��ǻ�޸�������ҧ��ѧ����

口腔修复的最终目标是恢复符合口颌面生理功能同时满足美现要求的咬合关系.由于患者个性化需求的提高,没有任何一种咬合模式能满足所有患者.所以针对不同患者做出正确的咬合诊断和制定符合生理要求的修复方案十分重要.如果原有咬合关系是非生理性的,或者说是病理性的,则要改善咬合关系.而在改善及重建咬合时,其目标是理想咬合关系.在咬合修复时,需要考虑下颌位、咬合垂直距离、咬合平面走向和位置、上下前牙位置和功能诱导、后牙咬合面解剖形态、咬合接触点位置和接触强度等重要影响因素.修复治疗不仅是获得美观的效果、功能的恢复,更需要维持对口颌面余留硬软组织无害的长期健康状态.     

Clinical protocol for occlusal adjustment: Rationale and application

Background: Occlusal adjustment can optimize the result of orthodontics, orthognathic surgery, and comprehensive restoration, and resolve adverse forces to the dentition that affect the entire masticatory system. Mounted diagnostic casts and computerized occlusal analysis offer complementary advantages for evaluating occlusal problems. Predictable occlusal adjustment is facilitated by precise, measured documentation of occlusal force by computerized occlusal analysis.

Clinical presentation: A conservative, structural correction of a pronounced, chronic occlusal problem by additive and subtractive occlusal adjustment was performed after a previous failed occlusal adjustment. The patient’s chief concerns were significant anterior teeth fremitus in maximum intercuspation and “pain in the teeth and a poor bite” after 30+ adjustments over 2.5 years.

Clinical Relevance: Confirmation of specific criteria for a therapeutic occlusion resolved the anterior teeth fremitus and uneven bite. Traumatic occlusal contact on posterior teeth may elicit protective mandibular repositioning affecting anterior teeth relationships and should be considered during comprehensive diagnosis.     

Application of "cusp writer" findings to practical and theoretical occlusal problems. Part II.

The cusp writer is a teaching aid to facilitate understanding of the correlation between cusp angulations and the various occlusal determinants. The cusp writer provides graphic evidence that the occlusal determinants which influence configurations (i.e., incisal guidance, condylar guidance, plane [curve] of occlusion, curve of Spee [compensating curve], and plane of motion) are reciprocal, one tempering the value of the other. Cusp writings demonstrate the following: (1) The angle of the plane (curve) of occlusion to the plane of motion in concert with the other occlusal infuluence determines the optimal height and angulation of the cusps. (2) Cusps appear to be steep or shallow relative to each other, to the plane of occlusion, and to the plane of motion. (3) The steepness of the curve of Spee determines the relative cusp height and angulation of one tooth to another, from an anterior to a posterior direction in the dental arch. (4) The angle of the tangent to any segment of the curve of Spee to the plane of motion determines the optimal height and angulation of the cusps of the segment. (5) The graphs show that the flatter the curve of Spee, the more uniform the cusp height and angulations are from anterior to posterior teeth. The steeper the curve of Spee, the more irregular the cusp height and angulations are with steeper anterior cusps and flatter posterior cusps. (6) The steeper the curve of Spee, the flatter the molar cusp angulations must be to avoid deflective and/or interceptive occlusal contacts on the balancing side. (7) With the syndrome of a steepening curve of Spee due to the loss of one or more lower posterior teeth, the cusps of the remaining opposing teeth must be constantly flattened by wear or selective grinding and reshaping to avoid traumatic occlusion, unless the drifting is interrupted by restorative dentistry. (8) Cusp angulation of artificial teeth should be chosen to harmonize with the angle of incidence of the compensating curve tangents to the plane of motion. (9) Condylar guidance has less influence on cusp angulation in comparison to incisal guidance and the other occlusal determinants. (10) Changing the hinge axis location 1/2 inch (12.5 mm.) distally and/or superiorly has very little effect on the influence of the above occlusal determinants on cusp configuration, if the vertical dimension of occlusion remains constant.     

Influence of altered occlusal guidance on masticatory muscle activity during clenching

This study investigated the influence of experimentally altered occlusal guidance on masticatory muscle activity. Twenty healthy human subjects (15 males and five females with an average age of 26.5 years) volunteered to participate in this study. Metallic occlusal overlays were fabricated for the lower working side canine and overlaid on the second molar and the non-working side second molar to simulate a canine-protected occlusion, group function occlusion and bilateral balanced occlusion. Electromyography (EMG) activities in the bilateral masseter, anterior and posterior temporalis were recorded during maximal clenching. The experimental occlusal pattern revealed to have statistically significant effects on EMG activity. As the most characteristic change, EMG activity in the anterior temporalis significantly increased in the simulated group function occlusion and the simulated bilateral balanced occlusion compared with the simulated cuspid protected occlusion. The increased teeth contacts to the posterior region altered the unilateral pattern of the anterior temporalis activity to the bilateral pattern, while that of masseter activity remained unchanged.     

The Value of Occlusion in Dentistry: A Clinical Report Showing the Correction of an Anterior Reverse Articulation with Selective Occlusal Adjustment

The subject of occlusion has been deemphasized by academia over the last 30 years. This marginalization in turn has negatively impacted recent graduates who are largely unfamiliar with the use of occlusal adjustment by selective reshaping as a treatment modality. Use of proper occlusal therapy enables clinicians to more effectively help patients recover from parafunctional wear of the anterior and posterior teeth. In addition, familiarity with this field enhances the correction of progressive posterior and anterior reverse articulations. This article aims to highlight the importance of occlusal principles in treatment planning. In addition, we illustrate the benefits of occlusal adjustment by using a conservative technique, selective reshaping, as an option to correct anterior reverse articulation in a 20‐year‐old patient. The knowledge of occlusal principles enhances diagnosis of malocclusion in the development of a treatment plan. When properly employed, the technique of occlusal adjustment by selective reshaping may be used to correct an adaptive anterior reverse articulation with a high degree of predictability for select patients.     

Clinical applications of the etched metal retainer

This article presents the treatment of several patients directed at the prevention of periodontal disease and restoration of an occlusion from an eating disorder. The disruption of the harmony between the anterior and posterior determinants of occlusion can lead to the loss of teeth. The lack of anterior guidance can create a molar-guided occlusion producing unfavorable occlusal interferences with destructive balancing side prematurities. Conversely, if the posterior teeth are permitted to drift into unstable occlusal relationships, the posterior dentition would develop an irregular guidance despite a suitable anterior guidance. The goal of the profession is preventing occlusal deterioration or disharmony between the anterior and posterior occlusal determinants and restore compromised occlusions when necessary. Etched metal retainers were fundamental to the treatment of specific patients while patient selection and perceptive tooth preparation were essential for success.     

固定修复重建咬合5年临床观察

目的 临床分析咬合失调患者的病因，采用固定修复术重建咬合，测定治疗前后的咀嚼效能及观察颞下颌关节紊乱病的临床变化。方法 65例经临床诊断为咬合失调病例，采用固定修复的方法施行咬合重建，并分别于修复前，修复后3个月和5年，采用过筛法进行咀嚼效率的测试，检查颞下颌关节紊乱病临床症状的变化。结果 统计学分析显示固定修复前后咀嚼效率有显著性差异（P＜0．01）；颞下颌关节紊乱病的临床症状得到缓解。结论 固定修复方法对恢复咬合关系是有效的，重建咬合后颞下颌关节紊乱病得到缓解，这种不可逆性咬合重建尚需长期的，大量的临床观察。     

侧方咬合运动中接触型及其分布特征

目的观察侧方咬合运动中接触点的分布特征,并对尖牙尖对尖颌位时的侧方型进行分类。方法利用T-ScanII咬合分析系统记录85名个别正常者侧方咬合运动过程中的接触信息,并进行统计分析。结果尖牙尖对尖颌位时的接触形式有六类:尖牙保护(44.1%)、组牙功能(20.6%)、工作侧多组前牙接触(2.9%)、仅工作侧第一前磨牙接触(8.8%)、工作侧前后牙同时存在接触(20.0%)、工作侧非工作侧同时存在接触(3.5%)。结论自然牙列侧方接触形式除尖牙保护与组牙功能外还存在其它一些型。     

Clinical diagnosis of trauma from occlusion and its relation with severity of periodontitis

The purpose of the present study was to determine the reliability of several selected signs of trauma from occlusion and their relations with severity of periodontitis. 32 moderate to advanced chronic periodontitis patients participated in the study. All teeth present were evaluated for various abnormal occlusal contacts, signs of trauma from occlusion, and the severity of periodontitis. Standardized periapical radiographs were also taken for each tooth. The results demonstrated that: (1) no significant difference occurred in probing pocket depth (PD), clinical attachment loss (AL), or percentage of alveolar bone height (BH) between teeth with and without various abnormal occlusal contacts, i.e., premature contacts in centric relation occlusion, non-working contacts in lateral excursions, premature contacts of anterior teeth or posterior protrusive tooth contacts; (2) teeth with either significant mobility, functional mobility, or radiographically widened periodontal ligament space (PDLS) had deeper PD, more AL and lower BH than teeth without these signs, while teeth with pronounced wear or radiographically thickened lamina dura had less AL than teeth without these findings; (3) 2 combined indices, i.e., the trauma from occlusion index (TOI) and the adaptability index (AI), were proposed for the identification of occlusal trauma and the response of periodontium to excessive biting forces in heavy function, respectively; TOI-positive teeth exhibit deeper PD, more AL and less osseous support than TOI-negative teeth; however, AI-positive teeth had less AL and more osseous support than AI-negative teeth; (4) with identical attachment level, TOI-positive teeth had less osseous support than TOI-negative teeth while the magnitude of difference became greater with an increase of attachment loss.     

Dahl appliances used for the restorative management of localized anterior tooth erosion

Dahl partial bite-raising appliances have been used over the past 30 years for the management of occlusal tooth tissue loss, particularly in patients who have lost normal occlusal vertical dimension. The more recent use of Dahl-type appliances for individual teeth has changed the restorative management of patients with localized anterior tooth erosion. The Dahl treatment principle can be applied to those patients with and without the loss of occlusal vertical dimension. Palatal bite-raising platforms can be used to re-establish anterior tooth guidance for disocclusion of the posterior teeth without occlusal interferences. The treatment principle is illustrated with clinical cases.     

The influence of anterior coupling on mandibular movement

The need for and use of anterior coupling in occlusal rehabilitation has been discussed. The anterior teeth can often be coupled to the posterior controls by modifying contours with selective grinding, full or partial coverage restorations, or composite. When anterior guidance is provided, the anterior teeth should harmonize with the TMJs so that the posterior teeth will disclude in excursive mandibular movements. Significant functional, esthetic, and phonetic alterations that change the anterior guidance must be carefully planned because the anterior guidance affects all excursive tooth contacts. Anterior coupling, as described, is often an overlooked entity in restorative dentistry. Evidence of its role in separating the posterior teeth, reducing parafunctional activity, and harmonizing the temporomandibular complex has been presented.     

多模态数据融合的可视化技术在咬合重建中的应用

目的　通过多模态医学数据融合,实现数字化升高咬合垂直距离并进行咬合重建,应用于临床诊断及修复。方法　利用软件手段,将口内扫描（IOS）、口外面部扫描（EOS）、锥形束计算机断层扫描（CBCT）、动态咬合运动轨迹进行多模态医学数据融合,创建可视化、可操作的四维虚拟牙科患者,对虚拟患者咬合及颞下颌关节进行系统性评估,在兼顾前牙美学及后牙修复空间的基础上,进行数字化升高咬合垂直距离,建立新的颌位并对接计算机辅助设计和计算机辅助制造（CAD/CAM）设备,实现咬合重建的固定修复。结果　通过多模态医学数据融合及CAD/CAM设备的对接,得到了可视化、可操控的四维虚拟牙科患者,使咬合重建的固定修复技术更加便捷与安全。结论　多模态数据融合创建四维虚拟患者创新地实现了同一患者各种数据在同时间、同空间的结合,方便、直观地展示了患者口颌系统解剖结构及功能状态,能够为临床医生提供有效的诊断与修复手段。     

An investigation of some factors associated with occlusal tooth wear in a selected high-wear sample

The aim of the present study was to investigate the influence of some factors associated with occlusal tooth wear in a selected high-wear Swedish sample. The material comprised 59 persons having a mean age of 35 yr within the range 16–70 yr, the criteria for selection being a full or near-full complement of natural teeth, and the presence of definite clinical signs of occlusal wear. A dentition wear index, in addition to anterior, posterior, and arch subindices, was derived from a tooth-by-tooth evaluation of casts. Factors which were found to correlate significantly with increased occlusal wear were age, sex, self-perception of wear, number of teeth, and general health, as well as a number of variables from study-cast analysis. On the basis of the findings, not only is the multifactorial etiology of occlusal tooth wear a reality, but so, too, is the complex interdependence of these factors in the severity of wear.     

Talon cusp causing occlusal trauma and acute apical periodontitis: report of a case

Abstract  – The talon cusp, or dens evaginatus of anterior teeth, is a relatively rare dental developmental anomaly characterized by the presence of an accessory cusp-like structure projecting from the cingulum area or cemento–enamel junction. This occurs in either maxillary or mandibular anterior teeth in both the primary and permanent dentition. One of the main problems caused by accessory cusps are occlusal interferences. The anomalous cusp even can generate occlusal trauma and reversible acute apical periodontitis of the opposing tooth. This article reports a case of talon cusp affecting the permanent maxillary left lateral incisor that caused clinical problems related to occlusal trauma and apical periodontitis caused by a premature contact. The treatment of the occlusal interference produced by the taloned tooth is described.     

T—ScanⅢ数字化咬合分析系统在全口义齿调[牙合]中的应用

目的：探讨T-ScanⅢ数字化咬合分析系统结合咬合纸印记指导全口义齿调[牙合]的效果。方法：选取门诊无牙颌患者21人,常规制作全口义齿,去除明显的咬合干扰点,戴入2周后,指导患者从下颌姿势位（MPP）咬合达牙尖交错位（ICP）。用T—ScanⅢ数字化咬合分析系统分析诊断患者的咬合情况,结合咬合纸印记,对早接触点及胎力异常大的接触点进行调[牙合],达到牙尖交错位的广泛接触,对调胎前后的咬合接触时间、后牙接触点、后牙接触面积,胎力分布平衡度进行比较,同时进行患者满意度问卷调查。结果：21例患者在调[牙合]前后的咬合接触时间明显缩短短（P〈0．05）,后牙接触点明显增加（P〈0．05）,后牙接触面积增加,[牙合]力分布平衡度明显减小（P〈0．05）;患者满意度〉9．0分。结论：咬合纸印记结合T-Scanm咬合分析仪指导全口义齿调[牙合]取得满意的临床效果。     

Fabricating a Gold Occlusal Platform on a Removable Partial Denture to Help Prevent Extrusion of Mandibular Incisors

A clinical procedure is presented in which a maxillary removable partial denture (RPD) replacing anterior teeth was fabricated with a cast gold anterior occlusal platform. This treatment is indicated to correct abrasion caused by extruded mandibular anterior teeth on the maxillary RPD. The advantages compared with prosthetic teeth supported by an acrylic resin base or metal-backed facings are discussed. This technique allows for development of optimal esthetics, strength, and durability, while preventing further extrusion and excessive wear of the teeth occluding against prosthesis.     

应用T-scan III系统对楔状缺损患者牙合接触的研究

目的 测量楔状缺损患牙的接触,探究因素与楔状缺损形成的关系。方法 从32例受检者中选取32颗口内单象限内单颗楔状缺损患牙和34颗同名未患楔状缺损牙分别作为实验组和对照组。应用直接接触测量法及T-scan Ⅲ系统分析受检牙干扰的分布,并应用T-scan Ⅲ系统对受检牙在正中、侧方及前伸运动中的接触进行动态、定量测量。结果实验组中单侧组与双侧组患牙的工作侧干扰牙数百分比（75.0%、70.0%）均高于各自对照牙（17.7%、18.2%）,差异有统计学意义（P＜0.05）;在侧方工作侧运动中,实验组患牙所分担的力及其咬合高点上接触强度,均高于对照牙,差异有统计学意义（P＜0.05）。结论 口内单象限内单颗牙楔状缺损的发生与干扰及力负担过重有关。     

Occlusal interferences in association with teeth left in the line of mandibular fractures

Abstract In order to evaluate whether teeth left in the line of mandibular fracture can predispose to occlusal interferences, the contact relationships between the maxillary and mandibular teeth in 37 mandibular corpus fracture patients were examined on the average 41 months after the injury. Control group consisted of 27 healthy dental students. It was shown that occlusal interferences were encountered in 38% (16/42) of teeth in the line of mandibular fracture in 38% (16/42) of their anterior and in 32% (9/28) of their posterior ones. Similar examination in the control group revealed interferences in 28% (113/400) so the ones found in teeth in the line of mandibular fractures can be supposed to have been caused by the injury and/or its treatment. It is also concluded that whether or not the interferences found in these patients were caused by the injury or its treatment or were signs of individual range they should be corrected with occlusal adjustment to prevent further pathological changes in these teeth and in the function of the masticatory system.     

Full mouth rehabilitation of the patient with severely worn dentition: a case report

The severe wear of anterior teeth facilitates the loss of anterior guidance, which protects the posterior teeth from wear during excursive movement. The collapse of posterior teeth also results in the loss of normal occlusal plane and the reduction of the vertical dimension. This case report describes 77-year-old female, who had the loss of anterior guidance, the severe wear of dentition, and the reduction of the vertical dimension. Occlusal overlay splint was used after the decision of increasing vertical dimension by anatomical landmark, facial and physiologic measurement. Once the compatibility of the new vertical dimension had been confirmed, interim fixed restoration and the permanent reconstruction was initiated. This case reports that a satisfactory clinical result was achieved by restoring the vertical dimension with an improvement in esthetics and function.     

多数牙缺失重建探讨

多数牙缺失的患者一般都存在的垂直距离降低，余牙面磨损，无对颌牙的余牙伸长，丧失正常的牙尖交错位等问题。目前发达国家多采用固定修复的方法（含种植义齿）进行咬合重建。本文应用学理论，结合我国目前的条件，采用整铸基托及功能印模技术对多数牙缺失后进行咬合重建，目的是总结临床实践经验，探讨多数牙缺失重建的有关问题。