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。     

上颌拔牙矫治对骨性Ⅲ类错牙合畸形正颌术前牙弓宽度影响研究

目的 评价骨性Ⅲ类错牙合畸形患者正颌术前正畸治疗中拔除与不拔除上颌第一前磨牙对牙弓横向宽度的影响,为是否在术前正畸中拔除上颌前磨牙提供一个参考指标。方法 选择2007年1月至2012年7月在大连市口腔医院接受正畸-正颌联合治疗的骨性Ⅲ类错牙合畸形患者28例,其中12例术前正畸采取拔牙矫治（拔牙组）,16例采取不拔牙矫治（非拔牙组）。对两组病例正畸治疗前后的模型进行牙弓宽度对比研究。结果 经过术前正畸治疗,拔牙组较非拔牙组的上颌后段牙弓宽度减小明显,差异有统计学意义（P < 0.05）;拔牙组与非拔牙组的下颌牙弓中段及后段宽度均有增加,但两组差异无统计学意义（P > 0.05）。结论 在骨性Ⅲ类错牙合畸形的正畸-正颌外科联合治疗中,拔除上颌第一前磨牙有利于术前正畸有效去除后牙代偿,协调上下牙弓间横向关系,为正颌手术创建良好条件。     

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.     

摆式矫治器治疗安氏Ⅱ类错(牙合)的牙弓形态变化

目的 研究摆式矫治器治疗安氏Ⅱ类错(牙合)的牙弓形态变化.方法 应用摆式矫治器治疗安氏Ⅱ类错(牙合)患者32例,定量测量矫治前后上下颌石膏模型的尖牙间宽度、第一磨牙间宽度,测量结果行t检验.结果 上颌尖牙间宽度、上颌第一磨牙间宽度分别增加3.49 mm和3.04 mm.上颌第一磨牙的轴倾度减少3.77°.下牙弓的拥挤改善,前牙覆(牙合)减少3.37 mm、覆盖减少4.42 mm.磨牙关系由安氏Ⅱ类转为安氏Ⅰ类.结论 摆式矫治器可用于治疗轻、中度安氏Ⅱ类错(牙合),且避免拔牙.     

安氏Ⅰ类错(牙合)非常规拔牙模式的矫治体会

目的:观察安氏Ⅰ类错耠拔除上颌第一前磨牙,下颌第二前磨牙后对支抗的不同需求,以及对咬合关系的影响.方法:选择安氏Ⅰ类错(牙合)需减数治疗病例25例,拔除上颌第一前磨牙,下颌第二前磨牙后,常规直丝弓矫治器矫治.结果:25例均获得正常覆(牙合)覆盖,尖牙和磨牙中性关系,患者侧貌发生明显改变.结论:安氏Ⅰ类错(牙合)非常规拔牙模式可消耗下颌支抗,保护上颌支抗,更好地维护了磨牙的中性关系,使疗程缩短.     

安氏I类错[牙合]非常规拔牙模式的矫治体会

目的：观察安氏I类错[牙合]拔除上颌第一前磨牙，下颌第二前磨牙后对支抗的不同需求，以及对咬合关系的影响。方法：选择安氏I类错[牙合]需减数治疗病例25例，拔除上颌第一前磨牙，下颌第二前磨牙后，常规直丝弓矫治器矫治。结果：25例均获得正常覆耠覆盖，尖牙和磨牙中性关系，患者侧貌发生明显改变。结论：安氏I类错[牙合]非常规拔牙模式可消耗下颌支抗，保护上颌支抗，更好地维护了磨牙的中性关系，使疗程缩短。     

拔牙与不拔牙矫正治疗对牙弓宽度的影响

目的比较拔牙与不拔牙矫正治疗对牙弓宽度的影响。方法选择25例拔除第一或第二前磨牙的正畸患者,25例未拔牙的正畸患者,测量治疗前后的牙颌模型,记录上、下颌牙弓宽度,其中包括尖牙间、前磨牙间及磨牙间宽度,比较拔牙与不拔牙矫正治疗对牙弓宽度的影响。结果上、下颌尖牙牙弓宽度的比较中,拔牙组比不拔牙组大,上颌大1.79mm,下颌大1.95mm,(P<0.01)。磨牙区牙弓宽度差异无显著性。结论拔牙治疗不会导致尖牙区宽度的减小。     

安氏Ⅱ类2分类错牙合扩弓后牙弓宽度的稳定性研究

目的 探讨安氏Ⅱ类2分类错牙合扩弓矫治后的牙弓宽度的稳定性.方法 分别测量17例安氏Ⅱ类2分类错牙合患者扩弓治疗前后及保持2年磨牙间及尖牙间牙弓宽度.结果 安氏Ⅱ类2分类错牙合患者扩弓治疗前后上下尖牙及磨牙间宽度均明显增大(P＜0.05),保持2年后上尖牙及磨牙宽度基本稳定,而下尖牙间宽度明显缩窄.结论 安氏Ⅱ类2分类错牙合扩弓矫治后,最好用舌侧保持器做永久保持.     

拔牙和非拔牙矫治对颊廊影响的研究

目的 研究拔牙和非拔牙矫治对颊廊的影响.方法 随机选取安氏Ⅰ类错(牙合)拔牙矫治患者和不拔牙矫治患者各25例,在其矫治前后的牙(牙合)模型上,分别对上下尖牙区和磨牙区唇颊面最突出的位置进行牙弓宽度的测量,同时在其矫治前后面部正位像上,测量笑容宽度和上颌可见牙列宽度,计算颊廊系数.所有数据均经统计学分析.结果 非拔牙组矫治前后牙弓宽度变化无统计学意义.拔牙组矫治后上、下颌尖牙间宽度分别增加了2.87 mm和1.30 mm(P＜0.05),但上下颌磨牙间宽度的变化无统计学意义.两组治疗前后颊廊系数变化均无统计学意义.结论 对于安氏Ⅰ类错(牙合)患者,拔牙和不拔牙矫治对颊廊均无明显的影响.     

扩弓和Ⅱ类牵引矫治成人安氏Ⅱ类2分类错（hé）

目的应用扩大上/下颌牙弓和Ⅱ类牵引方法矫治成人安氏Ⅱ类2 分类错(牙合),观察并比较矫治前后硬组织X线头影测量以及模型的变化.方法 选取临床矫治的安氏Ⅱ类2 分类错(牙合)成人病例15 例,矫治采用非拔牙矫治的扩大上/下颌牙弓以及Ⅱ类牵引的方法,测量矫治前后X线头影测量和模型测量的变化并比较.结果 头影测量治疗前后上颌骨矢状方向和垂直方向变化不明显,下颌骨矢状方向SNB平均增加2.5°,垂直方向下颌平面角平均增加了2.7°,下前面高平均增加了11.8 mm,上下切牙明显唇倾,下颌磨牙明显近移;模型测量治疗前后覆(牙合)明显减小,上下颌尖牙间、前磨牙间和上颌磨牙间宽度明显增加,下颌磨牙增加不明显.下颌尖牙和磨牙平均近移4.1 mm和3.6 mm.磨牙关系由Ⅱ类变为I类.结论成人安氏Ⅱ类2分类错牙合可以通过扩大上/下颌牙弓和II类牵引方法矫治,获得满意的治疗结果.     

The extraction of permanent second molars and its effect on the dentofacial complex of patients treated with the Tip-Edge appliance

The aim of this investigation was to assess the dentofacial changes in a group of patients consecutively treated with Tip-Edge appliances and the extraction of four permanent second molars by one specialist orthodontic practitioner. Before and after treatment lateral cephalograms and study cast measurements of 45 individuals, 26 females (mean age 13.8 years) and 19 males (mean age 13.9 years), were collated and statistically analysed. Cephalometric variables that exhibited, before treatment, significant sex differences, included SNA, SNB (both smaller in males, P < 0.05) and U1-NA degrees (P < 0.05), nasolabial angle (P < 0.05), and upper lip length P < 0.01 (all larger in males). After treatment, sex differences were demonstrated for SNA (smaller in males, P < 0.05), mandibular length (P < 0.01), upper face height (P < 0.05), lower face height (P < 0.01), anterior face height (P < 0.001), posterior face height (P < 0.01), nasolabial angle (P < 0.05), and upper lip length and thickness (P < 0.001; all larger in males). For the cast analysis, before treatment differences indicated larger values for males than females for lower arch inter-canine, premolar, and molar widths, arch depth (all P < 0.05), tooth size, and arch length (P < 0.01). Similar findings were noted in the upper arch except for inter-canine and premolar arch width. Despite most arch variables displaying sex differences, no gender effect was found for irregularity or crowding parameters. The same variables exhibited significant sex differences and changes after treatment (except tooth size, lower arch depth, and upper arch inter-canine width). Overall, the pattern of correction exhibited by the subjects included dental, skeletal, and soft tissue changes. Males tended to have greater mean increases in mandibular skeletal and soft tissue variables compared with females. Both males and females had increases in most dental arch variables measured from the study casts. Both sexes demonstrated a small uprighting, but statistically non-significant distalizing of the buccal segments. The lower incisors in the sagittal plane revealed a mean tendency to remain in their pre-treatment positions, with some individual variation. Overall, the treatment results were considered favourable, but case selection appeared to bias towards Angle Class I skeletal patterns of average to slightly reduced facial height, overbite and overjet < or = 4 mm, lip competence, no incisor protrusion, and moderate tooth size to arch length discrepancy (3-3.5 mm lower arch, 1 mm upper arch). Further evaluation of third molar eruption responses may provide insight into appropriate timing of second molar extractions.     

Posttreatment and postretention changes following orthodontic therapy.

This investigation was performed to determine the changes which occurred in treated orthodontic cases out of retention. The material consisted of 103 cases, of which 74 cases were treated nonextraction and 29 were treated with the extraction of four first premolars. The treatment was accomplished by the full-banded edgewise bioprogressive technique. Five measurements were taken: intercanine, inter-first premolar, intersecond premolar and inter-first molar widths, and incisor to molar distance. The measurements were made on the mandibular arch of the pretreatment, posttreatment, and prostretention casts. The postretention model was obtained a minimum of one year after all retaining devices were removed with an average of 5.2 years. The following conclusions were drawn from the changes in dimensions: 1. The intercanine width was expanded during treatment, but had a strong tendency to return to or close to its original pretreatment width in both nonextraction and extraction cases. 2. The inter-first premolar width showed the greatest treatment increase in width with only a minimal amount of postretention decrease. 3. The second premolar width for nonextraction cases showed a significant amount of increase with a slight tendency for postretention decrease. 4. The second premolar width for extraction cases showed a decrease with treatment and a slight continued decrease postretention. 5. The intermolar width of nonextraction cases showed a significant increase in width with treatment. The extraction cases showed a significant decrease with treatment. However, there were no changes in either extraction or nonextraction cases postretention. 6. The incisor to molar distance decreased with treatment and had a slight tendency to continue to decrease postretention.     

���������ζԹ��Ԣ�������ϻ��������ǰ�������Ӱ���о�

目的评价骨性Ⅲ类错矜畸形患者正颌术前正畸治疗中拔除与不拔除上颌第一前磨牙对牙弓横向宽度的影响,为是否在术前正畸中拔除上颌前磨牙提供一个参考指标。方法选择2007年1月至2012年7月在大连市口腔医院接受正畸一正颌联合治疗的骨性Ⅲ类错铪畸形患者28例,其中12例术前正畸采取拔牙矫治（拔牙组）,16例采取不拔牙矫治（非拔牙组）。对两组病例正畸治疗前后的模型进行牙弓宽度对比研究。结果经过术前正畸治疗,拔牙组较非拔牙组的上颌后段牙弓宽度减小明显,差异有统计学意义（P〈0．05）;拔牙组与非拔牙组的下颌牙弓中段及后段宽度均有增加,但两组差异无统计学意义（P〉0．05）。结论在骨性Ⅲ类错猞畸形的正畸一正颌外科联合治疗中,拔除上颌第一前磨牙有利于术前正畸有效去除后牙代偿,协调上下牙弓间横向关系,为正颌手术创建良好条件。     

Effects of bilateral upper first premolar extraction on the mandible

The purpose of this study was to evaluate the effects of bilateral upper premolar extraction on mandibular growth. Twenty-six subjects (eight males, 18 females) in maximum pubertal growth with an Angle Class II molar relationship, normal to mild overjet increase, mild or no lower arch length discrepancy but severe upper arch discrepancy and no severe skeletal discrepancy were divided into two groups equal in number and gender, as extraction and control groups. The median chronological age was 11.2 years in the extraction group and 12.6 years in the controls. The subjects were observed for a median period of 1.1 years in the extraction group after bilateral extraction of the upper premolars and 1.2 years in the controls until termination of pubertal growth (DP3u) without any orthodontic treatment. Twenty-nine linear and angular measurements were made on 52 lateral cephalograms and hand-wrist radiographs taken before and after the study period. The increase in SNB measured on the total superimposition was significantly greater in the controls than in the extraction group (P < 0.05). In addition, anterior mandibular (counter-clockwise) rotation was only significant (P < 0.05) in the control group. Thus, it might be suggested that bilateral upper premolar extractions might affect the mandibular rotation tendency.     

Evaluation of dental arch width and form changes after orthodontic treatment and retention with a new computerized method.

The purpose of this study was to evaluate longitudinal arch width and form changes and to define arch form types with a new computerized method. Maxillary and mandibular models of 21 Class II Division 1 patients were examined before treatment (T(0)), after treatment (T(1)), and an average of 3 years after retention (T(2)). Arch width measurements were made directly on scanned images of maxillary and mandibular models. Arch form changes at T(0)-T(1) and T(1)-T(2) were evaluated by superimposing the computer-generated Bezier arch curves with a computer program. Types of dental arch forms were defined by superimposing them with the pentamorphic arch system, which included 5 different types of arch forms: normal, ovoid, tapered, narrow ovoid, and narrow tapered. Maxillary arch widths were increased during orthodontic treatment. Mandibular posterior arch widths were also increased. The expansion of the mandibular arch forms was less than in the maxillary arch forms. Arch width changes were generally stable, except for reduction in maxillary and mandibular interlateral, inter-first premolar, and mandibular intercanine widths. Pretreatment maxillary arch forms were mostly tapered; mandibular arch forms were tapered and narrow tapered. In maxillary arch forms, 76% of the treatment changes were maintained. Mandibular arch form was maintained in 67% of the sample, both during treatment and after retention. In mandibular arches, 71% of orthodontically induced arch form changes were maintained.     

DAMON技术及MBT技术对安氏Ⅱ^1拔牙病例牙弓宽度影响的研究

目的：采用Damon-Ⅲ自锁托槽矫治技术和MBT矫治技术拔除四个第一双尖牙矫治治疗安氏Ⅱ^1错患者,研究治疗前后的牙弓宽度变化。方法：选择20例Damon-Ⅲ自锁托槽矫治技术及20例MBT矫治技术治疗安氏Ⅱ类1分类患者,均采用减数四颗第一双尖牙治疗方案,未额外使用增强支抗装置,治疗前后取寄存模型并进行测量。结果：患者经Damon矫治技术及MBT技术治疗后,均获得良好的咬合关系,Damon组治疗后上尖牙间宽度增大2.24 mm,下尖牙宽度增大1.02 mm,没有统计学意义;上双尖牙宽度减小1.57 mm,下双尖牙宽度减小1.86mm;上磨牙宽度减小1.83 mm,下磨牙宽度减小2.69 mm;MBT组治疗后上尖牙间宽度增大1.72 mm,下尖牙宽度增大1.21 mm;上双尖牙宽度减小1.03 mm,下双尖牙宽度减小1.65 mm;上磨牙宽度减小1.51 mm,下磨牙宽度减小2.37 mm;两组样本对比,上颌尖牙及双尖牙宽度变化有统计学意义。结论：Damon-Ⅲ自锁托槽矫治技术与MBT技术均可快速高效治疗安氏Ⅱ类1分类错[牙合],与MBT技术相比较,Damon-Ⅲ自锁托槽矫治技术在拔牙病例中并没有表现出明显的扩大牙宽度     

The effects of Fr?nkel II treatment on arch width and arch perimeter

Changes in dental arch width and total arch perimeter in 24 Class II, Division 1 patients treated with the Fr?nkel II appliance were compared with changes in an untreated control group. Measurements were made on pretreatment and posttreatment plaster casts at three points on each of four maxillary and four mandibular teeth. Increases in width were computed at the occlusal point and compared for the two samples. A significant increase in occlusal arch width for all measures was suggestive of both a minor tipping movement of the maxillary teeth and a bodily movement of the mandibular teeth. Width development in the maxilla was greater than in the mandible. Occlusal arch width increased more in the molar and premolar regions in the maxilla and in the premolar region in the mandible. Wide arches were found to have as much increase as narrow arches. The total arch perimeter decreased significantly less in the treatment sample than in the control sample. The documented gains in arch width and arch perimeter would not be sufficient to relieve severe crowding, but could be useful in avoiding removal of teeth in borderline extraction cases.     

牙列拥挤与前突病例拔牙矫正后牙弓宽度变化对比研究

目的：通过研究尖牙、第一磨牙及第二磨牙间宽度的变化,对比牙列拥挤和牙列前突病例以及年龄因素对拔牙矫治前后牙弓宽度变化的影响。方法：随机选择60例拔除四个第一前磨牙MBT矫治技术治疗患者,分为拥挤组和前突组及16岁以上组和16岁以下组进行对比研究,取治疗前后记存模型进行测量,并经统计学分析。结果：拔除四个前磨牙病例矫治后,磨牙区牙弓宽度均减小,尖牙区牙弓宽度均增加;拥挤组及16岁以下组尖牙间牙弓宽度增加更明显,磨牙区牙弓宽度减小在各组间无明显差异。结论：拔牙矫正后拥挤组及16岁以下组的尖牙间牙弓宽度增加更明显,所以治疗后的保持需要时间更长。