无托槽隐形矫治矩形附件对上颌磨牙远中移动力学影响的三维有限元分析

目的:建立无托槽隐形矫治远移上颌第二磨牙的三维有限元模型,计算牙周膜应力分布及第二磨牙位移趋势,为无托槽隐形矫治器远中移动上颌第二磨牙位移量、附件设计提供理论依据.方法:通过CT扫描获得患者上颌骨DICOM文件,采用Mimics、Geomagic Studio等软件分别建立无附件上颌第二磨牙远中移动0.2 mm(模型A...     

微小种植体支抗远移上颌磨牙的临床应用

目的:观察微小种植体作为强支抗远移上颌磨牙的作用及效果.方法:选取安氏Ⅱ类错(牙合)患者16 例,在上颌颊侧牙槽骨内共植入微小种植体22 颗,利用微小种植体做为支抗推磨牙向远中.拍摄磨牙移动前后的X线头影测量片,记录上颌磨牙及切牙移动情况,并进行统计分析.结果:利用微小种植体远移磨牙4～8 月后,所有病例磨牙达到中性关系.磨牙平均移动4.71 mm(P<0.01),上颌中切牙平均舌向移动2.16 mm(P<0.05);磨牙伸长、颊移、远中倾斜及上切牙伸长无统计学意义.结论:微小种植体可作为绝对强支抗,有效地整体远移上颌磨牙,特别适用于安氏Ⅱ类成人错(牙合)的矫治.     

口外弓联合滑动杆与单纯口外弓远移6│6的比较研究

目的　研究口外弓结合滑动杆推上颌第一磨牙远移矫治安氏Ⅱ类错牙合畸形磨牙远移的变化量。方法　 16例患者进行口外弓结合滑动杆与单纯口外弓推上颌第一磨牙远移的同体对照性研究 ,平均治疗 96 .37天 ,通过模型分析确定磨牙的移动量和扭转量。结果　口外弓结合滑动杆治疗侧磨牙均达安氏Ⅰ类关系 ,磨牙远移 3.0 0mm± 1.18mm ,而单纯口外弓治疗侧磨牙远移 0 .84mm± 0 .6 8mm(P <0 .0 1)。结论　口外弓结合滑动杆加速了磨牙远移的速度 ,同时兼有部分下颌磨牙的近中移动 ,加快了纠正磨牙安氏Ⅱ类牙合关系。     

改良钟摆式矫治器远移上颌磨牙的初步研究

目的 :本实验旨在对改良钟摆式矫治器在远移上颌磨牙的作用及效果进行初步研究。方法 :挑选 13名患者 ,其中男 7名、女 6名 ,年龄在 10～ 14岁之间 ,平均年龄 12 .6岁。患者均为牙性安氏Ⅱ类错 ,恒牙列且下颌牙弓排列较好。改良钟摆式矫治器是我科与杭州西湖生物材料研究所新近研制的一种远移上颌磨牙的装置 ,它包括两个磨牙和两个第一前磨牙 ,其支抗是腭侧的Nance腭托 ,设计有轨道、弹簧及制动螺丝在上颌腭侧连接磨牙与前磨牙。远移磨牙的力在腭侧传递到上颌第一磨牙。本研究采用 15 0 g力的Ni Ti螺旋推簧远移上颌第一磨牙 ,采用头影测量分析治疗前后数值变化及磨牙远移距离。结果 :安氏Ⅱ类错的上颌磨牙平均整体远移 5 .8mm ,平均远移时间为 3～ 4个月 ,在反作用力的影响下上颌第一前磨牙向近中移动 1.7mm ,上切牙向前移动 2 .1mm ,上切牙唇倾度增加 3.8° ,前牙覆减少 2 .9mm ,覆盖增加 3.4mm。远移完成后 ,为防止远中移动的上颌磨牙向近中移动 ,用Nance腭托保持三个月。结论 :1.只要病例选择合适 ,方法应用得当 ,改良钟摆式矫治器就可以在较少的支抗丧失情况下有效的远中移动上颌磨牙。 2 .改良钟摆式矫治器现已有成品生产 ,临床操作简便 ,可减少椅旁操作时间 ,患者易于接受。     

第二磨牙存在状态对远移第一磨牙效果的临床研究

目的分析上颌第二磨牙的不同存在情况对口外弓远移上颌第一磨牙的影响,并评价临床疗效。方法临床选取磨牙Ⅱ类Ⅰ分类关系口外弓远移磨牙病例30例,其中拔除上颌第二磨牙7例,平均年龄18.4岁;上颌第二磨牙未萌13例,平均年龄11.7岁;上颌第二磨牙已萌10例,平均年龄16.9岁。根据治疗前后牙列模型及头颅侧位片,测量分析磨牙远移总量、总时间、下磨牙近移量等指标,评价临床疗效。结果拔除组上颌第一磨牙远移速度最快;拔除组磨牙的远中倾斜显著小于已萌组;3组中上颌第二前磨牙向近中移动、上前牙轴倾度增加不明显,且拔除组小于其他2组。结论在严格把握适应证的前提下,对于某些特定病例,拔除上颌第二磨牙可以有效提高疗效和简化疗程。     

无托槽隐形矫治技术推磨牙向远中牙齿移动类型的研究

目的研究无托槽隐形矫治技术推磨牙向远中牙齿移动的类型。方法选取2016年3月至2018年10月于首都医科大学附属北京口腔医院正畸科就诊的患者58例,所有患者均采用无托槽隐形矫治技术推磨牙向远中。治疗前后均拍摄头颅侧位片及曲面体层片,分别测量上下颌第一、二磨牙远移量及牙长轴倾斜度。结果治疗前后上下颌第一、二磨牙到翼肌垂直平面(PTV)的距离比较,差异均有统计学意义(均P<0.05);治疗后上颌第一磨牙向远中移动(1.28±1.24)mm,上颌第二磨牙向远中移动(2.47±1.77)mm,下颌第一磨牙向远中移动(1.77±1.20)mm,下颌第二磨牙向远中移动(2.83±1.39)mm。治疗前后曲面体层片中的上下颌第一、二磨牙牙长轴与双侧眶下缘基准平面所成角比较,差异均无统计学意义(均P>0.05)。治疗前后头颅侧位片中上颌磨牙与前颅底平面(SN平面)所成角及下颌磨牙与下颌平面(MP平面)所成角比较,差异均无统计学意义(均P>0.05)。结论本研究初步证实了无托槽隐形矫治技术推磨牙向远中时磨牙是整体移动的,而非倾斜移动。     

改良式摆型矫治器远中移动上颌磨牙的疗效分析

目的 评价改良式摆型矫治器远中移动上颌磨牙的疗效。方法 选择14例牙性安氏Ⅱ类错的患者,应用改良式摆型矫治器远移上颌第一磨牙,通过矫治前和磨牙远移到位后的X线头影测量分析评价其疗效。结果 磨牙平均向远中移动3.85mm,牙冠远中倾斜3.22°;切牙近中倾斜移动2.08mm,覆盖增加1.68mm。结论 改良式摆型矫治器能有效地整体远中移动上颌磨牙,快速矫正磨牙关系,但也会引起少量的支抗丧失和切牙唇向移动。     

种植支抗整体远移上牙列的三维分析研究

目的:通过CBCT测量种植支抗整体远中移动上牙列正畸治疗后牙齿三维方向的变化,评价其移动方式及力学机制.方法:筛选满足纳入标准的23例种植支抗整体远中移动上牙列正畸成人患者,用Dolphin软件测量治疗前后牙齿三维方向上的变化,运用SPSS 23.0软件对其进行统计分析.结果:上颌第一磨牙、尖牙、切牙远中移动量分别为2.60 mm、2.66 mm、2.07 mm,远中倾斜角度分别为5.31°、5.42°、-4.68°.上颌第一磨牙颊尖和尖牙分别压低0.96 mm、0.40 mm.牙合平面顺时针旋转1.51°.第一磨牙颊向倾斜4.57°,远中旋转7.71°.尖牙区和磨牙区宽度分别增加1.18 mm、2.01 mm.结论:采用种植体支抗整体远移上牙列可以获得有效的远中移动量,远移的磨牙存在一定程度的压低、远中倾斜及远中扭转,上颌牙合平面发生顺时针旋转,尖牙区和磨牙区的宽度增加.     

GMD矫治器与钟摆矫治器远移上颌磨牙效果对比研究

目的：通过对GMD矫治器与钟摆矫治器的对比研究探讨该矫治器应用的可行性、优越性及其适应症.方法：对58例因上颌磨牙前移所导致的安氏Ⅱ类错[牙合]患者,分别使用GMD矫治器与钟摆矫治器进行推上颌磨牙向远中移动的非拔牙矫治,通过矫治前及磨牙远移到位后的X线头影测量及模型测量分析进行对比研究.结果：两种方法最终都实现了推磨牙远移的目的,但是GMD矫治器的磨牙移动更接近于整体移动,支抗控制也强于钟摆矫治器.结论：GMD矫治器能够有效、快速地远移磨牙,是一种新的有效远移磨牙的矫治器.     

微螺钉种植体支抗推磨牙向后的临床研究

目的研究临床上微螺钉种植体作为强支抗在推磨牙向远中的治疗效果。方法选取10例AngleⅡ类重度拥挤的患者作为研究对象,采用双侧颊侧植入微螺钉种植体作为强支抗远移上颌磨牙,施力为2.45～2.94N。在治疗前后拍摄头颅侧位片,测量上颌第一磨牙在矢状向的位置变化。取研究模型,通过三维扫描仪及测量软件测量上颌磨牙的三维方向的变化,进行统计学分析。结果所有病例都达到了预期的矫治效果,磨牙中性关系、面型得到了较好的改善。上颌第一磨牙平均向远中移动3.58±0.87mm;上颌磨牙的压低、颊倾、远中倾斜治疗前后均无显著性差异。结论微螺钉种植体作为强支抗,能成功远移上颌磨牙,没有出现支抗丧失,是非常有效的非依从性远移磨牙的方法。     

上颌第二磨牙萌出对“摆”式矫治器远中移动上颌磨牙疗效的影响

目的研究上颌第二磨牙不同萌出阶段对”摆”式矫治器远中移动上颌磨牙疗效的影响。方法选择上颌牙列轻中度拥挤，磨牙远中关系的病例25例。根据上颌第二磨牙萌出情况分为未萌组（15例）和萌出组（10例）。采用“摆”式矫治器远中移动上颌磨牙。以X线头影测量分析为测定手段。结果①两组的磨牙远中移动距离无显著差异。②未萌组的上颌第一磨牙远中倾斜要大于萌出组，但未萌组的上颌第二磨牙远中倾斜要小于萌出组。③萌出组的上颌第一磨牙相对伸长较多。④上颌中切牙唇向倾斜移动量和前牙覆盖增加量在萌出组较大。结论①萌出的上颌第二磨牙对上颌磨牙远中移动无明显影响。②上颌第二磨牙萌出与否对磨牙远中倾斜有较大影响。③萌出的上颌第二磨牙造成较多支抗丧失。④上颌第二磨牙萌出者在治疗后其上颌第一磨牙伸长较多。     

Distalization of maxillary first and second molars simultaneously with repelling magnets.

The aim of this study was to analyse the clinical and the dentofacial effects of using repelling SmCo5 magnets for distalization of maxillary first and second molars simultaneously. Ten consecutive patients, aged 12.0-15.6 years, with Class II malocclusion and moderate space deficiency in the upper jaw were orthodontically treated using prefabricated repelling SmCo5 magnets. The magnets were attached buccally in the premolar and first molar area to a fixed orthodontic applicance. When the magnets were activated, the molars could move freely distally. The tooth movements were analysed by measurements on dental casts, lateral photographs of dental casts, and lateral skull radiographs before and after treatment. The mean treatment time was 16.6 weeks and all maxillary molars could be distalized to a Class I relationship. The mean molar crown movement was 4.2 mm, and the maxillary first molars tipped distally and rotated disto-buccally by 8.0 and 8.5 degrees, respectively. The reciprocal forces resulted in a slightly increased inclination of the upper incisors. It was found that simultaneous distalization of first and second maxillary molars with repelling magnets could be an alternative to ordinary orthodontic treatment methods. As the molar distalization was achieved during a relatively short period, occlusal adjustment, including uprighting and derotation of the maxillary molars as well as post-treatment retention, seems recommendable.     

A comparative analysis of maxillary tooth movement produced by cervical headgear and pend-x appliance

The purpose of this study was to compare the effects of cervical headgear and pend-x on the maxillary first molar, second molar, first premolar, and upper incisors. Cephalometric radiographs were obtained at the start of treatment (T1) and after molar distalization was completed (T2) for 13 patients in a pend-x group and 13 patients in a cervical headgear group. The changes of the maxillary teeth were measured on maxillary superimpositions. Nonparametric Mann-Whitney U-test was used to compare the mean differences between the two groups. The mean amount of distalization for the headgear group was 3.15 +/- 1.94 mm and that for the pend-x group was 3.81 +/- 2.25 mm. The second molar teeth were also distalized to a mean amount of 2.27 +/- 1.33 mm in the headgear group and 2.04 +/- 2.15 mm in the pend-x group. The mean treatment time for distalization was 11.38 +/- 3.18 months for the headgear group and 7.31 +/- 4.09 months for the pend-x group. During distalization, the maxillary molars tipped distally in both groups, but intergroup differences were not significant. The anterior inclinations of the first premolar and upper incisor increased significantly in the pend-x group (P < .01). Maxillary molars showed no vertical movement in the pend-x group but extruded in the headgear group (P < .01). The anchorage loss of the pend-x appliance as well as the necessary patient compliance and greater treatment time with the cervical headgear should be taken into consideration.     

摆形矫治器与直丝弓矫治器治疗安氏Ⅱ类骨性Ⅰ类错畸形的研究

目的　分析安氏Ⅱ类骨性Ⅰ类错畸形患者经摆形矫治器结合直丝弓矫治器治疗后的牙颌面形态变化, 探讨此方法建立正常牙关系的机制。方法　10例接受摆形矫治器结合直丝弓矫治器治疗的安氏Ⅱ类骨性Ⅰ类 错患者,分别在治疗前(T1阶段)、摆形矫治器治疗后(T2阶段)及直丝弓矫治结束后(T3阶段)拍摄头颅定位侧位 片,对3个阶段牙齿、颌骨及软组织的位置变化进行测量及分析,同时观察上颌第二、三磨牙的位置和萌出情况。 结果　摆形矫治器治疗阶段上颌第一、二磨牙远中整体移动并适度远中倾斜,上切牙唇向倾斜,上齿槽座点前移; 直丝弓矫治后上颌第一、二磨牙位置与治疗前无明显差异,下齿槽座点和下颌第一磨牙明显前移;上颌第二磨牙萌 出顺利。结论　摆形矫治器可使上磨牙明显远中移动,但固定矫治结束后上磨牙前后位置因上颌骨生长和一定程 度的支抗丧失而有所复原;Ⅰ类磨牙关系的建立可能是上下磨牙差别移动和颌骨差别生长的综合结果。     

无托槽隐形矫治技术推磨牙向远中的机制与优势

对于轻中度的安氏Ⅱ类错牙合畸形患者,推磨牙向远中是一种常见的治疗方法。随着隐形矫治器的不断发展,应用无托槽隐形矫治技术改善磨牙关系,能达到很高的矫治效率。通过分析患者治疗前后的头颅侧位片及曲面断层片,测量上颌第一、二磨牙的后移量及倾斜角度,发现牙齿的移动方式接近整体移动。文章就无托槽隐形矫治技术推磨牙向远中的机制及优势做一介绍。     

摆形矫治器用于安氏Ⅱ类Ⅰ分类错(牙合)畸形对上颌牙列和骨骼的影响

目的 采用摆形矫治器对上颌磨牙远中移动的同时,观察对上颌前牙及双尖牙的副影响。方法 在临床上收集12名患者,男4名,女8名,平均年龄11.1岁,患者均为安氏Ⅱ类Ⅰ分类错(牙合)畸形,非拔牙矫治,均使用摆形矫治器远中移动磨牙来纠正Ⅱ类磨牙关系为Ⅰ类磨牙关系,牙弓内获得足够的间隙。比较治疗前后的头影测量片。结果 上颌磨牙远中倾斜8.34°(SD=8.37°),远中移动3.37mm(SD=2.10mm);上颌切牙移动2.4mm(SD=4.57);(牙合)平面向前上倾斜1.09°(SD=1.76°);下面高(ANS-Me)增加2.79mm(SD=2.03mm)。结论对摆形矫治器远中移动磨牙的疗效是肯定的,但是在治疗过程中,支抗的丧失,上颌切牙的唇倾、前牙覆(牙合)覆盖增加以及下面高的增加是治疗的副影响,而且磨牙远中移动的过程中,伴有牙冠较大量的远中倾斜。因此,提醒临床医生在使用类似的矫治器时应慎重。     

Unilateral correction of space loss in the mixed dentition

Distalization of maxillary molars is indicated for correction of Class II dental malocclusion and for space gain in cases of space deficiency. The ideal treatment with an intraoral fixed appliance for molar distalization should fulfill the following requirements: patient compliance; acceptable esthetics; comfort; minimum anterior anchor loss (as evidenced by inclination of incisors); bodily movement of the molars to avoid undesirable effects and unstable outcomes; and minimum time required during sessions for placement and activations. The purpose of this paper was to present an alternative treatment for space recovery in the area of the maxillary right second premolar when there has been significant mesial movement of the permanent maxillary right first molar. We used a modified appliance that allows unilateral molar distalization in cases of unilateral tooth/arch size discrepancy using the opposite side as anchor, thus reducing the mesialization of the anterior teeth.     

Effects of a segmented removable appliance in molar distalization

The aim of the present investigation was to evaluate the skeletal and dentoalveolar treatment effects of a segmented removable appliance [removable molar distalizer (RMD)] for molar distalization. The study was conducted on 28 patients (12 females and 16 males), with a mean age of 11.8 years. All presented with a skeletal Class I malocclusion and a bilateral dental Class II molar relationship. The pre- and post-distalization records included lateral head films, study models and standard photographs. The findings were evaluated with a paired samples t-test. The average maxillary first molar distalization with the RMD was 3.98 mm, with 4.61 degrees of distal tipping. The maxillary second premolars drifted distally 2.13 mm on average with 1.54 degrees of distal tipping, while the maxillary first premolars showed 1.23 mm of mesial movement and 1.98 degrees of mesial tipping. The incisors protruded 1.09 mm with 1.27 degrees of labial tipping. The RMD was effective in distal molar movement and all patients attained a bilateral Class I molar relationship in an average period of 4.5 months. Hygiene problems and mucosal irritations, frequently found with fixed intraoral distalization techniques, were not observed during the distalization period.     

Anchorage provided during intra-arch distal molar movement: a comparison between the Nance appliance and a fixed frontal bite plane

The aim of this retrospective study was to evaluate and compare the anchorage provided with the Nance appliance (NA) and the fixed frontal bite plane (FBP) during intra-arch distal molar movement. After a sample size calculation, 20 patients were recruited and randomly selected for each group from patients who fulfilled the following criteria: use of an intra-arch Ni-Ti coil appliance with either NA or FBP to provide anchorage during a six-month molar distalization period, no orthodontic treatment before molar distalization, and first and second maxillary molars in occlusion. The outcome measures assessed were anchorage loss, ie, anterior movement of maxillary central incisors, distal movement of maxillary molars, and bite opening effect. The mean age in the NA group was 14.7 years (SD 1.09) and in the FBP group 15.0 years (SD 0.99). The data revealed that the maxillary central incisors moved anteriorly 1.4 mm in the NA group and 1.9 mm in the FBP group. The difference in anchorage loss was not significant. The mean amount of molar distalization within the maxilla was 1.7 mm in the NA group and 1.8 mm in the FBP group. In both groups, the overbite was significantly reduced and the overbite was decreased significantly more in the FBP group. Because neither the NA nor FBP provided stable anchorage, a second treatment phase is recommended to reverse the anchorage loss after distal molar movement. If molar distalization is planned in deep bite cases, the FBP is the anchorage system of choice.