上颌扩弓后即刻牙槽骨变化的CBCT分析

目的：上颌快速扩弓（rapidmaxiIlaryexpansion,RME）通过打开腭中缝来矫正上颌宽度不足以及增大牙弓周长。本研究的目的是使用CBCT来评价牙槽骨结构在用Hyrax扩弓器快速扩弓后的即刻变化。方法：28位（女性19位．男性9位）需要进行上颌扩弓治疗的患者（平均年龄141岁．范围13～20岁）．在T1（扩弓前）和T2（扩弓后即刻）拍摄cBCT作为临床记录。测量第一前磨牙和第一磨牙处的上牙弓宽度、后牙段倾斜度、颊侧骨厚度。使用配对t检验检测统计学差异（P〈O05）。结果：上牙弓扩宽量在第一前磨牙处为4．7788±28474mm．第一磨牙处为46943±3．2198mm。上颌左右第一前磨牙和左上第一磨牙的腭根均发生了明显倾斜。片子上能显示颊侧骨板的所有牙根在扩弓后其颊侧骨质厚度均减小。结论：RME后．前磨牙间和磨牙间宽度均明显增加。牙根倾斜角度增大说明牙齿的移动是一种倾斜移动而非平行移动。颊侧骨板厚度在扩弓后即刻测量时减小。因此．我们应严格监测炎症水平以避免牙周破坏。有必要建立一个标准参考平面和有可比性的测量方法以使不同研究的结果大体一致。     

种植钉辅助上颌快速扩弓治疗年轻成人上颌牙弓狭窄的CBCT分析

目的 探讨种植钉辅助上颌快速扩弓治疗年轻成人上颌狭窄的效果.方法 样本包括15.5～28.0岁上颌骨性狭窄病例10例(男3例,女7例),平均年龄(20.1±5.4)岁.使用种植钉辅助上颌快速扩弓技术,分别于治疗前、扩弓后和保持3个月后拍摄CBCT,并对资料进行统计分析.结果 扩弓后腭中缝前部和后部分别增加3.49 mm和2.94 mm,后部腭中缝增量占扩弓器扩大量的47.9％,后部腭中缝增量占第一磨牙间宽度增量的52.3％.鼻腔宽度、上颌基骨和牙槽宽度扩弓后增加(P＜0.05),且保持三个月后增加量无明显改变.牙槽骨高度变化无统计学意义(P＞0.05).结论 种植钉辅助上颌快速扩弓能有效开展年轻成人腭中缝,矫正骨性牙弓狭窄,并减少牙支抗扩弓引起的副作用.     

成人上颌扩弓后牙颌结构的变化

目的探讨上颌扩弓对成人牙颌结构的影响。方法成人上颌扩弓组11例和非上颌扩弓矫治组(对照组)17例。测量矫治前、主动矫治结束时及保持2年时双侧上颌第一磨牙交角、临床牙冠高度、上颌第一磨牙间宽距、上颌中切牙根尖点宽距、上颌宽距、下颌平面角以及前下面高。结果保持2年较矫治前扩弓组上颌第一磨牙交角减小7.50±10.21°,对照组减小0.64±5.06°;扩弓组第一前磨牙临床牙冠高度增加0.61±0.45 m m,对照组增加0.21±0.51 mm;扩弓组上颌第一磨牙间宽距增加7.30±0.56mm,上颌中切牙根尖点宽距增加0.91±0.28mm,上颌宽距增加2.75±0.35mm;对照组上颌第一磨牙间宽距增加0.32±0.21mm,上颌中切牙根尖点宽距减少0.25±0.18mm,上颌宽距增加0.89±0.25mm,两组相比5项指标均具有显著性差异。结论成人上颌扩弓可以有效扩大上颌牙弓及上颌宽距,不会导致明显的下颌后下旋转和牙龈退缩。     

雷尼酸锶对大鼠上颌快速扩弓影响的实验研究

目的 探讨雷尼酸锶对大鼠上颌快速扩弓的影响。方法 36只6周龄雄性Wistar大鼠,随机分为3组,空白对照（A）组﹑扩弓（B）组﹑扩弓并给药雷尼酸锶（C）组,每组12只。A组不扩弓,也不给药雷尼酸锶;B﹑C组用双眼圈簧扩弓器扩弓,力值1 N;C组扩弓开始即每天定时给药雷尼酸锶（600 mg•kg-1）。实验第4﹑7﹑10天分批处死大鼠,测量上颌宽度,并对大鼠腭中缝进行组织学观察和成骨细胞计数。结果 扩弓结束后,A组大鼠上颌宽度无明显变化（P>0.05）,B﹑C组上颌宽度较扩弓前均增加（P<0.05）,而B﹑C两组间的上颌宽度无明显差异（P>0.05）。组织学观察,A组腭中缝见少量红染的纤维组织,可见间充质样细胞、软骨细胞及成骨细胞。B﹑C组腭中缝处见较多红染的纤维组织,成纤维细胞﹑软骨细胞增多,腭中缝近骨边缘处多见成骨细胞;C组成骨细胞计数多于B组。结论 上颌快速扩弓可开大发育期大鼠腭中缝,增加上牙弓及上颌宽度;雷尼酸锶可以促进大鼠上颌快速扩弓时腭中缝处成骨细胞分化,加速新骨形成及骨质沉积钙化,减少复发。     

三维锥体束CT评价Hyrax扩弓器治疗上颌第二前磨牙区的变化

目的：本研究旨在利用CBCT技术比较Hyrax扩弓矫治器治疗前后上颌第二前磨牙（P2）区颌-复合体宽度及牙齿、牙槽嵴倾斜度的变化。方法：23例,（女17例,男6例;平均年龄（12.70±1.89）岁上颌牙弓狭窄、后牙反的患者。所有患者经Hyrax扩弓治疗,治疗前后采用CBCT技术采集并重建双侧P2区的三维结构,测量牙齿、牙槽嵴和颌骨不同平面的宽度以及牙齿、牙槽嵴与腭骨的相关角度,然后进行配对样本t检验。结果：RPE治疗后P2区颌骨宽度变化无统计学意义;P2及其牙槽嵴宽度显著增加（p〈0.001）;牙齿和牙槽嵴倾斜度变化也有统计学意义（p〈0.05）。结论：Hyrax扩弓器对生长发育期患者P2区颌-复合体的作用主要表现为牙齿颊倾和牙槽嵴改建,颌骨宽度变化较小。     

上颌牙弓反复快速扩缩的动物模型的建立及初步研究

目的建立上颌牙弓反复快速扩缩的动物模型并进行初步研究。材料和方法选择6周龄健康雄性SD大鼠22只，随机分成3组：实验一组（单纯扩弓组）9只，连续扩弓5天；实验二组（反复扩缩组）9只，先扩弓5天，再缩弓5天，然后再扩弓5天…，如此反复25天，扩三次，缩两次；对照组4只，不进行任何处理。实验组在实验前、扩弓结束、缩弓结束时，拍腭中缝X线片，取大鼠上颌石膏模型。结果大鼠上颌咬合片中可以看到：扩弓后，大鼠腭中缝被打开，而缩弓结束后，腭中缝回复到扩弓前水平。模型测量发现：单纯扩弓组扩弓结束时中切牙间距离及第一磨牙间的距离比扩弓前增大（P〈0．05）。反复扩缩组每次扩弓结束时中切牙间距离及第一磨牙间的距离均增大（P〈0．05）；每次缩弓结束时，中切牙间距离及第一磨牙间的距离均缩小，与扩弓前水平相当（P〉0．05）。对照组腭中缝宽度、中切牙间距离及第一磨牙间的距离均无变化。结论本研究利用扩弓和缩弓装置成功建立了上颌牙弓反复快速扩缩的动物模型；腭中缝宽度、中切牙间距离及第一磨牙间的距离随着扩弓或缩弓而增大或回复，并且随着扩弓次数的增加，每次扩弓后中切牙间距离及第一磨牙间的距离均比前一次扩弓增大，第一扩弓和第三次扩弓的差异有显著性。     

年轻成人上颌快速扩弓(YA-RME)对牙颌结构的影响

目的探讨年轻成人上颌快速扩弓后患者牙颌结构的变化。方法以16例年轻成人上颌快速扩弓患者为观察组,32例替牙期上颌快速扩弓患者为对照组。比较扩弓前(T1期)扩弓后(T2期)患者牙颌结构的变化,测量项目包括上颌牙弓宽度、上颌第一恒磨牙(牙合)平面交角、临床牙冠高度、腭穹隆角、腭龈缘水平宽度、腭中部宽度、腭顶宽度差以及下颌平面角和下面高。t检验,α为0．05。结果①上颌快速扩弓后观察组6-6牙弓宽度增加4．2+2．7mm,对照组增加5．4+2．3mm,二者没有显著性差异。②上颌快速扩弓后观察组上颌第一恒磨牙(牙合)平面交角减小6．4+11．3°,对照组减小0．6+5．6°,二者具有显著性差异。③上颌快速扩弓后观察组腭穹隆角增加8．1+ 6．9°,对照组增加1．6+7．8°,二者具有显著性差异。④上颌快速扩弓后观察组腭顶宽度差为0．8+1．2mm,对照组为3．0+1．7mm,二者具有显著性差异。⑤上颌快速扩弓后观察组临床牙冠高度增加0．6+0．4mm,对照组增加0．2 +0．4mm,二者没有显著性差异。⑥上颌快速扩弓后观察组下颌平面角增加0．9+1．8°,对照组增加1．4+2．5°,二者没有显著性差异。结论年轻成人上颌快速扩弓可以有效地扩大上颌牙弓宽度,扩弓主要依靠牙齿及牙槽骨的颊向倾斜扩展,但是并不会引起明显的牙龈退缩和下颌顺时针旋转。     

上颌铸造式Hyrax快扩后鼻上颌复合体三维形态变化的锥体束CT观察

目的 使用锥体束CT(Cone-Beam computed tomography,CBCT)评估生长期儿童快速扩弓后鼻-上颌复合体、牙槽骨和牙齿的变化.方法 30例(男13例,女17例,年龄11.0±1.5岁)上牙弓狭窄的患者,经过上颌铸造式Hyrax快速扩弓,扩弓前后拍摄CBCT,重建上颌尖牙区和第一磨牙区三维结构,分别测量颌骨、牙槽骨在不同平面的变化以及磨牙间宽度和倾斜角度的变化,进行配对样本t检验.结果 铸造式Hyrax快扩后颌骨变化明显,骨性扩弓∶牙性扩弓=1∶1,鼻腔宽度平均增加(3.88±1.92) mm,第一磨牙区牙槽骨宽度平均增加(5.72±1.86) mm,差异有统计学意义(P＜0.001),磨牙颊向倾斜度右侧平均增加(2.12±3.99)°,左侧平均增加(3.27±4.32)°,差异有统计学意义(P＜0.05).结论 上颌铸造式Hyrax快扩对生长发育期患者鼻-上颌复合体的作用主要表现为鼻腔、颌骨宽度增加和牙槽骨改建.     

上颌快速扩弓联合固定矫治器治疗的稳定性研究

目的 观察患者接受上颌快速扩弓联合直丝弓矫治器治疗后覆牙合、覆盖及上牙弓宽度的变化。方法 选择2003年2月—2008年1月于青岛市口腔医院进行治疗的患者37例（男19例,女18例）,将患者分为4个不同的时期进行测量（N1:治疗前;N2:进行上颌快速扩弓后;N3:固定治疗后;N4:保持1年后）。分别测量每位患者的上颌尖牙间宽度、前磨牙间宽度、磨牙间宽度,并对前牙覆盖和覆牙合进行测量。患者的平均年龄（11.3±1.4）岁（10.2～15.3岁）。结果 治疗全部结束后、尖牙间宽度、前磨牙间宽度、磨牙间宽度、覆盖、覆牙合分别增加（2.6±2.3）mm、（3.7±2.1）mm、（5.2±2.5）mm、（0.3±0.6）mm、（-0.1±1.6）mm,患者复发率在尖牙宽度为47%,前磨牙间宽度为21％,磨牙间宽度为10%,覆盖复发率为9%,覆牙合为13%。结论 患者经过上颌快速扩弓后,在固定矫治阶段复发明显,保持阶段也有一定程度的复发。 上颌快速扩弓能够减小覆牙合,增加覆盖。     

扩弓辅弓与改良横腭杆扩大上颌牙弓的临床效果比较

目的比较扩弓辅弓和改良横腭杆扩大上颌牙弓的效果。方法分别应用扩弓辅弓与改良横腭杆对35例患者上颌牙弓进行扩弓,比较2组矫治前后的牙弓宽度改变。结果使用扩弓辅弓的病例第一前磨牙扩弓宽度变化不明显,增加2 mm左右,第二前磨牙和第一磨牙的磨牙宽度均有明显扩大,增加4 mm左右;使用改良横腭杆的病例第一、二前磨牙及第一磨牙间宽度均增加4 mm左右。结论上颌牙弓轻中度狭窄的病例采用扩弓辅弓和改良横腭杆扩弓均有较好的扩弓效果,可以根据各自的特点选择合适的病例。     

Assessment of vertical changes during maxillary expansion using quad helix or bonded rapid maxillary expander

Objective:To determine if there is a significantly different effect on vertical changes during phase I palatal expansion treatment using a quad helix and a bonded rapid maxillary expander in growing skeletal Class I and Class II patients.Materials and Methods:This retrospective study looked at 2 treatment groups, a quad helix group and a bonded rapid maxillary expander group, before treatment (T1) and at the completion of phase I treatment (T2). Each treatment group was compared to an untreated predicted growth model. Lateral cephalograms at T1 and T2 were traced and analyzed for changes in vertical dimension.Results:No differences were found between the treatment groups at T1, but significant differences at T2 were found for convexity, lower facial height, total facial height, facial axis, and Frankfort Mandibular Plane Angle (FMA) variables. A comparison of treatment groups at T2 to their respective untreated predicted growth models found a significant difference for the lower facial height variable in the quad helix group and for the upper first molar to palatal plane (U6-PP) variable in the bonded expander group.Conclusion:Overall, both the quad helix expander and the bonded rapid maxillary expander showed minimal vertical changes during palatal expansion treatment. The differences at T2 suggested that the quad helix expander had more control over skeletal vertical measurements. When comparing treatment results to untreated predicted growth values, the quad helix expander appeared to better maintain lower facial height and the bonded rapid maxillary expander appeared to better maintain the maxillary first molar vertical height.     

CBCT分析上颌磨牙牙根及其牙槽嵴顶与上颌窦底壁的位置关系

目的 利用CBCT分析上颌第一、第二磨牙各牙根根尖及其牙槽嵴顶与上颌窦底壁位置关系,为临床诊断和治疗提供可靠的参考依据。方法 选取大连医科大学口腔医学院附属口腔医院锥形束CT(CBCT)数据库中初诊180例,分为6～12岁、13～18岁和19～35岁三组,每组各60例。利用CBCT测量上颌第一、第二磨牙各牙根根尖与上颌窦底壁的距离、上颌磨牙牙槽嵴顶与上颌窦底壁距离,分别进行左右两侧与性别差异对比,记录上颌第一、第二磨牙各牙根根尖与上颌窦底壁的位置关系分型,并进行统计学分析。结果 上颌第一磨牙在6～12岁组距离上颌窦底壁平均距离最短的为近颊根(1.21±3.09)mm, 13～18岁组根尖均在上颌窦内,19～35岁组的腭根为(0.41±2.73)mm;上颌第二磨牙在13～18岁组与19～35岁组距离上颌窦底壁平均距离最短的均为近颊根,为(0.36±2.37)mm和(0.43±2.21)mm。随着年龄增长,牙槽嵴顶至上颌窦底壁的平均距离逐渐降低(P<0.05)。水平关系中,上颌第一磨牙13～18岁组、19～35岁组牙根根尖至根分叉区域观察到上颌窦最常见;垂直关系中,6～12岁组与19...     

汉族青年牙周健康人群上颌磨牙腭侧牙槽嵴骨突的CBCT研究

目的:研究汉族青年牙周健康人群中上颌腭侧牙槽嵴骨突的分布、位置及表面黏膜厚度.方法:采用CBCT观察245名受试者上颌第一磨牙至第三磨牙腭侧牙槽嵴骨突的分布,并测量骨突顶点距对应磨牙CEJ的距离和表面最薄处黏膜厚度.结果:245名受试者中在上颌第一、第二和第三磨牙腭侧牙槽嵴骨突的发现率分别为2.45％、31.22％和2...     

Dentoskeletal effects of a temporary skeletal anchorage device–supported rapid maxillary expansion appliance (TSADRME): A pilot study

Objective:To quantitatively evaluate maxillary skeletal expansion using cone-beam computed tomography (CBCT) images and propose a novel way to quantify the dental tipping effects of temporary skeletal anchorage device–supported rapid maxillary expansion appliance (TSADRME).Materials and Methods:Images from 25 patients receiving rapid maxillary expansion with incorporated temporary skeletal anchorage devices (TSADs) before activation (T1) and after removal (T2) were analyzed to detect dentoskeletal changes.Results:A significant increase from T1 to T2 was found for all linear measurements except buccal maxillary width at the canines. The greatest buccal expansion was at the first molar, decreasing anteriorly. However, the greatest palatal expansion was at the first premolar. All younger subjects (8–16 years old) exhibited less dental tipping and greater expansion overall compared with the older subjects. There was great variability in dental tipping of first molars (mean = 4.31°), with some subjects demonstrating mild uprighting of these teeth.Conclusions:The TSADRME appliance is an effective, clinically useful device that results in mild molar tipping and may positively affect expansion in the area of TSAD placement.     

Three-dimensional comparison of bone-borne and tooth-bone-borne maxillary expansion in young adults with maxillary skeletal deficiency

Objective

To compare the transverse dental and skeletal changes in patients treated with bone-anchored palatal expander (bone-borne, BB) compared to patients treated with tooth and bone-anchored palatal expanders (tooth-bone-borne, TBB) using cone-beam computer tomography (CBCT) and 3D image analysis.

Methods

The sample comprised 30 patients with transverse maxillary discrepancy treated with two different types of appliances: bone-borne (Group BB) and tooth-bone-borne (Group TBB) expanders. CBCT scans were acquired before (T1) and after completion of maxillary expansion (T2); the interval was 5.4 ± 3.4 and 6.2 ± 2.1 months between the T1 and the T2 scans of Group TBB (tooth-bone-borne) and Group BB (bone-borne), respectively. Transverse, anteroposterior and vertical linear and angular three-dimensional dentoskeletal changes were assessed after cranial base superimposition.

Results

Both groups displayed marked transverse skeletal expansion with a greater ratio of skeletal to dental changes. Greater changes at the nasal cavity, zygoma and orbital levels were found in Group BB. A relatively parallel sutural opening in an anterior–posterior direction was observed in Group TBB; however, the Group BB presented a somewhat triangular (V-shaped) opening of the suture that was wider anteriorly. Small downward-forward displacements were observed in both groups. Asymmetric expansion occurred in approximately 50% of the patients in both groups.

Conclusion

Greater skeletal vs dental expansion ratio and expansion of the circummaxillary regions were found in Group BB, the group in which a bone-borne expander was used. Both groups presented skeletal and dental changes, with a similar amount of posterior palate expansion. Asymmetric expansion was observed in both groups.     

上颌窦底壁与上颌后牙根尖位置关系的临床与锥形束CT研究

目的:通过锥形束CT影像分析无症状人群上颌窦底壁与上和后牙根尖位置关系,为上颌后牙区临床治疗提供理论依据。方法:选取53例98侧无症状人群的上颌窦锥形束CT影像,三维重建后在选取的截面上测量784个根尖与上颌窦底壁的距离,上颌后牙根尖的位置据此分为4类,并将各例上颌窦底壁与上颌后牙根尖距离的均值进行95%置信区间估计。结果:上颌第一磨牙远中颊根根尖距离上颌窦底壁的平均距离最短,为(0.44±0.61) mm(置信度95%).上颌磨牙根尖广泛存在于上颌窦底壁密切接触的情况,其中上颌第二磨牙与上颌窦底壁的关系最为密切。结论:上颌磨牙根尖与上颌窦底壁位置关系密切,锥形束CT可精确了解上颌后牙区的解剖情况,从而降低医源性上颌窦炎发生的概率。     

Reverse quad helix appliance: differential anterior maxillary expansion of the cleft area before bone grafting

ABSTRACT: Cleft-affected cases present a variable degree of transversal constriction of the maxilla. Our aim is to present a new method for differential expansion of the premaxillary area in unilateral cleft lip and palate-affected patients.The reverse quad helix appliance is made of a 0.036-in stainless-steel wire soldered to 2 bands placed on maxillary deciduous canines or first primary molars (or first permanent premolars). It incorporates 4 helical loops forming an inverse W-arch design. The spring is positioned posterior to the banded teeth; thus, the expansion effect is focused in the anterior maxillary region.A reverse quad helix appliance was activated and cemented in 20 patients for premaxillary expansion. Upper arch width was assessed by means of plaster study models in the anterior and posterior maxillary regions. The mean anterior occlusal expansion achieved by the reverse quad helix (9.60 [±5.24] mm) is statistically significantly larger than that achieved in the posterior region (5.50 [±3.07] mm) (P < 0.0001). The reverse quad helix is an efficient appliance for differential expansion of the anterior maxillary region as a preparatory stage for secondary bone graft procedures in unilateral cleft lip and palate-affected patients.     

Skeletal and dentoalveolar changes in the transverse dimension using microimplant-assisted rapid palatal expansion (MARPE) appliances

Conventional rapid palatal expansion (RPE) has been proven to be a reliable treatment for correcting transverse maxillary deficiency in young patients. However, side effects including dental tipping and risk of periodontal problem limited its application to young patients after the pubertal growth spurt. Surgically assisted rapid palatal expansion (SARPE), a supplement to RPE, could be applied in skeletally mature patients. However, SARPE was an invasive method, and the morbidity, risks and cost related to surgical treatment might discourage many adult patients. The use of Microimplant-Assisted Rapid Palatal Expansion (MARPE) appliance, which can potentially avoid surgical intervention, is gaining popularity in treatment of maxillary transverse deficiency (MTD) in young adolescent patients. However, the literature on the skeletal and dentoalveolar changes with this appliance is scarce. To evaluate the immediate skeletal and dentoalveolar changes in the transverse dimension with the maxillary skeletal expander (MSE), a MARPE appliance with hybrid anchorage, using cone-beam computed tomography (CBCT). Twenty-two patients (11 males and 11 females, mean age 14.97 ± 6.16 years) with transverse maxillary deficiency were treated using the MSE (Biomaterials Korea, Inc., Seoul, Korea). The appliance consisted of a central expansion screw that were welded to four tubes that served as guides for microimplant placement. The microimplants were 1.8 mm in diameter and 11 mm in length. The longer length of microimplants permitted bicortical engagement of the palatal and nasal floor, reducing the force transmitted to the anchored teeth during expansion. The appliance activation varied with age and skeletal maturity of the patient. The expansion was terminated when 2–3 mm of overexpansion was achieved. CBCT scans were taken before treatment (T1) and immediately after expansion (T2). Measurements were taken to evaluate the amount of total expansion, skeletal expansion, and angular dental tipping at the first molar region. A total expansion of 5.41 ± 2.18 mm was achieved, 59.23 ± 17.75% of which was attributed to skeletal expansion (3.15 ± 1.64 mm) with the first molars exhibiting buccal tipping of 2.56 ± 2.64°. The use of MARPE appliances such as MSE can be used to correct transverse maxillary deficiency in adolescent patients with minimal dentoalveolar side effects.     

Anatomical relationship of maxillary posterior teeth with the sinus floor and buccal cortex

This study aimed to evaluate the possibility of root fenestration or oroantral communication by evaluating the distance from root apex to the sinus floor and buccal cortex in maxillary posterior teeth using cone‐beam computed tomography (CBCT) images. The study included 2182 roots of the maxillary posterior teeth from 219 patients after reviewing CBCT images of 462 patients according to the location of roots by two endodontists. The distances from each root apex to the maxillary sinus floor and buccal and palatal cortices were evaluated according to sex and age, and the mean values were compared by one‐way analysis of variance and Mann–Whitney U‐test. The distance between root apex and maxillary sinus floor was the greatest in maxillary first premolars and shortest in the mesio‐buccal roots of maxillary second molars. The distances from root apex to the buccal and palatal cortical bones were significantly greater in male patients than those in female patients (P < 0·05). The palatal roots of maxillary first molars exhibited the highest incidence as well as the greatest mean length (1·96 mm) of protrusion into the maxillary sinus. The distance from root apex to the sinus floor was found to increase with age, except in case of maxillary second premolars. Understanding the relationship of maxillary posterior teeth with the sinus floor and buccal cortex could provide clinicians valuable information to help reduce iatrogenic damage.     

钟摆矫治器联合颊侧推簧远移磨牙的疗效分析

目的：评价钟摆矫治器联合颊侧推簧远移磨牙的疗效.方法：选择40例牙性安氏Ⅱ类错（牙合）畸形的患者,随机均分为两组：钟摆矫治器联合颊侧推簧远移磨牙组（组1）和头帽口外弓远移磨牙组（组2）,在治疗开始前（T0）和远移磨牙完成时（T1）分别拍摄侧位头影定位片进行头影测量,t检验分析组内和组间的差异.结果：组1和组2远移磨牙的平均距离分别是（4.48±1.63） mm、（2.68±1.71） mm;组1和组2磨牙远中倾斜的平均角度分别是5.46°±3.23°、1.02°±2.16°;组1上颌中切牙未发生明显的唇倾和唇向移位,而组2上颌中切牙发生了较为明显的腭侧移位.结论：钟摆矫治器联合颊侧推簧远移磨牙可有效防止前牙支抗的丧失、控制磨牙的近中颊侧旋转.