Hyrax快速与慢速扩弓矫治替牙晚期上颌狭窄疗效对比研究

目的 比较Hyrax快速与慢速扩弓矫治替牙晚期上颌狭窄的疗效。 方法 选取2011年1月至2012年12月来大连市口腔医院正畸科就诊的替牙晚期上颌基骨狭窄患者60例,随机分成2组,分别采用Hyrax快速扩弓与Hyrax慢速扩弓进行矫治,扩弓前后拍摄锥形束CT（cone beam computerized tomography ,CBCT）,通过Invivo5牙科软件三维重建,分别测量扩弓前后上颌第一磨牙、第一前磨牙冠状位硬腭水平基骨宽度、颊侧牙弓宽度、双侧牙槽骨倾斜角度的交角、双侧牙齿倾斜角度的交角,轴位颊、舌侧骨质厚度。扩弓前后数据采用SPSS 17.0统计软件进行分析。结果 冠状位：Hyrax快速扩弓与Hyrax慢速扩弓在骨性开展和牙弓总宽度变化上无差别,扩弓后牙弓总宽度增加,第一前磨牙平面的骨开展量大于第一磨牙平面,牙齿和牙槽嵴颊向倾斜,牙槽嵴倾斜的角度慢速扩弓组大于快速扩弓组,牙齿倾斜的角度快速扩弓组大于慢速扩弓组;轴位：颊侧骨质厚度减少,舌侧骨质厚度增加,但Hyrax慢速扩弓组颊侧的减少量小于Hyrax快速扩弓组,两组差异有统计学意义（P＜0.05）。结论 对于替牙晚期患者,与Hyrax快速扩弓相比,Hyrax慢速扩弓慢速轻力的特点更符合生理特性,并且对颊侧的骨质厚度影响小,是一种有效的扩弓方式。     

Hyrax�������������������������������խ��Ч�Ա��о�

目的 比较Hyrax快速与慢速扩弓矫治替牙晚期上颌狭窄的疗效。方法 选取2011年1月至2012年12月来大连市口腔医院正畸科就诊的替牙晚期上颌基骨狭窄患者60例,随机分成2组,分别采用Hyrax快速扩弓与Hyrax慢速扩弓进行矫治,扩弓前后拍摄锥形束CT(cone beam computerized tomography,CBCT),通过Invivo5牙科软件三维重建,分别测量扩弓前后上颌第一磨牙、第一前磨牙冠状位硬腭水平基骨宽度、颊侧牙弓宽度、双侧牙槽骨倾斜角度的交角、双侧牙齿倾斜角度的交角,轴位颊、舌侧骨质厚度。扩弓前后数据采用SPSS 17.0统计软件进行分析。结果 冠状位:Hyrax快速扩弓与Hyrax慢速扩弓在骨性开展和牙弓总宽度变化上无差别,扩弓后牙弓总宽度增加,第一前磨牙平面的骨开展量大于第一磨牙平面,牙齿和牙槽嵴颊向倾斜,牙槽嵴倾斜的角度慢速扩弓组大于快速扩弓组,牙齿倾斜的角度快速扩弓组大于慢速扩弓组;轴位:颊侧骨质厚度减少,舌侧骨质厚度增加,但Hyrax慢速扩弓组颊侧的减少量小于Hyrax快速扩弓组,两组差异有统计学意义(P<0.05)。结论 对于替牙晚期患者,与Hyrax快速扩弓相比,Hyrax慢速扩弓慢速轻力的特点更符合生理特性,并且对颊侧的骨质厚度影响小,是一种有效的扩弓方式。     

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。     

改良式Hyrax扩弓器矫治上颌牙弓狭窄的临床观察

目的观察改良式Hyrax扩弓器对生长发育期上颌牙弓狭窄的矫治作用。方法选择14例恒牙早期上颌牙弓狭窄病例,应用改良式Hyrax扩弓器进行扩弓。通过测量扩弓前后X线头颅定位侧位片和模型,进行统计学分析。结果14例上颌牙弓狭窄患者经2~3周扩弓后,后牙反全部解除并过矫治2~3mm,■间出现间隙2~4mm。上颌正中咬合片显示:腭中缝打开,低密度阴影出现。结论改良式Hyrax扩弓器是一种快速、有效、安全、经济实惠的扩弓装置。     

MSE骨性扩弓后上颌牙根及颊侧齿槽骨吸收状况的CBCT分析

目的:分析MSE骨性扩弓治疗后上颌牙根及颊侧齿槽骨的吸收变化情况.方法:选取上颌横向发育不足(上牙弓狭窄)患者16例(年龄16～24岁;男7例,女9例).应用MSE骨性扩弓器进行扩弓治疗,所有患者均在3个月内完成加力,扩弓结束后拍摄CBCT与扩弓前的CBCT比较,所有DICOM数据导入Mimics17.0软件进行牙齿三维重建,分析扩弓前后上中切牙,第一前磨牙,第二前磨牙,第一磨牙的牙根长度(体积)及颊侧齿槽骨高度和厚度的变化.结果:扩弓前后的CBCT对比显示:(1)所有测量牙齿的牙根长度及体积仅有轻微改变,但无统计学意义(P>0.05);(2)颊侧齿槽骨高度及厚度的测量发现支抗牙部位存在显著改变(P<0.05);非支抗牙部位的改变均无统计学意义(P>0.05).结论:MSE骨性扩弓后未见显著牙根吸收;颊侧齿槽骨高度和厚度在支抗牙部位的吸收显著高于非支抗牙部位,为临床选择扩弓器提供一定参考依据.     

MSE骨性扩弓后上颌牙根及颊侧齿槽骨吸收状况的CBCT分析

目的:分析MSE骨性扩弓治疗后上颌牙根及颊侧齿槽骨的吸收变化情况.方法:选取上颌横向发育不足(上牙弓狭窄)患者16例(年龄16～24岁;男7例,女9例).应用MSE骨性扩弓器进行扩弓治疗,所有患者均在3个月内完成加力,扩弓结束后拍摄CBCT与扩弓前的CBCT比较,所有DICOM数据导入Mimics17.0软件进行牙齿三维重建,分析扩弓前后上中切牙,第一前磨牙,第二前磨牙,第一磨牙的牙根长度(体积)及颊侧齿槽骨高度和厚度的变化.结果:扩弓前后的CBCT对比显示:(1)所有测量牙齿的牙根长度及体积仅有轻微改变,但无统计学意义(P>0.05);(2)颊侧齿槽骨高度及厚度的测量发现支抗牙部位存在显著改变(P<0.05);非支抗牙部位的改变均无统计学意义(P>0.05).结论:MSE骨性扩弓后未见显著牙根吸收;颊侧齿槽骨高度和厚度在支抗牙部位的吸收显著高于非支抗牙部位,为临床选择扩弓器提供一定参考依据.     

MSE骨性扩弓后上颌牙根及颊侧齿槽骨吸收状况的CBCT分析

目的:分析MSE骨性扩弓治疗后上颌牙根及颊侧齿槽骨的吸收变化情况.方法:选取上颌横向发育不足(上牙弓狭窄)患者16例(年龄16～24岁;男7例,女9例).应用MSE骨性扩弓器进行扩弓治疗,所有患者均在3个月内完成加力,扩弓结束后拍摄CBCT与扩弓前的CBCT比较,所有DICOM数据导入Mimics17.0软件进行牙齿三维重建,分析扩弓前后上中切牙,第一前磨牙,第二前磨牙,第一磨牙的牙根长度(体积)及颊侧齿槽骨高度和厚度的变化.结果:扩弓前后的CBCT对比显示:(1)所有测量牙齿的牙根长度及体积仅有轻微改变,但无统计学意义(P>0.05);(2)颊侧齿槽骨高度及厚度的测量发现支抗牙部位存在显著改变(P<0.05);非支抗牙部位的改变均无统计学意义(P>0.05).结论:MSE骨性扩弓后未见显著牙根吸收;颊侧齿槽骨高度和厚度在支抗牙部位的吸收显著高于非支抗牙部位,为临床选择扩弓器提供一定参考依据.     

下颌螺旋扩弓器的改良与临床应用

目的 介绍改良下颌螺旋扩弓器的制作及临床应用.方法 将下颌传统固定式螺旋扩弓器进行了改良,并使用这种改良式下颌扩弓器对89例患者进行上下颌联合扩弓正畸治疗,其中安氏Ⅰ类42例,安氏Ⅱ例37例,安氏Ⅲ类10例.错(牙合)问题有:牙齿拥挤、深覆(牙合)、反(牙合)、深覆盖、牙弓前突等.并对89例患者的下颌牙弓的宽度进行了测量分析.结果 89例正畸患者下颌尖牙、前磨牙、磨牙宽度均明显增宽,变化均有统计学意义.第二双尖牙间的宽度增加最大,平均6.14±2.56mm.结论 这种改良式下颌扩弓器将其所释放的力量同时施在下颌后牙和牙槽骨上,以期让后牙和牙槽骨都产生颊向移动,扩弓效果更为明显和稳定.     

改良唇挡扩弓后牙齿及牙槽骨变化的 CBCT 研究

目的：研究改良唇挡单侧扩弓后牙齿及牙槽骨的变化。方法：20例单侧完全性唇腭裂患者应用改良唇挡进行单侧扩弓,扩弓前后分别进行CBCT扫描重建,测量裂隙侧牙齿及牙槽骨的变化并进行统计学分析。结果：①未经扩弓治疗的单侧完全性唇腭裂隙患者裂侧尖牙和前磨牙相对于健侧均表现为舌倾,其中尖牙舌倾最明显;②牙及牙槽骨均发生颊倾;颊侧牙槽骨倾斜度大于腭侧,变化量与牙齿的颊倾程度呈正相关性;③根尖基骨宽度增加。结论：唇挡扩弓后牙槽骨随牙齿的颊倾发生适应性改建,同时唇挡刺激牵引牙根尖基骨的改建,在适应症范围内唇挡扩弓是安全有效的。     

改良唇挡单侧扩弓后牙槽骨高度与厚度变化的CBCT研究

目的 研究改良唇挡单侧扩弓后裂侧牙槽骨高度与厚度的变化.方法 对年龄在12～16岁应用改良唇挡完成单侧扩弓的18名单侧完全性唇腭裂患者扩弓前后的CBCT图像进行重建,测量扩弓后裂侧牙槽骨高度与厚度,对测量结果进行统计学分析.结果 裂侧尖牙、第一、第二前磨牙颊、腭侧牙槽骨的高度均降低,其中尖牙变化量最大(P<0.01),尖牙颊侧骨开裂的患者增多.第一、第二前磨牙颊侧牙槽骨在釉牙骨质界下4mm、6mm处厚度增加,尖牙颊侧在6mm处骨厚度增加(P<0.01),在4mm处骨厚度减少(P<0.05),尖牙、第一、第二前磨牙腭侧牙槽骨厚度减少.结论 唇挡扩弓后,裂侧牙齿颊侧牙槽骨的高度降低,厚度增加.对于裂侧尖牙正畸治疗前后的牙周状况应该引起重视.     

Tooth-borne vs bone-borne rapid maxillary expanders in late adolescence

Objective:To evaluate the immediate effects of rapid maxillary expansion (RME) on the transverse skeletal and dentoalveolar changes with bone-borne (C-expander) and tooth-borne type expanders using cone-beam computed tomography (CBCT) in late adolescents.Materials and Methods:A sample of 28 female late-adolescent patients was divided into two groups according to the type of expander: bone-borne (C-expander, n  =  15, age  =  18.1 ± 4.4 years) and tooth-borne (hyrax, bands on premolars and molars, n  =  13, age  =  17.4 ± 3.4 years). CBCT scans were taken at 0.2-mm voxel size before treatment (T1) and 3 months after RME (T2). Transverse skeletal and dental expansion, alveolar inclination, tooth axis, vertical height of tooth, and buccal dehiscence were evaluated on maxillary premolars and molars. Paired t-test, independent t-test, one-way analysis of variance, and Scheffé post hoc analysis were performed.Results:The C-expander group produced greater skeletal expansion, except in the region of the first premolar (P < .05 or < .01), which showed slight buccal tipping of the alveolar bone. The Hyrax group had more buccal tipping of the alveolar bone and the tooth axes, except in the region of the second molar (P < .05 or < .01 or < .001). Dental expansion at the apex level was similar in the banded teeth (the first premolar and the first molar). Vertical height changes were apparent on the second premolar in the hyrax group (P < .05 or < .01). Significant buccal dehiscence occurred at the first premolar in the hyrax group (P < .01 or < .001). There were no significant differences between tooth types for any variables in the C-expander group.Conclusions:For patients in late adolescence, bone-borne expanders produced greater orthopedic effects and fewer dentoalveolar side effects compared to the hyrax expanders.     

Arch perimeter changes on rapid palatal expansion

Relationships between changes in arch perimeter and arch width resulting from rapid palatal expansion with the Hyrax appliance were analyzed with the use of dental study casts of 21 adolescent patients. Photographs and measurements from the dental casts obtained before treatment and approximately 3 months after stabilization were used. Regression analysis indicated that changes in premolar width were highly predictive of changes in arch perimeter (r2 = 0.69) at approximately 0.7 times the premolar expansion. Without any orthodontic appliances attached to the mandibular teeth in 16 of the 21 patients, buccal uprighting of the posterior teeth was observed because of the redirection of occlusal forces. In addition, posterior movement of the maxillary incisors and buccal tipping of the anchor teeth were quantified. The prediction of arch perimeter change for a given amount of expansion is helpful in the treatment planning of rapid palatal expansion cases and may facilitate nonextraction orthodontic treatment.     

Rapid maxillary expansion--tooth tissue-borne versus tooth-borne expanders: a computed tomography evaluation of dentoskeletal effects

This study evaluated rapid maxillary expansion (RME) dentoskeletal effects by means of computed tomography (CT), comparing tooth tissue-borne and tooth-borne expanders. The sample comprised eight girls aged 11 to 14 years presenting Class I or II malocclusions with posterior unilateral or bilateral crossbite that were randomly divided into two treatment groups, palatal acrylic (Haas-type) and hygienic (Hyrax) expanders. All appliances were activated up to the full seven mm capacity of the expansion screw. The patients were subjected to a spiral CT scan before expansion and after a three-month retention period when the expander was removed. One-millimeter-thick axial sections were scanned parallel to the palatal plane, comprising the dentoalveolar area and the base of the maxilla up to the inferior third of the nasal cavity. Multiplanar reconstruction was used to measure maxillary transverse dimensions and posterior teeth inclination by means of a computerized method. The results showed that RME produced a significant increase in all measured transverse linear dimensions, decreasing in magnitude from dental arch to basal bone. The transverse increase at the level of the nasal floor corresponded to one-third of the amount of screw activation. Tooth-borne (Hyrax) and tooth tissue-borne (Haas-type) expanders tended to produce similar orthopedic effects. In both methods, RME led to buccal movement of the maxillary posterior teeth, by tipping and bodily translation. The second premolars displayed more buccal tipping than the appliance-supporting teeth. The tooth tissue-borne expander produced a greater change in the axial inclination of appliance-supporting teeth, especially first premolars, compared with the tooth-borne expander.     

Orthopedic outcomes of hybrid and conventional Hyrax expanders:: Secondary data analysis from a randomized clinical trial

ObjectivesTo compare the effects of a hybrid miniscrew-supported expander versus a conventional Hyrax (CH) expander in growing patients.Materials and MethodsForty patients were randomized into two groups: a hybrid Hyrax (HH) expander group using a Hyrax expander with two miniscrews and a CH expander group. The final sample had 18 subjects (8 female, 10 male; initial age of 10.8 years) in the HH group and 14 subjects (6 female, 8 male; initial age of 11.4 years) in the CH group. Cone-beam computed tomography examinations and digital dental models were obtained before expansion and 11 months postexpansion. The primary outcomes included the orthopedic transverse effects of expansion. Intergroup comparison was performed using analysis of covariance (P < .05).ResultsSignificantly greater increases in the nasal cavity width, maxillary width, and buccal alveolar crest width were found for the HH group. No intergroup differences were observed for dental arch width or shape changes.ConclusionsThe HH group showed greater increases in the nasal cavity width, maxillary width, and buccal alveolar crest width. No differences were observed for intermolar, interpremolar, or intercanine widths; arch length; or arch perimeter. Arch size and shape showed similar changes in both groups.     

Rapid Maxillary Expansion with Palatal Anchorage of the Hyrax Expansion Screw—Pilot Study with Case Presentation

Abstract. Background: Rapid maxillary expansion (RME) with the appliance fixed at the crowns of the first premolars and molars leads not only to transversal expansion but also to tipping of the anchorage teeth and a risk of increased tooth mobility as well as of root and bone resorptions. These disadvantages were to be avoided by fixing the transversal screw directly to the hard palate. Material and Method: Following preliminary experimental work to determine the extent to which the hard palate could be loaded with orthodontic implants, two female patients were treated for extreme transverse maxillary deficiency using a Hyrax expansion screw fixed on one side with an implant with the following dimensions: length 4.0 mm, diameter 3.5 mm, abutment diameter 5.00 mm (EO implant, Straumann, Freiburg i. Br., Germany), and on the other side with a bone screw between the roots of the second premolars and the first molars. Presurgical osteotomy according to Glassmann was followed immediately by loading, i. e. by expansion through activation of the screw several times per day. Additional anterior guidance of the right and left maxilla was provided by crossed segmented archwires and a tension coil spring for space opening in the incisor region. After adequate expansion by 8.0 mm and correction of the position of the buccal teeth, the Hyrax expansion screw and the osteosynthesis screw were removed. The implant served as orthodontic anchorage for a molar-to-molar transpalatal bar aimed at preventing relapse. Results and Conclusions: The tooth axis inclination measured on cut sections of the plaster casts made at the beginning and end of treatment was largely without transversal discrepancies. Direct fixing of the transversal screw in the palatal arch prevents buccal tipping of the posterior teeth, especially in patients with a small apical base. Compared with other direct procedures involving osteosynthesis plates, this technique offers adequate guiding stability and is minimally invasive.     

上颌快速扩弓与直丝弓矫治器联合应用的临床研究

目的 评价上颌快速扩弓和直丝弓矫治器联合应用对牙弓、基骨宽度的影响。方法 对18例恒牙早期牙列中度拥挤病例以上颌快速扩弓和直丝弓矫治器进行联合治疗，通过对矫治前后牙牙台石膏模型的测量比较，观察牙弓、基骨宽度的变化。结果 治疗后牙弓、基骨的宽度比治疗前增加，统计学分析有显著性差异。结论 上颌快速扩弓和直丝弓矫治器联合应用能使牙弓、基骨宽度快速增加，对牙列拥挤病例是一种安全、有效的治疗方法。     

A comparison of dentoalveolar inclination treated by two palatal expanders

The objective of the present study was to evaluate buccal dentoalveolar inclinations in subjects treated with a Hyrax (tooth-borne) or acrylic-bonded (tooth-tissue borne) palatal expander. The sample comprised 39 patients (10 males and 29 females) aged between 11 and 16 years randomly assigned to two groups. Rapid maxillary expansion (RME) was carried out with a Hyrax appliance in one group (n = 21) and with an acrylic-bonded appliance in the other (n = 18). Their mean ages were 13 years 9 months and 13 years 6 months, respectively. Orthodontic study models were obtained before RME (T1) and approximately 1 week after completion of maxillary expansion (T2). A line of barium sulphate solution was drawn between the upper first molars on the models, and radiographs were taken. The radiographic images of the models were transferred to digital medium, and buccal tipping of the molar crowns and alveolar processes were evaluated by means of a software program. The data were analysed by paired and Student's t-tests. Both RME appliances produced significant (P < 0.001) dentoalveolar tipping during RME, but this was greater in the Hyrax group (P < 0.05).     

Evaluation of miniscrew-supported rapid maxillary expansion in adolescents: A prospective randomized clinical trial

Objectives:To evaluate and compare the dental and skeletal changes with conventional and miniscrew-supported maxillary expansion appliances in adolescents.Materials and Methods:Forty patients were divided into two groups, with one group receiving a tooth-borne expander and the other group receiving an expander supported by four miniscrews (bone-borne). Multiplanar coronal and axial slices obtained from cone-beam computed tomography images were used to measure the changes in transverse skeletal widths, buccal bone thickness, tooth inclination, and root length. Paired t-tests and independent-sample t-tests were used to compare the two expansion methods.Results:Bone-borne expansion increased the maxillary suture opening more than 2.5 times than tooth-borne expansion both anteriorly and posteriorly. Between the maxillary first premolars, sutural expansion accounted for 28% and 70% of the total transverse width increase in the tooth-borne and bone-borne expander groups, respectively. Similarly, 26% and 68% of the total expansion was of skeletal nature in the tooth-borne and bone-borne expander groups between the maxillary first molars. The pattern of expansion was variable, with most of the patients in both groups demonstrating a triangular-shaped sutural opening that was wider anteriorly. Subjects in the conventional group experienced significantly more buccal bone reduction and greater buccal inclination of the teeth. No significant differences were observed for root length measurements between the two groups.Conclusion:Use of bone-borne expansion in the adolescent population increased the extent of skeletal changes in the range of 1.5 to 2.8 times that of tooth-borne expansion and did not result in any dental side effects.