改良Nance弓矫治后牙锁(牙合)的临床应用

后牙锁[牙合]是一种临床较为常见的错[牙合]畸形,以第二磨牙正锁[牙合]更为多见.锁[牙合]牙齿不仅在水平向,而且在垂直向及近远中向同时伴有其它各种畸形.临床根据不同情况矫治锁[牙合]的方法较多,本文介绍应用改良Nance弓矫治上颌第二磨牙正锁[牙合]伴前牙深覆[牙合]12 例,既矫正了锁[牙合]又能快速打开咬合,获得了满意的临床效果.     

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后牙锁[牙合]畸形一般需要通过拔牙手段才能得到有效矫治。结合临床,本文提出了以下矫治理念：（1）制定矫治计划时上下牙列尽可能选择正畸拔牙矫治;（2）欲矫治第二磨牙的错[牙合],应先拔除第三磨牙才能获得满意的疗效;（3）有时可直接拔除锁[牙合]的第二磨牙,让第三磨牙自行调整至正常位置;（4）为消除咬合干扰,在矫治之前在前牙区放置一平面导板,有利于锁[牙合]牙的快速纠正。     

用交互牵引和MEAW技术矫治后牙正锁(牙合)的临床观察

目的：应用交互牵引和多曲方丝弓（MEAW）技术矫治后牙正锁[牙合];评价其临床矫治效果。方法：选择后牙正锁[牙合]病例12例,采用交互牵引矫治正锁[牙合];锁[牙合]解除后MEAW技术调整后牙在三维方向的位置。结果：12例患者均取得良好的矫治效果,覆[牙合]覆盖关系正常,尖窝关系良好。结论：后牙正锁[牙合]病例通过交互牵引和MEAW技术的联合应用可有效地调整磨牙关系。     

单侧后牙正锁(牙合)伴牙龈肥厚的青少年正畸治疗1例

后牙锁(牙合)是较为常见的一种错(牙合)畸形,其中以第二磨牙锁(牙合)最为常见.锁(牙合)中更为严重的是正锁(牙合),即上颌后牙后牙舌斜面咬在下颌后牙颊斜面的颊侧,影响咀嚼功能、牙周健康、颞下颌关节发育,严重者会造成颌面部发育不对称[1].矫正后牙正锁(牙合)的方法有颌间交互牵引、MEAW 技术以及微种植钉等[2,3]...     

后牙锁的矫治及其常见问题的预防与处理

后牙锁 牙合是一种临床较为常见的错牙合畸形 ,以第二磨牙正锁牙合更为多见 ,也可见到第一磨牙及前磨牙锁牙合 ,可表现为个别牙锁牙合或多个牙锁牙合 ,影响患者咬合功能 ,并对美观及口腔健康带来危害。锁牙合牙齿不仅存在水平向(颊舌向 )而且存在垂直向及近远中方向。针对不同锁牙合应采用不同的治疗方法。治疗后牙锁牙合的固定矫治方法有改良腭杠腭侧牵引矫正法、方丝“T”形曲矫正法、附弓丝固定矫正法、腭杠或腭弓缩弓法、舌弓扩弓法、固定矫治器弓丝矫正法及拔牙矫治法等。在治疗后牙锁牙合中 ,解除拥挤开辟间隙是前提 ,对锁牙合牙齿进行垂直向控制是关键 ,根据锁牙合类型确定矫治方法是保证。拔牙矫治不失为一种治疗锁牙合的简便方法。     

改良[牙合]垫矫治器矫正后牙锁[牙合]的临床应用22例

目的观察改良[牙合]垫矫治器矫正后牙锁[牙合]的临床疗效和矫治特点。方法对22例后牙锁[牙合]患者采用改良[牙合]垫矫治器进行矫治。结果22例患者解除后牙锁[牙合],治疗时间为2．1—3．8个月,平均3．1个月,治疗后上下磨牙建立良好的咬合关系。结论改良[牙合]垫矫治器矫正后牙锁[牙合]支抗稳定,牵引方向灵活,效果良好。     

微种植体矫治第二磨牙正锁牙合疗效的三维评价

目的 探讨微种植体矫治第二恒磨牙正锁牙合的疗效。 方法 选择第二磨牙正锁牙合病例9例,男7例,女2例,年龄18～32岁,平均22.5岁。在锁牙合牙的颊侧及上颌腭侧植入微种植体,链状皮圈牵引竖直、压低倾斜的第二磨牙。对正锁牙合磨牙治疗前后的CBCT进行测量、分析。 结果 微种植体牵引矫治正锁牙合平均疗程4个月。三维测量结果：U7j-矢状面减小、L7j-矢状面增加,P<0.05,有显著差异,表明患侧正锁牙合上下磨牙的牙弓宽度恢复;U7-SN增加,L7-SN减小,P<0.05,有明显差异,说明正锁牙合磨牙的牙轴恢复正常。 结论 微种植体用于纠正磨牙正锁牙合,针对锁牙合发生的机制进行矫治,矫治锁牙合牙颊舌向异常的同时纠正了高度异常,疗程短、疗效好。     

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第二磨牙的错在临床上十分常见,给临床矫治带来不少麻烦。从本质上讲,第二磨牙错是拥挤的表现,主要在磨牙区。临床上表现为单个牙或几个牙出现正锁或反锁,牙齿的颊移位或舌移位,垂直阻生或近中阻生致无法正常萌出等。本文讨论了第二磨牙错的发生原因及危害,介绍了临床上第二磨牙错矫治的原则及主要方法。     

正畸矫治颞下颌关节紊乱病后牙锁

目的探讨采用正畸矫正后牙锁[牙合]的方法治疗颞下颌关节紊乱病的疗效。方法9例后牙段锁患者,健侧采用解剖式[牙合]垫,配合患侧的交互牵引,矫正锁[牙合],达到治疗患者颞下颌关节紊乱病的目的。结果9例患者经过平均30个月的治疗,锁[牙合]均得以矫治。前牙覆[牙合]覆盖正常,磨牙关系良好。9例患者颞下颌关节区疼痛消失或缓解,开口度明显改善,7例患者关节弹响消失,1例弹响减弱,1例未见好转。结论通过对锁[牙合]的矫治,改善咬合关系,可治疗因锁[牙合]引起的颞下颌关节疼痛。     

腭侧新装置纠正上颌第二磨牙颊移位

目的　探讨腭侧新装置纠正上颌第二磨牙颊移位的临床疗效。方法　对 6例因上颌第二磨牙颊移位所造成的第二磨牙单侧或双侧正锁牙合患者 ,采用腭侧新装置进行矫治。结果　 6例患者均在 2 5～ 3 3个月内完成第二磨牙正锁牙合的矫治 ,上下磨牙建立良好的咬合关系。结论　该腭侧新装置制作简单 ,方法灵活 ,效果显著。     

Stress distribution produced by the correction of the mandibular second molar in lingual crossbite

The purpose of this study was to evaluate the stress distribution produced in the dentoalveolar system by a mandibular posterior crossbite appliance used for the correction of mandibular second molars in lingual version. A photoelastic model was fabricated using a photoelastic material (PL-3) to simulate alvelolar bone and ivory-colored resin teeth. The model was observed anteriorly and posteriorly with a circular polariscope and photographically recorded before and after activation of mandibular posterior crossbite appliances. An uncontrolled tipping and an extrusive force were generated when the traction force was applied on the buccal surface of the mandibular second molar. A controlled tipping and an intrusive force were generated when the traction force was applied on the lingual surface of the mandibular second molar. We concluded that to escape the extrusion and uncontrolled tipping that creates occlusal interferences associated with the correction of mandibular second molars in lingual version, the lingual traction force is more useful than the buccal traction force.     

运用锥形束CT诊断上下颌横向发育不调的研究进展

上下颌横向发育不调是导致错畸形的重要因素,临床上常表现为后牙反、牙列拥挤、腭盖高拱、Wilson曲线过深、上颌磨牙颊倾、下颌磨牙舌倾等。本文就近年来上下颌横向发育不调在锥形束CT上的诊断方法、诊断标准的研究现状作一综述。     

Stress distribution produced by correction of the maxillary second molar in buccal crossbite

The purpose of this study was to evaluate the stress distribution produced in the dentoalveolar system by a maxillary posterior crossbite appliance used for the correction of maxillary second molars in buccal crossbite. A photoelastic model was fabricated using a photoelastic material (PL-3) to simulate alveolar bone and ivory-colored resin teeth. The model was anteriorly and posteriorly observed with a circular polariscope and photographically recorded before and after activation of the maxillary posterior crossbite appliance. An uncontrolled palatal tipping and a rotating force were generated when the traction force was applied on the palatal surface of the maxillary second molar. A controlled tipping and an intrusive force were generated when the traction force was applied on the buccal surface of the maxillary second molar.     

Extreme dentoalveolar compensation in the treatment of Class III malocclusion

The orthodontic treatment of an adult patient with a skeletal Class III malocclusion, increased anterior facial height, negative overjet, and bilateral posterior crossbite is presented. Treatment options included mandibular first premolar or third molar extractions with dentoalveolar compensation or combined surgical-orthodontic treatment. Mandibular third molar extraction with dentoalveolar compensation was the treatment choice. Biofunctional brackets, with accentuated lingual crown torque on the maxillary incisors and accentuated buccal crown torque on the mandibular incisors, were used. The anterior crossbite was corrected with intermaxillary elastics from the palatal aspect of the maxillary incisors to the labial aspect of the mandibular incisors. Class III elastics moved the maxillary teeth mesially and assisted in retruding the mandibular teeth. Patient compliance with the elastics was excellent, and satisfactory dentofacial esthetics were achieved. This treatment protocol has rigorous indications, and it is not a routine plan. The mechanotherapy and the pros and cons of this approach are discussed.     

Newtom QR-DVT 9000 imaging used to confirm a clinical diagnosis of iatrogenic mandibular nerve paresthesia

This article describes conventional orthodontic treatment of an adult patient leading to lower lip paresthesia. The paresthesia subsided when the cross elastics to correct the patient's single molar crossbite were removed. It was determined with Digital Volumetric Tomography that the inferior alveolar nerve was located lingual to the lower second molar root and was impinged upon with the tipping force of the cross elastic. Treatment to resolve the crossbite without further paresthesia is discussed.     

舌侧矫治上颌第一磨牙垂直向移动的有限元研究

目的:用有限元方法研究舌侧矫治过程中上颁第一磨牙垂直向移动的规律,并与颊侧矫治器对比.方法:用三维激光扫描方法建立上颌第一磨牙、牙周膜、牙槽骨及矫治器的有限元模型,分别对其进行不同方式的加载和位移计算.结果:在垂直力作用下,舌侧加载时牙齿的颊舌向倾斜度小于颊侧加载时牙齿的颊舌向倾斜度,倾斜方向相反.在牙齿趋向于整体移动时,舌侧加载的位移稍大于颊侧加载时位移,其中舌侧Mt/F=3.6:1,颊侧Mt/F=4.95:1.结论:舌侧矫治过程中上颌第一磨牙更易于升高或压低.     

偏颌畸形患者的牙弓特征

目的　分析偏颌畸形患者的牙弓特征,为临床矫治提供参考。方法　采用三维坐标测量仪在20例偏颌 畸形患者(试验组)和20例正常人(对照组)的牙模型上测量上下颌尖牙、前磨牙和磨牙牙尖的三维坐标值,分 析牙弓矢向和横向的对称性、上下牙弓的协调性和牙齿倾斜度,采用SAS 6·03进行统计学检验。结果　试验组上 颌尖牙和第一前磨牙距腭中缝的距离偏向侧大于偏离侧(P<0·05),下颌从尖牙到第二磨牙偏向侧距中线的距离 小于偏离侧(P<0·05);上颌尖牙和第一前磨牙的牙弓宽度比率较对照组小(P<0·05),而上颌第二前磨牙和第一 磨牙的牙弓宽度比率与正常无统计学差异(P>0·05);上颌后牙偏向侧颊向倾斜度大于偏离侧,下颌后牙偏向侧 舌向倾斜度大于偏离侧(P<0·05);上颌偏向侧和偏离侧牙齿的矢向位置无统计学差异(P>0·05)。结论　偏颌畸 形患者上牙弓前部窄于下牙弓,上颌牙齿矢向位置无差别,而上下颌两侧后牙颊舌向倾斜度存在明显差异。     

上腭快速扩大联合前牵引矫治乳牙期骨性Ⅲ类错

目的评估上腭快速扩大联合前牵引矫治乳牙期骨性Ⅲ类错[牙合]牙颌结构的变化。方法选择未做过正畸治疗的乳牙期骨性Ⅲ类错患儿16例,男9例,女7例,平均年龄6.2岁,前牙反[牙合]或合并后牙反[牙合],上颌后缩,乳磨牙终末平面呈近中阶梯,不存在功能性下颌前移。应用上腭快速扩大联合前牵引矫治,正畸治疗前后进行头影测量分析,采用配对t检验进行统计学分析。结果经上腭快速扩大联合前牵引矫治6个月后,凹面型改善,上颌长度增加,上颌前移,SNA平均增大2.0°,ANB增大2.9°,W its值增大了3.6 mm,差异有统计学意义。上前牙轻度唇倾,下切牙轻度舌倾。腭平面、下颌平面、[牙合]平面改变差异无统计学意义。结论上腭快速扩大联合前牵引矫治乳牙期骨性Ⅲ类错[牙合]疗程短,反[牙合]及凹面型明显改善。     

第二磨牙锁He与牙弓后部拥挤

目的选择第二磨牙锁的成年患者,通过对其Ｘ线头颅侧位片的测量,与正常进行比较,对第二磨牙锁的病因做初步分析,为今后的临床治疗工作提供参考。方法分别测量正常和后牙锁患者的头颅侧位片,测量上颌第一磨牙远中最突点在颅底平面的投影和翼上颌裂点在前颅底平面的投影两者之间的距离,测量数据进行ｔ检验。结果第二磨牙锁患者上颌第一磨牙到上颌骨后壁的距离明显小于正常。结论第二磨牙锁与后部牙弓间隙不足密切相关,分析牙列拥挤度时,还应考虑后牙段间隙问题,尤其是推磨牙向后的病例,如果预测后牙段有拥挤的可能,应尽早拔除第三磨牙。     

Buccolingual inclination of first molars in untreated adults: A CBCT study

Objective:To evaluate the buccolingual inclinations of maxillary and mandibular first molars in untreated adults.Materials and Methods:Fifty-nine subjects (14 males and 45 females; mean age, 41.2 years) with no missing teeth, no crossbite, and minimal crowding were included. For each subject, a CBCT was taken. The long axis of each first molar was determined, and the inclination of each molar was measured using the long axis and the floor.Results:One hundred seventeen out of 118 mandibular first molars measured had a lingual inclination, with a mean of 12.59° ± 5.47°. For the maxillary first molars, 107 out of 118 had a buccal inclination, with a mean of 4.85° ± 4.22°.Conclusions:There is a curvature to the inclinations of first molars in untreated adults, where the maxillary molars have a slight buccal inclination and mandibular molars have a slight lingual inclination.