A clinical and radiologic study of autotransplanted impacted canines

The aim of the present study was to evaluate the clinical and radiologic results of 20 autotransplantations of impacted canines performed in the Orthodontic and Pedodontic Department of the University of Geneva between 1979 and 1988. The sample, divided into two different age groups (group A: 13–20 years; group B: 20–48 years), demonstrated persistence of pulp vitality in 80% of the cases in group A, whereas routine endodontic treatment was instituted in all cases of group B. Periodontal healing was noted in 90% of the cases in group A, and in 70% of the cases in group B. The present clinical and radiologic data indicate that impacted canines can be transplanted at any age with good prognosis and are an alternative to orthodontic repositioning in selected cases of canine impaction.     

The effects of orthodontic tooth movement on the glycosaminoglycan components of gingival crevicular fluid

Abstract In this study, gingival crevicular fluid (GCF) was collected from around a canine tooth, in children, before and during orthodontic tooth movement. The aim was to identify and quantify the glycosaminoglycan (GAG) components of GCF and relate them to tooth movement, gingival inflammation, plaque accumulation, pocket probing depth and GCF volume recorded at the site of sampling. GAG in GCF samples, collected for a 15-min period into microcapillary tubes, were separated electrophoretically, stained with Alcian blue and quantified using a laser densitometer. 2 GAG components of hyaluronic acid (HA) and chondroitin sulphate (CS) were identified. The increase in GCF volume during orthodontic tooth movement was only partly due to increased gingival inflammation, GAG levels varied with different types of orthodontic tooth movement. In GCF, levels of CS, in particular, may reflect the changes in the deeper periodontal tissues which could be monitored during orthodontic tooth movements.     

Psychological and social effects of orthodontic treatment

Adolescents with commonly occurring forms of malocclusion often are presumed to be at risk for negative self-esteem and social maladjustment. A randomized control group design was used to assess the psychosocial effects of orthodontic treatment for esthetic impairment. Ninety-three participants, 11 to 14 years old, with mild to moderate malocclusions, were randomly assigned to receive orthodontic treatment immediately or after serving as delayed controls. A battery of psychological and social measures was administered before treatment, during treatment, and three times after completion of treatment, the last occurring one year after termination. Repeated measures analyses of variance assessed group differences at the five time points. Parent-, peer-, and self-evaluations of dental-facial attractiveness significantly improved after treatment, but treatment did not affect parent- and self-reported social competency or social goals, nor subjects' self-esteem. In summary, dental-specific evaluations appear to be influenced by treatment, while more general psychosocial responses are not.This research was supported by Grant NIH-NIDR-R01-DE06154 from the National Institute of Dental Research.     

离体牙多次粘结托槽的抗张强度测定

①目的　研究牙面多次酸蚀粘结托槽抗张强度的变化。②方法　选择因正畸需要而拔除的前磨牙为实验样本 ,分为 3组 ,每组 10颗牙齿。第 1组为首次酸蚀粘结托槽 ;第 2 ,3组为第 2 ,3次酸蚀粘结托槽。以材料力学实验机分别测定其抗张强度 ,统计每一牙面上的粘结剂残留量进行ARI计分 ,并对各组进行扫描电镜观察。③结果　 3组粘结托槽抗张强度比较 ,差异无显著性 (F =0 .175 ,P >0 .0 5 ) ;3组粘结剂残留指数 (ARI)计分比较 ,差异无显著性 (Hc=2 .2 38,P >0 .0 5 ) ;电镜观察 1,2次酸蚀的牙釉质表面 ,其蜂窝结构在不断增多。④结论　牙面的第 2 ,3次酸蚀粘结托槽仍能获得满意的粘结强度。     

大鼠磨牙三维有限元模型的建立

目的 :建立大鼠磨牙的三维有限元模型 ,探讨牙及牙周组织的应力分布状况。方法 :采用Sprague Dawley大鼠 2 0只 ,建立大鼠磨牙正畸移动的动物模型 ,制作大鼠上颌第一磨牙牙周连续切片 ;采用计算机技术 ,重建牙及牙周组织三维形态、结构 ,并建立其三维有限元模型。结果 :组织切片的应力分布显示牙周膜是一种存在于两种硬组织之间的软组织 ,有其特有的应力分布状态。结论 :本研究建立的正畸大鼠磨牙三维有限元模型是观察正畸牙移动过程中分析应力的一种简便、准确、可靠的模型及方法。     

上颌前牙平面导板在固定矫治中解除深覆(牙合)的临床观察

目的　探讨固定矫治技术中配合使用上颌前牙平面导板 (Maxillaryplanebiteplane ,MPP)的临床疗效。 方法　将临床深覆牙合需打开咬牙合病例随机分为两组 ,MPP组在固定矫治技术配合使用上颌前牙平面导板 ,对照组单纯使用固定矫治技术。MPP组覆牙合数为 (6 1± 1 3)mm ,对照组覆牙合数为 (5 9± 1 4)mm。结果　全部病例深覆牙合解除 ,矫治结束 ,MPP组打开咬牙合时间短于对照组 (P <0 0 1) ,疗程明显短于对照组 (P <0 0 1)。结论　上颌前牙平面导板在固定矫治第一阶段治疗中配合固定弓丝打开咬牙合 ,可明显提高矫治效果。     

大黄消炎痛含漱液对固定矫治患者牙周组织影响的研究

目的观察大黄消炎痛含漱液对固定矫治的患者牙周组织的影响。方法将60例需做正畸治疗的患者分为2组,A组和B组患者戴入矫治器前1周、戴入后2周、4周、8周下颌前磨牙菌斑指数、牙龈出血指数、牙周探诊深度。结果固定矫治器的放置会使牙周临床指标显著增高,牙龈出现轻、中度炎症,应用大黄消炎痛含漱液漱口能使牙周临床指标明显降低。结论固定矫治器的放置可影响牙周组织的健康,对接受固定矫治的患者应用抗菌、消炎药物漱口是非常重要的。     

微型种植体支抗在正畸治疗双颌前突中切牙及磨牙位置变化的研究

目的：研究微型种植体支抗治疗双颌前突病例的，临床应用效果。方法：选择在沈阳市口腔医院正畸科就诊，符合纳入标准的双颌前突患者14例，随机分成2组，分别采用微型种植体与传统方法加强支抗，通过术前术后X线头影测量结果变化评价2种支抗方法的临床有效性。结果：2组患者在6～8个月后上下颌前牙内收均达到预定位置，实验组上下颌第一恒磨牙牙冠分别近中移动0、29mm和0．56mm，上下颌切牙切缘分别腭侧移动6．93mm和6．03mm；对照纽上下颌第一恒磨牙牙冠分别近中移动1．36mm和1．96mm，上下切牙切缘分别腭侧移动5．79mm和4．21mm。结论：微型种植体支抗完全可以代替传统支抗方法，满足正畸临床治疗双颌前突的需要，实现前牙最大程度的内收。     

Orthodontic traction of a transmigrated mandibular canine using mini-implant: a case report and review

The patient in this case is an 11-year-old girl, whose mandibular left canine was transmigrated. The traction to the arch was assisted by using a temporary skeletal anchorage device. After 5 months of poor response to traction, the biomechanics were re-adjusted, obtaining effective traction in to the arch in 12 months. After this period, the treatment was completed with fixed orthodontic appliances.     

前牙开(牙合)患者颞下颌关节间隙及髁突形态的锥形束CT评价

目的应用锥形束CT(cone-beam CT,CBCT)对前牙开(牙合)患者的颞下颌关节间隙及髁突形态进行测量分析,探讨前牙开(牙合)患者与正常覆(牙合)患者的颞下颌关节的差异。方法选取2014年6月至2020年8月于南京大学医学院附属口腔医院正畸科就诊的前牙开(牙合)患者54例(前牙(牙合)开组)和正常覆(牙合)患者54例(正常覆(牙合)组),对其拍摄的颌面部CBCT图像使用多平面重建技术重建颞下颌关节矢状位及冠状位图像。使用Ka-melchuk法测量颞下颌关节上、后、前间隙,根据髁突骨质情况将髁突形态分为正常型与异常型2类,对前牙开(牙合)组和正常覆(牙合)组进行关节间隙及髁突形态的统计学分析。将前牙开(牙合)组根据开(牙合)的程度分为3个亚组:(1)Ⅰ°开(牙合)组(开(牙合)距离<3 mm);(2)Ⅱ°开(牙合)组(3 mm≤开(牙合)距离≤5 mm);(3)Ⅲ°开(牙合)组(开(牙合)距离>5 mm),比较3个亚组间关节间隙的差异。结果前牙(牙合)开组与正常覆(牙合)组相比,颞下颌关节前、上间隙差异无统计学意义(P>0.05),颞下颌关节后间隙显著增宽(P<0.01);前牙开(牙合)组髁突骨质异常占52.8%,正常覆(牙合)组骨质异常占21.3%,两组间具有显著性差异(P<0.01)。与Ⅰ°和Ⅱ°前牙开(牙合)患者相比,Ⅲ°前牙开(牙合)患者髁突在关节窝内更靠前(P<0.05)。结论前牙开(牙合)患者的髁突在关节窝内位置更加靠前、髁突骨质异常比例较高。