前方牵引对早期前牙反(牙合)患者软组织侧貌的影响

目的:探讨前方牵引矫治对早期前牙反软组织侧貌的影响。方法:选择前牙反伴有颜面形态异常(审美线明显异常)的儿童60人,男27人,女33人,年龄范围8～11岁,平均年龄9.3岁,将样本随机分为对照组和前方牵引治疗组,观察及治疗周期为11～13个月,平均12.1个月。治疗前后分别拍摄头颅侧位X线片,进行头影测量分析,统计学分析采用配对t检验。结果:治疗组矫治后的面突角、全面突角、下唇基角及鼻唇角明显减小,上下唇基角明显增大,上唇突点到审美线距离明显改善,与对照组间的差异均呈高度显著性,而上唇基角及下唇突点到审美线的距离治疗前后无明显变化。结论:前方牵引矫治后面部软组织侧貌明显改善,凹面型变为直面型或者接近正常面型,鼻、上唇、下唇以及颏部四者间的关系趋于协调,唇部曲线变得平缓、协调。     

Camouflage treatment of skeletal Class III malocclusion with multiloop edgewise arch wire and modified Class III elastics by maxillary mini-implant anchorage

Objective:To evaluate the effect of the multiloop edgewise arch wire (MEAW) technique with maxillary mini-implants in the camouflage treatment of skeletal Class III malocclusion.Materials and Methods:Twenty patients were treated with the MEAW technique and modified Class III elastics from the maxillary mini-implants. Twenty-four patients were treated with MEAW and long Class III elastics from the upper second molars as control. Lateral cephalometric radiographs were obtained and analyzed before and after treatment, and 1 year after retention.Results:Satisfactory occlusion was established in both groups. Through principal component analysis, it could be concluded the anterior-posterior dental position, skeletal sagittal and vertical position, and upper molar vertical position changed within groups and between groups; vertical lower teeth position and Wits distance changed in the experimental group and between groups. In the experimental group, the lower incisors tipped lingually 2.7 mm and extruded 2.4 mm. The lingual inclination of the lower incisors increased 3.5°. The mandibular first molars tipped distally 9.1° and intruded 0.4 mm. Their cusps moved 3.4 mm distally. In the control group, the upper incisors proclined 3°, and the upper first molar extruded 2 mm. SN-MP increased 1.6° and S-Go/N-ME decreased 1.Conclusions:The MEAW technique combined with modified Class III elastics by maxillary mini-implants can effectively tip the mandibular molars distally without any extrusion and tip the lower incisors lingually with extrusion to camouflage skeletal Class III malocclusions. Clockwise rotation of the mandible and further proclination of upper incisors can be avoided. The MEAW technique and modified Class III elastics provided an appropriate treatment strategy especially for patients with high angle and open bite tendency.     

骨种植钉前牵引对骨性Ⅲ类错患者软硬组织侧貌的影响

目的研究采用骨种植钉前牵引对骨性Ⅲ类错患者软、硬组织侧貌的改变。方法选取18例需行前牵引矫治的生长发育期骨性Ⅲ类错患者,采用双侧上颌颧牙槽嵴植入骨种植钉配合面框式前牵引,平均治疗时间为9个月,力值为（3.5±0.1）N。治疗前后头影测量采用Legan&Burstone软组织分析法以及相关硬组织测量,分析比较患者治疗前后软、硬组织变化情况。结果所有患者Ⅲ类错均得到改善,鼻底趋于丰满,颏部顺时针旋转,侧貌由凹面型变为直面型,下唇突度减小,软组织上下面高比、鼻唇角、上唇突度及颏唇沟深度无明显变化。上前牙无明显变化,下前牙舌倾,上颌骨向前生长,A点前移,SNA、ANB增大;SNB减小,下颌骨顺时针旋转。结论骨种植钉前牵引可促进上颌生长,使面中份丰满,且对上颌前牙轴倾度无影响,从而纠正骨性Ⅲ类错。     

骨性Ⅲ类畸形上颌前方牵引治疗的三维测量分析

目的： 通过锥形束CT（cone-beam computed tomography, CBCT）研究骨性Ⅲ类错颌畸形患者上颌前方牵引治疗前后的变化,从三维方向上探讨上颌前方牵引治疗的机制。方法：选取14例恒牙列早期骨性Ⅲ类错颌畸形患者,男6例,女8例,年龄10~12岁,平均10.9岁,采用上颌前方牵引治疗。牵引治疗前、后,进行CBCT三维扫描,采用Dolphin 11.0对骨组织及牙进行三维重建、建立三维坐标体系,选择23个标志点进行测量、分析。测量结果使用SPSS 17.0软件包进行统计学分析。结果：上颌前方牵引后,A-冠状面的距离、SNA、ANB均显著增大 (P<0.01);A-水平面的距离显著增大 (P<0.05),ANS-PNS增大,有显著差异 (P<0.05),上颌骨向前、向下生长。Po-S-N显著增大(P<0.01),SNB显著减小 (P<0.05),提示颏部向下、向后旋转,下颌生长得到抑制。U1j-冠状面的距离显著增大(P<0.01),提示上切牙前移;U1牙长轴-SN交角显著增大 (P<0.05),提示上切牙唇倾。U6j-水平面的距离、U6j-冠状面的距离均显著增大（P<0.05）,提示上颌磨牙近中移动、伸长。额颌缝等4条骨缝三维方向上均有变化,但无显著差异（P>0.05）。结论：上颌前方牵引后,经CBCT三维测量,证实翼腭缝等骨缝的生长改建在上颌骨生长过程中发挥了重要作用,上颌骨及上颌牙明显向前、向下生长;下颌骨生长得到抑制。     

Long-term stability of maxillary protraction therapy in Class III patients with complete unilateral cleft lip and palate

Objectives:This study evaluated the long-term stability of maxillary protraction (MP) in patients with complete unilateral cleft lip and palate (UCLP) and identified factors influencing relapse and long-term outcomes.Materials and Methods:Twenty-three adolescents with UCLP who underwent MP therapy were recalled when craniofacial growth was close to completion. Subjects exhibiting reverse/positive overjets were assigned to unstable/stable groups. Lateral cephalometric measurements were made before treatment (T0), after active treatment (T1), and at the end of the growth spurt (T2).Results:About 63% of the subjects exhibited positive overjets during follow-up. The unstable group demonstrated higher B–x and Co–Gn distances than the stable group (both P < .05) at T0. More short-term (T0–T1) sagittal advancement of point A (A–y) was evident in the unstable group than in the stable group (P < .05), but no long-term difference was apparent between the two groups (P = .481). During the posttreatment period (T1–T2), the SNA angle and maxillary incisor protrusion (U1–SN angle) were considerably lower in the unstable group than in the stable group (both P < .05). Overall, the unstable group exhibited a lower increase in the vertical extent of point A (A–x) than the stable group from T0 to T2 (P < .05).Conclusions:In the long term, MP affords favorable maxillary advancement in patients with UCLP. A mandibular excess at T0 and vertical maxillary hypoplasia may contribute to the long-term relapse of a reverse overjet.     

New treatment modality for maxillary hypoplasia in cleft patients: protraction facemask with miniplate anchorage

Objective:To present cleft patients treated with protraction facemask and miniplate anchorage (FM/MP) in order to demonstrate the effects of FM/MP on maxillary hypoplasia.Materials and Methods:The cases consisted of cleft palate only (12 year 1 month old girl, treatment duration  =  16 months), unilateral cleft lip and alveolus (12 year 1 month old boy, treatment duration  =  24 months), and unilateral cleft lip and palate (7 year 2 month old boy, treatment duration  =  13 months). Curvilinear type surgical miniplates (Martin, Tuttlinger, Germany) were placed into the zygomatic buttress areas of the maxilla. After 4 weeks, mobility of the miniplates was checked, and the orthopedic force (500 g per side, 30° downward and forward from the occlusal plane) was applied 12 to 14 hours per day.Results:In all cases, there was significant forward displacement of the point A. Side effects such as labial tipping of the upper incisors, extrusion of the upper molars, clockwise rotations of the mandibular plane, and bite opening, were considered minimal relative to that usually observed with conventional protraction facemask with tooth-borne anchorage.Conclusions:FM/MP can be an effective alternative treatment modality for maxillary hypoplasia with minimal unwanted side effects in cleft patients.     

弹性包绕式牙合垫加前方牵引矫治替牙期骨性反(牙合)

目的探讨弹性包绕式垫加前方牵引矫治替牙期骨性反的适用性及治疗前后的牙颌结构变化。方法选择替牙期骨性Ⅲ类错患者9例,平均年龄8.1±1.5岁,患者前牙反,上颌相对于下颌后缩,应用弹性树脂材料制作包绕上颌全部牙齿及部分牙槽骨的包绕式垫,中部连接螺旋扩弓器快速扩弓,加前方牵引矫治反。在头颅侧位片上测量矫治前后牙、牙槽骨及颌骨的变化。结果弹性包绕式垫固位良好,腭中缝在2～3周内打开,前牙反在6～11个月内解除;上颌骨前移,下颌骨轻度向下后旋转,SNA平均增大1.9°,ANB角平均增大2.8°;治疗后上切牙唇倾,下切牙舌倾。结论在替牙期采用弹性包绕式垫加前方牵引能够促进上颌骨生长,简便、有效地治疗替牙期骨性反。     

前方牵引治疗替牙期骨性Ⅲ类错的牙颌结构变化研究

目的:观察前方牵引在替牙期骨性Ⅲ类错牙合的应用及治疗前后的牙颌结构变化。方法:选择替牙期骨性Ⅲ类错牙合患者9名,应用前方牵引矫治前牙反牙合,正畸前后进行头影测量分析。统计学分析采用配对t检验。结果:SNA角增大4.2°,ANB角增加5.4°,NA-PA增加5.0°,A-VL增加6.1mm,SNB角减少1.2°,B-VL减少0.2mm,1-SN增加6.2°。结论:前方牵引可有效促进上颌骨向前生长,抑制下颌骨生长,同时可导致下颌骨向下向后旋转,上前牙唇倾,下切牙轻度舌倾。     

Class III camouflage using skeletal anchorage and Pendex appliance

This case report describes the orthodontic treatment for a young female, aged 18 years 4 months, with a Class III malocclusion on the right side, with a combination of a posterior and anterior crossbite. Two rigid orthodontic mini-implants were placed in the retromolar region in order to move the entire lower arch distally with nickel-titanium coil springs. In addition, a Pendex appliance was used to create space and to improve the arch form and the transverse relationship. The active treatment period was 17 months. Normal overjet and overbite were obtained, and facial balance was improved. Although the cephalometric superimposition has demonstrated the effects of dental compensation, the final dental and facial results were satisfactory and stable after the second year in retention.     

Skeletal changes of maxillary protraction without rapid maxillary expansion: a comparison of the primary and mixed dentition

Objective:To determine potential differences in treatment efficiencies of face mask therapy without rapid maxillary expansion (RME) at different early dental stages.Materials and Methods:Forty-nine Class III children who were treated with a face mask without RME were divided into two groups according to their pretreatment dental stage. The primary dentition treatment group consisted of 26 subjects and the mixed dentition treatment group consisted of 23 subjects. Lateral cephalograms before treatment (T0), at the end of treatment (T1), and at least 1 year after the end of treatment (T2) were calculated and analyzed. Fourteen cephalometric variables were evaluated by t-test to identify any significant differences in skeletal changes between the two groups during T1-T0, T2-T1, and T2-T0.Results:The primary dentition group showed not only a greater response to maxillary protraction without RME than did the mixed dentition group during T1-T0, but also a greater relapse tendency during T2-T1. As a result, no significant differences were noted between the two groups in the treatment effects of face masks without RME over the time period T2-T0.Conclusion:This study suggests that face mask therapy without RME may be postponed to the early to mid mixed dentition period because the therapy induces similar skeletal changes when initiated at primary or mixed dentition.     

上颌前方牵引对恒牙早期骨性Ⅲ类错上、下颌骨宽度影响的三维模拟分析

目的: 应用颅面部锥形束CT（CBCT）对恒牙早期骨性Ⅲ类错上、下颌后牙倾斜角度、牙弓及基骨弓宽度进行分析,通过模拟上颌前方牵引矫治,分析上、下颌矢状向变化对上、下颌骨宽度协调关系的影响,对骨性Ⅲ类错前方牵引治疗中上颌牙弓扩大的必要性进行探讨。方法: 选择2016年1月—2021年1月于上海交通大学医学院附属第九人民医院口腔正畸科就诊的恒牙早期骨性Ⅲ类错患者20例,Ⅰ类个别正常患者20例,共40例。所有患者治疗前均拍摄颅面部CBCT,使用Mimics 20.0软件测量2组患者第一磨牙的颊舌向倾斜度,上、下磨牙牙弓宽度及磨牙间基骨弓宽度。对Ⅲ类错患者上颌前方牵引进行三维模拟,对上、下颌骨矢状关系改变后的牙弓和基骨弓宽度进行测量。采用SPSS 21.0软件包对数据进行统计学分析。结果: Ⅲ类错患者上颌磨牙颊侧倾斜,下颌磨牙舌侧倾斜 (P<0.01);Ⅲ类和Ⅰ类错患者下颌基骨弓宽度无显著差异,上颌基骨弓宽度Ⅲ类患者显著小于Ⅰ类患者(P<0.01),上、下颌基骨弓宽度差Ⅲ类患者显著小于Ⅰ类患者 (P<0.01);而上、下颌牙弓宽度2组间无显著差异。上颌模拟前移3 mm时,Ⅲ类错患者上颌牙弓宽度显著大于下颌 (P<0.05);上颌模拟前移4 mm时,上、下颌牙弓宽度差Ⅲ类患者显著大于Ⅰ类患者 (P<0.05);上颌模拟前移2 mm时,上颌基骨弓宽度和上、下颌基骨弓宽度差Ⅲ类患者显著小于Ⅰ类患者(P<0.05);前移3 mm时,上颌基骨弓宽度和上、下颌基骨弓宽度差无统计学差异。结论: 恒牙早期骨性Ⅲ类患者表现出一定程度的上颌基骨宽度不足,上颌磨牙颊向和下磨牙舌向代偿性倾斜;但在上颌前牵引矫形治疗中,上、下牙弓和基骨弓宽度的协调程度随着上颌前移及下颌后下旋转的量而改变。上、下颌骨的矢状向变化是上颌骨是否需要扩弓的重要参考因素之一,如变化量超过3 mm,多数患者不需要在前方牵引治疗中配合上颌扩弓。     

种植体支抗前牵上颌体的三维有限元分析

目的：探讨对上颌种植体支抗施加不同大小和方向的前牵引力时颅面复合体骨缝处的应力变化。方法：用螺旋 CT扫描安氏Ⅲ类患者颅面部以获取原始二维图像 DICOM数据,建立颅面复合体的三维有限元模型,种植支抗设计在3223间。模拟前牵引力值1～10 N,1 N 递增,方向平行于眶耳平面向前下呈0°～60°,10°递增,两两组合共70种工况。分析各工况下颅面复合体各骨缝处第一主应力及 Von Miese 等效应力分布情况。结果：牵引角度相同力值不同时,各骨缝应力变化规律相同;牵引力值相同角度不同时,不同区间各骨缝应力变化不同。当牵引角度小于30°时,应力变化分析提示上颌体向前生长并向上旋转;等于30°时上颌体出现向前生长;在40°～50°时,上颌体向前生长方向与牵引方向大致相同;大于50°时,上颌体出现向前生长并向下旋转。结论：种植体支抗眶耳平面向前下30°～50°牵引加载力1～10 N 利于上颌体向前生长。     

上颌反复快速扩缩口内前方牵引的临床效果研究

目的 本研究目的是评价双轴扩弓器上颌反复快速扩缩口内前方牵引治疗上颌后缩患者的疗效.方法 29例7～13岁患者随机分入两组.观察组:双轴扩弓器上颌反复快速扩缩口内前方牵引;对照组:Hyrax扩弓器上颌单次快速扩弓面罩前方牵引.对治疗前后的头颅侧位片进行传统和直角坐标系头影测量分析.结果 观察组平均疗程7.04个月短于对照组11.04个月,差异有统计学意义(P＜0.01).观察组A-Np增加量1.28 mm小于对照组2.03 mm,差异有统计学意义(P＜0.05),观察组上颌前移量较小.观察组治疗后下颌向后下旋转移动显著小于对照组(P＜0.05).观察组功能(牙合)平面逆时针旋转显著(P＜0.01),与对照组旋转方向相反.结论 双轴扩弓器上颌反复快速扩缩口内前方牵引是一种快速、有效的早期治疗上颌后缩患者的方法,其治疗后上颌前移量有略小于传统的Hyrax扩弓器上颌单次快速扩弓面罩前方牵引的趋势.     

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随着种植体支抗技术的发展与广泛应用,种植体支抗辅助上颌前方牵引以矫治因上颌发育不足而导致的骨性前牙反受到了广大正畸医生的关注。借助种植体支抗形式进行上颌前方牵引,可将矫形牵引力直接作用于上颌骨,在矫治骨性上颌发育不足的同时,极大地避免了传统前方牵引方法所造成的难以克服的不利的牙性变化。本文将在以下几个方面进行简要介绍和回顾:种植体支抗辅助前方牵引的实验研究;临床常用种植体支抗前方牵引的方法和种类;传统牙性支抗的前方牵引与种植体支抗辅助前方牵引的疗效比较等。     

微钛板辅助上颌前方牵引支抗稳定性的三维有限元分析

目的　为临床不同方向下进行前方牵引时,不同形态微钛板的选用提供参考。方法　构建6种改良型微钛板及上颌骨的三维有限元模型。对该模型牵引位点施加大小为4.9N/侧,方向为与上颌平面夹角为0°-50°向前下的力,分析各工况下微钛板所受应力及其固位螺钉所受拉力和应力。结果 1.不同微钛板均可固定于上颌骨颧牙槽嵴处且无受力过大或应力中断现象。2.固位螺钉受力具有差异性。角度为0°时,Y3型微钛板固位螺钉受力离散程度较小为3.899,10°-40°时,L3型微钛板固位螺钉受力离散程度较小为4.544、4.170、3.820、3.547,50°时,L2型微钛板固位螺钉受力离散程度较小为2.687。结论　微钛板辅助上颌骨发育不足患者在不同方向下进行前方牵引时,应考虑选用不同形态：牵引方向与平面夹角为0°时,选用Y3型微钛板;夹角为10°-40°时,选用L3型微钛板;夹角为50°时,选用L2型微钛板。     

两种不同扩弓方法结合上颌前方牵引的初步研究

目的探索反复快速扩弓回缩结合上颌前方牵引的可行性和方法,对比上颌单次快速扩弓和反复快速扩弓回缩结合前方牵引治疗的效果。方法选择20例上颌后缩患者,每组10例。A组：上颌单次快速扩弓加前方牵引,B组：上颌反复快速扩弓回缩加前方牵引。对治疗前及前方牵引6个月后的头颅侧位片进行头影测量分析。结果两组病例扩弓并前方牵引6个月后上颌显著前移和逆时针旋转,下颌向后下方旋转,上切牙唇倾、下切牙舌倾。两组间对比：反复扩弓回缩组前方牵引后上颌前移量（A点3．56mm）显著大于单次扩弓组（A点2．12mm）。结论使用上颌反复扩弓回缩结合前方牵引的方法治疗上颌后缩患者是可行的,其对前移上颌的效果优于单次扩弓结合前方牵引治疗。     

上颌前牵引中两种口内固位装置的临床对比研究

目的探讨快速扩弓与包绕 垫式口内固位装置结合上颌前牵引矫治的效果差异,为临床治疗提供理论依据和参考。 方法选择23例骨性Ⅲ类上颌后缩患者,分为快速扩弓结合上颌前牵引组（13例）和包绕 垫结合上颌前牵引（10例）。对两组患者治疗前及前牵引后的头颅定位侧位片进行头影测量分析,并进行配对t检验;对两组患者治疗前、前牵引后的差值变化进行组间独立样本t检验。 结果两组患者矫治后均出现SNA增大、ANB减小、下颌骨长度增加、Y-axis、MP/FH、MP/SN、PP/MP、U1-SN增大、前下面高、前面高、后面高增加。这些指标的变化差异有统计学意义。快速扩弓组患者前颅底长、上颌骨长度（Ptm-A）明显增加,下切牙明显舌倾。包绕 垫组患者后颅底长明显增加,面角明显减小,前面高明显增加。两组间对比：S-Ba、NPg-FH变化两组差异有统计学意义（P < 0.05）,其余测量值变化差异无统计学意义（P > 0.05）。 结论使用快速扩弓与包绕 垫加上颌前牵引矫治骨性Ⅲ类上颌后缩患者在临床上是确实可行的,可取得满意的疗效。     

Bone-anchored maxillary protraction to correct a class III skeletal relationship: A multicenter retrospective analysis of 218 patients

This study evaluated the impact of class III correction by elastic traction on four miniplates and the failure rate of bone-anchored miniplates in nonsyndromic patients. A total of 218 patients (112 males and 106 females; average 11.4 years), treated by 38 orthodontists, received four miniplates (total 872 miniplates) from 2008 to 2016 at three maxillofacial centers in two countries. Factors affecting the success and failure of the miniplates were retrospectively examined and skeletal changes on cephalometric radiographs examined for 52 patients. Elastic traction was performed for 22.9 months, on average. The miniplate survival rate was 93.6%; 25.7% of the patients suffered failure of one of the miniplates. Postoperative antibiotics and placement of the neck of the miniplate in the attached gingiva significantly improved the success rate. Miniplate failure was six times higher in the maxilla and occurred more in younger patients. Self-drilling screws were significantly better than self-tapping screws for fixing the miniplate. Small cephalometric changes were seen: SNA (+1.9°), SNB (+0.4°), ANB (+1.4°), Wits analysis (+1.3 mm). In conclusion, bone-anchored maxillary protraction on four miniplates is an effective method for correcting a class III relationship, but has less skeletal effect than previously reported in the literature.