查询词典 premolar

PURPOSE: To study the influence of the first premolar extraction on the angulation and eruption space of third molar.

目的：探讨拔除第一前磨牙正畸治疗后对第三磨牙角度和萌出间隙的影响。

Carnassial : Last premolar of upper jaw, first molar of lower jaw.

裂齿 ：上颚最后的一只前臼齿，下颚最前的一只臼齿。

Unfortunately, the fourth premolar in the upper jaw is quite large and looks like the first molar in the lower jaw; it is known as a carnassial tooth.

不幸的是，上颚的第四颗前臼齿很大，看起来就象是下颚的第一颗臼齿，这颗前臼齿也被称作叫裂齿。

Methods Four three-dimensional finite element models were constructed by the data of spiral CT:1Mandibular second premolar restored directly by full crown;2Fill the perforating cavity with resin material and full crown restoration;3Cast nickel chromium alloy post core plus full crown restoration;4Fiber post and resin core plus...

方法采用螺旋式CT扫描获取数据，建立下颌第二前磨牙4种情况下的三维有限元模型：1直接全冠修复；2用树脂材料充填开髓洞形后全冠修复；3铸造镍铬合金桩核与全冠修复；4纤维桩树脂核与全冠修复。

Results The incidence of wedge-shaped defects reached 97.3 %,and the frequency of involved teeth was:first premolar,second premolar,first molar,cuspid.

结果 该组老年人楔状缺损的发病率为97 。3 %，且随年龄递增；楔状缺损的好发部位和缺损程度第一双尖牙列首位，其次为第二双尖牙，第一磨牙；其中第一磨牙比以往人们认为的尖牙更好发楔状缺损。

The measurement covered the tooth material,premolar diametre,premolar basal arch widthand basal arch length. The ratios of PMD/TM, PMBAW/TM and BAL/TM were calculate.

测量牙量、双尖牙弓宽径、双尖牙根尖基骨宽径、基骨弓长度，并计算PMD/TM、PMBAW/TM、BAL/TM值，对其进行统计学处理与分析。

Methods: 50 maxillary first premolar and 60 maxillary second premolar were included in the study.

挑选拔除的50颗上颌第一前磨牙及60颗上颌第二前磨牙。

Absence of one incisor or one canine, a third premolar or a fourth premolar or of one molar.

缺一个门齿或犬齿，第三前臼齿或第四前臼齿或一个臼齿。

This in vivo study was to examine the historical changes of implanted novel chitosan/collagen composite barrier for confirming the clinical feasibility. Four other commercial GTR membranes were chosen for comparison. Among the resorbable GTR membranes, BioMend Extend and Peri-Aid are collagen base, and GORE-TEX OSSEOQUEST is synthesized membrane, while GORE-TEX e-PTFE (Expanded polytetrafluoroethylene) is synthesized but non-resorbable. Beagle dogs were used as animal model. Buccal mucoperiosteal flaps were reflected in the bilateral mandibular premolar and molar areas. Buccal alveolar bone was reduced on 1st、2nd premolar and molar to a level 5 mm apical to the cemento-enemel junction. Root surface was denuded of periodontal ligament and cementum, and notches were placed at the bone level of each root. The tested GTR barriers were implanted in critical bone defect areas. Flaps were coronally positioned and sutured. Two beagle dogs were sacrificed each time as the designed time period after surgery. Histological and histometirc evaluation at 7 days、14 days、28 days、3 months were performed post-operatively to determine the healing response of each treatment modality.

本研究之目的在评估与工研院生医中心合作发展出可吸收性去乙醯几丁聚醣/胶原蛋白复合之组织导引再生膜片，并选择与可吸收性之BioMend Extend 及Peri-Aid 胶原蛋白膜片，和GORE-TEX OSSEOQUEST 合成高分子膜片，及不可吸收之GORE-TEX e-PTFE合成高分子膜片，等其他四种市售商品材料共同对照评估，应用8只年龄为12个月的雄性小猎犬，均分4组(分别为7天、14天、28天、3个月)，为动物活体评估模式，在实验犬之左、右下颚第一、二小臼齿及大臼齿的颊侧区制造骨缺损后，分别植入组织导引再生膜片，依实验设定时间将小猎犬牺牲，取下缺损区骨头，以光学显微镜观察量测其牙垩质再生高度与齿槽骨再生高度之变化，以探讨其组织再生模式及评估新膜片在临床应用之适用性。

Anchorage loss measured at the first premolar averaged 1.3 mm,but the crowns tipped 3.5?distally.During distalization with Distal jet,the first premolar did not tend to tip mesially as found in many investigation of other intraoral distalizing appliance.

每侧第一前磨牙的支抗丧失平均为1.3mm并伴3.5 的牙冠远中倾斜，这一结果不同于其它口内磨牙远移装置所造成的前磨牙牙冠近中倾斜，与国外对同类矫治器的观察结果相似。

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。