前牙类

"Any of four or five species of slender, agile elapid snakes (genus Dendroaspis, or Dendraspis) having large scales and long front teeth."

眼镜蛇科树眼镜蛇属4～5种体细长、敏捷的眼镜蛇类。鳞片较大，前牙颇长

"Any of four or five species of slender, agile elapid snake s (genus Dendroaspis, or Dendraspis) having large scales and long front teeth."

眼镜蛇科树眼镜蛇属4～5种体细长、敏捷的眼镜蛇类。鳞片较大，前牙颇长

In all case, centric relationship of canine and 1st molar was obtained, with normal overbite and over-jet of anterior teeth.

全部病例均达到尖牙和磨牙的Ⅰ类关系、牙列整齐、前牙覆覆盖正常。

objective the purpose of this study was to explore the method and effectiveness of apertognathia of anterior teeth in teenagers.methods the majority patients were corrected with edgewise appliance after draw four molars, all sorts of flexure were curved on the appliance, used perpendicular traction for anterior teeth and ii, iii maxillomandibular traction, fine adjust intercuspal position ,tip and cavity.

目的 探讨青少年前牙开牙合的矫治方法和效果。方法多数患者采取拔除4个磨牙之后使用方丝弓矫治器矫治，矫治中在弓丝上弯制各种曲，并使用前牙垂直牵引和颌间ⅱ类、ⅲ类牵引，精调牙位及尖窝关系。

Methods The majority patients were Corrected with edgewise appliance after draw four molars, all sorts of flexure were curved on the appliance, used perpendicular traction for anterior teeth and II, III maxillomandibular traction, fine adjust intercuspal position ,tip and cavity.

多数患者采取拔除4个磨牙之后使用方丝弓矫治器矫治，矫治中在弓丝上弯制各种曲，并使用前牙垂直牵引和颌间Ⅱ类、Ⅲ类牵引，精调牙位及尖窝关系。

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。

ConclusionThe orthodontic treatment mainly affects the position of upper and low teeth, and the nasolabial angle and soft tissue convexity.

青少年安氏Ⅱ~1类患者的正畸治疗主要引起前牙位置、软组织的变化，对骨骼结构无明显影响。

Most Angle class two division one subdivision malocclusion with mandibular retrusion have their characteristic condylar movement style, the difference from that of normal occlusion maybe correlate to condylar position, overbite and overjet.

下颌后缩型安氏Ⅱ类1分类错牙合的髁突运动轨迹有较典型的特征，可能与其髁突位置、前牙覆牙合覆盖有关。

objectivethe aim of this study was to evaluate the curative effects of the modified fixed reverse twin-block appliance combine edgewise on treatment of adult angle ⅲ anterior crossbite.methodsthe appliance was used on 15 adult subjects with angle ⅲ malocclusion and then compared clinical character and x-ray cephalometry before and after treatment.resultsafter 4 months treatment the appearance and profile were improve evidently, mandible retrusion was to lead molar and canine were angle i,overjet and overbite were normal.

目的：应用改良固定反式双阻板矫治器（twin-block appliance，tba）联合方丝弓技术矫治成人angleⅲ前牙反牙合，为成人前牙反牙合提供新的治疗方法。方法：矫治成人患者15例，进行临床表现及相关硬组织测量。结果：固定反式tba戴用4个月后下颌明显后退。所有患者在未拔牙的情况下前牙反牙合均得到有效治疗，磨牙及尖牙均达到i类关系。但上颌仅为牙及牙槽的代偿性变化。

Key words: anterior crossbite;skeletal class iii;early treatment; maxillary protraction; cephalometric analysis

前牙反牙合；骨性ⅲ类；早期治疗；前方牵引；头影测量分析

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。