全口义齿镶复中的技术要点(五)

<正> 五、人造牙的排列排牙是全口义齿制作中的一个重要环节,是在固位和咬合理论的指导下进行的,每一个步骤都要有明确的目的和符合规定的要求,才能确保义齿达到良好的镶复效果。 (一)排前牙应注意的问题: 1.前牙应避免深覆(牙合)或超(牙合)过大:全口义齿前牙的排列以美观为主,同时也要注意与后牙(牙合)曲线的协调,)上下前牙要排成浅覆(牙合)或中度覆(牙合),避免深覆(牙合)。如果前牙排成深覆(牙合),将不利于前伸(牙合)和侧(牙合)的平衡。因为覆(牙合)过深,则下颌作前伸运动时,下前牙的切缘向下运行的距离就长,往往超过后牙的牙尖高度,难以取得前伸(牙合)的平衡;前牙覆(牙合)深必然切道斜度大,     

全口义齿下颌排牙法

本文介绍了一种全口义齿下颌排牙法:前牙排列完成后,先排下后牙,使下后牙形成一定的司匹氏曲线和下横(牙合)曲线,然后再根据已排好的下后牙排列上后牙,形成与之相吻合的补偿曲线和上横(牙合)曲线。     

上颌前牙排列位置对全口义齿基托下支持组织应力分布的影响

目的：探讨上前牙排列的位置对全口义齿基托下支持组织应力分布的影响。方法：构建三种前牙排列位置的上颌全口义齿及支持组织的有限元模型,分别行4种咬合形式加载,分析全口义齿基托下支持组织的应力分布状况。结果：在前牙、双侧后牙、全牙列加载时,基托下支持组织的最大压应力区,分别位于唇系带切迹区、后牙槽嵴顶区、后牙槽嵴顶区及唇系带切迹区。随前牙排列位置的前移,基托下各支持组织区应力值呈增大或减小变化。结论：上前牙排列位置对全口义齿基托下支持组织应力状况产生影响,全牙列加载及前牙加载。在牙槽嵴唇侧唇系带切迹区承受较大的压应力。     

全口义齿后牙排列倾斜角度对义齿稳定性的影响

目的:研究全口义齿排牙后牙不同倾斜角度对义齿稳定性的影响。方法:随机抽取临床模型,参照丸森贤二的分类法分别采用Monson型排牙法、anti-Monson型排牙法及flat型排牙法[5]进行后牙区排牙,以1cm厚的橡胶垫在患者口内做咀嚼测试并进行分析。结果:上颌义齿后牙的排牙角度始终是Monson型排牙法最稳定,flat型排牙法和anti-Monson型排牙法不稳定;下颌义齿后牙的排牙角度应根据牙槽嵴的形态选择不同的排牙法;结论:全口义齿后牙区排牙时,倾斜角度不同对义齿固位与稳定有重要影响。     

全口义齿的功能协调排牙法

在全口义齿的制做过程中,假牙的排列是一个非常重要的环节．此步骤直接影响了全口义齿的固位,患者的美容、咀嚼等功能的恢复效果．目前在全口义齿的假牙的排法有多种多样．笔者在长期临床实践,总结出一种排牙法“功能协调排牙法”取得良好效果．临床资料对上下牙列缺失...     

不同排牙方法对全口义齿咀嚼效能的影响

目的:探讨不同排牙法的全口义齿咀嚼效能的异同。方法:采用上颌排牙法、下颌排牙法和综合排牙法为10名无牙颌患者分别制作3副全口义齿。戴用3个月后,通过吸光度法测定咀嚼效率,比较不同排牙法的全口义齿咀嚼效能的异同,并与有牙颌进行对比。结果:在单侧咀嚼和双侧咀嚼2种咀嚼方式下,全口义齿患者的咀嚼次数和咀嚼效能均少于有牙颌组,本实验3组全口义齿在3个月后均发挥了良好的咀嚼效能。下颌排牙法和综合排牙法全口义齿的咀嚼次数和咀嚼效能无统计学差异,但均好于上颌排牙法全口义齿。结论:下颌排牙法和综合排牙法的全口义齿排列的人工牙能够减少在咀嚼过程中不利于全口义齿稳定因素的影响,提高咀嚼效能。     

机器人辅助全口义齿排牙系统的初步研究

目的 研制机器人辅助制作全口义齿人工牙列的计算机系统。方法 利用CRS-450 6自由度机器人使被抓取的物体实现任意位置和姿态,研制可调式排牙器。用三维激光扫描测量系统获取无牙颌骨形态的几何参数。根据高级口腔修复专家排牙经验奸商的数学模型,用VC^ 和RAPL机器人语言编制了专家排牙、三维牙列模拟显示和机器人排牙控制程序。当排牙方案确定后,数据传给机器人,由机器人完成排牙器的定位工作,最终完成全口义齿人工牙列的制作。结果 建立了完整的机器人辅助全口义齿人工牙列制作系统。已用该系统为一例患者试作人工牙列。目前该牙列在咬合方面存在一些误差,尚需调整和完善。结论 首次实现了由机器人辅助制作人工牙列,具有科技进步意义。虽牙列在咬合方面还不十分理想,但实验结果已证明该系统的设计思想和技术路线是可行的。     

颌平面板在全口义齿修复中的应用

全口义齿的稳固性及咀嚼功能的恢复是修复中最重要的因素。运用颌平面板能准确地取得正中关系位置,按排牙原则正确排牙,达到咬合平衡。 材料和方法 1.临床资料 选择门诊48例无牙患者。男性20人,女性28人,年龄56～82岁,平均69岁。     

利用原始印模制作暂时冠桥的体会

在固定义齿修复中，基牙预备完成后需制作暂时冠桥，以暂时恢复患者缺牙后的美观及咀嚼功能，且具有保护基牙及维持牙龈正常形态的作用。作者近3年来利用原始印模制作暂时冠桥的方法，制作暂时冠桥102例，其中前牙固定桥42例，后牙固定桥32例，后牙单冠28例。方法介绍如下：1.适应症选择：基牙牙周健康，无松动，牙冠完整，咬合关系及邻接关系良好。后牙单（牙）冠如有缺损则直接以蜡恢复缺损及咬合关系。2.取印模：牙体预备前，前牙固定桥可用薄型树脂牙片磨改适合后，以蜡固定于缺牙间隙内；后牙则用人工树脂牙磨改。然后，用盛有藻酸盐印…     

牙尖工作斜面斜度的实验研究

前伸平衡(牙合)是指全口义齿患者下颌作前伸咬切运动时,上下前牙切缘及后牙相对牙尖皆保持接触的现象。在(牙合)架上则指当上颌体沿髁导面和切针尖端沿切导面向后上方运动时,下前牙切缘与上前牙舌面,下后牙近中斜面与相对的上后牙远中斜面间始终保持接触的现象。关于前伸平衡(牙合)的同心圆学     

计算机辅助全口义齿人工牙排列的研究

目的　研究开发一套计算机辅助全口义齿设计 (computeraidedcompletedenturedesign ,CACDD)系统。方法　经过对无牙颌模型、人工牙及具有正中关系位的上下托的三维 (3D)测量、数据处理与建模等环节后 ,根据全口义齿人工牙排列的原则和要求进行排牙。运用仿射和投影变换技术调整牙关系。结果　①生成了具有正中关系位的上、下颌虚拟基托 ,其数学模型为双 3次B样条曲面。②实现了全口义齿人工牙的计算机辅助排列和全口义齿的 3D显示。结论　该系统为计算机辅助全口义齿设计和教学提供了可行的工具     

Lingualized occlusion in the South African context]

The search for the ideal artificial tooth arrangement that maximizes denture stability, comfort, aesthetics, and function has occupied the dental literature for many years and still continues to do so. Of the many occlusal schemes that have been presented to the dental profession, that of lingualized occlusion has emerged as one of the more popular. The popularity of lingualized occlusion stems from the simplicity and flexibility of the concept and from its wide application to clinical practice (Parr & Ivanhoe, 1996). The registration of a repeatable correct centric jaw relation is not always possible. We don't know whether the patient will use centric relation during normal function. It is therefore useful to provide the patient with some freedom of movement around centric. lingualized occlusion provides freedom in centric. For many dentists the arrangement of artificial denture teeth into balanced occlusion is difficult and time consuming. As a result this task is most often performed by the dental technician. In the South African countryside dental laboratories are often far away. If dentists perform the arrangement of the denture teeth, time and costs can be saved. The mounting of denture teeth in lingualized occlusion is simple and fast. This will motivate dentists to arrange denture teeth themselves, with obvious benefits for both the patient and the dentist. The School of Oral Health Sciences of the University of Stellenbosch teaches this concept to its undergraduate students in order to improve the prosthetic service to the large edentulous population of South Africa.     

Finite element analysis of the effect of the bucco-lingual position of artificial posterior teeth under occlusal force on the denture supporting bone of the edentulous patient

To improve the quality of the complete denture prosthesis, the bucco-lingual position of the artificial posterior teeth must be determined with consideration of the shape of the maxillary and mandibular residual ridge and the relationship between them. The arrangement of posterior artificial teeth should be considered not only for the denture stability but also for the avoidance of high pressure on the supporting structures. A two-dimensional finite element method program to investigate the statics for the contour of the complete denture and the residual ridge was developed. With this program, the effect of the bucco-lingual position of the artificial posterior teeth under occlusal force on the denture supporting bone could be investigated.     

Definitive prosthodontic therapy for TMJ patients. Part I: Anterior and posterior condylar displacement

The final prosthodontic treatment procedure for anterior condylar displacement (functional centric relation) has been described. Deflective interferences in centric relation were removed and a removable partial denture constructed to the classical most retruded centric relation position of the mandible. Several patients with posterior condylar displacement (dysfunctional centric relation) have been documented. Anterior condylar repositioning was accomplished on a denture patient by merely establishing the correct vertical dimension of occlusion. Another patient required an increase in vertical dimension as well as anterior condylar repositioning.     

Anterior guidance--the key to successful occlusal treatment.

1. The occlusion of the anterior teeth is the key to developing and perpetuating an "ideal" occlusion. 2. The anterior teeth protect the posterior teeth by disoccluding them in eccentric positions, and the posterior teeth protect the anterior teeth by receiving most of the forces of closure in centric position. 3. The anterior guidance is a result of both anterior tooth position and condylar border movements; both factors must be considered in the creation of an anterior guidance.     

Checking the occlusal relationships of complete dentures via a remount procedure

Correct occlusal relationships are part of the successful prosthetic treatment of edentulous patients. Occlusal checking should be performed via a remount procedure because denture base materials and fabrication procedures cannot provide dimensionally accurate complete dentures. Occlusal errors caused by the adjustment of denture bases to the denture foundation after a certain period of wearing can also be corrected by means of remounting. The following remount procedures for complete dentures are described: fabrication of transfer casts, transfer of a maxillary denture with a facebow, centric relation record, and mounting of dentures with transfer casts in an articulator with a dental stone. Deflective occlusal contacts of denture teeth in centric occlusion can be eliminated by selective grinding and by tooth-guided excursive movements. In complete denture treatment, priority is given to anterior/canine-guided occlusion.     

104例佩戴全口义齿患者满意度与义齿质量间关系的研究

目的 研究患者对全口义齿满意度与义齿质量间是否存在联系.方法 对104例佩戴全口义齿3-10个月的患者进行满意度问卷调查,同时进行义齿质量相关检查,包括义齿基托边缘伸展、人工牙排列、义齿稳定状况、义齿的固位、咬合关系和息止(牙合)间隙.结果 影响全口义齿患者满意度的主要因素为义齿基托边缘伸展、人工牙排列、咬合关系和息止(牙合)间隙.结论 患者对全口义齿外观、咀嚼能力、义齿稳固性、舒适性方面的满意度受义齿质量临床评价相关参数的影响.     

Occlusal considerations for partially or completely edentulous skeletal Class II patients. Part II: Treatment concepts

Four basic concepts must be considered when developing the prosthetic occlusion for skeletal class II patients: (1) Centric relation must be used as a reference position to relate the mandible to the maxillae; (2) the posterior denture teeth must be positioned close to their former positions; (3) freedom of movement must be created in eccentric movements; and (4) multiple occlusal contacts must be provided in centric and eccentric positions. We have described a method that incorporates these basic concepts and provides a harmonious occlusal arrangement for both edentulous and partially edentulous class II patients.     

Occlusal schemes of complete dentures--a review of the literature

Occlusal scheme is defined as the form and the arrangement of the occlusal contacts in natural and artificial dentition. The choice of an occlusal scheme will determine the pattern of occlusal contacts between opposing teeth during centric relation and functional movement of the mandible. With dentures, the quantity and the intensity of these contacts determine the amount and the direction of the forces that are transmitted through the bases of the denture to the residual ridges. That is why the occlusal scheme is an important factor in the design of complete dentures. Three occlusal schemes are viewed in this review: bilateral balanced occlusion, monplane occlusion, and linear occlusion scheme. Each scheme represents a different concept of occlusion. Comparisons between these schemes are also reviewed and analyzed. The reasoning underlying the bilateral balanced occlusion scheme is that stability of the dentures is attained when bilateral contacts exist throughout all dynamic and static states of the denture during function. Anatomic teeth are used: the upper anterior teeth are set to satisfy aesthetics, and the posterior teeth are arranged in a compensatory curve and a medial curve. This scheme is adequate for well developed residual ridges, with skeletal class I relation. With highly resorbed residual ridges, the vectors of force that are transmitted through anatomic cusps will dislodge the lower denture and thus impair the comfort and efficiency of mastication experienced by the patient. In order to accommodate to the special needs posed by highly resorbed residual ridges and skeletal relations that are not class I, the monoplane scheme of occlusion was designed. This scheme consists of non anatomic (cuspless) teeth, which are set so that the anterior teeth provide the aesthetics, the premolars and the first molars are used for chewing, and the second molars do not occlude (although sometimes they are specifically used to establish bilateral contacts in lateral movements). Linear occlusion scheme occludes cuspless teeth with anatomic teeth that have been modified (bladed teeth) in order to achieve linear occlusal contacts. Linear contacts are the pin-point contacts of the tips of the cusps of the bladed teeth against cuspless teeth that create a plane. The specific design of positioning upper modified teeth on the upper denture and non anatomic teeth on the lower one is called lingualized occlusion. It is characterized by contacts of only the lingual (palatinal, to be more accurate) cusps of the upper teeth with the lower teeth. The lingualized occlusal scheme provides better aesthetics than the monoplane occlusion scheme, and better stability (in the case of resorbed residual ridges) than bilateral occlusion scheme of anatomic teeth. The results of studies that compared different occlusal schemes may well be summarized as inconclusive. However, it does seem that patients preferred anatomic or semi-anatomic (modified) teeth, and that chewing efficiency with anatomic and modified teeth was better than with non anatomic teeth. Similar results were found in studies of occlusal schemes of implant-supported lower dentures opposed by complete upper dentures. Conclusion: There isn't one occlusal scheme that fits all patients in need of complete dentures, in fact, in many cases more than one occlusal scheme might be adequate. Selection of an occlusal scheme for a patient should include correlation of the characteristics of the patient with those of the various occlusal schemes. The characteristics of the patient include: height and width of the residual ridge, aesthetic demands of the patient, skeletal relations (class I/II/III), neuromuscular control, and tendency for para-functional activity. The multiple characteristics of the occlusal schemes were reviewed in this article. Considering all of those factors in relation to a specific patient, the dentist should be able to decide on the most suitable occlusal scheme for the case.     

Occlusion for the Class II jaw relations patient

Each patient with a small mandible presents an occlusal pattern that differs from most of the criteria established for a class I occlusion. The components of a class II occlusion are unlike other occlusions. The anterior teeth do not provide the protection and guidance normally provided by horizontal and vertical overlap. The posterior teeth bear the full force of occlusion. Protrusive movement is the dominant and the most used movement. The posterior teeth must function from centric relation forward to an anterior separation. Most of the posterior teeth exhibit balancing contacts. This occlusion is a type of bilateral balanced occlusion. Greater interocclusal clearance must be provided and tested for adequacy of space during speech and function. A class II occlusion is a most exacting occlusion. The controlling factors are the posterior determinants of occlusion.