强支抗拔牙对双颌前突青少年上气道的影响

目的: 利用锥形束CT（cone beam computed tomography, CBCT）从三维方向上研究强支抗拔牙内收对双颌前突青少年上气道的影响。方法: 回顾分析本院50例予以强支抗拔牙治疗的双颌前突青少年治疗前、后的CBCT资料,测量治疗前、后上气道的变化。采用SPSS 17.0软件包对数据进行配对t检验和Pearson相关性分析。结果: 治疗后,口咽和咽下的体积、平均截面积、最小截面积显著减小(P<0.001);口咽、咽下的横截面形态更趋于椭圆形(P<0.001)。Pearson相关分析发现,下颌切牙内收、舌骨后移与咽下气道平均截面积减少有显著相关性(P<0.05);上、下颌切牙内收与舌骨后移有显著相关性(P<0.01)。结论: 对于青少年双颌前突患者,制订治疗计划时应兼顾上气道形态,避免造成上气道狭窄,影响患者正常发育。     

Comparison of the outcomes of the lower incisor extraction, premolar extraction and non-extraction treatments

The aim of this retrospective study was to evaluate the treatment outcome of lower incisor extraction and to compare it with premolar extraction and non-extraction treatment. The sample consisted of 60 subjects with Class I malocclusion and moderate crowding. The sample was separated into three groups: extraction of a lower incisor group, extraction of a four first premolar group and a non-extraction group. All groups involved 13 girls and 7 boys with a total of 20 patients. The Peer assessment rating (PAR) index was applied to a patient's pre-treatment (T1) and post-treatment (T2) dental casts. T1 dental casts were also used for determining Bolton discrepancy. One-way analysis of variance and post hoc Tukey HSD tests were used for statistical analysis. For the mean percentage PAR score reduction for each group, there was one significant difference seen between the lower incisor extraction group and the non-extraction group (P = 0.047). For the mean anterior ratios, there were significant differences among premolar extraction group versus non-extraction group (P = 0.042) and non-extraction group versus lower incisor extraction group (P = 0.000). For the mean overall ratios, there were significant differences among the premolar extraction group versus lower incisor extraction group (P = 0.048) and the non-extraction group versus lower incisor extraction group (P = 0.001). Orthodontic treatment without extraction has a better treatment outcome than the four-first premolar extraction and single lower incisor extraction protocols in Class I cases with moderate to severe mandibular anterior crowding.     

Evaluation of changes in the vertical facial dimension with different anchorage systems in extraction and non-extraction subjects treated by Begg fixed appliances: a retrospective study

The aim of the study was to evaluate and compare the effects of mesial movement of the maxillary and mandibular molars on the facial vertical dimensions following orthodontic treatment. Patients with an Angle Class I malocclusion were treated by four first premolar extractions and Begg fixed appliances (moderate and maximum anchorage groups), while those with an Angle Class II malocclusion were treated by Begg intraoral distalization mechanics without extractions (distalization group). Following treatment, the patients were grouped according to the mesial movement of the mandibular first molars and compared with an Angle Class I control group. All groups comprised 15 patients, their mean pre-treatment ages were 14.95 years for the moderate (13 females, 2 males), 14.88 years for the maximum (13 females, 2 males), 14.41 years for the distalization (10 females, 5 males), and 14.38 years for the control (13 females, 2 males) groups. Lateral cephalometric measurements were performed at two time points (T(1): pre-treatment/control, T(2): post-treatment/control). A paired t-test was used for within-group comparisons and non-parametric Kruskal-Wallis and Dunn's multiple-comparison tests to determine any differences. The increases in anterior and posterior face heights were similar between groups. The mandibular plane angle (SN/GoGn) was increased in all treatment groups, while it decreased in the control group. Although SN/GoGn increased more in the distalization and less in the moderate anchorage groups, these differences were not statistically significant. The change in SN/GoGn was significantly different only between the distalization and control groups. Facial vertical dimensions were not significantly affected by the amount of mesial movement of the molar teeth.     

最大支抗拔牙病例上切牙和上唇矢状向变化的研究

目的 研究使用最大支抗的青少年和成人拔牙矫治前后侧貌软硬组织矢状向变化及其相关情况.方法 对采用最大支抗的13例青少年和14例成人拔牙矫治病例前后9项软硬组织指标进行对比,通过配对t检验评价软硬组织的变化情况,并对其中部分指标进行相关性分析和直线回归.结果 1)青少年组的9项测量指标中,U1-SN、U1-PM和牙弓拥挤度的改变差异均有统计学意义.其中,上切牙内收量和上唇内收量均与治疗前的牙弓拥挤度呈负相关,与治疗前上唇至E线距离呈正相关.回归方程为:上唇内收量=-2.900+0.926×上切牙内收量.2)成人组的9项指标中,除SNA和Ls-PM外,其余指标改变差异均有统计学意义.其中,上切牙内收量与治疗前上切牙唇倾度呈正相关,与治疗前牙弓拥挤度呈负相关;上唇内收量仅与治疗前上切牙的唇倾度呈正相关.回归方程为:上唇内收量=-1.027+0.706×上切牙内收量.结论使用最大支抗的拔牙矫治对于成人解除拥挤、内收上切牙和上唇有很好的效果;青少年矫治后也能明显地解除拥挤、内收上前牙,但由于生长发育的关系,其上唇内收并不明显.     

临界病例拔牙与非拔牙矫治的判别分析

目的 用判别分析对临界病例拔牙非拔牙治疗进行判别及预测.方法 收集69例临界拔牙病例,其中35例接受拔牙矫治,其余34例接受了非拔牙矫治.两组之间的性别及年龄差异无显著性.为了评价所形成判别方程的准确性,其中9例患者被随机选出形成验正样本不参与判别分析,刺余60例患者作为研究样本进行判别分析.结果 判别分析选出了六项敏感的测量项目:Pog-NB、ANB、ANS-Me、U1-L1、L1-NP、L1-NB.判别1方程为:P=1/-(-4.07PONB 0.43ANB 0.37ANSME-0.13UILI 1.25LINB-2.22LINB)结论 (亥页)突度、上下齿槽突角、面下部高度、下中切牙突度、上下中切牙交角的变化对判别临界拔牙病例拔牙与非拔牙矫治有明显的影响作用.同时惠者本人对美 现标准的认可和功能性因素应加以考虑.     

Maxillary molar intrusion with fixed appliances and mini-implant anchorage studied in three dimensions

The intrusion of an overerupted maxillary molar using traditional orthodontic treatment is a real challenge. The aim of this study was to investigate the envelope of intrusive movements of a maxillary molar in cases using mini-implants as anchorage with partial or full-mouth fixed edgewise appliances. The cusp tips of the pretreatment and postintrusion dental casts were recorded by a three-dimensional (3D) digitizer. The 3D data of the serial dental casts were analyzed to distinguish the direction and magnitude of individual tooth movement. The mean intrusive movement of the maxillary first molars was three to four mm, with a maximum of over eight mm. For the adjacent maxillary second molars and second premolars, the amount of intrusion was two mm and 1-2 mm, respectively. This study demonstrated that significant true intrusion of maxillary molars could be obtained in a well-controlled manner by using fixed appliances with titanium mini-implants as bony anchorage.     

Class III malocclusion: a comparison of extraction and non-extraction techniques

A retrospective cephalometric study was made of the hard tissue changes in a group of 90 Class III, Skeletal III children, diagnosed as suitable for treatment by orthodontic means alone. Thirty-two were treated by a combination of upper incisor proclination and headgear to an intact mandibular dentition (Group 1), while in 28 the overjet was corrected with mid-arch extractions and Edgewise mechanics (Group 2). The remaining 30 children acted as controls (Group 3). Children were initially examined as male and female subgroups, and where no significant differences were seen data were pooled. In order to standardize the results, treatment/observation effects were presented as average changes per year. The three groups were essentially comparable pretreatment. Following overjet correction, the lower incisors uprighted in both groups, with an improved relationship to the A-Po line: the upper incisors were proclined in Group 1 only. Underlying skeletal changes were restricted to the mandible, which showed a downward and backward hinging, and an increase in lower face height. The improved mandibular position was significantly greater in the non-extraction group and was accompanied by an improvement in facial convexity. In addition, treatment could be started earlier and was completed in a significantly shorter time (Table 1). It would, therefore, appear that, in the short term at least, a non-extraction/headgear approach has advantages over a standard mid-arch extraction/Edgewise technique.     

数字化排牙试验在正畸病例拔牙与否判断中的应用

目的 探讨数字化排牙试验在正畸病例拔牙与否判断中的应用。方法 选取40例资料完整的正畸初诊病例作为研究样本。第1组由6名医师依据牙颌模型、X线片、面颌相片及传统的常规资料测量分析结果,对以上病例进行治疗方案设计。第2组由同样6名医师,根据以上资料再加上辅助数字化排牙试验的方法进行治疗方案设计。方案设计的结果分别判断为拔牙、不拔牙、临界3种情况。对2组拔牙与否判断的一致性进行统计分析和比较。结果 以6人拔牙与否判断的结果完全一致为标准,第1组中,拔牙,不拔牙、临界的例数分别为3例、1例、5例,符合率分别为7.50%、2.50%、12.50%,总体符合率为22.50%。第2组中,拔牙、不拔牙、临界的例数分别为17例、8例、1例,符合率分别为42.50%、20.00%、2.50%,总体符合率为65.00%。选择配对设计Wilcoxon符号秩检验,对第1组和第2组各40个病例的临界偏离度进行差异性分析,检验结果表明Z值为-0.756（P＜0.001）,说明第2组对于拔牙与否判断的一致性要显著高于第1组。结论 在正畸病例治疗方案设计中辅助数字化排牙试验,可以对拔牙与否提供有益参考。     

无托槽隐形矫治技术在拔牙临界病例非拔牙治疗中的应用研究进展

正畸拔牙临界病例的治疗设计错综复杂,不同的矫治技术采用的设计方案有所不同。随着医疗新技术的不断发展,无托槽隐形矫治器得以推广,其移动牙齿的效能不断被证实。有专家提出无托槽隐形矫治技术相对于传统唇侧固定矫治技术在拔牙临界病例的非拔牙治疗中显示出优势。该文就无托槽隐形矫治技术三维方向移动牙齿的特点进行回顾与展望,总结分析此技术在拔牙临界病例非拔牙治疗设计中移动牙齿的优势,从而为正畸拔牙临界病例的治疗设计提供参考。     

Evaluation of extraction and non-extraction treatment effects by two different superimposition methods

The aim of this study was to determine whether different evaluation methods may be the cause of the varied outcomes of research that have evaluated the effects of extraction and non-extraction therapy on jaw rotation. This retrospective study consisted of the pre- (T1) and post- (T2) treatment lateral cephalograms of 70 skeletal Class I subjects with an optimal vertical mandibular plane angle, who had undergone fixed orthodontic treatment. Thirty-five of the subjects (20 females and 15 males, mean age: 14.7 years) were treated with four first premolar extractions and 35 (22 females and 13 males, mean age: 15 years) without extractions. T1 and T2 radiographs were superimposed using Bj?rk's structural method and Steiner's method of sella-nasion line registered at sella. A Wilcoxon test was used to evaluate the changes between T1 and T2 and the Mann-Whitney U-test to determine differences between the extraction and non-extraction and Bj?rk and Steiner groups. No significant difference was found between the methods of Steiner and Bj?rk according to the spatial changes of the cephalometric points in the extraction and non-extraction groups. The maxilla showed forward rotation in the extraction group and backward rotation in the non-extraction group with both superimposition methods, but the differences were not significant in either inter- or intraclass comparisons. The mandible showed forward rotation in the extraction group with both superimposition methods but, in the non-extraction group, forward rotation was recorded with Bj?rk's method and backward rotation with Steiner's method. These findings were not significant in either inter- or intraclass evaluations. No significant difference was found between the groups or methods.     

拔牙与非拔牙矫治对正面微笑美学影响的meta分析

]目的：系统评价并比较拔牙与非拔牙矫治对正面微笑美学的影响。方法检索并收集自数据库建库至2014年8月31日期间万方数据库、中国学术期刊全文数据库(CNKI)、维普数据库(VIP)、中国生物医学文献数据库(CBM)以及Medline、Cochrane Library数据库所收录的有关拔牙与非拔牙矫治对正面微笑美学影响的临床对照研究。采用Review Manager 5.2软件对纳入文献的数据进行meta分析。结果共纳入8篇研究。Meta分析显示,经过拔牙与非拔牙矫治后,正面微笑美学的主观审美得分分别为5.74~7.05分和5.53~7.02分（10分制）[WMD=0.09,95%CI（-0.28,0.46）,P=0.64],颊廊系数分别为0.12~0.19和0.11~0.18 [WMD=0.01,95%CI（-0.00,0.02）,P=0.09],上颌可见牙列宽度分别为26.3~52.17 mm和25.43~52.37 mm [WMD=-0.13,95%CI（-1.01,0.75）,P=0.77]以及微笑高度分别为5.7~10.39 mm和5.4~9.97 mm [WMD=0.38,95%CI（-0.27,1.03）,P=0.25],各指标之间均无显著差异。结论目前的临床证据资料尚不足以支持拔牙矫治能够对正面微笑美学产生影响。由于纳入研究偏少及研究中存在的异质性,尚需开展更多设计良好的相关前瞻性分析。     

拔牙和非拔牙矫治对正面微笑和静态侧貌的美学影响

目的：探讨拔牙和非拔牙矫治对青少年微笑和侧貌的影响,拔牙是否内收青少年颊部。方法以拔牙组和非拔牙组各30例青少年矫治前后正面微笑以及静态侧貌45°和90°照片为研究对象,使用Photoshop CS3软件定点描线测量。矫治后正面微笑像以视觉模拟评分量表评分。应用t检验、卡方检验和Pearson相关分析对数据统计分析。结果两种治疗方式均能使上唇长度增大,口角宽度减小（P<0.05）。拔牙组矫治后,过鼻尖点垂线与过唇部最凸点垂线间距离明显增大（P<0.05）;非拔牙组颊部内收角（过鼻尖点的垂线与过面下1/3颊部最凸点的切线的夹角）明显减小（P<0.05）。拔牙组和非拔牙组正面微笑美学评分差异无统计学意义。结论两种矫治方式均能很好地改善患者的唇齿关系,拔牙矫治与青少年颊部变化关系不大,不会影响微笑美观。     

Jefferson skeletal classification system (JSCS) and how it helps in extraction and non-extraction orthodontic cases

Facial appearance depends mainly on bone support 1,2,3,4,5. Bone position is the first consideration when making an orthodontic treatment decision. The skeletal classification evolved to give us the opportunity for a better assessment and understanding of cases. Jefferson Skeletal Classification System (JSCS) shows the most common malpositioned jaws. This system will also help to asses extraction and non-extraction orthodontic cases.     

种植支抗关闭正畸拔牙间隙对上颌磨牙垂直向高度的影响

目的：研究种植支抗联合滑动法内收前牙间隙过程中上颌磨牙垂直向的改变。方法选择25例成人患者,根据治疗需要拔除上颌第一双尖牙,在上颌5、6之间植入种植钉,作为支抗内收前牙关闭间隙。将患者治疗前后的数字化模型进行重叠,比较上颌第一、第二磨牙的垂直向改变。结果上颌第一磨牙治疗后被压低（P<0.001）,第二磨牙没有明显改变。上颌第一磨牙的近中舌尖、远中舌尖、近中颊尖、远中颊尖四个牙尖的改变无显著性差异。结论使用种植支抗联合滑动法关闭正畸拔牙间隙,将会导致上颌第一磨牙的压低,但是第二磨牙没有显著改变,并且第一磨牙没有明显的颊侧倾斜。     

骨性Ⅲ类错牙合上颌拔牙与不拔牙去代偿对双颌手术矫治效果的影响

目的评价骨性Ⅲ类畸形双颌手术患者术前正畸上颌拔牙与不拔牙去代偿的效果及对术后的影响。方法选取36例在中国医科大学口腔医院进行正畸正颌外科联合治疗的骨性Ⅲ类错牙合畸形患者,其中18例术前正畸采取拔牙矫治,另18例未拔牙。对2组病例术前正畸后及治疗结束后的X线头颅定位侧位片进行对比研究。结果术前正畸后,拔牙组的U1-SN、鼻唇角（Cm-Sn-UL）和覆盖都较非拔牙组有明显变化,差异有统计学意义（P<0.05）。拔牙组下颌平均后退（8.66±1.42）mm,非拔牙组下颌平均后退（6.21±3.06）mm,二者间差异有统计学意义（P<0.05）;治疗结束后,拔牙组ANB、U1-SN、NA-PA在正常值范围内（P>0.05）。结论在骨性Ⅲ类畸形的正畸正颌外科联合治疗中,上颌拔牙术前正畸能够更彻底地去代偿,真实反映原有骨性畸形,使下颌能够后退至更加理想的位置,从而更好地矫治凹面型。