Interventions for accelerating orthodontic tooth movement: A systematic review

Objective:To evaluate the effectiveness of interventions on accelerating orthodontic tooth movement.Materials and Methods:We searched the databases of PubMed, Embase, Science Citation Index, CENTRAL, and SIGLE from January 1990 to August 2011 for randomized or quasi-randomized controlled trials that assessed the effectiveness of interventions on accelerating orthodontic tooth movement. The processes of study search, selection, and quality assessment were conducted independently in duplicate by two review authors. Original outcome data, if possible, underwent statistical pooling by using Review Manager 5.Results:Through a predefined search strategy, we finally included nine eligible studies. Among them, five interventions were studied (ie, low-level laser therapy, corticotomy, electrical current, pulsed electromagnetic fields, and dentoalveolar or periodontal distraction). Six outcomes were evaluated in these studies (ie, accumulative moved distance or movement rate, time required to move tooth to its destination, anchorage loss, periodontal health, pulp vitality, and root resorption).Conclusion:Among the five interventions, corticotomy is effective and safe to accelerate orthodontic tooth movement, low-level laser therapy was unable to accelerate orthodontic tooth movement, current evidence does not reveal whether electrical current and pulsed electromagnetic fields are effective in accelerating orthodontic tooth movement, and dentoalveolar or periodontal distraction is promising in accelerating orthodontic tooth movement but lacks convincing evidence.     

Effects of low-level laser therapy on the rate of orthodontic tooth movement

OBJECTIVES: To test the hypothesis that mechanical forces combined with low-level laser therapy stimulate the rate of orthodontic tooth movement. STUDY DESIGN: This study was a double blind, randomized placebo/control matched pairs clinical trial to test the efficacy of GaAlAs low-level laser therapy (LLLT) on 12 young adult patients who required retraction of maxillary canines into first premolar extraction spaces using tension coil springs with fixed edgewise appliance. LLLT was applied on the mucosa buccally, distally and palatally to the canine on the test side and using a pseudo-application on the placebo side. Dental impressions and casts were made at the commencement of the trial and at the end of the first, second and third months after starting the trial. Measurement of tooth movements was made on each stage model using a stereo microscope. RESULTS: There was no significant difference of means of the canine distal movement between the LLLT side and the placebo side for any time periods (p-value = 0.77). CONCLUSION: The energy density of LLLT (GaAlAs) at the surface level in this study (25 J/cm(2)) was probably too low to express either stimulatory effect or inhibitory effect on the rate of orthodontic tooth movement.     

Effectiveness of non-conventional methods for accelerated orthodontic tooth movement: A systematic review and meta-analysis

Objectives

To assess the available evidence on the effectiveness of accelerated orthodontic tooth movement through surgical and non-surgical approaches in orthodontic patients.

Methods

Randomized controlled trials and controlled clinical trials were identified through electronic and hand searches (last update: March 2014). Orthognathic surgery, distraction osteogenesis, and pharmacological approaches were excluded. Risk of bias was assessed using the Cochrane risk of bias tool.

Results

Eighteen trials involving 354 participants were included for qualitative and quantitative synthesis. Eight trials reported on low-intensity laser, one on photobiomodulation, one on pulsed electromagnetic fields, seven on corticotomy, and one on interseptal bone reduction. Two studies on corticotomy and two on low-intensity laser, which had low or unclear risk of bias, were mathematically combined using the random effects model. Higher canine retraction rate was evident with corticotomy during the first month of therapy (WMD = 0.73; 95% CI: 0.28, 1.19, p < 0.01) and with low-intensity laser (WMD = 0.42 mm/month; 95% CI: 0.26, 0.57, p < 0.001) in a period longer than 3 months. The quality of evidence supporting the interventions is moderate for laser therapy and low for corticotomy intervention.

Conclusions

There is some evidence that low laser therapy and corticotomy are effective, whereas the evidence is weak for interseptal bone reduction and very weak for photobiomodulation and pulsed electromagnetic fields. Overall, the results should be interpreted with caution given the small number, quality, and heterogeneity of the included studies. Further research is required in this field with additional attention to application protocols, adverse effects, and cost-benefit analysis.

Clinical significance

From the qualitative and quantitative synthesis of the studies, it could be concluded that there is some evidence that low laser therapy and corticotomy are associated with accelerated orthodontic tooth movement, while further investigation is required before routine application.     

低强度激光促进正畸牙移动的Meta分析和系统评价

目的：评价低强度激光治疗（low?level laser therapy ,LLLT）促进正畸牙移动的有效性及相关风险。方法依据Cochrane Handbook的规范化要求,检索1980年-2014年Medline、PubMed等数据库,运用Review Manager 5.1软件进行Meta分析。结果共纳入6个国家6篇随机对照试验,3篇不完全随机对照试验,211名患者。偏倚风险评价显示5个研究为中度偏倚风险,4个研究为高度偏倚风险。Meta分析结果显示：与对照组相比,LLLT组治疗后7 d,正畸牙移动速度显著增加（MD=0.19,95%CI 0.02?0.37,P=0.03）,该优势持续到治疗后2个月（MD=1.08,95%CI 0.16?2.01,P=0.02）;相对于高能量密度（20或25 J/cm2）的LLLT治疗,低能量密度（2.5,5或8 J/cm2）的LLLT治疗更为有效。结论低能量密度（2.5、5或8 J/cm2）的LLLT能有效促进正畸牙移动,但还需要更多临床随机对照试验支撑。     

Comparative study of gene expression during tooth eruption and orthodontic tooth movement in mice

Objective:  The aim of this study was to understand tooth eruption by comparing the gene expression during tooth eruption and orthodontic tooth movement (OTM).
Materials and methods:  Orthodontic force was applied on maxillary molars for 2, 4, 7 and 14 days to study tooth movement. Mice at PN 0, 7, 10, 15 and 21 were fixed to observe tooth eruption. Comparative study of two procedures was assessed by haematoxylin and eosin, tartrate-resistant acid phosphatase staining and in situ hybridization for matrix metalloproteinase ( Mmp ) 2 , 13 , bone sialoprotein ( Bsp ) and osteocalcin ( Ocn ).
Results:  Tartrate-resistant acid phosphatase activity and expression of Mmp2 , 13 were obviously detectable in the compression region during OTM. They were also identified in the occlusal and apical region of alveolar bone during tooth eruption. Strong expression of Bsp and Ocn was detectable at the tension side during OTM. These genes were also expressed in the inner lateral region of alveolar bone adjacent to the tooth, but absent in the inner surface of the occlusal and root apical regions during tooth eruption.
Conclusion:  The process of alveolar bone metabolism during developmental eruption and OTM shares the same mechanism. Internal force, as the orthodontic force for OTM, may be initiating factor for tooth eruption.     

Efficacy of piezocision on accelerating orthodontic tooth movement: A systematic review

Objectives:The aim of this systematic review was to evaluate the effect of piezocision as an adjunctive procedure to accelerate orthodontic tooth movement.Materials and Methods:Randomized controlled trials and controlled clinical trials that investigated the effectiveness of piezocision on accelerating orthodontic tooth movement were identified through electronic and manual searches. The literature search, study inclusion, risk of bias assessment, and data extraction were performed by two reviewers independently.Results:Four eligible studies were included in this review. All studies reported accelerated tooth movement after piezocision, and three reported a significant reduction of treatment duration in the piezocision group. No deleterious effects on periodontal status, pain perception, satisfaction, root resorption, or anchorage control were reported in any studies.Conclusion:Based on currently available information, weak evidence supports that piezocision is a safe adjunct to accelerate orthodontic tooth movement, at least in the short term. More high-quality clinical trials to determine the long-term effects and optimal protocol for piezocision are needed to draw more reliable conclusions.     

The effect of drugs on orthodontic tooth movement

OBJECTIVE: Molecules produced in various diseased tissues, or drugs and nutrients consumed regularly by patients, can reach the mechanically stressed paradental tissues through the circulation, and interact with local target cells. The combined effect of mechanical forces and one or more of these agents may be inhibitory, additive or synergistic. The objective of this review is to outline the mechanisms of action and effects of some commonly used drugs on tissue remodeling and orthodontic tooth movement. DESIGN: All the existing published literature on the effects of various drugs that are prescribed by orthodontists, which are consumed by patients for systemic diseases and those that are known to promote and retard the tooth movement process was obtained and subjected to thorough review process. RESULTS: All the drugs reviewed have therapeutic effects, as well as side effects, that may influence the cells targeted by orthodontic forces. Therefore, it is imperative that the orthodontist pays close attention to the drug consumption history of each and every patient, before and during the course of orthodontic treatment. When the use of drugs is revealed, their effects and side effects on tissue systems should be explored, to determine their potential influence on the outcome of mechanotherapy. CONCLUSION: Drug-consumption history must be an integral part of every orthodontic diagnosis and treatment plan.     

Changes in alveolar bone structure during orthodontic tooth movement in adolescent and adult rats: A microcomputed tomography study

Background

Increasing number of adults are willing to seek orthodontic treatment, but treatment duration for them is commonly longer. Although there have been studies on molecular biological changes during tooth movement, few have focused on microstructural changes in alveolar bone.

Objective

This study aims to compare the microstructural changes in alveolar bone during orthodontic tooth movement in adolescent and adult rats.

Methods

25 6-week-old and 25 8-month-old male Sprague–Dawley (SD) rats were used to build orthodontic tooth-movement models. On Days 0, 1, 3, 7 and 14, the rats were sacrificed. Microcomputed tomography was used to evaluate tooth movement, alveolar crest height loss and microstructural parameters of alveolar bone (bone volume fraction, trabecular thickness, trabecular separation and trabecular number).

Results

Tooth movement in the adult group was slower than in the adolescent group. Alveolar bone crest height in adults was lower than it was in adolescents on Day 0. Under orthodontic force, the alveolar crest in both groups decreased and the degree of decrease are higher at early stage in adolescents. The microstructural parameters indicated that the alveolar bone was originally denser in the adult rats. With orthodontic force, it tended to be looser.

Conclusions

Under orthodontic force, changes in alveolar bone differ between adolescent and adult rats. Tooth movements in adults are slower, and the decrease in alveolar bone density are more severe.     

正畸牙移动困难相关因素研究进展

正畸牙移动是以牙周组织塑建为生物学基础的复杂生理过程。许多因素如口颌复合体的解剖特征、咬合干扰、机械因素及系统性因素等都可能对其造成影响,导致正畸牙移动困难。近年来,国内外学者非常关注牙移动困难相关因素的研究,但当前有关正畸牙移动困难的研究多为动物实验及回顾性研究,亟需高质量的临床试验及循证医学研究。许多正畸牙移动困难相关因素的作用机制尚存在争议,未形成一个普遍认可的完善理论体系,目前认为牙槽骨缺损、上颌窦、牙龈、牙根粘连、骨岛和摩擦力等因素都可能导致正畸牙移动困难。了解正畸牙移动困难的相关因素有助于正畸医生为患者制定更全面的个性化治疗方案,实现更高效、安全的牙移动。本文对目前正畸牙移动困难的相关因素作一综述,为正畸临床治疗提供参考。     

大鼠正畸牙移动过程中转化生长因子β1在牙槽骨中的表达

目的：观察大鼠正畸牙移动过程中转化生长因子β1（TGF－β1）在牙槽骨中的表达变化,探讨TGF－β在正畸牙槽骨改建中的作用。方法：建立大鼠正畸牙移动模型,用免疫组织化学方法检测牙槽骨中TGF－β1的表达。结果：对照组正常牙槽骨组织TGF－β1呈弱阳性表达。实验组压力侧和张力侧牙槽骨组织TGF－β1阳性表达增强。牙齿移动5d组和7d组,压力侧破骨细胞和张力侧成骨细胞TGF－β1均呈阳性表达。结论：TGF－β1作为局部调控因子可能参与了正畸牙槽骨改建过程。     

Effect of diabetes on orthodontic tooth movement in a mouse model

Orthodontic tooth movement is achieved by the remodeling of alveolar bone in response to mechanical loading. Type 1 diabetes results in bone remodeling, suggesting that this disease might affect orthodontic tooth movement. The present study investigated the effects of the diabetic state on orthodontic tooth movement. An orthodontic appliance was placed in normoglycemic (NG), streptozotocin-induced diabetes (DB), and insulin-treated DB (IT) C57BL6/J mice. Histomorphometric analysis and quantitative PCR of periodontium were performed. The DB mice exhibited greater orthodontic tooth movement and had a higher number of tartrate-resistant acid phosphate (TRAP) -positive osteoclasts than NG mice. This was associated with increased expression of factors involved in osteoclast activity and recruitment (Rankl, Csf1, Ccl2, Ccl5, and Tnfa) in DB mice. The expression of osteoblastic markers (Runx2, Ocn, Col1, and Alp) was decreased in DB mice. Reversal of the diabetic state by insulin treatment resulted in morphological findings similar to those of NG mice. These results suggest that the diabetic state up-regulates osteoclast migration and activity and down-regulates osteoblast differentiation, resulting in greater orthodontic tooth movement.     

骨皮质切开加速大鼠正畸牙移动的机制研究

目的:研究骨皮质切开术加速大鼠正畸牙移动的组织学改建机制.方法:选用健康未孕雌性Sprague-Dawley(S-D)大鼠48只,随机分为骨皮质切开手术组和对照组.在手术组大鼠行骨皮质切开术,对照组大鼠行对照手术后,构建正畸牙移动模型.在牙移动0、1、3、7d分别处死2组大鼠各6只.测量牙移动距离并制备组织学切片,行抗酒石酸酸性磷酸酶(TRAP)染色和核因子κB受体活化因子配体(RANKL)免疫组织化学检测.采用SPSS16.0软件包对数据进行统计学分析.结果:骨皮质切开术可在牙移动第1天及3d后加速正畸牙移动,而牙移动3d时2组大鼠牙移动距离无显著差异.牙移动第3天和第7天,手术组大鼠压力区破骨细胞数目均显著高于对照组(P＜0.05),手术组压力区RANKL的表达也显著高于对照组.结论:骨皮质切开术可加速大鼠正畸牙移动,这可能是由于牙周组织中RANKL高表达介导的破骨增强所致.     

微创骨皮质切开术加速成人正畸牙移动的临床研究

目的:探讨微刨骨皮质切开术对成人正畸拔牙病例治疗时间及磨牙支抗的影响.方法:选择拔除4颗第一前磨牙的Angle Ⅰ牙列拥挤错(牙合)畸形的健康成人患者60例,分为微创骨皮质切开术辅助正畸治疗组(A组,20例)、经典改良骨皮质切开术辅助正畸治疗组(B组,20例)和单纯正畸治疗组(C组,20例).比较3组排齐整平、间隙关闭、精细调整等各阶段所用的时间和治疗的总时间;并比较3组支抗第一磨牙矢状向近中前移的量.结果:在排齐整平阶段,A、B、C组分别为(5.64±2.57)、(4.91±3.31)、(8.87±3.75)个月(A组与B或C组比较,P＜0.01);在间隙关闭阶段分别为(6.84 ±2.69)、(6.64±3.87)、(8.63±3.29)个月(A组与B或C组比较,P＜0.05);3组在精细调整阶段并无明显差异;总的治疗时间,A、B、C组分别为(16.07±6.21)、(15.77±5.11)、(21.94 ±5.74)个月(C组分别与A组和B组比较,P＜0.01);3组在支抗第一磨牙矢状向近中前移的量并无明显差异(P＞0.05).结论:微创骨皮质切开术能缩短矫治时间,不能减少前牙内收阻力.     

Efficacy of clear aligners in controlling orthodontic tooth movement: A systematic review

Objective:To assess the scientific evidence related to the efficacy of clear aligner treatment (CAT) in controlling orthodontic tooth movement.Materials and Methods:PubMed, PMC, NLM, Embase, Cochrane Central Register of Controlled Clinical Trials, Web of Knowledge, Scopus, Google Scholar, and LILACs were searched from January 2000 to June 2014 to identify all peer-reviewed articles potentially relevant to the review. Methodological shortcomings were highlighted and the quality of the studies was ranked using the Cochrane Tool for Risk of Bias Assessment.Results:Eleven relevant articles were selected (two Randomized Clinical Trials (RCT), five prospective non-randomized, four retrospective non-randomized), and the risk of bias was moderate for six studies and unclear for the others. The amount of mean intrusion reported was 0.72 mm. Extrusion was the most difficult movement to control (30% of accuracy), followed by rotation. Upper molar distalization revealed the highest predictability (88%) when a bodily movement of at least 1.5 mm was prescribed. A decrease of the Little''s Index (mandibular arch: 5 mm; maxillary arch: 4 mm) was observed in aligning arches.Conclusions:CAT aligns and levels the arches; it is effective in controlling anterior intrusion but not anterior extrusion; it is effective in controlling posterior buccolingual inclination but not anterior buccolingual inclination; it is effective in controlling upper molar bodily movements of about 1.5 mm; and it is not effective in controlling rotation of rounded teeth in particular. However, the results of this review should be interpreted with caution because of the number, quality, and heterogeneity of the studies.