"57 1","pages":"113-120"},"PeriodicalIF":0.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11759812/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143036305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Cyclic fatigue resistance of nickel-titanium files made by Gold heat treatment in simulated S-shaped root canals at different temperatures].","authors":"Wenxin Chen, Xiaomei Hou","doi":"","DOIUrl":"","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Objective: &lt;/strong&gt;To compare the cyclic fatigue resistance of nickel-titanium files made by 3 new heat treatment in simulated S-shaped root canals at different temperatures.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;Gold heat-treated nickel-titanium files TruNatomy (25 mm, tip size 26#/0.04) and ProTaper Gold (25 mm, tip size 25#/0.08) were selected as the experimental group, M wire technique nickel-titanium file ProTaper Next (25 mm, tip size 25#/0.06) was selected as the control group. It was speculated that the Gold technique used in TruNatomy nickel-titanium file was R phase separation technique, which included a complete intermediate R-phase, increasing its flexibility. ProTaper Gold was a CM wire nickel-titanium file and the increased phase transformation temperature by heat treatment introduced martensite at room temperature, while it underwent gold heat treatment on the surface, generating an intermediate R phase during phase transformation, providing hyperelastic. ProTaper Next used M wire technique, M wire included austenite at room temperature, where heat mechanical processing introduced hardened martensite, which was incapable of participating phase transformation. Because of the lower elastic modulus of hardened martensite than austenite, the flexibility of the file was increased. Twenty instruments of each nickel-titanium file were submitted to the cyclic fatigue test by using a simulated canal with double curvatures at room tem-perature (24 ℃) and 65 ℃, 10 instruments of each nickel-titanium file were selected at each temperature (&lt;i&gt;n&lt;/i&gt;=10). At the same temperature, the number of cyclic fatigue (NCF) and fragment length were analyzed by using One-Way analysis of variance at a significance level of &lt;i&gt;P&lt;/i&gt; &lt; 0.05. NCF and fragment length of the same nickel-titanium file at room temperature and 65 ℃ were compared by paired sample &lt;i&gt;t&lt;/i&gt; test and the significance level was α=0.05. Fractured surfaces were analyzed by using scanning electron microscope.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;In double-curved canals, all the failure of the files due to cyclic fatigue was first seen in the apical curvature before the coronal curvature. At room temperature, in the apical curvature, NCF of TruNatomy was 344.4±96.6, ProTaper Gold was 175.0±56.1, ProTaper Next was 133.3±39.7, NCF of Tru Natomy was the highest (&lt;i&gt;P&lt;/i&gt; &lt; 0.05). In the coronal curvature, NCF of TruNatomy was 618.3± 75.3, ProTaper Gold was 327.5±111.8, ProTaper Next was 376.6±67.9, NCF of TruNatomy was also the highest (&lt;i&gt;P&lt;/i&gt; &lt; 0.05). There was no significant difference among the apical and coronal fragment length of the 3 nickel-titanium files (&lt;i&gt;P&lt;/i&gt;&gt;0.05). At 65 ℃, in the apical curvature, NCF of TruNatomy was 289.6±65.8, ProTaper Gold was 187.5±75.4, ProTaper Next was 103.0±38.5, NCF of TruNatomy was the highest (&lt;i&gt;P&lt;/i&gt; &lt; 0.05). In the coronal curvature, NCF of TruNatomy was 454.2±45.4, ProTaper Gold was 268.3±31.4, ProTaper Next was 283.8±31.7, NCF of TruNatomy wa","PeriodicalId":8790,"journal":{"name":"北京大学学报（医学版）","volume":"57 1","pages":"136-141"},"PeriodicalIF":0.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11759792/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143036301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Hydrodynamic finite element analysis of biological scaffolds with different pore sizes for cell growth and osteogenic differentiation].","authors":"Yibo Hu, Weijia Lyu, Wei Xia, Yihong Liu","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Objective: </strong>The triply periodic minimal surface (TPMS) Gyroid porous scaffolds were built with identical porosity while varying pore sizes were used by fluid mechanics finite element analysis (FEA) to simulate the <i>in vivo</i> microenvironment. The effects of scaffolds with different pore sizes on cell adhesion, proliferation, and osteogenic differentiation were evaluated through calculating fluid velocity, wall shear stress, and permeability in the scaffolds.</p><p><strong>Methods: </strong>Three types of gyroid porous scaffolds, with pore sizes of 400, 600 and 800 μm, were established by nTopology software. Each scaffold had dimensions of 10 mm × 10 mm × 10 mm and isotropic internal structures. The models were imported to the ANSYS 2022R1 software, and meshed into over 3 million unstructured tetrahedral elements. Boun- dary conditions were set with inlet flow velocities of 0.01, 0.1, and 1 mm/s, and outlet pressure of 0 Pa. Pressure, velocity, and wall shear stress were calculated as fluid flowed through the scaffolds using the Navier-Stokes equations. At the same time, permeability was determined based on Darcy' s law. The compressive strength of scaffolds with different pore sizes was evaluated by ANSYS 2022R1 Static structural analysis.</p><p><strong>Results: </strong>A linear relationship was observed between the wall shear stress and fluid velocity at inlet flow rates of 0.01, 0.1 and 1 mm/s, with increasing velocity leading to higher wall shear stress. At the flow velocity of 0.1 mm/s, the initial pressures of scaffolds with pore sizes of 400, 600 and 800 μm were 0.272, 0.083 and 0.079 Pa, respectively. The fluid pressures were gradually decreased across the scaffolds. The average flow velocities were 0.093, 0.078 and 0.070 mm/s, the average wall shear stresses 2.955, 1.343 and 1.706 mPa, permeabilities values 0.54×10^-8 1.80×10^-8 and 1.89×10^-8 m² in the scaffolds with pore sizes of 400, 600 and 800 μm. The scaffold surface area proportions according with optimal wall shear stress range for cell growth and osteogenic differentiation were calcula-ted, which was highest in the 600 μm scaffold (27.65%), followed by the 800 μm scaffold (17.30%) and the 400 μm scaffold (1.95%). The compressive strengths of the scaffolds were 23, 26 and 34 MPa for the 400, 600 and 800 μm pore sizes.</p><p><strong>Conclusion: </strong>The uniform stress distributions appeared in all gyroid scaffold types under compressive stress. The permeabilities of scaffolds with pore sizes of 600 and 800 μm were significantly higher than the 400 μm. The average wall shear stress in the scaffold of 600 μm was the lowest, and the scaffold surface area proportion for cell growth and osteogenic differentiation the largest, indicating that it might be the most favorable design for supporting these cellular activities.</p>","PeriodicalId":8790,"journal":{"name":"北京大学学报（医学版）","volume":"57 1","pages":"97-105"},"PeriodicalIF":0.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11759801/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143035831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Accuracy of dynamic navigation system for immediate dental implant placement].","authors":"Hong Li, Feifei Ma, Jinlong Weng, Yang DU, Binzhang Wu, Feng Sun","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Objective: </strong>Dynamic navigation approaches are widely employed in the context of implant placement surgery. Implant surgery can be divided into immediate and delayed surgery according to the time of implantation. This retrospective study was developed to compare the accuracy of dynamic navigation system for immediate and delayed implantations.</p><p><strong>Methods: </strong>In the study, medical records from all patients that had undergone implant surgery between August 2019 and June 2021 in the First Clinical Division of the Peking University School and Hospital of Stomatology were retrospectively reviewed. There were 97 patients [53 males and 44 females, average age (47.14±11.99) years] and 97 implants (delayed group: 51; immediate group: 46) that met with study inclusion criteria and were included. Implant placement accuracy was measured by the superposition of the planned implant position in the preoperative cone beam computed tomography (CBCT) image and the actual implant position in the postoperative CBCT image. The 3-dimensional (3D) entry deviation (3D deviation in the coronal aspect of the alveolar ridge), 3D apex deviation (3D deviation in the apical area of the implant) and angular deviation were analyzed as the main observation index when comparing these two groups. The 2-dimensional (2D) horizontal deviation of the entry point and apex point, and the deviation of entry point depth and apex point depth were the secondary observation index.</p><p><strong>Results: </strong>The overall implant restoration survival rate was 100%, and no mechanical or biological complications were reported. The implantation success rate was 100%. The 3D entry deviation, 3D apex deviation and angular deviation of all analyzed implants were (1.146±0.458) mm, (1.276±0.526) mm, 3.022°±1.566°, respectively; while in the delayed group these respective values were (1.157±0.478) mm, (1.285±0.481) mm and 2.936°±1.470° as compared with (1.134±0.440) mm, (1.265±0.780) mm, 3.117°±1.677° in the immediate group. No significant differences (<i>P</i>=0.809, <i>P</i>=0.850, <i>P</i>=0.575) in accuracy were observed when comparing these two groups.</p><p><strong>Conclusion: </strong>Dynamic computer-assisted implant surgery system promotes accurate implantation, and both the immediate and delayed implantations exhibit similar levels of accuracy under dynamic navigation system that meets the clinical demands. Dynamic navigation system is feasible for immediate implantation.</p>","PeriodicalId":8790,"journal":{"name":"北京大学学报（医学版）","volume":"57 1","pages":"85-90"},"PeriodicalIF":0.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11759790/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143036201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Bacterial biofilm formation of peritoneal dialysis catheter in patients with peritonitis-associated catheter removal].","authors":"Aichun Liu, Huiping Zhao, Bei Wu, Shuying Zheng, Li Zuo, Mei Wang","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Objective: </strong>Peritoneal dialysis(PD)-associated peritonitis is a common and major complication of PD and the most common cause of technical failure of PD. The presence of bacterial biofilm may be an important factor leading to refractory or recurrence of peritonitis. To investigate the formation and characteristics of bacterial biofilms on PD catheters after peritonitis-associated catheter removal.</p><p><strong>Methods: </strong>The patients with maintenance PD who were regularly followed up in the Peking University People' s Hospital from June 2007 to January 2022 were retrospectively analyzed. The patients who withdrew from PD because of peritonitis and removed the PD catheter in our hospital and underwent the scanning electron microscope examination of the catheter were selected. The general information of the patients, the electron microscope results of the PD catheter and the bacterial culture results of the PD fluid were summarized.</p><p><strong>Results: </strong>(1) A total of 18 patients were included, 11 were female (accounting for 61.1%). The average age of the patients was (59.1±11.5) years, and the average duration of dialysis was (80.1±47.4) months. Primary kidney diseases were predominantly chronic glomerulonephritis (55.6%), followed by diabetic nephropathy (27.8%), and others (16.6%). The reasons for catheters removal in 18 patients were refractory peritonitis in 11 cases, recurrent peritonitis in 5 cases, and fungal peritonitis in 2 cases. (2) 16 of the 18 patients (88.9%) had catheter bacterial biofilm, and the bacterial biofilm forms were all cocci. Some were arranged in grape-like shapes, and their diameters ranged from about 500 nm to 1 000 nm. The bacterial culture results of peritoneal dialysis fluid showed that the three most common pathogens were <i>Escherichia coli</i>, methicillin-sensitive <i>Staphylococcus aureus</i> (MSSA), and <i>Staphylococcus epidermidis</i>. (3) Among the 18 patients enrolled, 13 patients (72.2%) had peritonitis in the past. The causative bacteria of peritonitis in 9 patients were cocci, including coagulase-negative <i>Staphylococci</i> (<i>Staphylococcus suis</i>, <i>Staphylococcus surface</i>, <i>Staphylococcus xylosus</i>, <i>Staphylococcus warneri</i>), <i>Staphylococcus aureus</i>, <i>Streptococcus</i> (<i>Streptococcus salivarius</i> and <i>Aerococus viridans</i>).</p><p><strong>Conclusion: </strong>Bacterial biofilm formation on the inner surface of PD catheter is common in peritonitis-associated catheter removal patients. Not all PD catheters removed due to peritonitis have bacterial biofilms. Bacterial biofilms and peritonitis pathogens may not be consistent.</p>","PeriodicalId":8790,"journal":{"name":"北京大学学报（医学版）","volume":"57 1","pages":"161-165"},"PeriodicalIF":0.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11759799/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143036258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Clinical features and risk factors of patients with oral bleeding in dental emergency].","authors":"Huaqiu Guo, Zhe Wang, Xue Yang, Jie Bai","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Objective: </strong>To analyze the clinical characteristics and risk factors of patients with oral bleeding.</p><p><strong>Methods: </strong>A retrospective study was performed on patients with oral bleeding in the Department of Oral Emergency in Peking University School and Hospital of Stomatology from January 2019 to December 2022. The distribution of the patients ' gender, age, cause of bleeding, systemic condition, treatment methods and risk factors of hemostasis methods, and number of visits were analyzed.</p><p><strong>Results: </strong>A total of 4 764 patients with oral bleeding were enrolled, including 2 660 males (55.84%) and 2 104 females (44.16%), with an average age of 40.7 years. The most common causes of oral bleeding were bleeding after tooth extraction (3 080 cases, 64.65%), followed by gingival bleeding (1 386 cases, 29.09%), bleeding after outpatient surgery (194 cases, 4.07%), maxillofacial mass bleeding (33 cases, 0.69%), postoperative bleeding of inpatient (24 cases, 0.50%), and bleeding from other causes (47 cases, 0.99%). Simple hemostatic methods were applied in 1 867 cases (39.19%) while 2 897 cases (60.81%) used complex methods, among which iodine strip tamponade and suture were the most commonly used methods of hemostasis. Logistic regression analysis showed that the male patients had a higher proportion of complex methods than the female patients; gingival bleeding were often stopped by simple hemostatic methods while complex methods were more likely to be applied in the patients with bleeding after tooth extraction. The patients with hypertension and coagulation disorders were more likely to visit the hospital for repeated bleeding. Gender and age did not affect the number of visits.</p><p><strong>Conclusion: </strong>Oral bleeding was one of the common diseases in oral emergency. The common causes were bleeding after tooth extraction and gingival bleeding. Most patients could be treated by compression, local suture and packing of iodine strips while some cases with severe bleeding needed further treatment to stop bleeding. A minority of patients with oral bleeding could induce systemic complications, which should be paid full attention by clinicians.</p>","PeriodicalId":8790,"journal":{"name":"北京大学学报（医学版）","volume":"57 1","pages":"142-147"},"PeriodicalIF":0.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11759785/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143036297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Frameshift mutation in <i>RELT</i> gene causes amelogenesis imperfecta].","authors":"Zhenwei Zhang, Xinran Xu, Xuejun Gao, Yanmei Dong, Hua Tian","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Objective: </strong>To analyze <i>RELT</i> gene mutation found in a pedigree with clinical features and inheritable pattern consistent with amelogenesis imperfecta (AI) in China, and to study the relationship between its genotype and phenotype.</p><p><strong>Methods: </strong>Clinical and radiological features were recorded for the affected individuals. Peripheral venous blood samples of the patient and family members were collected for further study, and the genomic DNA was extracted to identify the pathogenic gene. Whole exome sequencing (WES) was performed to analyze the possible pathogenic genes, and Sanger sequencing was performed for validation. SIFT and PolyPhen-2 were used to predict and analyze the mutation effect. Comparison of RELT amino acids across different species were performed by using Uniprot website. In addition, the three-dimen-sional structures of the wild type and mutant proteins were predicted by Alphafold 2.</p><p><strong>Results: </strong>The proband exhibited typical hypocalcified AI, with heavy wear, soft enamel, rough and discolored surface, and partial enamel loss, while his parents didn ' t have similar manifestations. WES and Sanger sequencing results indicated that the proband carries a homozygous frameshift mutation in <i>RELT</i> gene, NM_032871.3: c.1169_1170del, and both of his parents were carriers. This mutation was predicted to be pathogenic by SIFT and PolyPhen-2. Up to now, there were 11 mutation sites in <i>RELT</i> gene were reported to be associated with AI, and all of the patients exhibited with hypocalcified AI. Compared with the wild-type RELT protein, the mutant protein p. Pro390fs35 conformation terminated prematurely, affecting the normal function of the protein.</p><p><strong>Conclusion: </strong>Through phenotype analysis, gene sequencing, and functional prediction of a Chinese family with typical amelogenesis imperfecta, this study found that <i>RELT</i> gene frameshift mutation can lead to protein dysfunction in AI patients. Further research will focus on the role and mechanism of RELT in enamel development at the molecular and animal levels, providing molecular biology evidence for the genetic counseling, prenatal diagnosis, and early prevention and treatment of AI.</p>","PeriodicalId":8790,"journal":{"name":"北京大学学报（医学版）","volume":"57 1","pages":"13-18"},"PeriodicalIF":0.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11759784/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143035645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Influence of emergence profile designs on the peri-implant tissue in the mandibular molar: A randomized controlled trial].","authors":"Juan Wang, Lixin Qiu, Huajie Yu","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Objective: </strong>To compare the influence of different emergence profile of implants in mandibular molar on the peri-implant soft tissue.</p><p><strong>Methods: </strong>Forty-four implants were divided into two equal groups by mucosal thickness, ≥2 mm (group A) or < 2 mm (group B), and were randomly included in the test group and the control group. In the control group, the patients were treated by a prosthesis with no transmucosal modifications (subgroups A1 and B1). In groups A1 and B1, the prostheses maintained the original emergence profile of the healing abutment. In the test group, the prostheses were designed based on a width-to-height ratio (W/H) of 1.3 ∶ 1 (subgroups A2 and B2). In group A2, the buccal transmucosal configuration design was slightly concave, and in group B2, the prostheses were designed with convex buccal transmucosal configuration. Assessments were made before delivery of the definitive restoration (T0), one month (T1) and 12 months (T2) after loading. The soft tissue and prosthesis information were obtained by intraoral scan and were converted to digital models. The digital models of different time were superimposed together. Buccal mucosal W/H, emergence angle (EA) and buccal mucosal margin recession (ΔGM) were measured.</p><p><strong>Results: </strong>One year after loading, the buccal mucosal margin recession in the test group (groups A2 and B2) was significantly lower than that in the control group (groups A1 and B1). The ΔGM in group A2 was significantly lower than that in group A1 (<i>P</i>=0.033), but in groups B1 and B2, it was not significantly different. The W/H in group A2 increased significantly one month after loading, but remained stable at one year. In the A1 group, the W/H changed little from initial to one month, but increased significantly at one year after loading. The W/H in group B2 remained stable from the beginning to one year, while in group B1, it changed little one month after loading, but increased significantly by one year.</p><p><strong>Conclusion: </strong>When the initial mucosal thickness was ≥2 mm, the slightly concave prosthesis designed based on the biological W/H significantly maintained the level of buccal mucosa. When the mucosal thickness was < 2 mm, the slightly convex prosthesis design maintained a more stable W/H over one year.</p>","PeriodicalId":8790,"journal":{"name":"北京大学学报（医学版）","volume":"57 1","pages":"65-72"},"PeriodicalIF":0.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11759793/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143035969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}