正常者瞳孔间距与咬合垂直距离关系的研究

目的：研究正常[牙合]者瞳孔间距（Interpupillary Distance，IPD）与咬合垂直距离（Occlusal Vertical Dimension，OVD）的关系。方法：对116名福建籍青年正常[牙合]者测量其OVD与IPD，并进行两者相关回归分析。结果：总样本的OVD均值为65．35mm±4．70mm，IPD均值为63．98mm±3．26mm，男性正常[牙合]者OVD均值为68．16mm±4．23mm，IPD均值为65．46mm±2．96mm，女性正常[牙合]者的OVD均值为63．22mm±3．86mm，IPD均值为62．86mm±3．05mm;总样本的IPD与OVD的相关系数r=0．633，男性样本的IPD与0VD的相关系数r=0．563，女性样本的IPD与OVD的相关系数r=0．531。结论：IPD与OVD间存在显著相关性，IPD可以作为需咬合重建患者确定其OVD的参考指标。     

正常(牙合)者咬合功能的研究

目的研究正常[牙合]者的咬合功能状况。方法用T-scan Ⅱ型系统4．02版记录26名正常[牙合]青少年在牙尖交错位（ICP）的[牙合]力总值（TOF）、[牙合]力不对称指数（AOF）、[牙合]力中心点位置（COF）、[牙合]力中心点最大位移（MMCOF）、[牙合]干扰指数（0II）、[牙合]接触点数（NOC）、[牙合]接触面积不对称指数（AOA）。分析[牙合]力及咬合接触点的分布规律。结果①正常[牙合]者三次咬合记录的左右侧[牙合]力百分比及COF无显著性差异。②正常[牙合]者AOF、MMCOF、OⅡ均较小，男性[牙合]力总值大于女性（P〈0．05）。③正常[牙合]者NOC主要分布在磨牙区，前牙几乎无接触，咬合接触点与[牙合]力成正相关。结论①T-scan Ⅱ系统传感器薄膜具有良好的重复性。②正常[牙合]者具有平衡稳定的咬合。     

T-Scan Ⅲ咬合分析系统测量正常(牙合)(牙合)力分布初探

目的 探讨正常(牙合)不同(牙合)位(牙合)力分布规律,以期为临床提供参考.方法 选择正常(牙合)志愿者53名,男性29名,女性24名,年龄20 ～31岁[平均(25.9±2.1)岁],使用T-ScanⅢ咬合分析系统,测量正常(牙合)牙尖交错(牙合)、前伸(牙合)及侧方(牙合)各牙的(牙合)力百分比及咬合时间,分析侧方(牙合)的(牙合)接触类型.结果 正常(牙合)牙尖交错(牙合)时(牙合)力百分比最大的牙位依次为7｜、| 7、6|和|6,分别为(18.7±7.5)％、(15.7±7.1)％、(13.6±5.4)％和(13.3±4.3)％,7654 | 4567为(牙合)力集中区,(牙合)力百分比为(61.3±12.4)％;左侧(牙合)力百分比[(46.4±7.0)％]显著小于右侧[(53.6±7.0)％](P＜0.05).前伸(牙合)时21|12为(牙合)力集中区,(牙合)力百分比为(85.1±25.5)％,左前区(|123)与右前区(321|)的(牙合)力百分比分别为(49.2±26.4)％和(48.1±26.6)％,差异无统计学意义(t=-0.15,P＞0.05).左侧方(牙合)时尖牙保护(牙合)占28％(13/46),组牙功能(牙合)占33％ (15/46),多重保护(牙合)占39％ (18/46);右侧方(牙合)时尖牙保护(牙合)占30％(14/46),组牙功能(牙合)占44％ (20/46),多重保护(牙合)占26％ (12/46);侧方(牙合)时(牙合)力升高时间和咬合分离时间分别为(0.34±0.11)和(1.00±0.39)s.结论 20 ～ 30岁正常(牙合)牙尖交错(牙合)时第一前磨牙至第二磨牙是(牙合)力集中区,第二磨牙受力最大;前伸(牙合)时(牙合)力集中于21|12,侧方(牙合)(牙合)接触类型具有多样性.     

开(牙合)及个别正常(牙合)人群后牙倾斜度的测量研究

目的比较开(牙合)和个别正常(牙合)人群上下颌后牙近中倾斜度。方法选择34例开(牙合)患者和40例个别正常(牙合),拍摄曲面断层片;在曲面断层片上测量开(牙合)患者及个别正常(牙合)人群上下颌第一磨牙,第一、二前磨牙牙长轴的倾斜度并进行统计学分析。结果开(牙合)患者上下颌后牙近中倾斜度明显大于个别正常(牙合)人群,有统计学意义(P<0.0001)。无论开(牙合)还是正常(牙合)人群上下颌后牙的近中倾斜度由大到小依次为:第一恒磨牙、第二前磨牙、第一前磨牙。结论上下颌后牙近中倾斜是开(牙合)形成的机制之一,开(牙合)矫治的重点应放在竖直近中倾斜的上颌后牙及下颌第一磨牙。     

正常(牙合)牙齿切(牙合)面上下相对位置的测量研究

用三坐标测量仪对70付正常(牙合)青年的牙列模型进行了牙齿的切角与牙尖顶到(牙合)平面垂直距离的测量研究。结果表明,牙弓(牙合)面形态左右基本对称,牙弓(牙合)面为曲面。     

正常(牙合)人牙(牙合)特点在固定矫治器中的应用

目的　探讨使用固定矫治器治疗中国错畸形患者时的注意事项。方法　比较恒牙列正常中国人与 白种人的牙冠突距、冠角、牙冠转矩及磨牙补偿角的差异,以及测量正常中国人牙冠唇颊面中心区的近远中向、 龈向轮廓形态和牙弓形态。结果　正常的特征、牙弓形态以及牙冠唇颊面中心区的近远中向和龈向轮廓形 态,在中国人与白种人间存在人种差异。结论　使用方丝弓、直丝弓矫治器治疗中国错畸形患者时,弓丝弯制中 应进行必要的调整,有必要设计适合于中国人使用的直丝弓矫治器。     

不能随意调(牙合)——兼论规范化调(牙合)

调(牙合)是咬合治疗的重要手段,是口腔医师必须掌握的专门技术,但不当调(牙合)或是调(牙合)不准确,不仅治疗无效,还有可能破坏原有的咬合关系,甚至造成严重的后果.本文从引起咬合改变的生理病理因素,哪些因素不能调(牙合)或不能仅依赖调(牙合),不当咬合调整可能引起的损害等方面进行了分析,强调了进行准确调(牙合),精确调(牙合)的重要性,对如何准确调(牙合)进行了探讨,对调(牙合)原则的做了补充.提出了咬合调整的规范,提出了不能轻易调(牙合)的问题,强调了规范化调(牙合)的重要性,明确提出要重视其前序治疗和后续治疗.     

九江地区正常(牙合)青年颅面部硬组织线性测量距离与咬合垂直距离相关性研究

目的:分析咬合垂直距离(occlusal vertical dimension,OVD)与颅颌面相关测量线距的相关性.方法:按正常(牙合)标准筛选出57名志愿者进行头影测量分析,采用Winceph 8.0测量软件进行描点和测量.结果:ANS-Me的平均值为64.50±4.18(95％ CI:63.39 ～65.61);ANS-Me分别与S-N、N-ANS、ANS-PNS之间均存在显著性线性相关关系(P≤0.05);偏相关分析结果ANS-Me与N-ANS、ANS-PNS依然存在显著性相关(P≤0.05),而ANS-Me与S-N则无显著性相关(P＞0.05).结论:九江地区青年正常(牙合)者的N-ANS、ANS-PNS可以作为临床确定咬合垂直距离的参考指标.     

新疆哈萨克族青少年正常(牙合)模型测量研究

目的:建立新疆哈萨克族青少年正常(牙合)牙冠宽及牙量分析指数数据库.方法:选取新疆地区100名正常(牙合)哈萨克族青少年,制取牙颌模型并测量,对所测数据进行性别间比较,与西安汉族青少年相应数据进行比较.结果:建立了正常(牙合)哈萨克族青少年牙冠宽及牙量分析指数的均值及标准差;哈萨克青少年牙冠宽度性别间比较具有统计学差异,男性大于女性;与西安汉族青少年比较,牙弓宽度、牙量等各项数值,两民族比较均具有统计学差异,哈萨克族的各项数值均大于西安汉族数值.结论:本研究结果进一步证明了不同种族、民族、地区的牙齿、牙弓大小及形态存在着差异.     

Influence of occlusal vertical dimension on the masticatory performance during chewing with maxillary splints

Changing the occlusal vertical dimension is a common procedure in restorative dentistry, during treatment of patients with cranio-mandibular disorders, and during orthodontic and orthognathic treatment. The treatment may alter the length of the main jaw elevator muscles and the position of the mandibular head in the fossa temporalis. These changes may influence the bite forces that are generated during chewing and thus may affect the masticatory function. We measured the objective masticatory function, defined as masticatory performance, by determining an individual's capacity to pulverize a test food. The immediate influence of the increase in the occlusal vertical dimension on the masticatory performance was determined using three anatomical maxillary splints in a group of seven dentate subjects. The splints gave an increase in the occlusal vertical dimension of 2, 4 and 6 mm, respectively. Before we started the experiments the subjects practiced chewing with the splints during about 5 min. No significant differences were observed in masticatory performance among the conditions without and with the three splints. Thus, an increase in the occlusal vertical dimension up to 6 mm did not have a significant effect on the masticatory performance. Maxillary splints may be used to study the effect of occlusal factors on the chewing process by manipulating tooth shape and occlusal area of the splint.     

Periodic evaluation of the occlusal vertical dimension of maxillary dentures from the wax trial denture through 48 hours after polymerization

PURPOSE: This study measured the effects of commercial resin type on maxillary complete dentures with monoplane teeth by periodically comparing the occlusal vertical dimension of the polymerized dentures with the baseline, wax trial denture fiducial measurements. MATERIALS AND METHODS: Commercially available compression-molded, injection-molded, and fluid poly(methyl methacrylate) resins, as well as one compression-molded methyl acrylate ester copolymer, were evaluated. Ten dentures were fabricated from each resin using monoplane teeth. The occlusal vertical dimension at the articulator pin was measured at the wax denture stage for each specimen, and changes in occlusal vertical dimension for each denture were evaluated at a simulated laboratory remount, and at 0, 3, 6, 24, and 48 hours after a simulated clinical remount. Repeated measures analysis of variance (alpha = 0.05) and post hoc one-way factorial analysis of variance and Scheffe's F-Tests for each resin group were performed using ranks of raw data. RESULTS: Changes in the maxillary denture mean occlusal vertical dimensions were recognized throughout the evaluation periods compared with the wax-denture baseline, and time was a significant influence on displacement (p = .0001). Only the compression-molded poly(methyl methacrylate) dentures exhibited a mean laboratory remount occlusal vertical dimension that was significantly greater than the mean wax denture measurement, and all resin systems exhibited occlusal error that was significantly less than the laboratory remount measurements at 48 hours. At 48 hours, all resin groups exhibited mean occlusal vertical dimension changes that were less than 1 mm compared with the wax denture. Only compression-molded poly(methyl methacrylate) dentures exhibited a mean 48-hour clinical remount measurement that was statistically similar to the mean wax denture occlusal vertical dimension. CONCLUSIONS: Individual maxillary dentures from all resin types and at all intervals exhibited dimensional change. At the last evaluation period, the compression-molded poly(methyl methacrylate) showed no change in mean occlusal vertical dimension from baseline, whereas remaining groups exhibited occlusal vertical dimensions significantly less than baseline.     

咬合抬高对后牙重度磨耗患者咀嚼肌表面肌电值的影响

目的：探讨后牙重度磨耗患者咬合抬高后对咀嚼肌表面肌电反应的影响。方法：随机选取2012年1月至2014年1月在我北京航空总医院口腔诊疗中心就诊的,伴有双侧后牙重度磨耗的患者40名为受试对象,其中男性23名,女性17名,年龄40-50岁,治疗前及咬合抬高不同距离后分别进行咬肌及颞肌的肌电检查,并对结果采用多样本均数比较的单因素方差分析进行统计学处理。结果：切牙区颌间距离增加1mm时,双侧咬肌,双侧颞肌肌电值差异无统计学意义。切牙区颌间距离增加2mm时,左侧咬肌,右侧咬肌,左侧颞肌肌电值差异无统计学意义,右侧颞肌肌电值有所增加（17.08±3.27 VS 24.66±3.18,P〈0.05）。切牙区颌间距离增加3mm时,除右侧咬肌肌电值差异无统计学意义外（22.35±3.14 VS 27.74±4.26,P〉0.05）,左侧咬肌,左侧颞肌,右侧颞肌肌电值差异均有统计学意义。切牙区颌间距离增加4mm时,双侧咬肌,颞肌肌电值差异均有统计学意义。结论：切牙区颌间距离增加2mm时对咬肌和颞肌肌电值影响不大,切牙区颌间距离增加3mm会对咬肌和颞肌肌电值产生较大影响。     

角度评估咬合垂直距离的探索性研究

目的 通过头影测量的方法,对30例正常人群颅面部硬组织标志点进行分析,寻找一种更加精确量化的方法来评估咬合垂直距离。方法 选择30名年龄在20~30岁的正常人群进行头影测量分析。采用Winceph 8.0测量软件进行描点和测量。结果 面中心角（CA）与面下角（LA）均值分布差异无统计学意义（t=-1.490,P=0.147）。CA角和LA角之间存在显著线性相关（r=0.976,P=0.000）,得出回归方程为y=0.298+0.997x。结论 可以通过CA角对咬合垂直距离进行评估量化,并且可以通过CA角来指导临床确定咬合垂直距离。     

重度磨耗牙垂直距离评估与固定修复

目的:探讨重度磨耗牙垂直距离的变化与固定修复方法的选择.方法:对65例129颗重度磨耗牙,根据垂直距离有无变化,分为三类修复:①重度磨耗牙,垂直距离未减小,(牙合 )龈距离尚能进行常规固定修复;②重度磨耗牙,垂直距离未减小,(牙合)龈距离不足进行常规固定修复;③重度磨耗牙伴有垂直距离减小,(牙合)龈距离不足进行固定修复...     

The effects of increasing occlusal vertical dimension on the deep masseter of rat at different ages

ObjectiveTo investigate the influence of increasing the occlusal vertical dimension (iOVD) on the fibre-type distribution and ultrastructure of deep masseter of rat at different ages.DesignA total of forty-eight male Wistar rats were divided into two groups according to age: ‘teenage’ group (n = 24, 1.5 months) and ‘young adult’ group (n = 24, 8 months). Both the teenage and the young adult rats were then randomly divided into the control group (n = 12) and the experimental group (n = 12). The occlusal vertical dimensions of the rats in the experimental groups were increased by placing composite resin on all maxillary molars. The fibre-type distribution and ultrastructure of the deep masseter were subsequently observed on day 7 and day 14 after iOVD.ResultsIn the teenage experimental group, the proportion of type IIa fibres increased, while the proportion of type IIb and type IIx fibres decreased by day 7 after iOVD (P < 0.05). However, no significant fibre phenotype transformation was observed in the young adult experimental group until day 14 after iOVD. In addition, the proportion of type IIa in the teenage experimental group was higher than that of the young adult experimental group on day 7 and 14 (P < 0.05). Under the transmission electron microscope, muscle fibre reconstruction and the compensatory increase in the number and volume of mitochondria appeared earlier in the teenage experimental group. The cellular traumatic reaction was less than that in the young adult experimental group.ConclusionThe teenage rat alters masseter muscle structure to a slower phenotype earlier and to a greater degree than that of the young adult rat when increasing the occlusal vertical dimension.     

Clinical considerations for increasing occlusal vertical dimension: a review

The purpose of this article is to discuss the clinical considerations related to increasing the occlusal vertical dimension (OVD) when restoring a patient's dentition. Thorough extraoral and intraoral evaluations are mandatory to assess the suitability of increasing OVD. In the literature, multiple techniques have been proposed to quantify OVD loss. However, the techniques lack consistency and reliability, which in turn affects the decision of whether to increase the OVD. Therefore, increasing OVD should be determined on the basis of the dental restorative needs and aesthetic demands. In general, a minimal increase in OVD should be applied, though a 5 mm maximum increase in OVD can be justified to provide adequate occlusal space for the restorative material and to improve anterior teeth aesthetics. The literature reflects the safety of increasing the OVD permanently, and although signs and symptoms may develop, these are usually of an interim nature. Whenever indicated, the increase in OVD should be achieved with fixed restorations rather than a removable appliance, due to the predictable patient adaptation. The exception to this is for patients with TMD, where increasing the OVD should still be achieved using removable appliances to control TMD-associated symptoms before considering any form of irreversible procedure.