传统与改良Hyrax扩弓器对牙弓、牙槽骨、基骨影响的CBCT对比研究

目的应用CBCT比较传统Hyrax扩弓器与改良Hyrax扩弓器对牙弓、牙槽骨及基骨的影响。方法将30例上颌牙弓狭窄的患者随机分为2组,传统Hyrax扩弓器组15例患者,8男7女,平均年龄(14.1±2.5)岁,改良Hyrax扩弓器组15例患者,9男6女,平均年龄(13.9±2.6)岁。收集2组患者扩弓前及扩弓3个月后的CBCT扫描数据,重建三维影像并测量牙弓、牙槽骨及基骨的相应指标,应用配对样本的t检验分析2组扩弓后测量指标的变化,应用独立样本的t检验分析2组测量指标之间的差异。结果 2组都存在基骨的改变及牙弓宽度的增加,2组之间的比较显示传统Hyrax组的第一、二前磨牙牙弓宽度大于改良Hyrax组,第一磨牙颊侧及腭侧牙槽骨厚度的变化2组并无统计学的差异,而第一前磨牙颊侧及腭侧牙槽骨的厚度变化2组有统计学差异,此外,2组之间绝对牙倾斜度比较也并无统计学差异。结论两种快速扩弓方法对于纠正上颌牙弓狭窄都有较为明显的效果,传统Hyrax扩弓器对第一前磨牙牙弓宽度及颊腭侧牙槽骨厚度的影响更大。     

固定包绕式螺旋扩弓器扩弓对牙弓长度的影响

目的研究固定包绕式螺旋扩弓器扩弓前后牙弓宽度、长度变化及两者间的关系。方法选取上牙弓狭窄患者33例,戴用固定包绕式螺旋扩弓器扩大上牙弓,在扩弓前后的上颌石膏模型上测量牙弓宽度变化和牙弓长度变化。结果扩弓前后牙弓宽度增值为4.58±1.23mm,牙弓长度增值5.64±1.35mm。结论使用固定包绕式螺旋扩弓器扩大上牙弓后,牙弓长度增值大于牙弓宽度增值。     

下颌扩弓结合固定矫治后牙弓和WALA嵴宽度的变化

目的 应用下颌改良扩弓器,结合MBT直丝弓矫治技术治疗处于生长发育高峰期或末期中重度牙列拥挤伴牙弓狭窄的青少年患者,探讨矫治前后下颌牙弓和WALA嵴宽度的变化.方法 对29例10～15岁中重度牙列拥挤伴牙弓狭窄的青少年进行下颌扩弓,下颌为改良式网状支架扩弓器,运用直丝弓矫治技术完成矫治.矫治前后制取模型,采用Andrews关于牙弓,WALA嵴的定点方法测量下颌牙弓及WALA嵴宽度,并对治疗前后的测量结果进行配对t检验.结果 矫治完成后,下颌牙弓和WALA嵴宽度均不同程度增加(P＜0.05).均以第二前磨牙区扩大最多,其次是第一前磨牙区、磨牙区,而尖牙区最小,矫治效果良好.结论 下颌改良扩弓器结合固定矫治对下颌中重度拥挤伴牙弓狭窄青少年患者的矫治效果良好.     

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。     

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。     

固定支架式扩弓器扩大上下颌牙弓初探

目的 探讨替牙(牙合)早期采用固定支架式扩弓器扩大上下颌牙弓矫治牙列拥挤的方法.方法 在1例9岁男童的上下颌同时黏结固定支架式螺旋扩弓器,上颌扩弓1个月,下颌扩弓2.5个月后,用"2×4"技术排齐拥挤的上下颌前牙,并用Hawley保持器保持.结果 上颌尖牙间宽度扩大5.4 mm,磨牙间宽度扩大9.0 mm;下颌尖牙间宽度扩大3.4 mm,磨牙间宽度扩大6.6 mm;上下牙列排列整齐,咬合关系良好.结论 对于基骨丰满、牙弓狭窄的轻度或边缘性中度牙列拥挤拟不拔牙患者,可在替牙(牙合)早期或中期试行上下颌同时扩弓治疗.     

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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。     

Quad-Helix扩弓器的制作与临床应用研究

目的 探讨Quad-Helix扩弓器的制作、临床戴用技巧、适应证及疗效。方法 对15例混合牙列后期及恒牙期的牙弓狭窄患者,运用Quad-Helix扩弓器进行扩弓治疗。结果 通过病例总结发现,上颌第一双尖牙扩弓距离平均为4.5mm,上颌第二双尖牙扩弓距离平均为5.4mm,上颌第一磨牙扩弓距离平均为5.5mm。最大扩弓距离为7.5mm,最小扩弓距离为2.0mm,平均扩弓时间为42d。结论 Quad-Helix扩弓器适用范围广,疗效确切,而且还可用于移动个别牙齿及增强支抗。     

方丝弓矫治器联合快速扩弓器临床应用研究

目的 探讨方丝弓矫治器联合快速扩弓器尽早治疗上颌狭窄、牙列拥挤、前牙局部反牙合、后牙反牙合畸形的临床效果分析。方法 运用螺旋快速扩弓器,直接打开腭中缝,纠正宽度不调和促进上颌骨发育,同时尽早戴上、下牙弓方丝弓矫治器。结果 对20例早期恒牙列错牙合患者,以方丝弓矫治器联合快速扩弓器进行联合尽早治疗,通过对矫治前后牙尖测量比较,观察牙弓、基骨的宽度的变化。结论 方丝弓矫治器尽早联合快速扩弓器,是治疗上颌狭窄、牙列拥挤、前牙局部反牙合、后牙反牙合畸形一种快捷、高效、稳定的方法。     

Quad-Helix矫治器扩弓疗效的临床研究

目的：观察应用Quad-Helix(QH)扩弓器扩弓的应用效果。方法：临床应用Quad-Helix扩弓器扩弓12例，测量扩弓前后第一磨牙及第一前磨牙宽度变化。结果：所有采用QH扩弓器的患者，均在半年左右的时间内有效地扩大了牙弓，平均磨牙区宽度扩大了8.95mm，前磨牙区宽度扩大了5.7mm，平均扩弓时间为20.75周，平均每周扩大后牙牙弓0.43mm。结论：QH扩弓器是配合固定矫治扩弓的有效装置，而且优于其他类型的扩大狭窄牙弓的扩弓器。     

上颌骨牵引成骨术矫治上颌牙弓狭窄

目的 观察上颌骨牵引成骨术矫治上颌牙弓狭窄的疗效。方法 对１０例成年患者行上颌Ｌｅ Ｆｏｒｔ Ｉ型截骨术（不移动骨块）,并手术截开腭中缝骨联结。以上颌快速扩弓装置（６４１４６带环）,每日打开螺旋４次,共１．０ｍｍ。其中２例行单侧扩大牙弓,矫正上颌单侧牙弓宽度不足。利用计算机图形数据分析系统对扩弓前后的后前位头颅定位片进行测量（上颌骨、上颌牙弓基骨、上颌后牙间的宽度）并通过上颌前部咬合片观察腭中缝的     

Assessment of the relationship between the upper and lower arch changes with the opening of the expanding screw after the rapid maxillary expansion

Objective: The purpose of this study is to assess the relationship of the upper and lower arch dimension changes after the rapid maxillary expansion (RME) with the screw opening of the modified Hyrax type appliance. Materials and methods: Initial (T1) and final (T2) models of study of 63 children between 7 years and 6 months and 16 years and 5 months were performed. From these, 21 showed maxillary atresia and/ or posterior crossbite and were submitted to expansion and 42 children formed the control group .The appliance used in this work was the modified Hyrax appliance using the 7mm expanding screws "Dentarum". The measures of the upper intercanine and the upper and lower intermolar distances were performed in plaster models with the help of a "Digital Paquimeter". The opening of the appliance's screw was also assessed. Results: the RME provoked a statistically significant increase in the upper interdental distances and no statistic significance in the lower interdental distances, i.e. the change in the 16 - 26, 13 - 23 e 36 - 46 distance was of 5,85 mm, 5,31 and 0,34 mm respectively. The average opening of the expander screw, which was of 6,27 mm. Conclusion: the appliance's opening is related to the interdental distance changes, i.e. for each appliance's opening mm, a 0,94 variation in the upper intermolar distance, a 0,87 in the upper intercanine distance and 0,054 in the lower intermolar distance are provoked. KEY WORDS: Rapid maxillary expansion, posterior crossbite, transverse maxillary deficiency, dental arch.     

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.     

Dental arch size and shape after maxillary expansion in bilateral complete cleft palate: A comparison of three expander designs

Objective:The objective of this study was to compare the effects on upper dental arch size and shape after maxillary expansion with Hyrax, Quad-helix, and a differential opening expander in bilateral cleft lip and palate (BCLP) patients.Materials and Methods:Seventy-five BCLP patients were divided into three groups: Hyrax (H), Quad-helix (QH), and Expander with differential opening (EDO). Digital models were obtained before (T1) and after 6 months (T2) of maxillary expansion. Twelve landmarks were placed by one investigator on T1 and T2 dental models of each group, and x,y coordinates for each landmark were collected. For dental arch size analysis, centroid size of each dental arch at T1 and T2 was calculated from raw coordinates and was used as the measure of size. Procrustes Analysis was performed for dental arch shape analysis. Analysis of variance was used to compare the groups for size and shape differences (P < .05).Results:There were no significant dental arch size differences among the expanders at T1 or T2. Differences in arch shape were found between all groups at T2. Intragroup arch shape showed a significant variation for the QH and EDO groups. while it remained stable in the H group.Conclusions:Both the QH and the EDO create dental arch shape changes with greater intercanine than intermolar increase. The H does not change the dental arch shape.     

下颌双侧体部牵引成骨联合上颌手术辅助快速扩弓治疗双侧髁突自溶性吸收继发重度骨性Ⅱ类错畸形伴上牙弓狭窄的效果

目的 介绍一种治疗双侧髁突自溶性吸收（ICR）继发重度骨性Ⅱ类错畸形伴上牙弓狭窄的方法。方法 纳入6例双侧ICR继发重度骨性Ⅱ类错畸形伴上牙弓狭窄的病例,进行下颌双侧体部牵引成骨（DO）联合上颌手术辅助快速扩弓（SARME）。依照计算机辅助手术模拟（CASS）技术标准流程进行下颌体部DO术模拟,根据临床检查及影像学检查,设计牵引方向及距离。在T0、T1、T2及T3分别进行头颅CT、颞下颌关节（TMJ）问卷、TMJ磁共振、多导睡眠监测（PSG）等检查,从面型、咬合关系、颞下颌关节情况及睡眠呼吸功能4个方面评估手术效果、二期手术必要性及关节稳定性等。结果 纳入病例中,3例已完成全部治疗。下颌体部分别牵引13.0 mm、6.7 mm和8.1 mm,二期颏成形分别前移7.2 mm、0（未做）和11 mm,上颌分别扩弓5.3 mm、7.3 mm和4.9 mm,PSG数据显示重度阻塞性睡眠呼吸暂停低通气综合征（OSAHS）痊愈。最终面型及咬合关系均达到预期,改建期无复发,TMJ亦无明显变化。结论 下颌体部DO联合SARME,可有效纠正双侧ICR继发重度骨性Ⅱ类错畸形伴上牙弓狭窄。运用CASS技术进行手术设计及模拟,可有效预计牵引方向及距离,使治疗效果及稳定性更加可靠。     

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.     

Modified Hyrax expander for the correction of upper midline deviation: a case report

This article describes a case report of a patient treated by the modified version of the Hyrax rapid palatal expander described by Farronato et al. in 2009. This device can be utilized for the treatment of patients in mixed dentition who, due to the maxillary hypoplasia and to the premature exfoliation of some deciduous teeth, manifest a migration of the permanent incisors with a reduction or closure of the space for the permanent teeth substituting those previously exfoliated. This expander presents a vestibular arm for correcting maxillary asymmetric transverse discrepancies. The activation method, the therapeutic benefits as well as the clinical advantages are described. The use of this appliance allows to restore the correct transverse maxillary diameters, to regain space and at the same time to restore the symmetry of the midlines up to 5-6 mm. Moreover, a recovery of the arch length can be obtained, as demonstrated by the case report presented. The expander with vestibular arm represents an interceptive treatment which can reduce the duration of the orthodontic therapy with fixed appliances.