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.     

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.     

亚历山大矫治技术治疗安氏Ⅰ类非拔牙患者的临床研究

目的探讨亚历山大矫治器治疗安氏Ⅰ类非拔牙拥挤病例的牙弓变化特征及矫治器应用特点。方法选取33例使用亚历山大托槽系统进行非拔牙矫治的安氏Ⅰ类轻、中度拥挤病例。对治疗前后的研究模型进行三维测量。应用SPSS16．0统计软件分析治疗前后牙弓宽度、牙弓长度变化、排齐阶段所用时间以及下牙列弓丝使用情况。结果牙列治疗后与治疗前阶段相比,牙弓长度、下颌尖牙宽度、前磨牙间宽度和第一磨牙间宽度均显著增加,上颌尖牙间宽度无显著变化。上下牙列排齐时间分别为（2．41±1．13）月和（2．42±1．23）月,下牙列排齐阶段13例患者使用1根弓丝,19例使用2根弓丝,1例使用3根弓丝。结论对于牙列轻、中度拥挤的患者,应用亚历山大矫治技术可以较快实现牙列排齐,并使上下颌牙弓宽度、牙弓长度增大,提高矫治效率。     

MBT矫治前后牙弓宽度变化的模型分析研究

目的 分析牙列拥挤患者不拔牙与拔牙的MBT矫治对牙弓宽度变化的影响。方法 选择我院正畸科2008—2011年MBT矫治器治疗的牙列拥挤患者40例。其中轻中度牙列拥挤患者20例,使用MBT矫治器进行不拔牙正畸;中重度牙列拥挤患者20例,使用MBT矫治器进行拔除4颗第一前磨牙的拔牙正畸。测量术前术后石膏模型的牙弓宽度,对矫治前后不拔牙组和拔牙组的测量数据分别进行组内、组间统计学分析。结果 矫治前后不拔牙组:上颌尖牙间宽度增大,上下颌第一前磨牙、第一磨牙间宽度增大,有统计学意义;拔牙组:上颌尖牙间宽度增大,上下颌第二前磨牙、第一磨牙间宽度变小,有统计学意义。矫治前2组上下颌尖牙、第一磨牙间牙弓宽度相近,无统计学差异;矫治后不拔牙组上下颌第一磨牙间牙弓宽度大于拔牙组,有统计学意义,2组上下颌尖牙间牙弓宽度相近,差异无统计学意义。结论 不拔牙矫治牙弓宽度变化与拥挤部位、拥挤程度有关,拔牙矫治牙弓宽度变化主要与牙齿移动方向有关。拔牙矫治后尖牙间宽度不会减小。     

安氏Ⅰ类边缘型牙列拥挤非拔牙快速扩弓矫治的临床疗效研究

目的研究安氏Ⅰ类边缘型牙列拥挤病例非拔牙快速扩弓矫治的牙弓参数变化,探讨其临床疗效.方法对9例安氏Ⅰ类边缘型牙列拥挤病例采用上颌快速扩弓配合上下固定矫治技术进行非拔牙正畸治疗,分别在T1(正畸治疗前)、T2(快速扩弓三个月后)和T3(正畸治疗结束进入固定保持期)三个时间点结合模型分析对牙弓参数进行分析.结果上颌第一磨牙、第一双尖牙和尖牙间宽度在T1、T2和T3相互之间均有显著性差异.下颌第一磨牙间宽度(T1-T2,T1-T3)和下颌尖牙间宽度(T1-T2)有显著性增加.上颌牙弓周径、上颌第一磨牙及第一双尖牙颊倾度有显著性增加(T1-T2),但有少量复发(T2-T3).下颌牙弓周径、下颌第一磨牙和第一双尖牙颊倾度随治疗均有显著性增加.结论快速扩弓能够通过改变上颌牙弓宽度增加其牙弓周径,下颌舌弓配合固定矫治也能显著增加下颌牙弓周径.因此可以较好地解决边缘型牙列拥挤中牙量/骨量不调问题,并有利于建立良好的咬合关系和疗效的稳定.     

应用Quick自锁托槽系统矫治上颌牙列拥挤的牙弓测量分析

目的 探讨Quick自锁托槽系统非拔牙矫治上颌牙列拥挤病例的牙弓变化特征。方法 选取37例上颌牙列轻到中度拥挤的正畸患者,使用Quick自锁托槽系统进行非拔牙矫治。对治疗前和上颌牙列排齐整平时的研究模型进行多项指标测量。应用SPSS 12.0统计软件分析治疗前后上颌牙弓宽度、牙弓长度及周长的变化。结果 上颌牙列排齐后与治疗前阶段相比,牙弓长度、周长、前磨牙间宽度和第一磨牙间宽度均显著增加,尖牙间宽度和第二磨牙间宽度无显著变化。结论 对于上颌牙列轻到中度拥挤的患者,在应用Quick自锁托槽系统排齐和整平牙列的初期,就可使上颌牙弓宽度、牙弓长度及周长均显著增大,扩大临床不拔牙矫治的范围。?     

结扎尖牙关闭远中间隙的临床应用

对于牙列拥挤的病例 ,无论采用何种矫治器 ,都要经过排齐和整平阶段 ,在固定矫治器中目前采用橡皮圈、螺旋弹簧或推簧 ,这些方法的作用力将使尖牙的牙冠移动大于牙根的移动 ,引起冠根倾斜 ,尤其在方丝弓矫治器中使用弹力牵引将严重影响牙弓的排齐和整平 ,将Ｂｅｎｎｅｔｔ和Ｍｃｌａｕｇｈｌｉｎ在其滑动机制直丝弓矫治技术使用的尖牙向后结扎法(ＣａｎｉｎｅＬａｃｅｂａｃｋ) ,应用在方丝弓矫治器中 ,对其疗效、机制、使用方法进行初步探讨。一、临床资料因牙列拥挤而进行拔牙矫治的病例 6 0例 ,年龄 11岁～19岁 ,平均年龄 13.5岁 ,所有病…     

矫治实例

病例五　李×,女,12岁,双侧磨牙关系为近中尖对尖,前牙OB2mm,OJ1.5mm,上牙弓拥挤3mm,下牙弓无拥挤,面中1/3稍凹,颏唇沟不明显。诊断:1Angle′s;2mao1s1+1矫治设计:1、拔除5　54　4　;2、Stringhtwire矫治技术;3、下颌强支抗,颌间类牵引。矫治过程:1、96年5月戴全口Straightwire矫治器,开始第一期排齐,整平牙列。2、96年9月,拉下颌尖牙远中移动,配合类牵引。3、97年6月,下颌关闭曲关闭间隙,类+垂直牵引调整磨牙关系。4、1999年4月19日拆除Straightwire矫治器,戴Hawley's保持器。矫治体会:患者磨牙类关系,基骨类关系,前牙OB,OJ基本正常,…     

自锁托槽非拔牙矫治下牙列拥挤的临床研究

目的 比较自锁托槽和传统结扎式托槽非拔牙矫治牙列拥挤患者的下牙列变化,探讨自锁托槽解除牙列拥挤的机制.方法 选择26例下牙列拥挤患者,分为自锁组和传统组,每组13例,分别使用自锁托槽(Damon3)和传统托槽(传统结扎式托槽)进行非拔牙矫治.对矫治前后变化进行配对t检验,逐步回归分析拥挤解除机制以及影响下切牙唇倾度改变量的相关因素.结果 矫治前后两组患者下颌尖牙间、前磨牙间牙弓宽度改变量及下切牙唇倾度改变量比较,差异均无统计学意义(P>0.1);矫治后自锁组下颌第一磨牙间牙弓宽度增加1.42 mm、下切牙凸距增加2.66 mm,传统组下颌第一磨牙间牙弓宽度增加0.65 mm、下切牙凸距增加1.57 mm,两组比较,差异有统计学意义(P<0.1).回归分析显示,自锁组对下切牙唇倾度变化量解释的总测定系数高达96.6%,被选入模型的变量为矫治前下颌拥挤度、下颌平面角、第一磨牙间牙弓宽度,以及矫治前后尖牙及第一前磨牙间牙弓宽度改变量.结论 非拔牙矫治下牙列拥挤时,自锁组和传统组患者均出现下切牙唇倾及下牙弓宽度增加,自锁组第一磨牙间牙弓宽度增加量及下切牙前移量较传统组多;自锁组下切牙唇倾度的改变不仅受拥挤度和矫治前牙弓宽度影响,而且受患者自身骨面型及牙弓宽度变化的影响.     

非拔牙矫治前后牙弓宽度改变的模型测量分析

目的 研究非拔牙矫治患者矫治前后牙弓宽度的改变.方法 选取牙弓轻度拥挤、采用非拔牙简单排齐的安氏I类错(牙合)患者77例,在模型上测量矫治前后尖牙间及磨牙间的牙弓宽度,并将测量结果进行配对t检验.结果 矫治后上颌尖牙间宽度增加(1.00 1.79)mm,下颌尖牙间宽度增加(0.51±1.66)mm,矫治前后上、下颌尖牙间宽度的改变有统计学意义(P＜0.05).矫治后上颌磨牙间宽度增加(0.23±1.36)mm,下颌磨牙间宽度增加(0.14±1.53)mm,矫治前后上、下颌磨牙间宽度改变无统计学意义(P＜0.05).结论 安氏I类非拔牙矫治患者矫治后上、下颌尖牙间宽度均有增加,而上、下颌磨牙间宽度相对稳定.     

Factors contributing to mandibular anterior crowding in the early mixed dentition

The aim of this study was to uncover the possible factors contributing to mandibular anterior crowding in the early mixed dentition. Mandibular dental casts of 60 children in the early mixed dentition were divided into two groups according to the severity of mandibular anterior crowding. The space available for the mandibular permanent incisors, total incisor width, deciduous intercanine width, deciduous intermolar widths, permanent intermolar width, interalveolar width, and total arch length were compared between the crowded group (CG) and noncrowded group (NCG), and correlations with crowding were investigated. The mandibular deciduous intercanine width, mandibular deciduous intermolar widths, mandibular permanent intermolar width, mandibular interalveolar width, space available for the mandibular permanent incisors, and total arch length were significantly larger in the NCG. The total width of the four mandibular incisors did not differ significantly between CG and NCG. Significant inverse correlations were found between crowding and available space, deciduous intercanine width, deciduous intermolar widths, permanent intermolar width, and interalveolar width. Total incisor width was directly correlated with crowding. No significant correlation was found between crowding and total arch length. The results of this study suggested that individual variations play an important role in treatment planning. However, one must not overlook arch length discrepancies and transverse discrepancies in patients with mandibular anterior crowding.     

Stability of mandibular incisors following excessive proclination: a study in adults with surgically treated mandibular prognathism

The purpose of this study was to determine if mandibular incisors could be proclined markedly without increasing the potential for relapse of crowding. Patients with surgically treated mandibular prognathism were selected. In 29 patients the mandibular incisors were proclined more than 10 degrees during the presurgical orthodontic phase. The remaining 33 patients had only minimal change in incisor inclination. A long-term follow-up examination was performed 10.0 (SD 2.3) and 11.1 (SD 3.1) years postoperatively in 26 and 24 patients, respectively. Study casts were measured before and after treatment, three years after surgery, and long-term. Cephalograms were evaluated before and after treatment, immediately before and after surgery, and three years after surgery. Prior to therapy the patients treated with presurgical proclination had less dental arch length and more retroclined and crowded mandibular incisors than the patients in the other group. No differences in parameters were observed at later intervals. Dental arch length and intercanine width decreased and incisor irregularity increased in both groups during the follow-up periods. No intergroup differences in changes were observed. Indications for proclination of mandibular incisors are discussed.     

Short- and long-term evaluation of mandibular dental arch dimensional changes in patients treated with a lip bumper during mixed dentition followed by fixed appliances

Objective:To evaluate short- and long-term mandibular dental arch changes in patients treated with a lip bumper during the mixed dentition followed by fixed appliances, compared with a matched control sample.Materials and Methods:Dental casts and lateral cephalograms obtained from 31 consecutively treated patients before (T₀) and after (T₁) lip bumper, after fixed appliances (T₂), and a minimum of 3 years after fixed appliances (T₃) were analyzed. The control group was matched as closely as possible. Arch width, arch perimeter, arch length, and incisor proclination were evaluated. Repeated measures ANOVA was used to analyze changes in measurements over all four time points between treatment and control groups.Results:Arch widths and crowding were always significantly different except at T₂−T₁. At T₁−T₀, only crowding decreased 3.2 mm while intercanine, interpremolar, and intermolar widths increased by 3.8, 3.3, and 3.9 mm, respectively. Changes at T₃−T₂ showed a significant decrease of 2.1 mm for crowding and an increase of 3.5, 2.9, 2.7, and 0.8 mm for intercanine, interpremolar, and intermolar widths and arch perimeter, respectively. Finally, at T₃−T₀, the reduction in crowding of 5.03 mm was significant and clinically important in the treated group. The differences between intercanine, interpremolar, and intermolar widths were also significant (2.1, 3.8, and 3.6 mm, respectively). All those differences favored the treated group.Conclusions:Mandibular dental arch dimensions were significantly changed after lip bumper treatment. At follow-up, all arch widths were slightly decreased, generating an increase of 0.4 mm in crowding, considered clinically irrelevant. Overall changes remained stable after an average 6.3-year follow-up.     

自锁托槽与传统托槽不拔牙矫治软硬组织及牙弓变化的对比研究

目的　比较自锁托槽和传统托槽不拔牙矫治对于软硬组织的变化及牙弓形态的变化。方法　选择36例安氏Ⅰ类患者分为自锁托槽组和传统托槽组,分别为18例。分别使用自锁托槽和传统托槽进行不拔牙矫治,对治疗前后的头颅侧位片及模型进行测量,并对测量结果进行配对和成组t检验。结果　矫治后2组下牙弓周长都有增长,自锁组下牙弓周长增加3.29 mm,传统组增加1.67 mm,差异有统计学意义（P<0.05）;自锁托槽组和传统托槽组牙弓各段宽度都有一定程度的扩大,但是2种托槽之间差异没有统计学意义;自锁托槽组LL-EP增加0.63 mm,传统托槽组LL-EP增加1 mm,差异有统计学意义（P<0.05）;∠U1- NA、∠L1 - NB自锁组较普通组少增加1°,但是2组之间没有统计学差异（P<0.05）;2组的SNA、SNB、ANB、MP／SN角的治疗前后变化量差异无统计学意义。结论　应用自锁托槽和传统托槽不拔牙矫治牙列拥挤时,2种托槽都不能改变骨骼关系,都有一定程度的扩弓作用和使上下前牙唇倾,但两者之间的差异没有统计学意义。     

Long-term skeletal and dental effects of mandibular symphyseal distraction osteogenesis.

The purpose of this study was to evaluate the effects of mandibular symphyseal distraction osteogenesis using a tooth-borne expansion device. The sample included 20 Hispanic nonsyndromic patients (11 males and 9 females) between 13.5 years and 37.3 years of age. Predistraction (1.5 months before surgery), postdistraction (1 month after surgery), and long-term follow-up (1.3 year after surgery) records included posteroanterior, lateral, and panoramic radiographs and models. Postdistraction radiographic evaluation showed that symphyseal distraction osteogenesis produced insignificant increases in the bicondylar, bigonion, and biantegonion widths; intermolar and, especially, intercanine widths increased significantly and a distraction gap was observed in the symphyseal region. Follow-up model analysis showed the largest width increases between the first molars and second premolars and the smallest width increases between canines and first premolars. The difference between the postdistraction and long-term follow-up width changes was explained by the postdistraction orthodontic effect, which modified the shape of the dental arch. A disproportionate pattern of distraction, characterized by significantly greater dental than skeletal widening, was observed in the second molar and antegonion region. Distraction osteogenesis without presurgical orthodontic treatment produced significant proclination of the mandibular incisors; no proclination was observed in cases with predistraction orthodontic treatment. Dental crowding was resolved by the movement of teeth into the distraction regenerate and concomitant orthodontic treatment. Follow-up radiographs showed transverse skeletal stability of the distraction procedure. We conclude that mandibular symphyseal distraction osteogenesis increased mandibular arch width and partially corrected dental crowding, with a potential for disproportionate distraction patterns and proclination of the mandibular incisors.     

A comparison of the effects of rectangular and round arch wires in leveling the curve of Spee.

A prospective randomized clinical study was designed to evaluate the effects of full continuous arch wires, rectangular in cross section, on the axial inclination of lower incisors. The intention of rectangular arch wires is to counteract the labial crown moment usually produced during leveling the curve of Spee with full arch mechanics. Patients were randomly assigned to 2 groups. Group 1 (N = 12) received round arch wires throughout the leveling stage. Group 2 (N = 16) started with flat 0.016 x 0.022 nickel titanium arch wires progressing to 0.016 x 0.022 stainless steel. The preadjusted 0.018 x 0.025 edgewise appliance was used in all cases. Lateral cephalometric radiographs and mandibular study models were taken before treatment and when the curve of Spee was leveled (or in some cases when the overbite was considered clinically acceptable). In group 1, the lower incisor proclined a mean of 6.75 degrees +/- 4.85 degrees (P <.01) and in group 2 it proclined a mean of 6.10 degrees +/- 3.95 degrees (P <.01). However, no significant difference in proclination was detected between the 2 groups. Statistically significant, but low, correlations were demonstrated between change in lower incisor axial inclination and relief of crowding r = 0.45) and change in mandibular arch depth r = 0.54), which was in turn inversely correlated with change in intercanine width r = -0.45). In both groups, the lower incisors proclined with uncontrolled tipping that can probably be attributed to the intrusive force introduced by the arch wire being labial to the center of resistance of the lower incisors. The ability of the rectangular arch wires to control labial proclination following leveling of the curve of Spee, as used in this study, was not supported.     

Age-Related Long-Term Posttreatment Occlusal and Arch Changes

Objective:To evaluate differences in long-term postretention changes between adolescents and adults.Materials and Methods:The sample included 96 subjects, 51 adolescents and 45 adults (14.2 ± 0.8 and 21.5 ± 6.8 years of age, respectively, at the end of treatment) retained for 3 years and followed approximately 16 years post treatment, who were randomly selected from two private practices. Prior to treatment, 38 and 58 had Class I and Class II malocclusions, respectively.Results:With the exception of adult midlines, all of the occlusal variables (overjet [0.50–0.77 mm], overbite [0.85–0.95 mm], the maxillary incisor irregularity [0.69–0.80 mm], the mandibular incisor irregularity [0.85–1.50 mm] and the PAR score [0.86–1.92 points]) showed significant increases over time. Adolescents consistently showed greater increases of the occlusal variables than adults, with mandibular incisor irregularity and the PAR index attaining statistically significant (P < .05) levels. Arch length and mandibular intercanine width showed statistically significant decreases over time in both groups; maxillary intercanine and intermolar widths did not change significantly. Overjet increased significantly more in Class II patients than in Class I patients, whereas Class I patients showed significantly greater decreases in mandibular intermolar width than Class II patients.Conclusions:Over the 16-year posttreatment period, adolescents showed significantly greater increases in mandibular incisor irregularity, and the PAR index than adults. Treated Class I patients demonstrated less increase in overjet and greater decreases in mandibular intermolar width than Class II patients.     

Maxillary arch changes with transpalatal arch treatment followed by full fixed appliances

Objective:To evaluate short- and long-term maxillary dental arch dimensional changes in patients treated with a transpalatal arch (TPA) during mixed dentition followed by full fixed appliances in the permanent dentition compared with an untreated sample.Materials and Methods:Dental casts and lateral cephalograms obtained from 36 consecutively treated patients before TPA treatment (T₀), after TPA treatment (T₁), after fixed appliance treatment (T₂), and a minimum of 3 years after fixed appliance treatment (T₃) were analyzed. The control group was matched as closely as possible. Arch widths, perimeter, and length, as well as crowding and incisor proclination, were evaluated.Results:In the treated group, intercanine, interpremolar, and intermolar widths and arch perimeter increased significantly at T₁. At T₂, only the intercanine width increase was still significant. At T₃ all arch dimensions decreased, remaining larger than they were at T₀. The arch length increased after T₁, significantly decreased at T₂, and slightly decreased at T₃. The crowding decreased significantly at T₁, was eliminated at T₂, and increased at T₃. At T_3, 50% of the patients showed relapse with crowding ranging from 0.5 to 2 mm. In the control group at T1, only slight changes were noted but crowding increased. At T2, crowding and upper incisor inclination increased but arch length decreased. At T3, intercuspid width, arch perimeter, and arch length continued to decrease, thereby increasing crowding.Conclusion:Maxillary dental arch dimensions changed significantly after TPA followed by treatment with fixed appliances. Relapse occurred to some extent, especially in intercanine width and arch perimeter, but most of the dental arch changes remained stable.     

Arch width changes in extraction and nonextraction treatment in class I patients

The aim of this retrospective study was to examine the dental arch width changes of extraction and nonextraction treatment in Class I patients. The study was performed on pretreatment and posttreatment dental casts of 60 patients (30 extraction and 30 nonextraction). The mean ages were 14.3 +/- 2.02 years for the extraction group and 14.1 +/- 2.9 years for the nonextraction group. The maxillary and mandibular crowding was -6.7 +/- 3.1 and -6.3 +/- 2.8 mm for the extraction group and -4.5 +/- 3.6 and -2.1 +/- 3.5 mm for the nonextraction group, respectively. The intercanine and intermolar arch width measurements were measured using a digital caliper. Paired samples t-test was used to evaluate the treatment changes within each group. To compare the changes between groups, independent samples t-test was performed. At the start of treatment, the maxillary and the mandibular intercanine and intermolar widths of both groups did not differ statistically. At the end of treatment, maxillary and mandibular intercanine widths of both groups increased significantly. The mandibular intermolar width decreased significantly for the extraction group and the maxillary intermolar width increased significantly for the nonextraction group. The decrease in maxillary intermolar width for the extraction group and the increase in mandibular intermolar width for the nonextraction group were not significantly different. No differences were observed between the groups in maxillary and mandibular intercanine widths. Maxillary and mandibular intermolar width indicated a significantly larger value in the nonextraction group than that in the extraction group.