正常He肌接触位,下颌后退接触位咬合接触的计算机图像分析

目的研究正常肌接触位及下颌后退接触位咬合接触的基本规律。方法采集35名正常肌接触位及下颌后退接触位的硅橡胶记录，进行计算机图像分析。结果肌接触位33人前牙无接触，单颌后牙区接触数为16．6±7．2，所有受试者均为双侧接触。肌接触位咬合接触均在牙尖交错位重复出现。接触频率超过50％的部位位于上颌磨牙颊尖和舌尖的远中斜面，下颌磨牙颊尖和舌尖的近中斜面。下颌后退接触位所有受试者均为双侧接触，有接触的牙齿数目单颌单侧2．7士0．8，接触点数目单颌8．0±2．3，前牙无接触，接触数目及比率从第二磨牙到第一前磨牙依次减少。接触频率超过40％以上的斜面上颌为前磨牙舌尖、磨牙远中舌尖及第二磨牙近舌尖的近中颊斜面，下颌为前磨牙及第二磨牙颊尖的远中舌斜面。结论以硅橡胶为记录材料准确采集到肌接触位及下颌后退接触位记录，经计算机图像分析，得出其咬合接触的基本特征。     

深覆牙尖交错位咬合接触的计算机图像分析

目的 :研究深覆牙合患者牙尖交错位咬合接触的异常表现。方法 :采集 2 4名深覆牙合患者牙尖交错位的硅橡胶牙合记录 ,进行计算机图像分析。结果 :深覆牙合单颌咬合接触数目为 2 2 .1± 9.4,明显低于正常牙合。前牙区75 .0 %的人有咬合接触 ,接触数目及频率明显增加。后牙区接触数目明显减少 ,咬合接触类型与正常牙合有明显差异 ,不稳定的接触增多。结论 :深覆牙合咬合接触与正常牙合明显差异 ,牙合的稳定性不良。深覆牙合易致颅颌功能紊乱可能与其异常的咬合接触有密切联系。     

牙齿楔状缺损与侧方工作侧咬合接触关系的调查

目的　研究牙颈部楔状缺损与牙齿咬合接触的关系。方法　选取 12 3名中年机关干部。用 0 .0 2mm厚的超薄咬合纸 ,临床检查侧方运动工作侧上颌尖牙、第一、二前磨牙、第一磨牙颊尖各斜面上及咀嚼循环各个时期中的牙齿咬合接触情况 ;评估接触程度。结果　患楔状缺损牙齿咬合接触程度明显高于未患楔状缺损牙。上颌尖牙和前磨牙楔状缺损患牙在远中 (上第一磨牙的近、远中 )斜面上咬合接触程度高于未患牙 ,患牙在咀嚼侧方运动循环的中、末 (上第一磨牙在初、中或末 )期咬合接触程度增加。结论　牙颈部楔状缺损的发生与牙齿的咬合接触程度加重有关。     

牙齿楔状缺损与侧方he工作侧咬合接触关系的调查

目的 研究牙颈部楔状缺损与牙齿咬合接触的关系。方法 选取123名中年机关干部。用O．02mm厚的超薄咬合纸，临床检查侧方运动工作侧上颌尖牙、第一、二前磨牙、第一磨牙颊尖各斜面上及咀嚼循环各个时期中的牙齿咬合接触情况；评估接触程度。结果 患楔状缺损牙齿咬合接触程度明显高于未患楔状缺损牙。上颌尖牙和前磨牙楔状缺损患牙在远中(上第一磨牙的近、远中)斜面上咬合接触程度高于未患牙，患牙在咀嚼侧方运动循环的中、末(上第一磨牙在初、中或末)期咬合接触程度增加。结论 牙颈部楔状缺损的发生与牙齿的咬合接触程度加重有关。     

牙齿楔状缺损与侧方(牙合)工作侧咬合接触关系的调查

目的研究牙颈部楔状缺损与牙齿咬合接触的关系.方法选取123名中年机关干部.用0.02mm厚的超薄咬合纸,临床检查侧方运动工作侧上颌尖牙、第一、二前磨牙、第一磨牙颊尖各斜面上及咀嚼循环各个时期中的牙齿咬合接触情况;评估接触程度.结果患楔状缺损牙齿咬合接触程度明显高于未患楔状缺损牙.上颌尖牙和前磨牙楔状缺损患牙在远中(上第一磨牙的近、远中)斜面上咬合接触程度高于未患牙,患牙在咀嚼侧方运动循环的中、末(上第一磨牙在初、中或末)期咬合接触程度增加.结论牙颈部楔状缺损的发生与牙齿的咬合接触程度加重有关.     

牙齿楔状缺损与侧方工作侧咬合接触关系的调查

目的研究牙颈部楔状缺损与牙齿咬合接触的关系.方法选取123名中年机关干部.用0.02mm厚的超薄咬合纸,临床检查侧方运动工作侧上颌尖牙、第一、二前磨牙、第一磨牙颊尖各斜面上及咀嚼循环各个时期中的牙齿咬合接触情况;评估接触程度.结果患楔状缺损牙齿咬合接触程度明显高于未患楔状缺损牙.上颌尖牙和前磨牙楔状缺损患牙在远中(上第一磨牙的近、远中)斜面上咬合接触程度高于未患牙,患牙在咀嚼侧方运动循环的中、末(上第一磨牙在初、中或末)期咬合接触程度增加.结论牙颈部楔状缺损的发生与牙齿的咬合接触程度加重有关.     

正常牙尖交错位咬合接触的计算机图像分析

目的 :研究正常牙合牙尖交错位咬合接触的基本规律。方法 :采集 35名正常牙合受试者牙尖交错位硅橡胶牙合记录 ,计算机图像分析系统定量测量。结果 :75 .0 %的前牙有 80 μm牙合间距离 ,仅 3.3%的前牙接触。后牙区牙合接触数为 71.4± 7.4,磨牙区占 70 %以上 ,以第一磨牙最多。牙合接触人群左右两侧无明显差异 ,其中仅 4人一侧牙合接触数目超过总数 6 0 %。 86 .1%的后牙牙合接触为稳定型 ,9.6 %为不稳定型 ,4.3%没有接触 (均为前磨牙 )。结论 :前牙不接触 ,有利于前牙免受移位性冲击     

深覆牙尖交错位咬合接触的计算机图像分析

目的研究深覆患者牙尖交错位咬合接触的异常表现。方法采集24名深覆患者牙尖交错位的硅橡胶记录,进行计算机图像分析。结果深覆单颌咬合接触数目为22．1±9．4,明显低于正常。前牙区75．0％的人有咬合接触,接触数目及频率明显增加。后牙区接触数目明显减少,咬合接触类型与正常有明显差异,不稳定的接触增多。结论深覆咬合接触与正常明显差异,的稳定性不良。深覆易致颅颌功能紊乱可能与其异常的咬合接触有密切联系。     

正常牙尖交错位咬合接触的计算机图像分析

目的研究正常牙尖交错位咬合接触的基本规律.方法采集35名正常受试者牙尖交错位硅橡胶记录,计算机图像分析系统定量测量.结果75.0%的前牙有80μm间距离,仅3.3%的前牙接触.后牙区接触数为71.4±7.4,磨牙区占70%以上,以第一磨牙最多.接触人群左右两侧无明显差异,其中仅4人一侧接触数目超过总数60%.86.1%的后牙接触为稳定型,9.6%为不稳定型,4.3%没有接触(均为前磨牙).结论前牙不接触,有利于前牙免受移位性冲击.     

正常牙尖高度的测量研究

用三坐标测量仪对70副正常(牙合)青年的牙列模型进行了牙尖高度的三维测量研究。结果:在上颌,双尖牙颊尖高于舌尖,磨牙除第一磨牙远中颊尖略高于远中舌尖外均为舌尖高于同名颊尖,双尖牙颊尖高于磨牙颊尖,在下颌,后牙均为颊尖高于同名舌尖,磨牙舌尖高于双尖牙舌尖。上下颌后牙的牙尖高度左右侧比较均无显著性差异,所用测量方法具有测量速度快、数值准确、精度高、可以直观,操作方法简便等优点。     

Relationship between tooth contacts in the retruded contact position and mandibular positioning during retrusion

We conducted a series of studies with the purpose to investigate the locations of tooth contacts in the retruded contact position (RCP) and to discuss their significance in the stomatognathic system. In the present study, the relationship between the locations of RCP contacts and mandibular positioning during retrusion was examined. Thirty dentists and clinical residents were selected as subjects. One specialist in prosthetic dentistry examined each subject for the location of the RCP contacts. The mandibular positioning during retrusion was measured using a mandibular movement analysis system with six degrees of freedom. Originally programmed software was developed. Five reference points were selected: the central lower incisor (point I), the first molars on both sides (points RM and LM) and the condyles on both sides (points RC and LC). Tooth contact was observed most frequently at the second molar, followed by the first premolar. Points I, RM and LM all moved in an inferior-posterior direction, whereas points RC and LC moved in various directions ranging from superior-posterior to inferior-posterior. When the subjects were divided into two groups according to the most anterior tooth of occlusion in the RCP, the condylar positioning tended to be more superior in the group with molar contact than that with premolar contact. These results suggest that the locations of RCP contacts could be an important factor in jaw guidance during retrusion.     

Tooth contacts at the mandibular retruded position,influence of operator's skill on bite registration

Occlusal conditions at the retruded contact position (RCP) have been thought to be among the aetiological factors for temporomandibular disorders. However, the role of these occlusal factors still remain unclear. The purpose of a series of studies was to investigate the locations of RCP contacts and to discuss their implication by the authors. In the study reported here, the influence of the operator's skill on bite registration was surveyed. Eighty-six dental students were selected as subjects. One specialist in prosthetic dentistry moved the subject's mandible up and down while guiding it gently backward until it rotated on its retruded axis. Once the initial tooth contacts were established, the operator checked them by using a thin articulating paper (direct method). On the other hand, six younger operators following precise instruction from the specialist about the technique of jaw guidance examined each of the subjects for location of RCP contacts using the indirect method. Silicone-based impression material was used for bite registration while the subject kept the jaw at this contact position (indirect method). Wilcoxon signed rank test was applied to evaluate differences between the expert operator and six younger operators regarding locations of RCP contacts. Results from the expert operator (direct method) showed that tooth contact at the first premolar was most frequently observed and the number of subjects who possessed unilateral tooth contacts was more than that with bilateral tooth contacts. On the other hand, in the case of the indirect method performed by younger operators, tooth contact patterns significantly differed from those of the direct method.     

Tooth contacts at the mandibular retruded position,comparison of two different methods for bite registration

Occlusal conditions at the retruded contact position (RCP) have been thought to be among the aetiological factors for temporomandibular disorders. However, the role of these occlusal factors remains still unclear. The purpose of this series of studies was to investigate the locations of RCP contacts and to discuss their meaning. In this part of the study, two different methods for bite registration at the RCP have been compared. Twenty dentists were selected as subjects for this study. One expert operator moved the subject's mandible up and down while guiding it gently backward until rotating on its retruded axis. Once the initial tooth contacts were established, the operator checked them using a thin articulating paper (direct method). Silicone-based impression material was used for bite registration while the subject kept the jaw at this contact position (indirect method). Differences between the two registration methods regarding locations of tooth contacts were evaluated. Results from the direct method showed that tooth contact at the first premolar was most frequently observed. Statistical difference was not shown between the two registration methods regarding locations of RCP contacts.     

Mobility of premolars under load in partially edentulous dentition

The mobility of the upper and lower premolars under load was investigated in relation to the interproximal contact and occlusal facets. The mobility was measured on ten subjects with the molars missing in the bucco-lingual and mesio-distal direction, using a non-contact sensor system, when a 500 gram load was applied in the horizontal direction, during hard biting in intercuspation and biting of foods. The ratio of the tooth movement in the bucco-lingual direction to the mesio-distal direction was larger in the upper premolars than in the lower ones. As the total mobility increased, the tooth movement was larger on the buccal side than on the lingual side of the upper jaw, on the lingual side than on the buccal side of the lower jaw, and on the mesial side than on the distal side of both jaws. The direction of the movement did not coincide with the direction of the load, due to the horizontal rotation. When biting, the first premolars showed a mesial movement and the second premolars showed a more distal movement than the first premolars. A correlation between the direction of the tooth movement during hard biting and that of the facets was observed.     

Photoocclusion analysis for the reduction of occlusal table dimension of the pontics]

50 cases of mandibular dentitions with normal morphology and occlusion are analyzed by using photoocclusion. The occlusal surfaces of the molars are divided into four regions buccolingually. That are the buccal inclines and lingual inclines of the buccal and lingual cusps of the molars. The relationship of sigma epsilon value among these four regions is 3:5:2:0 respectively. This indicates that it is effective to get force reduction by adjusting the buccal incline of the pontic in fixed bridge restoration.     

The occlusal contact mode during lateral excursion

The purpose of this study is to clarify the occlusal contact mode between the upper and lower molars on the working side of group function occlusion during lateral excursion. After the intercuspal position (IP) and two lateral positions (L1, the middle point between IP and L2; L2, the edge-to-edge occlusal position of the molars) on the Gothic arch were defined, occlusal contact relations in these three occlusal positions were recorded, using black silicone. Digital data of real occlusal contacts and visualized data of close (less than 30 microns) occlusal areas, by computer image processing, were analyzed. The conclusions are as follows: 1. Although the numbers of real occlusal contacts and the visualized occlusal area tend to decrease toward L2 during lateral excursion, the former, in some cases, goes up and down. 2. Functional cusps play an important part in occlusal contact at the intercuspal position. 3. Occlusal contact points are on the functional cusps of the upper and lower molars, which can be clinically regarded as certain points, and these points slide on the inclining non-functional cusps of antagonistic teeth during lateral excursion. 4. Each upper and lower molar has 2 to 6 occlusal contact points near the top functional cusps at the intercuspal position, and some of them contact continuously during lateral excursion.     

Influence of clenching level on intercuspal contact area in various regions of the dental arch

The purpose of this study was to evaluate the relationship between the clenching level and the intercuspal contact area in different regions of the dental arch. Twenty-five healthy subjects with natural normal dentitions and good occlusal support performed clenching tasks in the intercuspal position at four different levels (10, 30, 70 and 100% levels of maximum voluntary contraction) through EMG visual feedback from bilateral masseter and anterior temporal muscles. Simultaneously, the occlusal contacts were recorded with a silicone occlusal contact checking material (Black Silicone, GC Dental Industrial Corp., Tokyo, Japan). The occlusal records were analysed by an image analyser. Every area of the thickness less than 50 microm was determined to be an occlusal contact area. The occlusal contact areas on the anterior teeth (incisors and canines), the premolars (first and second premolars) and the molars (first and second molars) were calculated separately. The posterior occlusal contact area increased with an increase in the clenching levels but that of the anterior did not. The results of this study indicate that the increase in clenching forces affects the anterior and posterior occlusal contact areas differently.     

Occlusal splints: a critical assessment of their use in prosthodontics

A bstract — An essential aid in diagnosis and treatment planning for occlusal dysfunctions is an interocclusal splint to disocclude the dental arches, to provide bilaterally balanced jaw support in the retruded jaw position (RP) and bilateral simultaneous contacts on anterior and posterior teeth in the median occlusal position (MOP). The design of the splint processed in heat cured acrylic should ensure coverage of the lingual and occlusal surfaces and 2–3 mm of the labial and buccal surfaces of the teeth. The splint should have sufficient bulk to permit appropriate adjustment on its occlusal aspects. The physiological and psychological effects in relation to jaw function must be recognised and their influence on general muscle performance interpreted with care.     

����ѧ���������������о���״

是上下颌牙列之间的静态接触或动态咬合接触关系,以及在口颌系统功能和功能紊乱中控制牙接触的系统各组成成分之间的一种动态的生物学关系。学以咬合研究为中心,探索咬合的生理病理特性及临床应用,理解咬合形态与功能的辩证关系。与颌位是学研究的基本概念,对牙尖交错位、后退接触位、下颌姿势位及正中关系的正确理解在临床工作有重要意义。