富血小板血浆影响正畸牙齿移动效率的研究进展

富血小板血浆(PRP)是一种从自体血液中提取的血小板浓缩物,含有丰富的细胞因子和生长因子,其中血小板衍生生长因子、转化生长因子β、血管内皮生长因子主要对成骨细胞和破骨细胞的活性产生影响,促进骨重建过程。正畸牙的移动效率受到骨重建的影响,故局部注射PRP将是加速正畸牙齿移动效率的新方向。该文主要对PRP在正畸治疗中加速正畸牙移动效率的相关实验及其基础研究进行了综述,有助于进一步探讨PRP应用于临床治疗中加速正畸牙移动效率的可行性。     

Temporary loss of plasma membrane integrity in orthodontic tooth movement

In these studies, a rat model of orthodontic tooth movement was used to support the premise that periodontal ligament (PDL) cells experience plasma membrane disruption and resealing events upon application of mechanical stress. Immunoelectron microscopy, showed albumin in the cytoplasm of PDL and bone lining cells in the tension side of moved molars. The intracellular localization of this large molecule (60 KDa) suggests that these cells have undergone plasma membrane disruption and resealing. To further assess these and previous findings, fluorescent dyes (FITC-dextran and rhodamine-dextran) were delivered into the vascular system followed by application of 50 g of static load. These large dextran molecules (10 KDa) were preferentially taken up by PDL cells of the buccal (tension side) of moved molars. These cells were determined to be viable since dead cells do not retain these diffusible tracers. These studies provide evidence of a novel cellular mechanism for uptake and release of molecules and suggest a potential role for plasma membrane disruption in the mechanotransduction of orthodontic tooth movement.     

加速正畸牙齿移动的辅助干预措施

正畸治疗周期通常为2~3年,较长的治疗周期常伴随着较高的并发症发生风险,对患者预后产生不利影响。因此,缩短治疗周期,探索安全有效的辅助干预措施加速正畸牙齿移动具有非常重要的临床意义。目前,加速正畸牙齿移动的辅助干预措施较多,主要可以分为手术干预和非手术干预两大类。但是,尚无一种干预措施得到公认,为正畸临床所常规采用。本文旨在针对目前常见的加速正畸牙齿移动的辅助干预措施作一综述,以期指导临床,缩短治疗周期,改善患者预后。     

加速正畸牙齿移动的辅助干预措施

正畸治疗周期通常为2~3年,较长的治疗周期常伴随着较高的并发症发生风险,对患者预后产生不利影响。因此,缩短治疗周期,探索安全有效的辅助干预措施加速正畸牙齿移动具有非常重要的临床意义。目前,加速正畸牙齿移动的辅助干预措施较多,主要可以分为手术干预和非手术干预两大类。但是,尚无一种干预措施得到公认,为正畸临床所常规采用。本文旨在针对目前常见的加速正畸牙齿移动的辅助干预措施作一综述,以期指导临床,缩短治疗周期,改善患者预后。     

加速正畸牙齿移动的生物学方法

正畸治疗的平均疗程在两年以上,较长的正畸治疗周期可能增加牙周、牙体并发症发生的风险。因此科学有效地加速牙齿移动,缩短正畸周期具有重要的临床意义。目前加速牙齿移动的方法主要有两大类：一类是外科手术法,包括截骨术、皮质切开术、压电皮质切开术、微骨手术等;另一类是非手术理化刺激法,包括低能激光辐照疗法、低强度脉冲超声、共振震动、脉冲电磁场、低频脉冲疗法、化学物质局部注射等。本文对以上方法的研究进展作一综述,以期为临床医生选择加速牙齿移动的方法提供参考。     

加速正畸牙齿移动的生物学方法

正畸治疗的平均疗程在两年以上,较长的正畸治疗周期可能增加牙周、牙体并发症发生的风险。因此科学有效地加速牙齿移动,缩短正畸周期具有重要的临床意义。目前加速牙齿移动的方法主要有两大类：一类是外科手术法,包括截骨术、皮质切开术、压电皮质切开术、微骨手术等;另一类是非手术理化刺激法,包括低能激光辐照疗法、低强度脉冲超声、共振震动、脉冲电磁场、低频脉冲疗法、化学物质局部注射等。本文对以上方法的研究进展作一综述,以期为临床医生选择加速牙齿移动的方法提供参考。     

Effect of injectable platelet-rich fibrin (i-PRF) on the rate of tooth movement:: A randomized clinical trial

ObjectivesTo evaluate the efficiency of injectable platelet-rich fibrin (i-PRF) in accelerating canine tooth movement and to examine levels of the matrix metalloproteinase-8 (MMP-8), interleukin-1β (IL-1β), receptor activator of nuclear factor kappa-light-chain-enhancer of activated B cells ligand (RANKL), and osteoprotegerin (OPG) in the gingival crevicular fluid during orthodontic treatment.Materials and MethodsTwenty patients (mean age = 21.4 ± 2.9 years) with Class II Division 1 malocclusion were included in a split-mouth study. The treatment plan for all patients was extraction of maxillary first premolars followed by canine distalization with closed-coil springs using 150 g of force on each side. The study group received i-PRF two times, with a 2-week interval, on one side of the maxilla. The contralateral side served as the control and did not receive i-PRF. Maxillary canine tooth movement was measured at five time points (T1–T5) on each side. Also, the activity of inflammatory cytokines was evaluated at three time points in the gingival crevicular fluid samples.ResultsThere was a significant difference in canine tooth movement between the two groups (P < .001). i-PRF significantly increased the rate of tooth movement, and stimulation in the levels of inflammatory cytokines supported this result (P < .001). The levels of cytokines changed in both groups between T1 and T2. The IL-1β, MMP8, and RANKL values were significantly increased in the study group compared with the control group, while the OPG values were significantly decreased.Conclusionsi-PRF-facilitated orthodontics is an effective and safe treatment modality to accelerate tooth movement, and this method can help shorten orthodontic treatment duration.     

Effect of platelet-rich plasma on the rate of orthodontic tooth movement:: A split-mouth randomized trial

ObjectiveTo investigate the effect of local injection of platelet-rich plasma (PRP) on the rate of orthodontic tooth movement.Materials and MethodsSixteen female patients were randomly allocated in a split-mouth study design to receive PRP injections with CaCl₂ activating solution on one side (intervention side) while the other side received CaCl₂ injection only (control side). Canine retraction was performed on 0.017 × 0.025-inch stainless steel archwire applying 1.5 N retraction force. PRP and CaCl₂ injections were done at 0, 3, and 6 weeks. The duration of the study was 4 months. Data were collected from digitized models. Assessment of pain accompanying the procedure was done using a visual analogue scale.ResultsThe rate of canine retraction was faster on the intervention side in the first 2 months, with a statistically significant difference in the first month (P = .049). On the other hand, the rate was statistically significantly slower on the intervention side in the third month following cessation of PRP injections (P = .02). Pain increased following injections on both sides.ConclusionsPRP showed a positive potential to accelerate the rate of tooth movement when injected in the first 2 months. Repeated injections of PRP to maintain a steady rate of accelerated tooth movement warrant further investigation.     

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.     

Adiponectin prevents orthodontic tooth movement in rats

ObjectiveThe objective was to examine the effects of repetitive local administration of adiponectin on experimental tooth movement in rats.Materials and methodsThe maxillary right first molar of male Wistar rats (n = 24) was moved mesially for 14 days, with local adiponectin injections (0.2 or 2 μg) every third day. Micro-computed tomography was performed at days 0, 6 and 14 and molar movement, bone density and bone volume fraction were calculated from the scans. Changes in extracellular matrix collagen and cell numbers in the periodontal ligament were analyzed histologically, and levels of circulating cytokines were measured by Luminex and ELISA.ResultsAdiponectin injections induced a reduction in tooth movement after 12 and 14 days compared to controls. No tooth movement was observed between days 3 and 14 in the group receiving the highest dosage (2 μg) of adiponectin. Differences in bone density and bone volume fractions between treatment and control groups were not identified. Relative size and morphology of collagen fibrils, and cell number in the periodontal region after adiponectin injections were unchanged compared to controls. Levels of circulating adiponectin or other selected factors in plasma were not influenced by the adiponectin injections.ConclusionsSubmucosal injections of adiponectin prevented experimental tooth movement in rats. The effect was dosage-dependent and local. Adiponectin injections caused no detectable changes in bone density, periodontal cell number or collagen content.     

The effectiveness of locally injected platelet-rich plasma on orthodontic tooth movement acceleration:: A systematic review of animal studies

ObjectivesTo critically appraise the current evidence available from animal studies pertaining to the effectiveness of platelet-rich plasma (PRP) in accelerating orthodontic tooth movement.Materials and MethodsElectronic searches of nine databases were conducted up to June 2020, followed by a hand search of the reference list of eligible studies. The study design required was prospective controlled animal studies. The primary outcome assessed was the rate of orthodontic tooth movement. The secondary outcome evaluated was histological changes after PRP application. Following study retrieval and selection, relevant data were extracted. Risk-of-bias (RoB) assessment was done using the Systematic Review Center for Laboratory Animal Experimentation''s Risk of Bias Tool (SYRCLE''s Risk of Bias Tool). Two review authors conducted the work of searching, study selection, and quality assessment independently and in duplicate.ResultsOf 193 studies, 5 animal studies were included in this systematic review. Three studies found a positive correlation between PRP injection and tooth movement acceleration, along with corresponding histological changes. Two studies detected no significant difference in tooth movement rate after PRP application.ConclusionsBased on the current limited evidence, the efficacy of PRP on tooth movement acceleration remains debatable. More well-designed randomized controlled trials involving humans are called for to obtain more clinically significant conclusions.     

Osteoimmunology in orthodontic tooth movement

The skeletal and immune systems share a multitude of regulatory molecules, including cytokines, receptors, signaling molecules, and signaling transducers, thereby mutually influencing each other. In recent years, several novel insights have been attained that have enhanced our current understanding of the detailed mechanisms of osteoimmunology. In orthodontic tooth movement, immune responses mediated by periodontal tissue under mechanical force induce the generation of inflammatory responses with consequent alveolar bone resorption, and many regulators are involved in this process. In this review, we take a closer look at the cellular/molecular mechanisms and signaling involved in osteoimmunology and at relevant research progress in the context of the field of orthodontic tooth movement.     

不同浓度木通皂苷D对大鼠正畸牙移动的影响

目的:探讨局部注射不同浓度的木通皂苷D对大鼠正畸牙移动的影响。方法:40只6周龄雌性Wistar大鼠,随机分为4组,建立正畸牙移动动物模型。以上颌两中切牙为支抗,牵引上颌第一磨牙向近中移动,镍钛拉簧加力40 g。ASD1组以5 mg/kg的剂量局部注射ASD溶液;ASD2组以10 mg/kg的剂量局部注射ASD溶液;PGE2组以25 μg/kg的剂量局部注射PGE2溶液;空白对照组注射生理盐水。4组动物分别于正畸加力3、7、14、21、28 d后分批处死,测量各期上颌第一磨牙的移动距离,H-E染色观察切片牙周组织及破骨细胞数量的变化,采用SPSS13.0软件包对数据进行统计学分析。结果:各实验组动物牙移动距离均大于对照组,加力第3天,只有PGE2组与对照组相比有显著差异（P<0.05）。加力第7天,ASD2组和PGE2组与对照组相比均有显著差异（P<0.05）。加力第14、21、28天,ASD1组、ASD2组和PGE2组与对照组相比均具有统计学意义（P<0.05）。各时间段ASD2组和PGE2组之间牙移动距离相比无统计学意义（P>0.05）。组织学观察,压力侧多核破骨细胞数目随时间推移呈上升趋势,第21天达到高峰,随后逐渐减少。结论:局部注射ASD可促进大鼠正畸牙移动,ASD以10 mg/kg的剂量局部注射,其作用与PGE2促进正畸牙移动的效果相似,较5 mg/kg剂量的ASD促进牙移动的效果明显。     

蛇床子素对大鼠正畸牙牙周组织改建的影响

目的 探讨灌服蛇床子素对大鼠正畸牙移动过程中牙周组织改建的影响。方法 72只8周龄雄性SD大鼠随机分3组,高浓度（40 mg/kg）、低浓度（20 mg/kg）蛇床子素组和对照组。建立大鼠正畸牙移动模型,分别灌服蛇床子素溶液和等量溶剂,加力7、14、21、28 d后分批处死,获取包含上颌磨牙的上颌骨,测量第一磨牙近中移动距离。分别采用H-E、抗酒石酸酸性磷酸酶染色观察牙周组织变化及对破骨细胞进行计数,采用SPSS 20.0软件包对数据进行统计学分析。结果 加力后7、14、21、28 d,上颌第一磨牙近中移动距离逐渐增大。加力第7天,低浓度组与对照组无显著差异（P>0.05）,其余各时间点实验组牙移动距离均较对照组显著增加（P<0.05）;高浓度组与低浓度组之间也有显著差异（P<0.05）。组织学观察可见,张力侧成骨细胞出现,实验组较对照组明显。压力侧破骨细胞计数于加力第7天达到高峰,与对照组有显著差异（P<0.05）,高浓度组较低浓度组多,且有显著差异(P<0.05);加力第14天,3组均减少,实验组仍较对照组多,有显著差异（P<0.05）,高、低浓度组间无显著差异（P>0.05）;21 d和28 d时继续减少,组间无显著差异（P>0.05）。结论 灌服蛇床子素能加快正畸牙移动,在早期阶段增加牙周组织中破骨细胞数量,加快牙周组织改建,其作用受剂量影响。     

偏侧咀嚼对正畸牙移动影响的实验研究

目的通过建立偏侧咀嚼大鼠模型,探讨偏侧咀嚼对正畸牙移动过程的影响。方法选择30只6～8周龄,（250±10）g,雄性SD大鼠,随机分为实验组与对照组,每组各15只。通过拔除实验组大鼠右下颌所有磨牙使右上颌第一磨牙丧失咬合接触建立大鼠偏侧咀嚼动物模型,同时,在两组大鼠双侧上颌切牙和第一磨牙间放置镍钛拉簧,初始力值为50g,近中移动磨牙。分别于第0、3、7、10、14天测量大鼠上颌第一磨牙近中移动的距离并通过HE染色观察大鼠上颌第一磨牙牙周组织形态学变化。结果各时间点代偿性咀嚼增强侧牙移动速率均小于对照组（P〈0.05）,牙周组织变化与对照组相似;失咬合侧牙移动速率大于对照组（P〈0.05）,牙周组织出现退行性改变;但三种咬合状态下牙齿移动速率曲线均表现为瞬时运动、迟滞期及后期移动三个阶段。结论动物实验证实偏侧咀嚼引起正畸牙牙周组织发生相应改变最终影响牙移动速率,但无论牙移动速率快慢,牙移动均符合正畸性牙移动的一般规律。     

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.