前磨牙正锁对下颌骨矢状向位置的影响

目的 研究前磨牙正锁对青少年下颌骨矢状向位置的影响,为正确诊断和掌握正畸治疗时机及制定合理临床治疗方案提供参考。方法 选择2004—2017年间就诊于中国医科大学附属口腔医院正畸科的前磨牙正锁青少年患者100例为研究对象,其中男54例、女46例,单侧前磨牙正锁70例、双侧前磨牙正锁30例。选用其正畸治疗前的X线头颅侧位片,利用Winceph 9.0软件测量16项上、下颌骨矢状向相关硬组织指标,采用SPSS 21.0软件包将所得测量数据与正常标准值进行比较。结果 研究组区分单侧前磨牙正锁与双侧前磨牙正锁,与正常值相比,Beta角、SNB、SND、ANB、AB平面角、APDI、颌凸角、面角、Wits值、S-Co、Co-Po的差异均有统计学意义（P<0.05）。相比于正常值,单侧前磨牙正锁组Go-Pog差异亦有统计学意义（P<0.05）。结论 青少年前磨牙正锁患者,矢状向上颌骨位置正常,下颌骨位置后退,有形成骨性Ⅱ类面型的趋势。前磨牙正锁影响下颌骨发育,导致下颌体、下颌骨长度偏小。提示正畸诊治过程中,应提高对青少年前磨牙正锁的关注,及早进行正畸治疗,预防对下颌骨发育及矢状骨面型造成的不利影响。     

Beta角评价前牙反患者颌骨矢状关系的准确性分析

目的探讨Beta角判断替牙期与恒牙期前牙反[牙合]患者颅面矢状关系的可靠程度。方法应用X线头颅定位侧位片,比较替牙期与恒牙期前牙反[牙合]患者的Beta角、ANB角、Wits值和APDI指数的差异,并进行相关性和变异程度分析。结果替牙期与恒牙期前牙反[牙合]患者Beta角间差异有统计学意义（P〈0．05）;Beta角与ANB角、Wits值和APDI指数显著相关（P〈0．05）,但变异较ANB角和Wits值小,与APDI指数接近。结论Beta角可准确评价前牙反[牙合]患者的颌骨矢状关系。     

七项上下颌骨矢状关系头测量评价指标间的相关研究

上下颌骨矢状关系协调与否,对整个颜面部的美观和口颌系统功能的完善影响极大。在诸多的评价方法中,以X线头影测量技术最为广大学者所应用。本文从这些指标中,选出临床上常用的七项指标进行相关分析,观察这七项指标在评价上下颌基骨矢状关系协调程度方面有无内在联系,目的是在临床上更好地运用这些指标所提供的信息,对上下颌骨矢状关系作出客观的评价,为治疗计划的制定提供更可靠的参考依据。     

头颅矢状水平向平面角与面部生长型的相关研究

目的 研究面部生长型与头颅矢状水平向平面解的关系。验证面部后前面高比的诊断意义。方法 摄取６５ 青年恒牙Ｈｅ头颅侧位Ｘ一片,计算机图形分析系统出包括ＰＰ、ＭＰ、ＯＰ、ＳＮ平面在内的七顶测量值及后前面高比值,并进行相应统计学分析。结果 ①四个水平向平面角（ＯＰ－ＦＨ,ＭＰ－ＦＨ,ＰＰ－ＦＨ,ＳＮ－ＦＨ）与后前面高比呈负相关,确定系数９０．７％。②上下颌面角与后前面高比值有极高相关性,确定系数为６８．     

四种上下颌骨矢状位置关系评估方法的比较

目的:比较ANB角、Wits值、AFBF值和APDI四种方法评估上下颌骨矢状位置关系的稳定性及相关性。方法:随机选择50例错牙合畸形病例正畸治疗前的X线头颅侧位定位片,同时测量其ANB角、Wits值、AFBF值和APDI,测量结果进行相关性及变异度分析。结果:APDI的变异系数最小,Wits值变异系数最大;四值之间均存在相关性,以ANB角与AFBF值相关性最强。结论:每种评估方法影响因素不同,宜采用综合分析。     

ANB角与Wits值评价颌骨矢状不调的研究

目的分析X线头影测量参数ANB角与Wits值在评价安氏Ⅱ类错颌骨矢状位置不调中的差异。方法为84例青少年安氏Ⅱ类与40例安氏Ⅰ类错患者正畸治疗前拍摄X线头颅侧位片,选择与ANB角和Wits值相关的十项头影测量项目,将安氏Ⅱ类错患者分为两组后与安氏Ⅰ类错组进行单因素方差分析。结果ANB角与Wits值在评价安氏Ⅱ类错颌骨矢状位置不调时具有显著性差异;差值较大组,平面较陡,矢状不调更显严重。结论患者颌骨矢状不调较严重且平面较陡者,ANB角与Wits值差异较大,ANB角更能反映其真实性。     

第三磨牙牙胚与矢状面型关系的初步研究

目的探讨第三磨牙牙胚与上下颌骨矢状关系间的联系.方法选近四年我科收治的正畸患者234例,年龄在14-18岁之间.通过测量ANB角,将样本分属于三类矢状骨面型,通过全景曲面断层片判定第三磨牙牙胚的缺失情况.对不同骨面型的第三磨牙牙胚缺失情况进行统计学(x2检验)分析.结果在全部患者中,第三磨牙牙胚缺失率以人数计为29.5%、以牙胚数计为14.9%.无论上颌还是下颌,第三磨牙牙胚缺失率与左右侧无关.骨型Ⅰ、Ⅱ类间的差别无统计学意义.结论错(牙合)患者中,约有30%者存在一个或数个第三磨牙的缺失;矢状骨面型与第三磨牙牙胚缺失可能存在某种关系,Ⅲ类骨面型上颌第三磨牙牙胚缺失要高于Ⅰ、Ⅱ类.     

颌骨前后向不调指数与骨性安氏Ⅲ类骨性错矢状关系的分析

目的:探讨颌骨前后向不调指数(APDI)与上、下颌骨矢状向的位置关系,以利于骨性安氏Ⅲ类错的诊断及治疗。方法:测试对象共100例,其中正常成人组20例,正常青少年组20例,骨性安氏Ⅲ类错成人组28例,早期骨性安氏Ⅲ类错治疗组24例,早期骨性安氏Ⅲ类错治疗失败组8例。头颅侧位定位片测量指标为,腭平面角、面角、AB平面角及APDI值。采用SAS6.12软件包对数据进行t检验。结果:正常人群的APDI均值在85°以下,骨性安氏Ⅲ类错APDI均值在90°以上,青少年的各项测量值相对成人小,需行正颌外科的患者,APDI均值超过100°。APDI值各组间均有显著性差异,P<0.01。结论:APDI均值超出正常标准值越多,上、下颌骨骨性矢状向畸形就越严重。APDI值是评价骨性安氏Ⅲ类上、下颌骨矢状向关系较为有效的指标。     

应用数字化X线头影测量法对无牙颌颌位关系的初步研究

目的 研究无牙颌面部结构特点，探讨临床应用吞咽法确定颌位关系的理论依据。方法 57～70岁的无牙颌患者43例，新全口义齿戴用舒适后，使用德国SIRONA数字化X线口腔医疗系统，拍头颅定位侧位片，戴义齿正中He位与不戴义齿吞咽位各1张。结果 无牙颌患者男性垂直向面部高度比女性大，前下面高／前上面高比值在男女性均约为6／5，S-N-Po角约为78～80度。在垂直向和前后向，戴义齿正中He位与不戴义齿吞咽位2组数据的差异无显著性。可认为戴义齿正中He位与不戴义齿吞咽位是同一个位置。结论 用SIRONA数字化X线口腔医疗系统进行头影测量，方法便捷，有自身特点。证实吞咽咬合法是确定无牙颌颌位关系的准确可靠的方法之一。     

Comparison between cephalometric classification methods for sagittal jaw relationships

The present study evaluated how 2 widely used cephalometric sagittal analyses, ANB angle and WITS appraisal, classify skeletal classes I, II, and III in a random selection of 497 Finnish boys aged 4–20 years. This distribution was also compared with the visual inspection of cephalometric structures judged by 2 university instructors in orthodontics. The results, showed remarkable differences and even sparked controversy concerning classification of the sagittal jaw relationships. The ANB angle and the WITS appraisal emphasized the role of class II based on a failure to distinguish the proportion of class I. The low-angle influence skewed the distribution of the ANB pattern in the class III direction, and the WITS pattern, conversely, towards class II. High-or low-angle influence had only minor effects on the visual inspection of cephalometric structures. This cross-sectional study showed an age-related decreasing mean value for the ANB angle and increasing mean value for the WITS appraisal, thus explaining the remarkable difference in the distribution of sagittal classes. However, the findings of age-related changes makes the use of the fixed norms questionable. For extreme or controversial cephalometric interpretations, visual inspection provides an essential aid in diagnosis and skeletal classification.     

A fully digital workflow to register maxillomandibular relation using a jaw motion tracer for fixed prosthetic rehabilitation: A technical report

Objective

This technique aimed to describe a fully digital workflow to register maxillomandibular relation for fixed prosthetic rehabilitation.

Clinical Considerations

Mandibular kinematics could be reproduced in a four-dimensional (4D) virtual patient based on the intraoral scan, facial scan, cone beam computed tomography, and jaw motion trajectory, which helped record centric relation and determine a proper occlusal vertical dimension in a virtual environment. The therapeutic position could be exported directly to the dental computer-aided design software for digital waxing design with a facial scan. The 4D virtual patient was also used to verify the functional and esthetic outcomes of provisional restorations.

Conclusions

This novel approach digitized the process of determination, delivery, and double-check of maxillomandibular relation, thus contributing to the establishment of a completely digital workflow for fixed prosthetic rehabilitation.

Clinical Significance

Registration of maxillomandibular relation, including centric relation and occlusal vertical dimension is critical to the success of prosthetic rehabilitation. Traditional procedures are complex and time-consuming, and heavily rely on the clinical experience of dentists. A fully digital approach to creating a 4D virtual patient and registering the maxillomandibular relation is established, which guides to determine a proper occlusal vertical dimension in centric relation. Digital delivery and double-check can simplify the conventional procedure and ensure that the determined maxillomandibular relation is reliable.     

无牙颌患者(牙合)关系记录仪的研制与临床应用

目的探讨一种记录全口无牙颌患者(牙合)关系的简易装置,达到省时、省材的目的.方法通过螺柱在螺管内旋转,调整螺柱外露长度,以适应不同患者上下颌牙槽嵴间相应垂直高度.运用水平可调板,依据歌德氏弓(Gothic arch)描绘原理,调整引导球固位圈到达自然位置,记录患者(牙合)间水平关系.临床应用35例患者,方法可行.结果临床运用该记录仪记录(牙合)关系所修复的全口义齿,患者面形自然、美观,咀嚼有力.结论该记录仪取材方便,设计科学,调节灵活,记录快速、精确.     

Magnetic resonance imaging-verified temporomandibular joint disk displacement in relation to sagittal and vertical jaw deformities

This retrospective study was designed to analyze the relationships between temporomandibular joint (TMJ) disk displacement and skeletal deformities in orthodontic patients. Subjects consisted of 460 adult patients. Before treatment, lateral cephalograms and TMJ magnetic resonance imaging (MRI) were recorded. Subjects were divided into six groups based on TMJ MRI according to increasing severity of TMJ disk displacement, in the following order: bilateral normal TMJs, unilateral disk displacement with reduction (DDR) and contralateral normal, bilateral DDR, unilateral disk displacement without reduction (DDNR) and contralateral normal, unilateral DDR and contralateral DDNR, and bilateral DDNR. Subjects were subdivided sagittally into skeletal Class I, II, and III deformities based on the ANB (point A, nasion, point B) angle and subdivided vertically into hypodivergent, normodivergent, and hyperdivergent deformities based on the facial height ratio. Linear trends between severity of TMJ disk displacement and sagittal or vertical deformities were analyzed by Cochran–Mantel–Haenszel test. The severity of TMJ disk displacement increased as the sagittal skeletal classification changed from skeletal Class III to skeletal Class II and the vertical skeletal classification changed from hypodivergent to hyperdivergent. There were no significant differences in the linear trend of TMJ disk displacement severity between the sexes according to the skeletal deformities. This study suggests that subjects with skeletal Class II and/or hyperdivergent deformities have a high possibility of severe TMJ disk displacement, regardless of sex.     

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目的    探讨吞咽法所获得的全口义齿水平颌位关系的临床效果。方法    选择2008年5月至2009年9月在承德市口腔医院进行全口义齿修复的无牙颌患者80例,随机分为2组,每组40例。分别用吞咽法和卷舌法确定水平颌位关系,并完成全口义齿的制作。观察两组全口义齿在口内的咬合关系与模型的一致性。结果    用吞咽法所确定水平颌位关系的全口义齿在口内的咬合关系与模型一致性Ⅰ、Ⅱ、Ⅲ类者分别为39、1、0例,而对照组分别为29、7、4例,两组比较差异具有统计学意义（χ2 =7.382,P = 0.023 ）。结论    利用吞咽法所获得的全口义齿水平颌位关系准确性较高,可以做为确定全口义齿水平颌位关系的有效方法。     

矢状骨面型与上气道形态和舌骨位置关系的研究

目的 研究不同矢状骨面型上气道形态和舌骨位置的差异。方法 对182名恒牙早期青少年按ANB角大小分为I类、Ⅱ类和Ⅲ类三种不同矢状骨面型组，三组的年龄、性别相匹配，垂直骨面型以及腺样体情况三组间分布一致。对上气道矢状径和舌骨位置进行X线头影测量分析，并比较三组间的差异。结果三组间鼻咽段和腭咽段矢状径无显著差异；从悬雍垂尖向下，随ANB角的增大咽腔矢状径有减小趋势，Ⅱ类患者的舌咽矢状径显著小于Ⅲ类。舌骨的垂直向位置三组间无显著差异；水平方向上，Ⅲ类、Ⅰ类、Ⅱ类舌骨位置逐渐后移，Ⅱ类和Ⅰ类比Ⅲ类显著后位。结论 以ANB角为代表与面部矢状发育与上气道鼻咽、腭咽和舌骨垂直向位置无明显关系，而对上气道下段的舌咽和舌骨的矢状位置有显著影响，这可能与不同矢状骨面型下颌大小位置发育差异有关。     

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咬合重建修复是对现有牙列咬合状态进行改造和重新建立,通常涉及全牙弓面的再造及颌位的改变,因此属于修复领域的疑难问题。修复前需要充分评估患者的现有口腔条件,制订周密的修复计划并与患者充分沟通;修复过程一般包括颌位调整、临时冠桥过渡、永久修复体完成及修复后维护4个阶段,每个阶段因患者的个体差异而致内容各不相同。修复中应注意咬合垂直距离的升高、临时修复体的选择、咬合设计的个性化以及修复各阶段新建颌位的稳定等问题。成功的咬合重建修复充分体现口腔修复的整体观、精品意识和团队合作理念。