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.

Regular nicotine intake increased tooth movement velocity,osteoclastogenesis and orthodontically induced dental root resorptions in a rat model

Orthodontic forces have been reported to significantly increase nicotine-induced periodontal bone loss. At present, however, it is unknown, which further （side） effects can be expected during orthodontic treatment at a nicotine exposure corresponding to that of an average European smoker. 63 male Fischer344 rats were randomized in three consecutive experiments of 21 animals each （A/B/C） to 3 experimental groups （7 rats, 112/3）. （A） cone-beam-computed tomography （CBCT）; （B） histology/serology; （C） reverse- transcription quantitative real-time polymerase chain reaction （RT-qPCR）/cotinine serology--（1） control; （2） orthodontic tooth movement （OTM） of the first and second upper left molar （NiTi closed coil spring, 0.25 N）; （3） OTM with 1.89 mg-kg- 1 per day s.c. of L（- ）-nicotine. After 14 days of OTM, serum cotinine and IL-6 concentration as well as orthodontically induced inflammatory root resorption （OIIRR）, osteoclast activity （histology）, orthodontic tooth movement velocity （CBCT, within 14 and 28 days of OTM） and relative gene expression of known inflammatory and osteoclast markers were quantified in the dental-periodontal tissue （RT-qPCR）. Animals exposed to nicotine showed significantly heightened serum cotinine and IL-6 levels corresponding to those of regular European smokers. Both the extent of root resorption, osteoclast activity, orthodontic tooth movement and gene expression of inflammatory and osteoclast markers were significantly increased compared to controls with and without OTM under the influence of nicotine. We conclude that apart from increased periodontal bone loss, a progression of dental root resorption and accelerated orthodontic tooth movement are to be anticipated during orthodontic therapy, if nicotine consumption is present. Thus patients should be informed about these risks and the necessity of nicotine abstinence during treatment.

Three-dimensional Finite Element Analysis of the Mechanical Stress on Root from Orthodontic Tooth Movement by Sliding Mechanics

In order to study mechanical stress on root from orthodontic tooth movement by sliding mechanics, a 3-dimensional finite element model incorporating all layers of a human mandibular dental arch with orthodontic appliance has been developed to simulate mechanical stress on root from the orthodontic tooth movement. Simulated orthodontic force of 2 N at 0, 30 and 45 degree from the horizontal axis was applied to the crown of the teeth. The finite element analysis showed when orthodontic forces were applied to the tooth, the stress was mainly concentrated at the neck of the tooth decreasing uniformly to the apex and crown. The highest stress on the root was 0.621 N/mm^2 for cervical margin of the canine, and 0.114 N/mm^2 for apical region of the canine. The top of canine crown showed the largest amount of displacement （2.417 μm）, while the lowest amount of displacement was located at the apical region of canine （0.043 μm）. In conclusion, this model might enable one to simulate orthodontic tooth movements clinically. Sliding force at 2 N is ideal to ensure the bodily orthodontic tooth movement. The highest stress concentration in the roots was always localized at the cervical margin when orthodontic force of 2 N at 0, 30 and 45 degree from the horizontal axis, so there may be the same risk of root resorption when orthodontic force of 2 N at 0, 30 and 45 degree was used in clinic cases.

Histological changes following surgically-assisted rapid tooth movement through resistance reduction and distraction osteogenesis in dogs

Objective To investigate the histological changes of rapid tooth movement in dogs treated by resistance reduction and distraction osteogenesis,aiming to establish an animal model and further to reveal the remodeling mechanism of rapid tooth movement. Methods A total of 8 local hybrid dogs were selected as subjects for this study. The second pre-molar was extracted on both sides. The experimental side underwent alvelor surgery for resistance reduction and a home-made tooth-borne intraoral distraction device was installed for rapid tooth movement,while for the other side (control side) only tooth-borne intraoral distraction device was used for rapid tooth movement. The longest active force-delivery span was 2 weeks,followed by 6-week retention. The distance between the moved tooth and anchor unit was recorded weekly,and radiography was performed for each side before and after distraction. The surrounding tissues including periodontal ligament and alveolar bone were sectioned for histological analysis. Results The average distance of tooth movement was 3.55mm on the experimental side and 1.11mm on the control side. The rate of tooth movement was notably higher (P<0.01) and no significant apical root resorption was detected by X-ray on the experimental side. The active alvelor bone remodeling was found on the tension and pressure sides. However,there was no significant difference between the experimental side and the control side after the retention period. Conclusion The rate of orthodontic tooth movement can be accelerated through resistance reduction and periodontal distraction without any unfavorable effects but at minimal anchorage loss.

Dynamic Analysis of the Expression of HSP70 during Experimental Tooth Movement in Rats

In this study, the expression of HSP70 during experimental tooth movement was dynamically observed and the relationship between HSP70 and orthodontic periodontal tissue remodeling were observed. The orthodontic appliance was placed between the right maxillary first molar and maxillary central incisors of adult SD rats to establish a rat molar movement model. Immunohistochemistry was performed 1, 3, 5, 7 and 14 day（s） after orthodontic force application to observe the expression and localization of inducible HSP70. The expression of HSP70 was strongly positive in the early stage of the tooth movement, became gradually less positive, and was weakly positive in the restoration stage. There was difference in staining pattern between different parts of PDL during the same period. These results suggest that the expression of HSP70 and difference in staining pattern among different parts of PDL during orthodontic tooth movement in rats may be implicated in stress response and remodeling of periodontal tissue.

External Root Resorption During Standardised Orthodontic Tooth Movement In Young And Adult Rats

目的 :比较研究幼鼠和成年鼠正畸牙齿移动过程中的牙根吸收。方法 :本研究包括两组大鼠 ,其中幼鼠 30只 (年龄约 6周 ) ,成年鼠 30只 (年龄约 912个月 )。大鼠上颌牙一侧用于实验侧 ,另一侧用于对照。实验侧的三颗磨牙用结扎丝颌粘接剂固为一个整体 ,在超弹性拉簧作用下 (力值为 0 .1牛顿 )向切牙侧移动。 1,2 ,4 ,8和 12周时给予大鼠过量麻醉剂 ,材料用于组织学研究。上颌第一磨牙的近中颊侧根为根吸收研究对象。压力侧和张力侧的牙根吸收程度在显微镜下进行长度测量。实验侧与对照侧 ,压力侧与张力侧 ,幼鼠与成年鼠之间的牙根吸收程度分别以实验时间为参照 ,在统计学手段下进行了组间和组内分析和比较 ,以探讨牙齿移动时间和年龄因素对于牙根吸收的影响。结果 :实验侧的牙根吸收在幼鼠与成年鼠之间在 1,2 ,4 ,8周时均没有统计学差异。而在第 12周时 ,成年鼠实验侧牙根吸收大于幼鼠 (P <0 .0 5 )。成年鼠实验组压力侧的牙根吸收明显大于对照组压力侧 ,而在幼鼠组没有发现这一差异。两组年龄幼鼠的实验组其压力侧和张力侧的牙根吸收均高度相关。结论 :相对于对照侧 ,正畸牙齿移动并没有在幼鼠的实验侧诱发更多的牙根吸收。在成年鼠 ,长期的正畸作用力倾向于诱发更多的牙根吸收。这些研究结果表明对于正?

TRAIL Immunolocalisation in the Rat Periodontal Ligament during Experimental Tooth Movement. A Preliminary Study

The aim of this study was to evaluate immunohistochemically TRAIL (TNF-Related Apoptosis Inducing Ligand) expression in the periodontal ligament of rats’ molars considering its distribution pattern in the tension and compressive regions of ligament during orthodontic movement. Sixteen Sprague-Dawley rats, weighing between 120 and 200 gwere used in the present study. Tooth movement was induced by placing elastic bands between the maxillary first and second molars. The elastic bands were left in place for 12 (time T1) and 24 (time T2) hours. After rats’ euthanasia, maxillae were dissected free and the sections were exposed to a primary rabbit polyclonal anti-TRAIL anti-body. The staining status was identified as either negative or positive by using 3,3’-diaminobenzidine (DAB) to develop the immunoreaction. Data were analyzed using ANOVA test and a post-hoc Dunn’s Multiple Comparison test. P-values of less than 0.05 were considered statistically significant. The staining for TRAIL in the tension side appeared darker (intensity of staining = 2) than in the compressive side (intensity of staining = 1) 12 h after the tooth movement. The stainings of both sides of PDL were observed to be up-regulated 24 h after the application of the force (tension side = 3, compression side = 2;P 0.05). TRAIL is expressed in the periodontal ligament of rats’ molars during experimental tooth movement both in the compression and in the tension sides. The latter showed the highest amount of TRAIL immunolabeling.

Interleukin-1α and tumor necrosis factor-α expression on the compressed side of gingiva during orthodontic tooth movement

Objectives: The aim of this study was to investigate the effect of orthodontic loading on the expression of interleukin-1α (IL-1α) and tumor necrosis factor-α (TNF-α) in compressed gingiva. Materials and Methods: Twenty-four male Wistar rats were used with four rats as controls at day 0. In ten rats, corticotomy was performed on either left or right side and the re-maining side was served as control, and killed at 7 and 14 days. In the remaining ten rats, maxillary right and left first molars were moved orthodontically with a constant force of 20 g;appliance and appliance in conjunction with cortictomy (appliance-corticotomy) were sequentially alternated between left and right sides and euthanized at 7 and 14 days. Real time polymerase chain reactions of compressed gingiva excised from the euthanized rats was performed to measure mRNA expressions of IL-1α and TNF-α. Results: There were no significant differences in the expression of IL-1α between all the groups. On the other hand, TNF-α from the pressure side in the ap- pliance group and the appliance in conjunction with corticotomy group showed significant increase on the 7th day compared to that of either control or corticotomy group. Conclusions: Orthodontic loading induced the elevation of TNF-α in compressed

Cell biology in orthodontic tooth movement:The known and the unknown

This review is aimed at providing, at the cellular level, a concise and complete overview of the important knowledge on the mechanism of orthodontic tooth movement to orthodontists and postgraduates who are involved or interested in basic research. The construction of this article was oriented to the following key questions: Where an osteoclast starts to its first resorption site? When the cascade of a resorption cycle starts? What are the factors involved in bone remodeling and how they orchestrate? What happens before and after the formation of a resorption pit? Major findings in these aspects were summarized and discussed. In addition, related biological phenomenon such as orthodontically induced root resorption was intensively reviewed. By means of an updated and systematic review, the author intended to introduce more biological evidence to orthodontic intervention and to encourage evidence-based treatment in daily orthodontic practice.

EFFECT OF PULSED ELECTROMAGNETIC FIELD AND BIOMECHANICAL FORCE ON ORTHODONTIC TOOTH MOVEMENT

The purpose of this experiment is to investigate the effect of pulsed electromagnetic field (PEMF) and biomechanical force on orthodontic tooth movement by means of measurement of gross tooth movement anatomic data, light microscopic evaluation and transmission electromicroscopic evaluation. The results indicate that PEMF combined with biomechanical force could accelerate the rate and amount of orthodontic tooth movement, enhance bone deposition in tension side and resorption in compression side. The results also suggest that PEMF could accelerate orthodontic tooth movement as a result of increase in quantity of active cells, PEMF couldn’t change the ultrastructure of cells.

Factors Associated with Orthodontic Tooth Movement in Periodontally Compromised Patients

There is no consistent relationship between malocclusion and periodontal disease but certain characteristics of malocclusion can promote a pathologic environment conducive to periodontal disease. One of the dramatic means available to improve the local environmental factors is through orthodontic tooth movement. The pretreatment periodontal conditions can include excessive tooth mobility, advanced crestal bone loss, infrabony defects, tipped molars, furcation involvement, and hard and soft tissue dehiscences. Movement of teeth in the presence of periodontal inflammation can result in an increased loss of attachment and irreversible crestal loss. Although absolute reduction in bone and attachment levels does not contraindicate orthodontic correction, it does increase the difficulty of delivering controlled orthodontic mechanics that would potentially minimize further bone loss. The present review article discusses the various factors that are associated with orthodontic tooth movement in periodontally compromised patients namely: 1) tooth movement into infrabony pockets;2) tooth movement into compromised bone areas;3) tooth movement through cortical bone;4) extrusion (eruption);5) intrusion;6) tipping.

Effective techniques and emerging alternatives in orthodontic tooth movement:A systematic review

Orthodontic procedures can be inconvenient in nature.To overcome this problem,accelerated orthodontics play a very important role to reduce existing trouble and discomfort.The most common inconvenience caused during orthodontic treatment procedures is that they are very time consuming which can result in several drawbacks,including an increased risk of tooth decay,gingival recession,and root resorption.Various methods can be employed to expedite orthodontic treatment by accelerating tooth movement,including surgical-assisted procedures,biological interventions,and the utilization of devices.These approaches effectively reduce the overall period of treatment.The purpose of this review is to study the effective techniques for orthodontic tooth movement as well as highlight various orthodontic accelerating methods in the respective approaches.Some nonsurgical studies indicated that drug-induced methods can have a therapeutic effect on tooth movement.One of the approaches involves the local administration of Vitamin 1.25D,which has been found to expedite tooth movement.Vibrational orthodontic devices are a painless and cost-effective option that is considered the least invasive approach for accelerating tooth movement.Meanwhile,surgical approach is also a successful method,wherein great results and strong PDL tissue response were observed,but they cause a lot of pain and discomfort to the patient.Therefore,due to the strengths and limitations of each procedure covered in the study,more research should be done to identify the fastest way to speed up tooth mobility。

Rapid tooth movement through distraction osteogenesis of the periodontal ligament in dogs

Background Animal models are needed for the study of rapid tooth movement into the extraction socket through distraction osteogenesis of the periodontal ligament. Methods Modified distraction devices were placed on eight dogs between the first and third mandibular premolars on the left sides; similar placement of traditional straight wise appliances on the right sides served as the control. The experimental distractors were activated （0.25 mm/d） twice a day and the control devices were activated （100 g） for two weeks with consolidation periods at weeks two, three, six, and ten. Two dogs were sacrificed at each consolidation time point; rates and patterns of tooth movement, loss of anchorage, and periapical films were evaluated, and the affected premolars and surrounding periodontal tissues were decalcified and examined histologically. General observations, X-ray periapical filming and histology examination were performed. Results Distal movement （（3.66±0.14） mm） measured two weeks after modified distraction exceeded that achieved using the traditional device （（1.15±0.21） mm; P 〈0.05）. Loss of anchorage was minimally averaged （0.34±0.06） mm and （0.32±0.07） mm in the experimental and control sides, respectively. By radiography, apical and lateral surface root resorptions on both sides were minimal. Alveolar bone lesions were never evident. Fibroblasts were enriched in periodontal ligaments and bone spicules formed actively along directions of distraction. Conclusions The canine model is suitable for the study of rapid tooth movement through distraction osteogenesis of the periodontal ligament. The technique accelerates tooth movement, periodontal remodeling, alveolar bone absorption, and may induce fibroblast formation, as compared to the traditional orthodontic method, without adversely affecting root absorption, bone loss, tooth mobility and anchorage loss.

Lithium chloride promotes osteogenesis and suppresses apoptosis during orthodontic tooth movement in osteoporotic model via regulating autophagy

Osteoporosis is a widely distributed disease that may cause complications such as accelerated tooth movement,bone resorption,and tooth loss during orthodontic treatment.Promoting bone formation and reducing bone resorption are strategies for controlling these complications.For several decades,the autophagy inducer lithium chloride(LiCl)has been explored for bipolar.In this study,we investigated the autophagy-promoting effect of LiCl on bone remodeling under osteoporotic conditions during tooth movement.Ovariectomy was used to induce osteoporosis status in vivo.The results showed that LiCl rejuvenated autophagy,decreased apoptosis,and promoted bone formation,thus protecting tooth movement in osteoporotic mice.Furthermore,in vitro experiments showed that LiCl reversed the effects of ovariectomy on bone marrow-derived mesenchymal stem cells(BMSCs)extracted from ovariectomized mice,promoting osteogenesis and suppressing apoptosis by positively regulating autophagy.These findings suggest that LiCl can significantly decrease adverse effects of osteoporosis on bone remodeling,and that it has great potential significance in the field of bone formation during tooth movement in osteoporosis patients.

Biocompatible reduced graphene oxide stimulated BMSCs induce acceleration of bone remodeling and orthodontic tooth movement through promotion on osteoclastogenesis and angiogenesis

We has synthesized the biocompatible gelatin reduced graphene oxide(GOG)in previous research,and in this study we would further evaluate its effects on bone remodeling in the aspects of osteoclastogenesis and angiogenesis so as to verify its impact on accelerating orthodontic tooth movement.The mouse orthodontic tooth movement(OTM)model tests in vivo showed that the tooth movement was accelerated in the GOG local injection group with more osteoclastic bone resorption and neovascularization compared with the PBS injection group.The analysis on the degradation of GOG in bone marrow stromal stem cells(BMSCs)illustrated its good biocompatibility in vitro and the accumulation of GOG in spleen after local injection of GOG around the teeth in OTM model in vivo also didn’t influence the survival and life of animals.The co-culture of BMSCs with hematopoietic stem cells(HSCs)or human umbilical vein endothelial cells(HUVECs)in transwell chamber systems were constructed to test the effects of GOG stimulated BMSCs on osteoclastogenesis and angiogenesis in vitro.With the GOG stimulated BMSCs co-culture in upper chamber of transwell,the HSCs in lower chamber manifested the enhanced osteoclastogenesis.Meanwhile,the co-culture of GOG stimulated BMSCs with HUVECs showed a promotive effect on the angiogenic ability of HUVECs.The mechanism analysis on the biofunctions of the GOG stimulated BMSCs illustrated the important regulatory effects of PERK pathway on osteoclastogenesis and angiogenesis.All the results showed the biosecurity of GOG and the biological functions of GOG stimulated BMSCs in accelerating bone remodeling and tooth movement.

Photobiomodulation therapy assisted orthodontic tooth movement:potential implications,challenges,and new perspectives

Over the past decade,dramatic progress has been made in dental research areas involving laser therapy.The photobiomodulatory effect of laser light regulates the behavior of periodontal tissues and promotes damaged tissues to heal faster.Additionally,photobiomodulation therapy(PBMT),a non-invasive treatment,when applied in orthodontics,contributes to alleviating pain and reducing inflammation induced by orthodontic forces,along with improving tissue healing processes.Moreover,PBMT is attracting more attention as a possible approach to prevent the incidence of orthodontically induced inflammatory root resorption(OIIRR)during orthodontic treatment(OT)due to its capacity to modulate inflammatory,apoptotic,and anti-antioxidant responses.However,a systematic review revealed that PBMT has only a moderate grade of evidence-based effectiveness during orthodontic tooth movement(OTM)in relation to OIIRR,casting doubt on its beneficial effects.In PBMT-assisted orthodontics,delivering sufficient energy to the tooth root to achieve optimal stimulation is challenging due to the exponential attenuation of light penetration in periodontal tissues.The penetration of light to the root surface is another crucial unknown factor.Both the penetration depth and distribution of light in periodontal tissues are unknown.Thus,advanced approaches specific to orthodontic application of PBMT need to be established to overcome these limitations.This review explores possibilities for improving the application and effectiveness of PBMT during OTM.The aim was to investigate the current evidence related to the underlying mechanisms of action of PBMT on various periodontal tissues and cells,with a special focus on immunomodulatory effects during OTM.

3D打印个性化正畸装置对单根牙垂直移动的三维有限元分析

背景:基于牙齿垂直移动原理,通过数字化设计结合3D打印制作个性化正畸装置,可使个性化正畸装置与单个切牙形成支抗系统。借助微种植体绝对支抗作用可对单根牙在三维方向上进行精准控制。目的:基于生物力学原理设计了牙位11、12、21、22压低移动与伸长移动的个性化正畸装置,通过三维有限元法分析个性化正畸装置的安全性与其对牙齿的移动作用。方法:应用Mimics、Geomagic Wrap、SolidWorks和Ansys Workbench软件分别建立了上颌前牙区(牙位11、12、21、22)牙槽骨-牙周膜-上颌切牙-个性化悬臂微种植体-连接板-个性化托槽的三维有限元模型,每个牙位分别设置个性化压低移动与伸长移动正畸装置,加载300 g拉力或推力,分析个性化正畸装置各部件应力水平,计算牙齿位移与牙周膜应力分布情况。结果与结论:①个性化压低移动正畸装置受到的最大等效应力为162.90 MPa,个性化伸长移动正畸装置受到的最大等效应力239.57 MPa,二者的最大等效应力均位于个性化托槽加力附件的垂直部分,个性化正畸装置各部件所受等效应力均在屈服强度内,均具有良好的安全性;②在个性化正畸装置作用下,牙齿初始位移呈现整体压低或伸长移动的趋势,垂直方向上的位移远远超过在水平方向和矢状方向上的位移;牙周膜根尖或颈部位置出现等效应力峰值,在根尖区牙周膜出现等效应力集中区域;③结果显示,个性化正畸装置可以使牙位11、12、21、22近似达到压低移动或伸长移动的目的,初步证实了个性化垂直移动正畸装置的有效性。

正畸过程中牙齿三维方向变化的模型测量方法研究进展

牙齿三维方向上移动效率的评价是评估正畸疗效的重要内容之一。随着科学技术的发展,矫治器及矫正技术不断进步,用于研究正畸矫治牙齿三维方向移动效率的方法和工具也在不断更新。本文以牙齿移动测量方式发展为主线,介绍了由手工石膏模型测量转向利用计算机软件对数字化模型的测量过程和依据,并对三维数字化模型数据获取方式、储存文件格式及可选择的分析处理软件进行了说明,以及回顾了前人对三维数字化模型进行三维重叠的部分研究,总结了目前对光学扫描及X线扫描得到的两种三维模型数据常用的配准方法和配准区域的选择。

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.

无托槽隐形矫治器内收前牙时后牙移动趋势及牙周膜应力分布

目的 :利用三维数字化技术对无托槽隐形矫治器内收前牙时后牙移动趋势及牙周膜应力分布进行分析。方法 :选择广西壮族自治区人民医院2017年6月—2022年6月收治的88例患者CBCT数据,将其输入Mimics 20.0软件中,对其各部位进行初步抽取,使用STL文件进行存储。通过Geomagic Studio 2014软件进行修补和优化,在优化基础上,构建无托槽隐形矫治器和牙周膜模型。利用Ansys Workbench19.0 FEM软件对6个FEM模型进行模拟仿真与观测,分析当前牙整体回收时,不同组别患者支抗牙的初始移动趋势与牙周膜范式等效应力分布。采用SPSS 21.0软件包对数据进行统计学分析。结果:所有患者支抗牙均发生不同程度牙根部颊向移动等倾向,其中,第二前磨牙位置移动在近中咬合方向上表现最为明显;而水平矩形附件组与垂直矩形附件组成相对关系,牙周膜最大范式等效应力大范围分布于牙颈部,接着是根尖区,以NA组支抗牙的范式等效应力值最大。附件垂直矩形组中,所有患者牙周膜最大范式等效应力值显著小于水平矩形组。结论:正畸牙附件设计对前牙回收时的位置移动具有较强抑制作用,在一定程度上提升了牙三维方向移动的精确性。无托槽隐形矫治器应用初期,患者牙周膜受到的范式等效应力较大。