Corticotomy is a clinical procedure to accelerate orthodontic tooth movement characterized by the regional acceleratory phenomenon(RAP).Despite its therapeutic effects,the surgical risk and unclear mechanism hamper th...Corticotomy is a clinical procedure to accelerate orthodontic tooth movement characterized by the regional acceleratory phenomenon(RAP).Despite its therapeutic effects,the surgical risk and unclear mechanism hamper the clinical application.Numerous evidences support macrophages as the key immune cells during bone remodeling.Our study discovered that the monocyte-derived macrophages primarily exhibited a pro-inflammatory phenotype that dominated bone remodeling in corticotomy by CX3CR1CreERT2;R26GFP lineage tracing system.Fluorescence staining,flow cytometry analysis,and western blot determined the significantly enhanced expression of binding immunoglobulin protein(BiP)and emphasized the activation of sensor activating transcription factor 6(ATF6)in macrophages.Then,we verified that macrophage specific ATF6 deletion(ATF6f/f;CX3CR1CreERT2 mice)decreased the proportion of pro-inflammatory macrophages and therefore blocked the acceleration effect of corticotomy.In contrast,macrophage ATF6 overexpression exaggerated the acceleration of orthodontic tooth movement.In vitro experiments also proved that higher proportion of pro-inflammatory macrophages was positively correlated with higher expression of ATF6.At the mechanism level,RNA-seq and CUT&Tag analysis demonstrated that ATF6 modulated the macrophage-orchestrated inflammation through interacting with Tnfαpromotor and augmenting its transcription.Additionally,molecular docking simulation and dual-luciferase reporter system indicated the possible binding sites outside of the traditional endoplasmic reticulum-stress response element(ERSE).Taken together,ATF6 may aggravate orthodontic bone remodeling by promoting Tnfαtranscription in macrophages,suggesting that ATF6 may represent a promising therapeutic target for non-invasive accelerated orthodontics.展开更多
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,...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.展开更多
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 a...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.展开更多
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 tis...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.展开更多
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 applia...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.展开更多
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 m...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.展开更多
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 applia...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.展开更多
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...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.展开更多
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: ...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展开更多
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 o...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.展开更多
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, l...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.展开更多
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 m...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.展开更多
Orthodontic tooth movement(OTM)depends on periodontal ligament cells(PDLCs),which sense biomechanical stimuli and initiate alveolar bone remodeling.Light(optimal)forces accelerate OTM,whereas heavy forces decelerate i...Orthodontic tooth movement(OTM)depends on periodontal ligament cells(PDLCs),which sense biomechanical stimuli and initiate alveolar bone remodeling.Light(optimal)forces accelerate OTM,whereas heavy forces decelerate it.However,the mechanisms by which PDLCs sense biomechanical stimuli and affect osteoclastic activities under different mechanical forces(MFs)remain unclear.This study demonstrates that mechanosensitive ion channel Piezo1-medi-ated Ca^(2+)signal conversion is crucial for sensing and delivering biomechanical signals in PDLCs un-der heavy-force conditions.Heavy MF up-regulated Piezo1 in PDLCs,reducing mitochondrial Ca^(2+)influx by inhibiting ITPR3 expression in mitochondria-associated membranes.Decreased mito-chondrial calcium uptake led to reduced cytoplasmic release of mitochondrial DNA and inhibited the activation of the cGAS-STING signaling cascade,subsequently inhibiting monocyte-to-osteo-clast differentiation.Inhibition of Piezo1 or up-regulation of STING expression under heavy MF conditions significantly increased osteoclast activity and accelerated OTM.These findings suggest that heavy MF-induced Piezo1 expression in PDLCs is closely related to the control of osteoclast activity during OTM and plays an essential role in alveolar bone remodeling.This mechanism may be a potential therapeutic target for accelerating OTM.展开更多
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 o...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。展开更多
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 ei...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.展开更多
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 resor...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.展开更多
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 angiogen...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.展开更多
Objective: To compare the stress distribution in the periodontal ligament under different orthodontic forces during canine distalization using long-arm brackets, and to determine the optimal force value for this devic...Objective: To compare the stress distribution in the periodontal ligament under different orthodontic forces during canine distalization using long-arm brackets, and to determine the optimal force value for this device in orthodontic treatment. Methods: A finite element model was constructed after extracting the mandibular first premolar, and a long-arm bracket with a traction height of 6 mm was placed on the labial side of the mandibular canine. Three working conditions of 50 g, 100 g, and 150 g were simulated, and the magnitude and distribution of von Mises stress in the periodontal ligament were compared for each condition. Results: The maximum von Mises stress in the periodontal ligament was 0.013281 MPa in the 50 g condition, 0.02536 MPa in the 100 g condition, and 0.035549 MPa in the 150 g condition. As the orthodontic force increased, the stress distribution area in the periodontal ligament also expanded. Conclusion: A 100 g orthodontic force is the most suitable when using long-arm brackets, providing a relatively uniform stress distribution in the periodontal ligament and keeping the stress within a reasonable range.展开更多
基金supported by the National Natural Science Foundation of China(82071143,82371000,82270361)Key Research and Development Program of Jiangsu Province(BE2022795)+2 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX22_1801)the Jiangsu Province Capability Improvement Project through the Science,Technology and Education-Jiangsu Provincial Research Hospital Cultivation Unit(YJXYYJSDW4)Jiangsu Provincial Medical Innovation Center(CXZX202227).
文摘Corticotomy is a clinical procedure to accelerate orthodontic tooth movement characterized by the regional acceleratory phenomenon(RAP).Despite its therapeutic effects,the surgical risk and unclear mechanism hamper the clinical application.Numerous evidences support macrophages as the key immune cells during bone remodeling.Our study discovered that the monocyte-derived macrophages primarily exhibited a pro-inflammatory phenotype that dominated bone remodeling in corticotomy by CX3CR1CreERT2;R26GFP lineage tracing system.Fluorescence staining,flow cytometry analysis,and western blot determined the significantly enhanced expression of binding immunoglobulin protein(BiP)and emphasized the activation of sensor activating transcription factor 6(ATF6)in macrophages.Then,we verified that macrophage specific ATF6 deletion(ATF6f/f;CX3CR1CreERT2 mice)decreased the proportion of pro-inflammatory macrophages and therefore blocked the acceleration effect of corticotomy.In contrast,macrophage ATF6 overexpression exaggerated the acceleration of orthodontic tooth movement.In vitro experiments also proved that higher proportion of pro-inflammatory macrophages was positively correlated with higher expression of ATF6.At the mechanism level,RNA-seq and CUT&Tag analysis demonstrated that ATF6 modulated the macrophage-orchestrated inflammation through interacting with Tnfαpromotor and augmenting its transcription.Additionally,molecular docking simulation and dual-luciferase reporter system indicated the possible binding sites outside of the traditional endoplasmic reticulum-stress response element(ERSE).Taken together,ATF6 may aggravate orthodontic bone remodeling by promoting Tnfαtranscription in macrophages,suggesting that ATF6 may represent a promising therapeutic target for non-invasive accelerated orthodontics.
基金Hainan Provincial Finance Fund for Science and Technology Program-2020 Hainan Province Key R&D Program for Social Developmen(No.ZDYF2020166)2023 Hainan Province Key R&D Program for Social Development(No.ZDYF2023SHFZ095)。
文摘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.
基金the ReForM-A-research funding programme of the Faculty of Medicine(University of Regensburg)for their financial supportsupported by a ReForM-A grant from the ReForM research funding programme of the Faculty of Medicine of the University of Regensburg,Germany(Kirschneck 31 March 2015)the German Research Foundation(DFG)within the funding programme Open Access Publishing
文摘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.
基金supported by the National Natural Science Foundation of China (Nos.81991500 and 81991502).
文摘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.
文摘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.
基金supported by the Traditional Chinese Medicine Research Fund of the Administration of Traditional ChineseMedicine of Shaanxi Province (jc34)
文摘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.
文摘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.
文摘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.
文摘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
文摘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.
文摘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.
文摘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.
基金supported by the Natural Science Foundation of China (No.82471016,81470772)Chongqing Talent Program:Innovative Leading Talents (Medical Field,No.CQYC20210303384)+1 种基金Chongqing Medical Scientific Research Project (China) (No.cstc2020jcyj-msxmX0307)Youth Innovation in Future Medicine (Chongqing Medical University) (No.W0033).
文摘Orthodontic tooth movement(OTM)depends on periodontal ligament cells(PDLCs),which sense biomechanical stimuli and initiate alveolar bone remodeling.Light(optimal)forces accelerate OTM,whereas heavy forces decelerate it.However,the mechanisms by which PDLCs sense biomechanical stimuli and affect osteoclastic activities under different mechanical forces(MFs)remain unclear.This study demonstrates that mechanosensitive ion channel Piezo1-medi-ated Ca^(2+)signal conversion is crucial for sensing and delivering biomechanical signals in PDLCs un-der heavy-force conditions.Heavy MF up-regulated Piezo1 in PDLCs,reducing mitochondrial Ca^(2+)influx by inhibiting ITPR3 expression in mitochondria-associated membranes.Decreased mito-chondrial calcium uptake led to reduced cytoplasmic release of mitochondrial DNA and inhibited the activation of the cGAS-STING signaling cascade,subsequently inhibiting monocyte-to-osteo-clast differentiation.Inhibition of Piezo1 or up-regulation of STING expression under heavy MF conditions significantly increased osteoclast activity and accelerated OTM.These findings suggest that heavy MF-induced Piezo1 expression in PDLCs is closely related to the control of osteoclast activity during OTM and plays an essential role in alveolar bone remodeling.This mechanism may be a potential therapeutic target for accelerating OTM.
基金Dr.Vishwanath Karad MIT-World Peace University,Pune,411038 India and Dr.D.Y.Patil Dental College,and Hospital,Pimpri,Pune-411018 India.
文摘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。
文摘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.
基金This work was supported by National Natural Science Foundation of China(Grants No.81801019,81701032,82071150)National Key Research and Development Program of China(Grant No.2018YFC1105703).
文摘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.
基金funded by China Postdoctoral Science Foundation(2021M692249)National Key R&D Program of China 2017YFC1104304(YB)+1 种基金National Natural Science Foundation of China grant 82071144,Shanghai Rising-Star Program(21QA1405400)Innovative research team of high-level local universities in Shanghai(SSMU-ZDCX20180900).
文摘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.
文摘Objective: To compare the stress distribution in the periodontal ligament under different orthodontic forces during canine distalization using long-arm brackets, and to determine the optimal force value for this device in orthodontic treatment. Methods: A finite element model was constructed after extracting the mandibular first premolar, and a long-arm bracket with a traction height of 6 mm was placed on the labial side of the mandibular canine. Three working conditions of 50 g, 100 g, and 150 g were simulated, and the magnitude and distribution of von Mises stress in the periodontal ligament were compared for each condition. Results: The maximum von Mises stress in the periodontal ligament was 0.013281 MPa in the 50 g condition, 0.02536 MPa in the 100 g condition, and 0.035549 MPa in the 150 g condition. As the orthodontic force increased, the stress distribution area in the periodontal ligament also expanded. Conclusion: A 100 g orthodontic force is the most suitable when using long-arm brackets, providing a relatively uniform stress distribution in the periodontal ligament and keeping the stress within a reasonable range.
