High-resolution CT-scan data reveals the tooth replacement pattern of the Late Jurassic tyrannosauroid Guanlong wucaii (Dinosauria, Theropoda)

The Tyrannosauridae,which is characterized by specialized pachydont dentition and putative bone-cracking predatory strategies,is one of the most extensively studied theropod lineages.Although tooth replacement patterns,crucial for understanding feeding behaviors,have been thoroughly studied in this group,studies on non-tyrannosaurid tyrannosauroids are relatively scarce.This study utilizes high-resolution CT data to investigate the tooth replacement pattern in two specimens of Guanlong wucaii,a Late Jurassic tyrannosauroid,and provides insights into the evolution of tooth replacement across Tyrannosauroidea.Second-generation replacement teeth,a rarity observed mainly in giant predatory theropods(e.g.some tyrannosaurids),were detected in the dentary dentition of the juvenile Guanlong.Zahnreihen reconstructions display a consistent cephalad alternating tooth replacement pattern in the maxilla and the dentary of both of the examined individuals,with Z-spacing values exceeding 2.0.As Guanlong grows,the Z-spacing value in the maxillary dentition increases,resembling the ontogenetic changes documented in the Tyrannosauridae.Additionally,like Tarbosaurus,Guanlong also displays a discontinuity between the tooth replacement waves at the premaxilla-maxilla boundary.This study thus demonstrates that some tyrannosaurid-like tooth replacement patterns were acquired before the origin of the Tyrannosauridae.

Effect of different interventions on orthodontic tooth movement acceleration:A network meta-analysis

Objective: To explore the effectiveness of various interventions in accelerating tooth movement, a systematic review and net-work meta analysis were used to draw a conclusion. Methods: MEDLINE, EMBASE, Willey Library, EBSCO, Web of Science Databases, and Cochrane Central Register of Controlled Trials databases to identify relevant studies. ADDIS 1.16.6 and Stata 16.0 software were used for NMA. Results: Five thousand five hundred and forty-two articles were searched out. After screening by two independent investigators, forty-seven randomized controlled trials, 1 390 participants, were included in this network meta-analysis. A total of 11 interventions involving Piezocision (Piezo), Photobiomodulation therapy (PBMT), Plate- let-rich plasma(PRP), Electromagnetic field(EF), Low intensity laser therapy(LLLT), Low intensity pulsed ultrasound(LI-PUS), Low-frequency vibrations(LFV), Distraction osteogenesis(DAD), Corticotomy(Corti), Microosteoperforations (MOPS), Traditional orthodontic(OT)were identified and classified into 3 classes including surgical treatment, non-surgical treatment and traditional orthodontic treatment. According to SUCRA probability ranking of the best intervention effect, when orthodontic treatment lasted for 1 month, PBMT (90.6%), Piezo(87.4%) and MOPs(73.6%)were the top three interventions to improve the efficiency of canine tooth movement. When orthodontic treatment lasted for 2 months, Corti (75.7%), Piezo (69.6%) and LFV(58.9%)were the top three interventions for improving the mobility efficiency of canine tooth movement. When orthodontic treatment lasted for 3 months, Cort (73.3%), LLLT(68.4%)and LFV(60.8%)were the top three interventions for improving the mobility efficiency of canine tooth movement. Conclusion: PBMT and Piezo can improve the efficiency of canine tooth movement significantly after 1 month, while Corti and LFV can improve the efficiency of canine tooth movement better after 2 and 3 months.

Parental Knowledge of Pre-Hospital Management of Avulsed Permanent Tooth in Children at Kath

BACKGROUND: Permanent tooth avulsion is one of the severe forms of dental traumatic injuries. The immediate action taken at the site of the accident is crucial to the prognosis of the tooth. Replantation is considered as the treatment of choice. OBJECTIVE: The study was undertaken to assess the knowledge of parents who accompany their children to the pediatric dental clinic, KATH on the pre-hospital management of avulsed permanent tooth in children. METHODS: A researcher administered structured questionnaire was used to collect data on the knowledge of pre-hospital management of avulsed permanent tooth from 83 parents who accompanied their wards to the pediatric dental clinic at KATH. RESULTS: A total of 83 parents were involved in the study. 30 (36%) were males while 53 (64%) were females. The majority of the parents (57%) were either university trained or had attended college of education. Only 32 parents (39%) were aware of the possibility of replantation. Majority of the parents chose non-physiologic media as the transport media of choice and only 10% would attempt self-replantation before seeking professional help. 76 parents (92%) had no previous education on pre-hospital management of avulsed tooth. CONCLUSION: The results obtained from this study indicate that parental knowledge on pre-hospital management of avulsed permanent tooth is low hence the need for massive public educational campaigns.

Association between Tooth Loss and Hypertension: A Systematic Review

Background: An independent relationship between tooth loss and hypertension appears to exist. Objectives: The aim of this study was to systematically review the relationship between tooth loss/number of teeth and hypertension. Materials and Methods: This review was conducted based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Guidelines. We searched all the relevant studies in international databases of PubMed and Google Scholar search engines from January 2000 to December 2023. Results: Fourteen studies (11 cross sectionals, 2 descriptives and 1 Cohort) met the inclusion criteria for this review. Most cross-sectional studies showed that participants with more tooth loss exhibited a greater proportion of hypertension and higher systolic blood pressure than those with less tooth loss. Cohort study showed that the loss of 8 or more teeth was associated with a higher risk of developing hypertension. Descriptive studies reported that missing teeth were marginally significantly associated with hypertension. Conclusion: This study has revealed a significantly higher SBP in patients with fewer remaining teeth or more tooth loss. In addition, those with more tooth loss showed a higher risk of hypertension than those with less tooth loss.

Single Tooth Segmentation on Panoramic X-Rays Using End-to-End Deep Neural Networks

In dentistry, panoramic X-ray images are extensively used by dentists for tooth structure analysis and disease diagnosis. However, the manual analysis of these images is time-consuming and prone to misdiagnosis or overlooked. While deep learning techniques have been employed to segment teeth in panoramic X-ray images, accurate segmentation of individual teeth remains an underexplored area. In this study, we propose an end-to-end deep learning method that effectively addresses this challenge by employing an improved combinatorial loss function to separate the boundaries of adjacent teeth, enabling precise segmentation of individual teeth in panoramic X-ray images. We validate the feasibility of our approach using a challenging dataset. By training our segmentation network on 115 panoramic X-ray images, we achieve an intersection over union (IoU) of 86.56% for tooth segmentation and an accuracy of 65.52% in tooth counting on 87 test set images. Experimental results demonstrate the significant improvement of our proposed method in single tooth segmentation compared to existing methods.

The Design of Form Milling Cutter as the Curve of the Back of Tooth Is Logarithmic Spiral

Form milling cutter is built-for-purpose cutter which process the form surface, for example, usually process male and female circular arc face and form trench and so on. From the traditional concept, form milling cutter is divided into pointed tooth and relieving follow its structure. Relieving shaped cutter is more convenient than pointed tooth milling cutter, because only its rake face is needed to grind after it turn into blunting, so the current books which are used in college almost select relieving shaped cutter in order to introduce how to design the form milling cutter.The curve of the back of tooth of relieving cutter is the transversal which is formed by the rear face of tooth in the end cut plane of the milling cutter. In the past, because of the limit of the manufacturing technology, the curve of the back of tooth is often selected Archimedes’ curve, in order that the shovel-nose tool acquire the uniform motion when the cutter shovel the back, in other word, the rear face of the milling cutter rotate its axis by the new cutting lip, in the same time, it move uniformly to the axis in order to form the surface. Although this curve of the back of tooth meet the fixedness of the form of blade around grinding the cutter, the rear angle of the dot of the cutting lip don’t keep fixedness. With the development of the modern manufacturing technology, the unmanageable problem of many complex curves is already easily solved. So it is need to study the optimum profile of the curve of the back of tooth in theory, and study the design theory of the relieving shaped cutter under the condition of new manufacture, in order to ensure that the rear angle of the dot of the cutting lip keep fixedness after the relieving shaped cutter is grinded. The paper derive the curve profile of tooth of the form cutter and the modifier calculation formula of the profile of the cutter edge from the definition of the rear angle of the cutter, which establish the foundation for the precision design and manufacture of other form cutter.

Comparative Study of the Rock-breaking Mechanism of a Disc Cutter and Wedge Tooth Cutter by Discrete Element Modelling

The operation of a shield tunnel boring machine(TBM)in a high-strength hard rock stratum results in significant cutter damage,adversely affecting the thrust and torque of the cutter head.Therefore,it is very important to carry out the research on the stress characteristics and optimize the cutter parameters of cutters break high-strength hard rock.In this paper,the rock-breaking performance of cutters in an andesite stratum in the tunnel of Qingdao Metro Line No.8 was investigated using the discrete element method and theoretical analysis.The rock-breaking processes of a disc cutter and wedge tooth cutter were simulated by software particle flow code PFC^(3D),and the rock-breaking degree,stress of the cutter,and rock-breaking specific energy were analyzed.The rock damage caused by the cutter in a specific section was divided into three stages:the advanced influence,crushing,and stabilizing stages.The rock-breaking degree and the tangential and normal forces of the wedge tooth cutter are larger than that of the disc cutter under the same conditions.The disc cutter(wedge tooth cutter)has the highest rock-breaking efficiency at a cutter spacing of 100 mm(110 mm)and a penetration depth of 8 mm(10 mm),and the rock-breaking specific energy is 11.48 MJ/m^(3)(12.05 MJ/m^(3)).Therefore,two types of cutters with different penetration depths or cutter spacing should be considered.The number of teeth of wedge tooth cutters can be increased in hard strata to improve the rock-breaking efficiency of the shield.The research results provide a reference for shield cutterhead selection and cutter layout in similar projects.

Three-Dimensional Conjugate Tooth Surface Design and Contact Analysis of Harmonic Drive with Double-Circular-Arc Tooth Profle

A three-dimensional conjugate tooth surface design method for Harmonic Drive with a double-circular-arc tooth profle is proposed. The radial deformation function of the fexspline (FS), obtained through Finite Element (FE) analysis, is incorporated into the kinematics model. By analyzing the FS tooth enveloping process, the optimization of the overlapping conjugate tooth profle is achieved. By utilizing the hobbing process, the three-dimensional machinable tooth surface of FS can be acquired. Utilizing the coning deformation of the FS, simulations are conducted to analyze the multi-section assembly and meshing motion of the machinable tooth surface. The FE method is utilized to analyze and compare the loaded contact characteristics. Results demonstrate that the proposed design method can achieve an internal gear pair consisting of a circular spline with a spur gear tooth surface and the FS with a machinable tooth surface. With the rated torque, approximately 24% of the FS teeth are engaged in meshing, and more than 4/5 of the tooth surface in the axial direction carries the load. The contact patterns, maximum contact pressure, and transmission error of the machinable tooth surface are 227.2%, 40.67%, and 71.24% of those on the spur gear tooth surface, respectively. It clearly demonstrates exceptional transmission performance.

Single cell RNA sequencing reveals mesenchymal heterogeneity and critical functions of Cd271 in tooth development

BACKGROUND Accumulating evidence suggests that the maxillary process,to which cranial crest cells migrate,is essential to tooth development.Emerging studies indicate that Cd271 plays an essential role in odontogenesis.However,the underlying mechanisms have yet to be elucidated.AIM To establish the functionally heterogeneous population in the maxillary process,elucidate the effects of Cd271 deficiency on gene expression differences.METHODS p75NTR knockout(Cd271-/-)mice(from American Jackson laboratory)were used to collect the maxillofacial process tissue of p75NTR knockout mice,and the wildtype maxillofacial process of the same pregnant mouse wild was used as control.After single cell suspension,the cDNA was prepared by loading the single cell suspension into the 10x Genomics Chromium system to be sequenced by NovaSeq6000 sequencing system.Finally,the sequencing data in Fastq format were obtained.The FastQC software is used to evaluate the quality of data and CellRanger analyzed the data.The gene expression matrix is read by R software,and Seurat is used to control and standardize the data,reduce the dimension and cluster.We search for marker genes for subgroup annotation by consulting literature and database;explore the effect of p75NTR knockout on mesenchymal stem cells(MSCs)gene expression and cell proportion by cell subgrouping,differential gene analysis,enrichment analysis and protein-protein interaction network analysis;understand the interaction between MSCs cells and the differentiation trajectory and gene change characteristics of p75NTR knockout MSCs by cell communication analysis and pseudo-time analysis.Last we verified the findings single cell sequencing in vitro.RESULTS We identified 21 cell clusters,and we re-clustered these into three subclusters.Importantly,we revealed the cell–cell communication networks between clusters.We clarified that Cd271 was significantly associated with the regulation of mineralization.CONCLUSION This study provides comprehensive mechanistic insights into the maxillary-process-derived MSCs and demonstrates that Cd271 is significantly associated with the odontogenesis in mesenchymal populations.

Tooth arrangement design of retractable DTH hammer bit used for drilling while casing

Down-the-hole(DTH)hammer with casing while drilling(CWD)is a technology that has been proven to be able to alleviate many of the problems faced by complex formations.However,the drill bit is suffered from rapid wear,low drilling efficiency,and high energy consumption due to the unreasonable tooth arrangement and impact energy selection in drilling process,which affect the application effect of this technology.ABAQUS software was used for numerical simulation of rock breaking behavior under impact load with the single,three,and five teeth arrangement drill bit respectively,to improve the application effect and solve the aforementioned technical problems.Based on the calculated parameters of tooth arrangement,we designed a novel drill bit for hard rocks and provided a theoretical basis for the tooth arrangement of largediameter drill bits.

A Rare Case: Multiple Mandibular Arteriovenous Malformation with High Output: May a Tooth Extraction Alone Turn to a Catastrophic Condition?

Background: Arteriovenous malformations (AVM) in mandible and neck are potentially life-threatening conditions because of possible massive hemorrhage. They are often first diagnosed by dentists as bleeding. In this case, we report how a tooth extraction turned to a catastrophic condition in a patient with multiple AVMs in the mandibular, submandibular and hyoid region. Case: A 19-year-old male patient diagnosed with AVMs in the mandibular and submandibular regions was admitted to our hospital with the complaint of leaky hemorrhage around the lower left 3rd molar tooth. Tooth extraction was planned after embolization procedure. The patient was intubated uneventfully using video laryngoscope. However, an acute bleeding of more than 1600 ml occurred in one minute just after the mouth opener was inserted. The patient was transferred to the Interventional Radiology and other branches of the high-flow AVM were embolized. The patient was taken back to the operating room and the tooth was extracted uneventfully. Conclusion: In AVM cases, trauma should be minimized during induction of general anesthesia and intubation should be performed gently with fiberoptic bronchoscopy or video laryngoscopy. We conclude that a multidisciplinary approach as applied to our patient would be valuable in such cases.

Charcot-Marie-Tooth病的遗传、临床和电生理观察(附20例临床分析)

本文报道 ２０例 Ｃｈａｒｃｏｔ－Ｍａｒｉｅ－Ｔｏｏｔｈ病的遗传、临床和电生理资料。其中男 １６例，女 ４例，平均发病年龄为２６．７５岁。发现４例显性遗传，３例隐性遗传，１０例散发，３例遗传情况不详。主要症状有高弓足、垂足、鹤腿和腱反射消失；上肢前臂有肌萎缩者占１／４。所有病人电生理检查均有失神经现象，特别是ＭＣＶ有明显减慢。且发现ＭＣＶ的减慢和临床严重程度无相关联系。

Labial inverse dilaceration of bilateral maxillary central incisors: A case report

BACKGROUND Dilaceration is a rare dental developmental anomaly characterized by an abrupt deviation along the longitudinal axis of the root in which an angulation forms between the root and the crown.Here,we report on dilacerated bilateral maxi-llary central incisors in mixed dentition.CASE SUMMARY A 10-year-old girl presented with a chief complaint of unerupted central incisors.An oral examination and radiography provided the basis for a diagnosis of dilaceration of the maxillary central incisors.After surgical exposure of the impacted teeth,a button with an attached chain was applied to the palatal surface of teeth 11 and 21.After 8 mo,a button was bonded to the labial surface of the crown to fix an elastic chain and move the teeth toward the maxillary arch.Finally,a fixed appliance was applied to tooth alignment to Class 1 malocclusion using a 0.019×0.025-inch nickel-titanium wire.After 3 years of follow-up,the clinical findings and radiographic assessment showed that the roots had developed with vital dental pulp and healthy periodontium,were acceptable aesthetically,and showed no resorption.CONCLUSION The rare occurrences of dilacerated bilateral maxillary central incisors can be successfully treated through surgical exposure and orthodontics.

Low-intensity pulsed ultrasound reduces alveolar bone resorption during orthodontic treatment via Lamin A/C-Yes-associated protein axis in stem cells

BACKGROUND The bone remodeling during orthodontic treatment for malocclusion often requires a long duration of around two to three years,which also may lead to some complications such as alveolar bone resorption or tooth root resorption.Low-intensity pulsed ultrasound(LIPUS),a noninvasive physical therapy,has been shown to promote bone fracture healing.It is also reported that LIPUS could reduce the duration of orthodontic treatment;however,how LIPUS regulates the bone metabolism during the orthodontic treatment process is still unclear.AIM To investigate the effects of LIPUS on bone remodeling in an orthodontic tooth movement(OTM)model and explore the underlying mechanisms.METHODS A rat model of OTM was established,and alveolar bone remodeling and tooth movement rate were evaluated via micro-computed tomography and staining of tissue sections.In vitro,human bone marrow mesenchymal stem cells(hBMSCs)were isolated to detect their osteogenic differentiation potential under compression and LIPUS stimulation by quantitative reverse transcription-polymerase chain reaction,Western blot,alkaline phosphatase(ALP)staining,and Alizarin red staining.The expression of Yes-associated protein(YAP1),the actin cytoskeleton,and the Lamin A/C nucleoskeleton were detected with or without YAP1 small interfering RNA(siRNA)application via immunofluorescence.RESULTS The force treatment inhibited the osteogenic differentiation potential of hBMSCs;moreover,the expression of osteogenesis markers,such as type 1 collagen(COL1),runt-related transcription factor 2,ALP,and osteocalcin(OCN),decreased.LIPUS could rescue the osteogenic differentiation of hBMSCs with increased expression of osteogenic marker inhibited by force.Mechanically,the expression of LaminA/C,F-actin,and YAP1 was downregulated after force treatment,which could be rescued by LIPUS.Moreover,the osteogenic differentiation of hBMSCs increased by LIPUS could be attenuated by YAP siRNA treatment.Consistently,LIPUS increased alveolar bone density and decreased vertical bone absorption in vivo.The decreased expression of COL1,OCN,and YAP1 on the compression side of the alveolar bone was partially rescued by LIPUS.CONCLUSION LIPUS can accelerate tooth movement and reduce alveolar bone resorption by modulating the cytoskeleton-Lamin A/C-YAP axis,which may be a promising strategy to reduce the orthodontic treatment process.

局部破损下考虑摩擦的直齿轮系统多状态啮合-碰撞动态特性研究

局部破损是直齿轮常见的故障之一,影响齿轮传动的平稳、安全运行。轮齿碰撞不可忽略,揭示局部破损下齿轮系统啮合-碰撞动态特性对提高齿轮系统安全稳定运行尤为重要。基于齿轮啮合原理和能量耗散碰撞接触力模型,考虑齿背接触的瞬时性,建立局部破损下齿面啮合模型和齿背碰撞模型。根据齿轮副接触状态及受力环境,对局部破损下多状态啮合-碰撞行为进行分类,建立局部破损下渐开线直齿轮系统啮合-碰撞离散动力学模型,探讨局部破损对齿轮系统啮合刚度和载荷分配的影响特征。分析局部破损下接触力变化机理,定义Poincaré映射截面,研究载荷系数和啮合频率变化下系统混沌、分岔特性。研究发现,局部破损影响接触力单双齿啮合区域,降低齿轮局部承载能力;较大载荷抑制齿背碰撞,较小载荷诱发周期运动共存现象和齿背碰撞;较大和较小啮合频率诱发齿背碰撞;混沌运动和周期运动共存现象诱发齿背碰撞,局部破损影响多周期共存现象,加剧系统运动的复杂性。揭示主动轮局部破损下考虑能量耗散的齿轮系统动力学模型及非线性振动机理,探究齿背碰撞发生条件。研究成果为故障齿轮系统非线性动力学建模和分析提供了新的方法和思路。

人体词“牙/齿”和“tooth”语义转移的认知研究

人体词"牙/齿",对应的英文词"tooth",基本义指称人体重要的部位之一。在漫长的语言演变过程中,主要借助隐喻和转喻的作用下,构成了一个连续统一的语义转移系统——基于突显和邻近原则的转喻所指:"年龄、口味、言语、情感";基于形貌相似的隐喻所指:"齿状物";基于隐喻转喻互动的隐转喻所指:"战争"。这说明了英汉民族某些共同的身体体验决定了认知的相通性。同时,在英汉民族思维中牙齿的言语交际功能都占有很突显的地位,汉民族还注重牙齿的外貌特征。

Calculation and Analysis of TVMS Considering Profile Shifts and Surface Wear Evolution Process of Spur Gear

Profile shift is a highly effective technique for optimizing the performance of spur gear transmission systems.However,tooth surface wear is inevitable during gear meshing due to inadequate lubrication and long-term operation.Both profile shift and tooth surface wear(TSW)can impact the meshing characteristics by altering the involute tooth profile.In this study,a tooth stiffness model of spur gears that incorporates profile shift,TSW,tooth deformation,tooth contact deformation,fillet-foundation deformation,and gear body structure coupling is established.This model efficiently and accurately determines the time-varying mesh stiffness(TVMS).Additionally,an improved wear depth prediction method for spur gears is developed,which takes into consideration the mutually prime teeth numbers and more accurately reflects actual gear meshing conditions.Results show that consideration of the mutual prime of teeth numbers will have a certain impact on the TSW process.Furthermore,the finite element method(FEM)is employed to accurately verify the values of TVMS and load sharing ratio(LSR)of profile-shifted gears and worn gears.This study quantitatively analyzes the effect of profile shift on the surface wear process,which suggests that gear profile shift can partially alleviate the negative effects of TSW.The contribution of this study provides valuable insights into the design and maintenance of spur gear systems.

Autophagy-targeting modulation to promote peripheral nerve regeneration

Nerve regeneration following traumatic peripheral nerve injuries and neuropathies is a complex process modulated by diverse factors and intricate molecular mechanisms.Past studies have focused on factors that stimulate axonal outgrowth and myelin regeneration.However,recent studies have highlighted the pivotal role of autophagy in peripheral nerve regeneration,particularly in the context of traumatic injuries.Consequently,autophagy-targeting modulation has emerged as a promising therapeutic approach to enhancing peripheral nerve regeneration.Our current understanding suggests that activating autophagy facilitates the rapid clearance of damaged axons and myelin sheaths,thereby enhancing neuronal survival and mitigating injury-induced oxidative stress and inflammation.These actions collectively contribute to creating a favorable microenvironment for structural and functional nerve regeneration.A range of autophagyinducing drugs and interventions have demonstrated beneficial effects in alleviating peripheral neuropathy and promoting nerve regeneration in preclinical models of traumatic peripheral nerve injuries.This review delves into the regulation of autophagy in cell types involved in peripheral nerve regeneration,summarizing the potential drugs and interventions that can be harnessed to promote this process.We hope that our review will offer novel insights and perspectives on the exploitation of autophagy pathways in the treatment of peripheral nerve injuries and neuropathies.

Poor oral health was associated with higher risk of gastric cancer: Evidence from 1431677 participants

BACKGROUND In recent years,the association between oral health and the risk of gastric cancer(GC)has gradually attracted increased interest.However,in terms of GC incidence,the association between oral health and GC incidence remains contro-versial.Periodontitis is reported to increase the risk of GC.However,some studies have shown that periodontitis has no effect on the risk of GC.Therefore,the present study aimed to assess whether there is a relationship between oral health and the risk of GC.AIM To assess whether there was a relationship between oral health and the risk of GC.METHODS Five databases were searched to find eligible studies from inception to April 10,2023.Newcastle-Ottawa Scale score was used to assess the quality of included studies.The quality of cohort studies and case-control studies were evaluated separately in this study.Incidence of GC were described by odds ratio(OR)and 95%confidence interval(CI).Funnel plot was used to represent the publication bias of included studies.We performed the data analysis by StataSE 16.RESULTS A total of 1431677 patients from twelve included studies were enrolled for data analysis in this study.According to our analysis,we found that the poor oral health was associated with higher risk of GC(OR=1.15,95%CI:1.02-1.29;I2=59.47%,P=0.00<0.01).Moreover,after subgroup analysis,the outcomes showed that whether tooth loss(OR=1.12,95%CI:0.94-1.29;I2=6.01%,P>0.01),gingivitis(OR=1.19,95%CI:0.71-1.67;I2=0.00%,P>0.01),dentures(OR=1.27,95%CI:0.63-1.19;I2=68.79%,P>0.01),or tooth brushing(OR=1.25,95%CI:0.78-1.71;I2=88.87%,P>0.01)had no influence on the risk of GC.However,patients with periodontitis(OR=1.13,95%CI:1.04-1.23;I2=0.00%,P<0.01)had a higher risk of GC.CONCLUSION Patients with poor oral health,especially periodontitis,had a higher risk of GC.Patients should be concerned about their oral health.Improving oral health might reduce the risk of GC.

Effects of personalized oral hygiene management on oral health status of pregnant women

BACKGROUND The Cariostat caries activity test(CAT)was used to evaluate the effectiveness of personalized oral hygiene management combining oral health education and professional mechanical tooth cleaning on the oral health status of pregnant women.AIM To investigate whether personalized oral hygiene management enhances the oral health status of pregnant women.METHODS A total of 114 pregnant women who were examined at Dalian Women’s and Children’s Medical Center were divided into four groups:High-risk experimental group(n=29;CAT score≥2;received personalized oral hygiene management training),low-risk experimental group(n=29;CAT score≤1;received oral health education),high-risk control group(n=28;CAT score≥2),and low-risk control group(n=28;CAT score≤1).No hygiene intervention was provided to control groups.CAT scores at different times were compared using independent samples t-test and least significant difference t-test.RESULTS No significant difference in baseline CAT scores was observed between the experimental and control groups,either in the high-risk or low-risk groups.CAT scores were reduced significantly after 3(1.74±0.47 vs 2.50±0.38,P<0.0001)and 6 months(0.53±0.50 vs 2.45±0.42,P<0.0001)of personalized oral hygiene management intervention but not after oral health education alone(0.43±0.39 vs 0.46±0.33,P>0.05 and 0.45±0.36 vs 0.57±0.32,P>0.05,respectively).Within groups,the decrease in CAT scores was significant(2.43±0.44 vs 1.74±0.47 vs 0.53±0.50,P<0.0001)for only the high-risk experimental group.CONCLUSION Personalized oral hygiene management is effective in improving the oral health of pregnant women and can improve pregnancy outcomes and the oral health of the general population.