球帽覆盖义齿粘固球帽前后咬合特征变化研究

目的：定量研究球帽附着体覆盖全口义齿（complete overdenture,COD）修复后咬合接触分布的变化,初步说明球帽附着体对义齿影响,为临床调（牙合）提供理论依据.方法：采用T-ScanⅡ咬合分析仪进行体内咬合分布特征及咬合时间的测定.全口义齿及球帽附着体覆盖全口义齿修复后患者各16例.球帽覆盖义齿修复患者于粘固球帽前,粘固后3月进行咬合检测,全口义齿修复患者于义齿修复3月后检查咬合分布.记录咬合力中心（center of force,COF）前后位移值（Y）,咬合力前后向分布比率,咬合时间.结果：双侧球帽覆盖义齿粘固球帽后咬合力逐渐增加,高于同期全口义齿,差异有统计学意义（P＜0.05）.球帽覆盖义齿粘固3个月时咬合中心较粘固前前移,与同期全口义齿咬合中心差异有统计学意义（P＜0.05）.全口义齿咬合时间为0.29sec,双侧球帽粘固球帽前为0.27sec,粘固3个月时双侧球帽为0.25sec.差异无统计学意义（P＞0.05）.结论：粘固球帽前覆盖义齿与全口义齿咬合分布状态相似.球帽覆盖义齿粘固球帽3个月内咬合力增大,前牙咬合接触增多,咬合中心前移明显.提示临床对球帽覆盖义齿应在双侧咬合分布平衡同时,注意调整前牙咬合分布.     

两种磁性附着体固位的种植全口覆盖义齿光弹应力分析

目的 :评价在种植全口覆盖义齿中应用缓冲型磁性附着体来缓冲咀嚼压力的作用 ,为其临床应用提供理论依据。方法 :在下颌种植全口覆盖义齿的修复中 ,采用 2种不同的磁性附着体即缓冲型与非缓冲型磁性附着体作为固位体 ,利用光弹应力分析法比较单侧垂直和斜向加载时支持组织内的生物力学特征。结果 :加载后 ,与普通型磁性附着体相比 ,应用缓冲型磁性附着体使种植体周围应力减小 ,但牙槽嵴区应力增加 ,同时能够将应力传导至加载对侧。结论 :缓冲型磁性附着体用于种植全口覆盖义齿 ,具有明显的应力缓冲作用 ,能使种植体周围的应力减小 ,应力在支持组织中分布更均匀 ,利于种植体骨界面的健康     

Occlusal force pattern in dentitions with mandibular implant-supported fixed cantilever prostheses occluded with complete dentures

Naturally occurring axially directed closing and chewing forces were measured in ten patients with mandibular fixture-supported cross-arch prostheses occluding with maxillary complete dentures. The design of the mandibular constructions was characterized by bilateral posterior two-unit cantilevers. The forces were measured using eight miniature strain gauge transducers mounted in the maxillary denture and evenly distributed over the tooth arch. Forces were thus measured at four occlusal contact points over the fixture segment and over each of the four posterior cantilever units simultaneously, giving a detailed picture of the force distribution. The total forces developed during maximal closing in habitual occlusion and chewing were of the same magnitude as previously reported for patients with tooth-supported cross-arch fixed partial dentures occluding with natural teeth using the same method. Contradictory to previous findings, in dentitions with comparable tooth-supported cantilever constructions occluding with natural teeth, local closing and chewing forces increased bilaterally in the distal direction. On average, 70% of the forces were borne by the cantilevers and 30% by the fixture-supported segment of the prostheses.     

Occlusal force distribution on the dental arch during various levels of clenching

The purpose of this study was to explore the occlusal force distribution on the dental arch in the intercuspal position and to evaluate the relationship between the clenching strength and the occlusal force distribution. These variables were recorded using the Dental Prescale System in 16 healthy young adults. The number of tooth contacts, occlusal force and occlusal contact area increased linearly as clenching strength increased. The distribution of the occlusal force was greatest at the molar region followed by the premolar and anterior teeth region. The proportion of occlusal force (occlusal force at each region/total occlusal force) on molar regions increased as clenching strength increased. On the contrary, the proportion of occlusal force on the premolar and anterior teeth regions decreased as clenching strength increased. These findings suggest that control of occlusal force is important in diagnosis of the nature of occlusal contacts.     

Occlusal plane orientation in complete denture construction

Guides to the orientation of the occlusal plane in complete denture construction are reviewed and the current opinions of some British dentists are reported.

It is concluded that this element of complete denture construction owes less to the intelligent application of scientific principles than to a form of guesswork.     

Occlusal vertical dimension in removable complete dentures

In removable complete dentures, the occlusal vertical dimension is an important factor for patients' satisfaction with aesthetics. An excessively reduced occlusal vertical dimension is especially likely to lead to complaints about aesthetics, whereas an increased occlusal vertical dimension may lead to discomfort and a decision not to wear the complete dentures. There are various methods for determining the occlusal vertical dimension in complete dentures, based on the vertical dimension in the rest position of the mandible or on phonetics. However, none of the methods have proven to be clearly superior, in terms of reliability, than the others. The assessment of the occlusal vertical dimension will become more reliable if several methods are used simultaneously. Moreover, knowledge of the characteristics of the ageing face is essential.     

总义齿、覆盖义齿和种植覆盖义齿修复后患者满意度的比较研究

目的：比较总义齿（CD）、覆盖义齿（COD）和种植覆盖义齿（IOD）修复后的患者满意度。方法：选取CD、COD和IOD修复后的患者各14例，对三组患者分别进行满意度的问卷调查。结果：三组患者对义齿总的满意度的差异没有显著性，对咀嚼功能的满意度IOD组显著高于CD组。三组患者戴用旧义齿的经验没有显著差异。义齿的松动和食物受限情况IOD组明显少于CD组，而义齿修复后的牙槽嵴疼痛和感觉咀嚼无力的情况三组间没有显著差异。结论：IOD修复后患者对咀嚼功能的满意度较CD修复的患者高，出现的问题少，是一种较好的修复无牙颌的方法。     

Occlusal force discrimination by denture patients

A study was conducted on subjects with conventional dentures and with overlay dentures to compare their abilities to discriminate between occlusal forces. Perpendicular forces were applied to the dynamic center of the occlusal table of the mandibular denture. Each subject's ability to distinguish differences in values of force was observed and recorded.All subjects with dentures showed sensory threshold values close to those reported for natural teeth. A graphic plotting showed that the responses of subjects with overlay-type dentures were more closely correlated with the psychophysical law as expressed by Stevens⁴ as a power function. Since this phenomenon holds true for natural teeth, the overlay denture more closely resembles natural teeth in this type of sensory function than does the conventional denture.In addition to recognized advantages, such as preservation of the ridge and improved retention and stability,^7–9 the overlay denture provides more typical sensory function than is provided by the conventional denture. This advantage should further motivate dentists and patients to consider the retention and utilization of at least two suitable teeth in an overlay-type denture service.     

Magfit磁性附着体在全口义齿修复中的应用

评价以Magfit磁性附着体改善全口覆盖义齿固位的远期效果。方法：采用铸接法设置报面伤铁,并对应用Magfit磁性附着体的长期效果,如义齿的固位、稳定状态,以及义齿应用后出现的问题进行16～38月的随访观察。结果：①设置2只以上MagfitEX600或设置3只以上MagfitEX400磁性附着体即可使全口覆盖义齿获得保证行使各种口腔功能所需的长期稳定的固位力;②铸接式衔铁较粘接式衔铁有更好的密合性,可有效地防止继发龋;③Co－Cr合金可以被用于待接式衔铁的制作;④应用MagfitEX系列磁性附着体的全口覆盖义齿戴用后并发症发生率较低。结论：Magfit磁性附着体,能有效改善全口覆盖义齿的固位,并发症少,具有良好的远期效果。     

(牙合)力在牙硬组织非龋性损伤病因学中的研究进展

牙齿硬组织非龋性损伤在临床上大致可归纳为磨损、楔形缺损、隐裂和牙折。其病因复杂多样，其中[牙合]力被认为是共同的致病因素之一，但在不同的疾病中又起着不同的作用。     

Occlusal force transmission by overdenture attachments.

This investigation utilized a composite photoelastic model to examine the load-transfer characteristics of several overdenture attachments. Tissue bar (Hader and King Connector) and stud (extracoronal) attachments (Rotherman, Gerber, and Ancrofix) were studied. The following observations may provide guidelines for the selection of overdenture attachments. 1. The more retentive tissue bar and extracoronal attachments produced higher stress concentrations. 2. Of the tissue bars tested, the Hader Bar produced less torquing forces on the abutment teeth. 3. The Ancrofix appeared to share the forces of occlusion between abutments and the posterior edentulous regions. 4. It must be emphasized that several other factors will also influence the choice of overdenture attachments, such as the judgment of the dentist, economics with respect to the patient, and the availability of laboratory expertise.     

Occlusal force after partial mandibular resection.

Surgical resection of a segment or loss of mandibular continuity can adversely affect most of the structures essential for maximum occlusal force. Five subjects who had partial mandibular resections for treatment of squamous cell carcinoma were studied. Occlusal force was recorded before and after cancer treatment and following prosthetic rehabilitation. A gnathodynamometer was used to record anterior occlusal force. Five edentulous and five dentate cancer-free subjects matched for age were studied to establish comparable normative data. The null hypothesis that partial mandibular resection would not affect maximum occlusal force was rejected (p = 0.0101). Mandibular resection did alter maximum occlusal force. The impact of the decrease in maximum occlusal force on masticatory function is yet to be determined.     

Masticatory function and bite force of mandibular single-implant overdentures and complete dentures: a randomized crossover control study

PurposeThe study aimed to compare the mixing ability (MA), comminuting ability (CA), and maximum bite force (MBF) of single-implant overdentures (IODs) and clinically acceptable complete dentures (CDs) through a randomized crossover control trial.MethodsNew CDs were fabricated for 22 patients. One implant was inserted in the middle of the symphyseal region for each patient. The patients were randomly allocated into two groups: group IC received an IOD, whereas group CI received a CD, for 2 months; the treatments were interchanged for the next 2 months. The MA, CA, and MBF were evaluated with the old CDs, new CDs (at the end of CD treatment period), and IODs (at the end of IOD treatment period).ResultsThe MA, CA, and MBF of the IODs were significantly higher than those of the old and new CDs (p < 0.01). New CDs only showed a significant improvement in MA (p < 0.05), while there were no significant differences in CA and MBF between the old and new CDs.ConclusionsCompared with the CD, IOD is more effective in restoring the MA, CA, and MBF of edentulous mandibles.     

在全口义齿修复中联合应用按扣式附着体与磁性附着体的探讨

目的：利用按扣式附着体，磁性附着体的不同优点，改善全口覆盖义齿部位。方法：针对残根牙周不同条件，制作按扣式附着体和磁性附着体，通过水平研究磨仪确定附着体的共同就位道。结果：二的联合应用使全口义齿的固位明显提高。所有修复义齿固位稳定、咀嚼良好。结论：按扣式附着体和磁性附着体的联合应用，充分利用了剩余残根，提高了义齿的稳定、固位，值得临床推广。