查询词典 premolar

The sample comprised 25 patients with the first premolar removed during orthodontic treatment. Digital models and lateral cephalometric records were taken pre- and post- treatment. We chose two kinds of regional superimposition methods on the digital models (One was the mesial zone of the third primary ruga and regional palatal vault, the other was the palate) and Baumrind's best-fit for cephalometric superimposition. The amounts of incisor and molar movement were measured and a comparative study was performed.

三。选择25例拔除上颌第一双尖牙正畸患者治疗前、后的上颌模型进行三维重建，分别使用第三腭皱近心端局部腭穹隆和腭部对同一患者治疗前、后的数字化模型进行局域重叠，以治疗前后头颅侧位片的 best-fit重叠为评价标准，比较三种方法之间的差异，对应用三维数字化牙颌模型纵向重叠评价正畸治疗前、后的牙齿移动进行探索性研究。

Methods Bacterial plaque index of submaxilla premolar, gum bleeding index and probing depth of rhubarb and indomethecin rinse group and placebo group were measured at 1 week before and 2, 4, 8 weeks after placing orthodontic appliances.

方法将60例需做正畸治疗的患者分为2组，A组和B组患者戴入矫治器前1周、戴入后2周、4周、8周下颌前磨牙菌斑指数、牙龈出血指数、牙周探诊深度。

This article is a report of sever maxillary protrusion or bimaxillary protrusion cases. They had four first premolar extraction, but the outcomes were not so satisfied. So four first molars were extracted later, and this contributed to a good profile.

此篇文章的主要目的即以骨骼性或齿槽性之严重上颚或上下颚前突病例，在拔除第一小臼齿矫正处置后，因必要再拔除大臼齿继续处置，最后得一良好侧貌的报告。

Methods The Chatillon force measuring instrument was used to record the retention of gold alloy casting Akers clasps when they were dislodged from the undercuts of different depths (0.25 mm, 0.375 mm, 0.50 mm and 0.75 mm) on the premolar and molar. All data were analyzed by ANOVA.

采用Chatillon测力仪，测定临床常用金合金铸造三臂卡在磨牙和前磨牙的0.25、0.375、0.50、0.75 mm倒凹深度上的固位力，同时进行统计学分析。

Methods Ten volunteers with experimental premature contact at the first premolar, the first molar and the second molar were asked to clench in CO and their electromyographic activity of the masseters, anterior temporalis and anterior belly of digastric muscles were measured simultaneously.

测定 10名志愿者在正中牙合；左右两侧下颌第一双尖牙、第一磨牙、第二磨牙实验性早接触状态下，嚼肌、颞肌前束及二腹肌前腹肌电活动的积分值与频谱值。

In the soft tissue measurements, the value of soft tissue facial angle and B'-Pos-FH in the first extraction group was less than those in the second extraction group significantly. After treatment all the patients had an increase in S-Ns-Pos angle, soft tissue facial angle, B'-Pos-FH and depth of mentolabial groove. At the same time, soft tissue convexity angle was diminished obviously. But the change was not significant between the two premolar extraction groups.

2在对软组织项目的测量中，治疗前第一前磨牙拔除组的软组织面角、颏沟倾角均小于第二前磨牙拔除组，治疗后2组均出现软组织面凸角减少，颏凸角、软组织面角、颏沟倾角、颏唇沟深度增加；但2组在各项测量项目的变化上无显著组间差别。

Methods:7 cases of classⅡ,division 1 maloclusion were treated.Upper first premolar and lower second premolars were extracted in all cases.Lower first molars were mesially moved by means of segmental arch. Cephalometric analysis was used to evaluate the effects of the treatment.

应用片段弓技术对7例安氏Ⅱ类1分类患者，通过拔除上颌第一前磨牙及下颌第二前磨牙，使下颌第一磨牙较快地向近中移动，纠正磨牙Ⅱ类错牙合关系。

The clinical characters of oligodontia concluded from this study are following:(1) There is significant difference that more teeth absent and more existent teeth anomalies in patients of oligodontia/S group than in patients of oligodontia/I group, and the peg-shaped upper lateral incisor is the most frequently affected teeth with shape anomaly.(2) Both of the two groups have no significant differences in number of teeth missing between maxilla and mandible as well as that between left and right side.(3) The distribution of teeth missing is bilateral symmetry in both groups, but the frequency of teeth lost are different: excluding the third molar, in oligodontia/I group, the lower second premolar is the most frequently congenitally missing tooth followed by the upper lateral incisor, while in oligodontia/S group, the most frequently missing teeth are mandibular canine and maxillary lateral incisor. Nevertheless, the first molars are the most stable teeth in both groups.(4) In oligodonita/I group, the mean mesiodistal dimensions of all type of existent teeth are significantly smaller than normal value. It is implied that oligodontia is not an isolated phenomenon, but is related to a complex of other dental changes.

对于口腔多个恒牙先天缺失的临床特点有以下初步结论：(1)综合征型先天缺牙患者较单纯型先天缺牙患者恒牙缺失数目更多，平均分别为23.9个和14.9个，且现存牙齿有更多的形态异常，分别为7／10例（70％）和6／22例（27.3％），其中最常见的是上颌侧切牙畸形；(2)两种类型的多个恒牙先天缺失患者的缺牙数目在上下颌及左右侧之间均无差别；(3)两种类型的多个恒牙先天缺失患者在缺失牙位上均呈对称分布，但在具体牙位上有所差异：不计第三磨牙，单纯型先天缺牙最常缺失的牙位是下颌第二双尖牙、其次为上颌侧切牙；而综合征型先天缺牙最常缺失的牙位是下颌尖牙和上颌侧切牙；无论何种情况，第一磨牙均为牙列中最稳定的牙齿；(4)在单纯型先天缺牙患者中，现存恒牙的牙冠宽度较国人正常值偏小，差异显著，提示牙齿形态与多个牙先天缺失有一定相关性。

Methods: Fifty-fix adolescents were chosen and divided into first premolar extraction and nonextraction groups, with 30 and 26 patients respectively. The pretreatment and posttreatment panoramic radiographs were taken. The indexes of third molar eruption space, distance from third molar to occlusal plane and the length of mandible were measured and analyzed.

选择56例上下颌第三磨牙均存在的患者进行方丝弓正畸治疗，按照第一前磨牙拔除与否分为拔牙组（30例）和非拔牙组（26例），利用术前术后曲面断层片对患者上下颌第三磨牙萌出间隙、第三磨牙与胎平面的距离以及下颌长度进行测量分析。

After bridge insertion, the pontic of fixed bridge re- stored additional force, but the change of stress in the peri- odontium of premolar and molar is very diffierent.

固定桥修复后桥体承受了增加的载荷，双尖牙和磨牙牙周膜应力的变化规律是不相同的，双尖牙牙周膜应力的增加幅度大于磨牙。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。