无托槽隐形矫治器设计平面导板对上牙列牙齿移动的影响

目的 探讨无托槽隐形矫治器设计平面导板,对上中切牙压低效率的影响及支抗前磨牙、磨牙的变化,以期对无托槽隐形矫治器设计平面导板矫治深覆(牙合)提供参考.方法 分别选取无托槽隐形矫治器设计平面导板和无平面导板矫治深覆(牙合)的病例各6例,两组均设计上中切牙不少于0.7mm的压低,通过前牙压低矫正深覆(牙合).前磨牙及磨牙作为支抗牙不设计移动.以腭穹窿为参照,重叠设计压低前后的数字化模型,比较两组上颌中切牙压低效率的差异,以及两组支抗前磨牙和磨牙的差异.结果 平面导板组上中切牙压低效率为33％,无平面导板组上中切牙压低效率为8％,二者的差异无统计学意义(P＞0.05);平面导板组第一前磨牙、第二前磨牙、第一磨牙和第二磨牙分别伸长0.3、0.1、0.2和0.1mm;无平面导板组第一前磨牙、第二前磨牙、第一磨牙和第二磨牙分别压低0.0、0.2、0.1和0.1mm,两组的差异均有统计学意义(P＜0.05);平面导板组和无平面导板组未设计移动的第一磨牙分别颊倾0.0mm和0.3mm,二者的差异有统计学意义(P＜0.05).结论 无托槽隐形矫治器设计平面导板对上颌中切牙的压低无明显影响,但能有效伸长支抗前磨牙及磨牙,克服无托槽隐形矫治器"(牙合)垫效应"造成的后牙压低,并维持磨牙水平向的位置,对深覆(牙合)的矫正发挥一定作用.     

隐形矫治中上颌第一磨牙压低的生物力学分析

目的：探讨无托槽隐形矫治器设计压低上颌第一磨牙时结合不同微种植钉辅助支抗下上颌各牙齿的生物力学效应以及矫治器与牙周膜的应力分布情况。方法：选取符合纳排患者的上颌CBCT数据,采用三维有限元的分析方法,建立单纯矫治器、双侧植入微种植钉、颊侧植入微种植钉、腭侧植入微种植钉4种不同的三维有限元模型,分析各牙齿的位移变化及矫治器与牙周膜的应力分布情况。结果：当单纯使用矫治器时,第一磨牙垂直向、矢状向、横向移动量分别为5.59E-03 mm、-3.97E-04 mm、-2.12E-03 mm,表现为远中颊向压低的移动趋势,结合微种植钉后可以增加第一磨牙的压低移动趋势,但不同的设计会产生不同的作用结果。结论：增加微种植钉支抗能够实现对后牙段的辅助压低和牙齿控制。其中,在颊腭双侧植入微种植辅助钉效果最佳。3种微种植钉植入方式均不能显著抑制无托槽隐形矫治器造成的中牙段及前牙段移动趋势,这意味着我们需要额外增设附件去辅助牙齿控制。     

无托槽隐形矫治器推磨牙向远中的阶段性研究

目的研究无托槽隐形矫治器远中移动磨牙三维方向上的移动量及表达效率。方法选择安氏Ⅰ类和安氏Ⅱ类的成人患者,使用无托槽隐形矫治器推磨牙向远中移动,其中安氏Ⅰ类组9例,患者平均年龄23岁,向远中移动上颌下颌磨牙,安氏Ⅱ类组10例,患者平均年龄24岁,向远中移动上颌磨牙。根据矫治前和推磨牙结束后拍摄的头颅侧位片,计算出磨牙三维方向上的移动线距,角度,远中移动效率,前牙支抗变化情况,将所有数据进行统计分析。结果安氏Ⅱ类组:上颌第一磨牙远中移动表达率为65.86%,第二磨牙远中移动表达率为71.68%;安氏Ⅰ类组,上颌第一磨牙远中移动表达率为73.88%,第二磨牙远中移动表达率为77.73%,下颌第一磨牙远中移动表达率为69.1%,第二磨牙远中移动表达率为75.03%。磨牙远中移动过程中有轻度压低,还存在一定程度的远中倾斜。前牙支抗无明显丧失(P>0.05)。结论利用无托槽隐形矫治器能够有效的远中移动磨牙,但伴有一定程度的磨牙远中倾斜,垂直向上的压低,前牙支抗基本无丧失。     

无托槽隐形矫治器整体内收上颌前牙的三维有限元分析

目的:研究无托槽隐形矫治器整体内收上颌前牙过程中上颌前牙所受的应力情况及初始移动规律.方法:采用CBCT扫描已拔除双侧上颌第一前磨牙患者,建立上牙列、牙周膜及牙槽骨的初始复合体模型.激光扫描患者牙冠外形并与初始模型三维重叠建立终模型.应用ANSYS Workbench软件分析安装无托槽隐形矫治器时上颌前牙的应力分布及初始位移趋势.结果:建立了具有高仿真度的上颌复合体三维有限元模型;上颌双侧中切牙及侧切牙初始位移趋势一致,表现为远中舌向倾斜移动,且均有伸长趋势,其牙周膜应力分布与其位移趋势相一致;上颌双侧尖牙表现为远中倾斜移动趋势.结论:无托槽隐形矫治器在整体内收上颌前牙时,上颌前牙均表现为倾斜移动,且有伸长趋势.     

改良无托槽隐形矫治器压低过长磨牙辅助种植修复的临床研究

目的 评价应用改良无托槽隐形矫治器压低过长磨牙辅助种植修复治疗的有效性.方法 本研究包括25名种植修复前正畸患者,平均年龄39.2±10.1岁.样本人群总计41颗过长磨牙需正畸压低治疗,其中上颌第一磨牙21颗,上颌第二磨牙16颗,下颌第一磨牙1颗,下颌第二磨牙3颗.完善牙周治疗并达到健康牙周状况.所有患者均接受了无托槽数字化隐形矫治器(IROK隐形矫治系统,西安恒惠科技有限公司)治疗.为了使压低磨牙的力量有更好的贮存和释放形式,我们改良设计了无托槽隐形矫治器压低牙齿的结构形式.过长磨牙压低治疗前后分别拍摄头颅侧位定位片,并进行头影测量的分析比较.结果 25名患者的41颗过长磨牙均取得良好的正畸压低治疗效果,压低治疗的平均时间7.4±2.3个月.21颗过长上颌第一磨牙和16颗过长上颌第二磨牙,相对于腭平面,分别平均压低3.3 mm(P＜0.001)和2.8 mm(P＜0.001).相对于下颌平面,3颗过长下颌第二磨牙平均压低2.7mm,一颗过长下颌第一磨牙治疗后压低3.5 mm.磨牙压低治疗后未见明显根吸收.结论 应用改良无托槽数字化隐形矫治器压低过长磨牙,是一种有效的辅助种植修复的正畸治疗方法.     

应用CBCT评价隐形矫治技术远中移动上颌磨牙的临床疗效

目的 通过锥形束计算机断层扫描(CBCT)三维测量评估隐形矫治技术远中移动上颌磨牙的疗效.方法 收集应用Invisalign隐形矫治器作上颌磨牙远中移动的病例,共15例,平均年龄27岁8个月.使用微种植体或Ⅱ类牵引增强前牙支抗,治疗前后分别拍摄CBCT.使用SimPlant 11.04软件测量上颌磨牙三维方向移动量和切牙近远中向移动量,与预期牙移动量作比较,使用SPSS 19.0软件包进行统计分析.结果 第一和第二磨牙预期远中移动量平均为(2.33±1.06) mm,实际移动量为(1.92±1.00)mm,表达率为82.4％.与预期移动量相比,上颌磨牙实际远中倾斜4.12°、颊向倾斜4.19°,第一磨牙压人0.99mm,第二磨牙压入1.88mm.磨牙三维方向的实际与预期移动量之间的差异均有统计学意义(P＜0.01),而切牙的实际与预期近远中向位移无统计学差异(P.0.05).结论 Invisalign隐形矫治技术能够有效地远中移动上颌磨牙,伴有压入和轻微的远中和颊向倾斜.远中移动上颌磨牙时,使用微种植支抗或Ⅱ类牵引能够有效控制前牙支抗.     

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...     

无托槽隐形矫治器配合微种植钉远移磨牙的三维有限元研究

目的 应用三维有限元模型研究无托槽隐形矫治器配合不同植入位置微种植钉远移磨牙时的初始上颌前牙位移及尖牙区应力分布情况。方法 选取于2021-02-16在大连市口腔医院正畸科就诊的需采用无托槽隐形矫治器行远移磨牙非减数正畸治疗的1例女性患者作为建模对象。构建三维有限元模型,模拟微种植钉位于第二前磨牙与第一磨牙之间、第一磨牙与第二磨牙之间,分别距离牙槽嵴顶4、6、8、10 mm的8种工况,并在微种植钉与尖牙唇面的舌侧扣之间加载1.47 N正畸力。分析加力1 s后8种工况的上颌前牙位移及尖牙牙周膜应力分布情况。结果 8种工况中,上颌中切牙均呈现牙冠唇向、牙根腭向的位移趋势;上颌中切牙牙冠唇向位移量随微种植钉高度的增加而减小,且微种植钉位于相对近中（上颌第二前磨牙与第一磨牙之间）时产生的位移量更小。8种工况中,上颌尖牙均呈现牙冠唇向、牙根腭向的位移趋势,且牙冠呈现唇倾趋势;上颌尖牙牙周膜最小主应力绝对值随微种植钉高度的增加而增大,且微种植钉位于相对近中时产生的最小主应力更大。结论 无托槽隐形矫治器配合微种植钉远移上颌磨牙时,配合本实验8种工况中相对近中的更高位微种植钉利于切牙转矩控制,配合相对...     

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。     

双轨道装置同时推上颌第一、第二磨牙向远中的临床研究

目的 :观察双轨道装置 (Greenfieldmolardistalization ,GMD)在临床上同时推上颌第一、第二磨牙向远中的疗效。方法 :通过口内测量、模型测量和X线头影测量方法进行分析。结果 :平均 5个月可获得所需的牙间隙 ,其中上颌第一磨牙平均远移 4.5mm ,第二磨牙平均远移 3 .5mm。能较好地控制磨牙的颊舌向摆动、旋转、远中倾斜以及垂直方向的升高和压低 ,且支抗丧失较少。结论 :GMD技术能同时快速有效地推上颌第一、第二磨牙整体向远中移动。     

Unilateral molar distalization with a modified slider

Although there are numerous publications on bilateral non-compliance molar distalization appliances, there is limited information on problems such as asymmetrical unilateral Class II malocclusions. The aim of the present investigation was to examine the distalization of molars unilaterally in patients with a unilateral Class II molar relationship utilizing a Keles Slider, designed without a bite plane. Ten girls (mean age 13.94 +/- 2.13 years) and seven boys (mean age 13.12 +/- 1.51 years) comprised the study material. Following insertion of the appliance, the patients were seen monthly and the screw was reactivated every 2 months. After a super-Class I molar relationship was achieved, the appliance was removed and the molars were stabilized with a Nance appliance for 2 months before the second-phase of orthodontic treatment. The Nance appliance was maintained in the palate until the end of canine distalization. Lateral cephalometric radiographs were obtained before and immediately after insertion of the molar distalizer. The results showed that the maxillary first molars were distalized bodily on average by 2.85 mm. The maxillary first premolars moved forward bodily 2 mm and were extruded 2.03 mm. In all, 1.32 mm of protrusion, 1.12 mm of extrusion, and 1.79 degrees of proclination of the upper incisors were observed. The mandibular incisors and mandibular molars erupted 0.83 and 0.95 mm, respectively. The unilateral Keles Slider distalized molars successfully to a Class I molar relationship.     

无托槽隐形矫治技术远中移动磨牙效果的三维分析与评价

目的:对应用无托槽隐形矫治技术远中移动上颌磨牙的效果进行三维的测量分析并评价该方法的可行性.方法:选取5名需进行上颌磨牙远中移动的患者,应用无托槽隐形矫治技术顺序远中移动上颌第二磨牙、第一磨牙,并分别对其移动到位后的阶段模型进行数字化重建.通过三维重叠软件将阶段模型与治疗前模型进行重叠对比,测量磨牙远中移动后所获得的绝...     

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。     

早期远移磨牙矫治上颌第二前磨牙阻生的临床研究

目的:探讨远中移动上颌第一磨牙,结合直丝弓矫治伴有第二前磨牙阻生的II类错畸形的有效性。方法:选取处于替牙晚期、上颌中重度拥挤的24例患者,采用活动矫治器单侧或双侧远移上颌第一磨牙,开辟间隙并进行第二期固定矫治;统计学分析治疗前后的X线头影测量结果,评估临床疗效。结果:上颌第一磨牙平均远中移动4.5 mm,两侧磨牙和尖牙达到I类关系,上颌前牙唇倾度增加。结论:早期远中移动上颌第一磨牙并结合直丝弓技术可促进第二磨牙正常萌出。     

Dentoalveolar and skeletal changes associated with the pendulum appliance.

The purpose of the study was to examine the dentoalveolar and skeletal effects of the pendulum appliance in Class II patients at varying stages of dental development and with varying facial patterns (high, neutral, and low mandibular plane angles). Specifically, the amount and nature of the "distalization" of the maxillary first molars and the reciprocal effects on the anchoring maxillary first premolars and incisors were studied, as were skeletal changes in the sagittal and vertical dimensions of the face. Pretreatment and posttreatment cephalometric radiographs obtained from 13 practitioners were used to document the treatment of 101 patients (45 boys and 56 girls). The average maxillary first molar distalization was 5.7 mm, with a distal tipping of 10.6 degrees. The anchoring anterior teeth moved mesially, as indicated by the 1.8-mm anterior movement of the upper first premolars, with a mesial tipping of 1.5 degrees. The maxillary first molars intruded 0.7 mm, and the first premolars extruded 1.0 mm. Lower anterior facial height increased 2.2 mm; there was no significant difference in lower anterior facial height increase between patients of high, neutral, or low mandibular plane angles. In patients with erupted maxillary second molars, there was a slightly greater increase in lower anterior face height and in the mandibular plane angle and a slightly greater decrease in overbite in comparison to patients with unerupted second molars. Similar findings were observed in patients with second premolar anchorage versus those with second deciduous molar anchorage. The results of this study suggest that the pendulum appliance is effective in moving maxillary molars posteriorly during orthodontic treatment. For maximum maxillary first molar distalization with minimal increase in lower anterior facial height, this appliance is used most effectively in patients with deciduous maxillary second molars for anchorage and unerupted permanent maxillary second molars, although significant bite opening was not a concern in any patient in this study.     

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.     

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.     

Maxillary molar distalization with a bone-anchored pendulum appliance

To obtain an effective and compliance-free molar distalization without an anchorage loss, we designed the bone-anchored pendulum appliance (BAPA). The aim of this study was to evaluate the stability of the anchoring screw, distalization of the maxillary molars, and the movement of teeth anterior to maxillary first molars. The study group comprised 10 patients (mean age 13.5 +/- 1.8 years) with Class II molar relationship. A conventional pendulum appliance was modified to obtain anchorage from an intraosseous screw instead of the premolars. The screw was placed in the anterior paramedian region of the median palatal suture. Skeletal and dental changes were measured on cephalograms, and dental casts were obtained before and after distalization. A super Class I molar relationship was achieved in a mean period of 7.0 +/- 1.8 months. The maxillary first molars distalized an average of 6.4 +/- 1.3 mm in the region of the dental crown by tipping distally an average of 10.9 degrees +/- 2.8 degrees . Also, the maxillary second premolar and first premolar moved distally an average of 5.4 +/- 1.3 mm and 3.8 +/- 1.1 mm, respectively. The premolars tipped significantly distally. No anterior incisor movement was detected. The BAPA was found to be an effective, minimally invasive, and compliance-free intraoral distalization appliance for achieving both molar and premolar distalization without any anchorage loss.     

利用种植体支抗远移下颌磨牙的效果评价

目的：研究安氏Ⅲ类错患者中,采用微型种植体作支抗,远移下颌磨牙的临床效果及其作用特点。方法：选择16例成人患者,将32枚微型种植体植于下颌第二前磨牙与第一磨牙之间颊侧牙槽骨内,Ni-Ti螺旋弹簧压缩后置于下颌第一前磨牙与下颌第一磨牙之间,推磨牙远移。通过测量下颌第一磨牙在近远中方向、垂直向的位置变化,以衡量磨牙的位置改变。并通过下颌中切牙的位置变化,评价支抗强弱。结果：下颌第一磨牙平均远中移动4.5mm,疗程5.4个月,平均移动速度0.8mm/月;磨牙长轴向远中倾斜角度为3.9°。下颌中切牙位置基本无改变。结论：所有下颌磨牙被远移到了恰当的位置。未见前牙支抗丧失。种植体作支抗推下颌磨牙远移的过程中,发挥了强支抗的作用。临床操作较方便,是一种值得推广的方法。