唇挡扩大下颌牙弓的作用

唇挡 (Ｌｉｐｂｕｍｐｅｒ)一直被用作增加支抗、破除咬下唇不良习惯的矫治器 ,但是 ,随着人们对牙颌畸形矫治后软组织侧貌的重新评价 ,牙列拥挤的不拔牙矫治近年来引起了人们的重视。为达到不拔牙矫治的目的 ,对能在牙弓内获得间隙的方法和矫治器进行了长期的理论与实践的探索。唇挡这一结构简单的功能矫正器由于能增加牙弓周径 ,减少牙齿大小与牙弓大小间的不协调 ,减少前牙拥挤 ,达到不拔牙矫治的目的 ,并且能缩短疗程 ,提高矫治结果的稳定性 ,因而引起了人们越来越多的关注。本文从唇挡的构成、功用及矫治机理、治疗后的稳定性等几个方…     

唇挡治疗下牙弓拥挤

随着人们对牙颌畸形矫治后的侧貌越来越重视,牙列拥挤的不拔牙矫治近年来又重新引起了人们的重视。为达到不拔牙矫治的目的,对能在牙弓内额外获得间隙的方法和矫治器进行了长期的探索。唇挡(lip bumper),曾用作增加支抗,防治不良唇习惯等的矫治器正在引起正     

唇挡对儿童面下部硬软组织侧貌影响的研究

目的　研究唇挡对替牙期及恒牙初期儿童面下部硬软组织侧貌形态的影响。方法　选择替牙期及恒牙初期下颌发育不良伴下牙列轻度或中度拥挤患儿 30例 (男 14例 ,女 16例 ) ,采用下颌唇挡治疗 6～ 10个月 ,进行治疗前后面部硬软组织X线头影测量分析。结果　唇挡治疗后下切牙唇倾 3.2 5°,呈以根尖为转动中心的倾斜移动 ,下颌第一磨牙远中倾斜 6 .13° ,呈以根分叉为转动中心的远中倾斜移动。下颌平面角增加 1.15° ,SNB角与面角无明显改变。颏唇沟厚度平均增加 1.2 3mm ,致使颏唇沟变浅 ,下唇角增大 (6 .0 5°) ,下唇及颏唇沟形态改善。结论　在儿童颌面部生长发育高峰期 ,唇挡可有效促进下颌牙弓生长发育 ,改善面下部硬软组织侧貌形态。     

硬腭裸露骨面积对上颌骨及牙弓生长发育的影响

已有研究表明硬腭裸露骨面的位置与上颌骨生长发育有密切的关系，但裸露面积与上颌骨生长发育的关系尚未见报道。现报道如下。     

儿童牙和牙弓生长发育的研究

儿童青少年期,牙齿和颜面都在不断地发育,是颌面部发育的重要时期.在这个时期,众多的因素均可对儿童牙和牙弓的生长发育造成影响,从而导致错(殆)畸形.在儿童牙科的临床诊治中,经常需要对影响儿童青少年牙和牙弓生长发育的各种因素及时加以干预,从而促成恒牙列正常咬殆关系的建立即咬合诱导(occlusive guidance)治疗.在临床咬合诱导的治疗中,需要了解儿童牙和牙弓自身生长发育的特点与规律.因此,在这一领域的研究具有重要的临床参考和指导意义.     

唇挡对替牙期下颌牙弓的作用

唇挡是正畸中常用的矫治装置,近年来越来越多的学者提出使用唇挡促进前牙唇展,推动磨牙直立或远移,扩展牙弓长度与宽度,可达到增加牙弓弧形长度的目的,为解除轻度至中度拥挤开辟间隙。本文着重讨论了唇档的组成、作用机理、影响因素、适应证和禁忌证、以及疗效与复发等问题。     

唇挡对替牙期下颌牙弓的作用

唇挡是正畸中常用的矫治装置,近年来越来越多的学者提出用唇挡牙唇展,推动磨牙直立或远移,扩展牙弓长度与宽度,可达到增加牙弓弧形长度的目的,为解除轻度至中度拥挤开辟间隙。本文着重讨论了唇挡的组成、作用机理、影响因素、适应证和禁忌证、以及疗效与复发等问题。     

牙弓形态及其影响因素

牙弓型是对牙弓形态的完整描述,包括牙弓大小和形状两方面。—般认为牙弓型受基骨结构、牙萌出顺序、口周肌肉系统及口内功能力的影响[1] 。在颅面部生长发育过程中,软硬组织结构的改变会持续影响牙弓型;同时不同的种族、地域、历史年代,牙弓型有很大差异。现就近年来有关牙弓型及其影响因素的研究作一综述。一、牙弓型方程早期阶段,牙弓曲线被描述为椭圆形、抛物线形、U形、两端固定的链形,并用多种曲线匹配数学模型来重建,如抛物线方程、十椭圆方程、链形曲线方程,圆锥截面曲线方程[2 ] ,但都未能对成人牙弓型作出完整准确的表述。Stanle…     

儿童骨性下颌偏斜患者的牙弓形态及颌骨对称性分析

目的：研究骨性下颌偏斜儿童的牙弓形态,并对颌骨对称性进行分析。方法：选择13例骨性下颌偏斜患者作为研究对象,在模型上以腭中缝为参考标准,测量两侧的牙弓宽度,分析其对称性;在X线片上测量两侧下颌升支高度、下颌体长度及下颌骨综合长度,并进行统计分析。结果：骨性下颌偏斜患者的牙弓形态存在明显的不对称,偏斜侧的牙弓宽度明显大于对侧（P〈0.05）;偏斜侧下颌升支高度和下颌体综合长度明显小于对侧（P〈0.05）,而两侧下颌体长度无明显差异（P〉0.05）。结论：骨性下颌偏斜患者的下颌骨存在明显不对称,牙齿也出现了不同程度的代偿,在临床正畸治疗中,应进行综合分析。     

上颌唇挡早期矫治引起的牙弓三维变化分析

目的 研究唇挡早期矫治上颌拥挤病例引起的牙弓三维改变.方法 选取正畸患者12例,平均年龄9.8岁.为缓解上颌的拥挤,戴用唇挡8个月.戴用唇挡前后取记存模型,进行三维数字化,以第三腭皱为参考将治疗前后的模型重叠,分析牙齿三维位置改变及倾斜度的变化.配对t检验比较治疗前后牙弓宽度和上牙弓弧形长度的差异.结果 戴用唇挡后,牙齿三维方向的改变以后部牙弓的变化最为显著,矢状向上颌第一前磨牙、第一磨牙分别远中移动2.08、2.03mm,上牙弓弧形长度增加5.12mm;垂直向上颌第一前磨牙升高1.17mm,第一磨牙升高0.72mm;横向上颌第一前磨牙间宽度增加2.62mm,第一磨牙间宽度增加3.08mm;以上各测量均有统计学意义(P＜0.05).同时上颌切牙存在少量前移、扩宽和唇倾.上颌切牙唇倾度增加3.90°,第一磨牙远中倾斜度增加8.23,有显著性差异(P＜0.05).结论 上颌唇挡可以缓解轻中度的牙弓拥挤.唇挡引起的牙弓长度增加主要是由于磨牙的远中移动、后倾以及牙弓的扩宽.     

Dental arch relationships in Yorkshire children with unilateral cleft lip and palate.

OBJECTIVE: To assess the dental arch relationships of children with a complete unilateral cleft lip and palate (UCLP), born consecutively between 1983 and 1987, who had undergone primary cleft repair in the West Yorkshire region of the United Kingdom. The treatment outcome of this UCLP sample was then compared with the results of a previously published intercenter European study. DESIGN: A retrospective study with standardized record collection and blind assessment. SETTING: Regional dental hospital providing secondary and tertiary health care to the local population. PATIENTS: 35 UCLP patients whose primary repair had been performed within West Yorkshire. INTERVENTIONS: Dental casts obtained for each subject within 12 months of their 10th birthday. MAIN OUTCOME MEASURES: The West Yorkshire models were randomly mixed with an anonymous sample of 115 UCLP cases from other cleft centers in the U.K. The dental arch relationships of the 10-year-old models were assessed by applying the Goslon Yardstick. RESULTS: One-third of the West Yorkshire cleft sample were rated as belonging to Goslon group 2 (good result), another third to group 3 (fair result), and the remaining third to groups 4 and 5 (poor/very poor result). Numerically, the results were of a slightly higher standard than that previously published for other U.K. and European cleft centers but were inferior to the treatment outcome of two European centers. No statistically significant differences were found between the outcome results of the West Yorkshire group and the other cleft centers. CONCLUSIONS: These results provide useful baseline data against which progress in achieving improved treatment outcome for West Yorkshire UCLP children can be determined by future research.     

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近年来,许多正畸医生对安氏Ⅱ1错畸形伴下颌前牙轻度唇向倾斜的患者多倾向于不拔牙治疗而运用唇挡这一功能性矫治器进行治疗,这一技术受到人们越来越多的关注。本文就唇挡的作用原理、制作要求、矫治效果及效果的稳定性等几方面加以综述。     

Bronchogenic carcinoma metastatic to the lip and the mandible.

Two cases of metastatic bronchogenic carcinoma are reported. Possible pathways of dissemination are discussed, along with the symptoms, diagnosis, and management of these lesions.     

Predictors of poor dental arch relationship in young children with unilateral cleft lip and palate

The aim of this cross-sectional outcome study using retrospective data capture of treatment histories was to examine the characteristics of young children with unilateral cleft lip and palate who had poor dental arch relationship (i.e., Goslon 5). The study sample comprised 120 children born with nonsyndromic complete unilateral cleft lip and palate between 1995 and 2003, and were aged between 5.0 and 7.0 years (mean age, 5.1 years) at the time of data collection. The dental arch relationship was assessed using the Goslon yardstick from intraoral dental photographs. An independent investigator recorded treatment histories from the clinical notes. The inter- and intraexaminer agreements evaluated by weighted kappa statistics were high. There was no association between dental arch relationship and the type of presurgical orthopedics or pharyngeal flap. Dental arch relationship was associated with the initial cleft size (odds ratio, OR = 1.3; 95% confidence interval, CI = 1.1-1.5, p < 0.01), surgeon grade for palate repair (OR = 5.0, 95% CI = 1.2-19.9, p < 0.05), and primary gingivoperiosteoplasty (OR = 2.8, 95% CI = 1.0-8.1, p = 0.05). These data suggest that intraoral dental photographs provide a reliable method for rating dental arch relationship. Wide initial cleft, high-volume surgeon, and primary gingivoperiosteoplasty are predictors of poor dental arch relationship outcome in young children with unilateral cleft lip and palate. These findings may improve treatment outcome by modifying the treatment protocol for patients with unilateral cleft lip and palate.     

Growth in the width and length of the dental arch in children with unilateral cleft lip and cleft palate]

A study of casts of the dentitions of children with cheilognathopalatoschisis made over an extended period emphasizes that the development and the growth of the maxillary dental arch in width and length are considerably reduced as compared to children without clefts. Consequently, therapeutical measures must be taken to maintain the length and width of the maxillary dental arch.     

Biomechanics of the mandible and growth extension

Background and objective

One way of determining the direction of growth of the mandible is to consider the temporomandibular joint and movement of the mandible as a four-joint gear system, regarding growth then as an extension of the gear system. Our aim was to examine any correlations between the type of biomechanical growth extension and change in the maxilomandibular relation after Class?II therapy.

Subjects and methods

A total of 130?lateral cephalograms??before and after orthodontic treatment??were available from 65?adolescent class?II patients with open bite or deep bite. The two lateral cephalograms from each patient were superimposed on the occlusal plane. Cephalometric values and the vertical base point deviation were determined from biomechanical analyses, together with three distances and three angles.

Results

No correlation between the cephalometric data and distances or angles were observed. Although there were no significant differences in the distances, we did note significant differences in all three angles (p?Conclusion If gear system extension during growth is considered, this can be interpreted as meaning that the occlusal plane of those patients with an initially open bite dropped during treatment, but that it rose in patients with an initially deep bite.