【作者】 杨志伟；

【导师】 罗倩云；

【作者基本信息】 遵义医学院 ， 口腔临床医学， 2011， 硕士

【摘要】 临床上对于安氏Ⅱ类错(?)伴牙源性前牙拥挤的病例,需要开拓间隙排齐拥挤前牙同时矫正Ⅱ类磨牙关系。正畸临床中开拓间隙的主要手段是减小牙量或(和)扩大牙弓,使牙量与骨量趋于协调,同时兼顾牙、颌、面三者之间的协调性、稳定性和颜面美观。减小牙量的方法包括拔牙和邻面去釉；牙弓扩展包括长度和宽度扩展,是增加骨量的主要措施。近年来,国内外正畸医生对拔牙矫治多持慎重态度,在结合患者颅、颌、面关系后,多采用少拔或不拔牙原则,作为非拔牙矫治技术重要内容的推磨牙远移开拓间隙则成为临床研究热点之一。推磨牙远移装置分为依赖型与非依赖型两大类,然而,磨牙在远移时经常发生支抗丧失,这也正是此类矫正器最大的副作用,对于依赖型推磨牙远移矫正正器,若患者配合欠佳,支抗丧失的副作用表现更为明显。正畸治疗不再依赖患者的配合已经成为一种全球性趋势,在此背景下,种植体支抗在推磨牙远移技术中得到了广泛的研究和应用。本课题旨在利用颊腭侧正畸种植体作为联合支抗远移上颌磨牙,矫治远中磨牙关系,并与临床常用的摆式矫正器远移磨牙的疗效对比,探讨一种既能发挥强支抗作用,又能有效、简便、更好地控制磨牙水平扭转和远中倾斜的远移磨牙方法。目的：利用上颌正畸种植体作为暂时性支抗,借助附牵引钩的舌弓和颊侧镍钛推簧远中移动上颌磨牙,在磨牙远移前后拍摄头颅定位侧位片、制取记存模型,与临床上常用的摆式矫正器相比,观测远移磨牙效果及远移磨牙前后头颅软硬组织的变化。探讨正畸微种植体支抗在远移磨牙技术中的特点,为临床Ⅱ类非拔牙矫治提供一种有效简便的方法。方法：选取2009～2010年就诊于贵阳市口腔医院正畸科的安氏Ⅱ类错(?)伴轻中度牙源性前牙拥挤患者20例。所有病例均通过严格的诊断分析,确诊为远移双侧上颌磨牙适应证。根据随机化原则将20例病例分为种植体组(A组)和摆式矫正器组(B组),每组各10例患者。A组利用上颌颊区与上磨牙腭侧正畸种植体联合作为暂时性支抗,借助颊区镍钛推簧和附牵引钩的舌弓远中移动上颌磨牙；B组利用传统摆式矫正器远中移动上颌磨牙。分别于远移磨牙前后拍摄头颅定位侧位片、制取记存模型,利用Winceph8.0头影测量软件分析两组病例磨牙远中移动效果及治疗前后头颅软硬组织的变化,借助记存模型分析磨牙宽度及旋转度的变化。结果：通过对头颅定位侧位片和记存模型的测量,发现两组病例在磨牙远移效果和软硬组织的变化方面有一些相同与不同之处：1、种植钉脱落率：植入一月后,颊侧微螺钉脱落3枚,脱落率15%,腭侧脱落2枚,脱落率10%,总脱落率为12.5%。2、上颌磨牙移动距离：A组病例平均远移6.63±0.67mm,B组病例平均远移6.71±1.09mm。组间比较结果无统计学意义(p>0.05)。3、上颌磨牙移动时间和速率：A组平均疗程6.00±0.14月、远移速率1.11±0.10mm/月,B组平均疗程5.17±0.32月、远移速率1.31±0.21 mm/月,组间比较均有统计学意义(p<0.01)。4、上颌磨牙移动方式：A组上颌磨牙远中倾斜4.31±0.60。、远中腭向扭转0.17±0.40°、磨牙间距增宽0.08±0.22mm, B组上颌磨牙远中倾斜16.54±3.38°、远中腭向扭转2.39±1.06mm、磨牙间距增宽0.07±0.04mm,组间比较结果均有统计学意义(p<0.01)；A组磨牙垂直压低2.71±0.12mm、B组磨牙垂直压低2.86±0.60mm,组间比较结果无统计学意义(p>0.05)。5、支抗稳定性比较：A组上切牙唇倾0.20±0.28°、唇移0.06±0.07mm,B组上切牙唇倾7.75±1.34。、唇移1.98±1.05mm,组间比较结果均有统计学意义(p<0.01)；6、对软硬组织的影响：A组上唇突度治疗前后变化无统计学意义(p>0.05)、B组上唇略有前突,但组间比较无统计学意义(p<0.01)；A、B两组治疗前后ANS—Me、SN—MP均有增加,但组间比较均无统计学差异(p>0.05)。结论：1、种植体支抗与摆式矫正器均能有效远中移动上颌磨牙。2、种植体支抗组病例,治疗前后上前牙唇倾度、突距等变化量均小于摆式矫正器组。可以认为,微种植体在推磨牙远移矫治中发挥了绝对支抗的作用。3、从磨牙远中移动效果观察,利用种植体支抗联合附牵引钩的舌弓和颊区镍钛推簧远移磨牙方法,与摆式矫正器相比较均可明显压低磨牙、但对磨牙水平向(旋转度和磨牙间距)及矢状向的控制要优于摆式矫正器。更多还原

【Abstract】 Clinically, treatment of ClassⅡmalocclusion with anterior crowding usually requires space gaining to achieve Class I molar relationship and align anterior crowding. Common strategies to gain space are to reduce dental material and/or expand arch, which can coordinate dental-skeletal discrepancy and to achieve a functional and aesthetically harmonious occlusion. The reduction of dental material includes teeth extraction and interproximal enamel reduction. The expansion arch involves anteroposterior and tranverse expansions, which are effective measures to create spaces.In recent years, advanced in mechanotherapy and changes in treatment concepts have curtailed the need for extraction in orthodontists. Molar distalizatin techniques, as one of treatment modality in arch expansion, has shown great promise as a simple and more efficient solution for obtaining spaces, which play an important role in non-extraction orthodontic treatment. The appliances used for the purpose of the distalization of molars can be classified as compliance-dependent appliances and non-compliance appliances. When used distalizing appliances to create spaces, they have some undesirable side effects that diminish their clinical effectiveness, including anchorage loss. Especially, these side effects can worsen without patients’ compliance when use compliance-dependen appliance. Reducing the need of patient cooperation and placing the treatment result more under the control of the orthodontists are paying more attentions. As a result, micro implants as an absolute anchorage used to distalize molars have gained wider acceptance and utilization.Thus, we conducted this study to investigate the effect of buccal and palatal micro implants on the distalization of maxillary molars, compared with the effect of pendulum appliance. Furthermore, we are looking forward to search a convenient and efficient way to either maintain anchorage or much better controll molar movement in the distalization of maxillary molars. Objective:The aim of this study was to compare the dentoalveolar, skeletal and soft tissue effects obtained with 2 types of molar distalizing appliance with different anchorage designs:buccal and palatal micro implants and conventional pendulum appliance. To explore the clinical features of micro implants in the distalization of molars in order to provide an effective and efficient measures to correct ClassⅡmalocclusion.Methods:20 patients treated at the Department of Orthodontics, Guiyang Stomatology Hospital in Guizhou between 2009 and 2010 were included in the study. The criteria for patient selection were strictly included dentoalveolar ClassⅡmalocclusion with mild to moderate anterior crowding. The patients were divided randomly into two groups of ten: the micro implants group (group A) and the pendulum group (group B). To achieve molar distalization, the group A was provided by 2 micro implants that were placed buccal and palatal region between the first molar and the second permolars, while the group B was provided by conventional pendulum appliance. Lateral cephalograms and study models were taken and analyzed before and after molar distalization. The dental and skeletal changes in the sagittal and vertical planes were measured by using Winceph 8.0 software and the angular and linear changes in the transverse width of the dental arch and rotation of the maxillary first molars were measured on the dental casts.Results:1 Rate of micro implants failure:3 of 20 buccal micro implants (15%) and 2 of 20 palatal micro implants (10%) showed mobility during the first month after placement. Thus, the failure rate was 12.5%.2 Distance of the maxillary first molar:On the dental casts, the mean distalization amounts were 7.10±0.16 mm for group A and 7.50±2.53 mm for group B. There was no statistically significant between two groups (p>0.05).3 Time and rate of maxillary molar movement:The average distalization times were 6.00±0.14 months for group A and 5.17±0.32 months for group B. The rate of molar movement of group A was 1.18±0.04mm per month and 1.45±0.42 mm per month for the pendulum appliance group. There was statistically significant between two groups (p<0.01).4 effects on the maxillary molars:On the cephalograms, the maxillary first molars were tipped distally 4.31±0.60 degrees in group A and 16.54±3.38 degrees in group B, which was statistically significant (p<0.01). The maxillary molars were intruded 2.71±0.12 mm in group A and 2.86±0.60 mm in group B, the differences were not statistically significant (p>0.05) On the dental casts, the mean molars width were increased 0.08±0.22 mm for group A and 0.07±0.04 mm for group B. In group A, the maxillary molars were rotated distopalatally 0.17±0.40 degrees and 2.39±1.06 degrees in group B, which was statistically significant between two groups (p<0.01).5 effects on the anterior teeth:The maxillary anterior teeth were mesially inclined 0.20±0.28 degrees and protruded 0.06±0.07mm in group A and 7.75±1.34 degrees and 1.98+1.05mm in group B. There were statistically different between two groups (p<0.01).6 effects on the soft and hard tissue:the upper lip convexity in the group B showed slightly increase after distalization, whereas there was no statistically significant change in the upper lip convexity in the group A. There was no statistically significant between two groups (p>0.05). The lower anterior facial height (ANS-Me) and the SN to mandibular plane angle (SN-MP) were increased in two groups after distalization. However, no differences were found between the groups (P>0.05)Conclusion:1 Both micro implants anchorage and pendulum are effective and efficient noncompliance appliances to distalize the maxillary first molars2 the tipping of anterior teeth was significantly decreased in the micro implant anchorage group compared with the pendulum group during treatment period. The results might support the use of the micro implants as an absolute anchorage for distal movement of the maxillary molars.3 Significant intrusion of the maxillary first molars produced by both two groups. The micro implant anchorage is a valid alternative distalizing appliance that generates more better controlled molar position transversely and anteroposteriorly than pendulum appliance.更多还原