关键词: Tweed-Merrifield，正畸治疗，种植支抗，J钩

Abstract: Abstract: Correct design ,control and applications of anchorage in orthodontic treatment are important factors that made the good correction effect,and traditional Tweed edgewise correction technology of anchorage system in preparing various types of malocclusion orthodontic technology has played a key role in the development.Nowadays the clinic has a variety of enhanced anchorage device for orthodontists choice,but still cannot afford to absolute anchorage effect.Therefore,in the cases clinically accompanied by serious crowding, deep over jet and so on that do not want to lose the anchorage,teeth alignment and profile improvement were affected,Although extra oral device is the effective method to improve the anchorage,patients often have psychological repellency clinically because the operation is complicated. in recent years the appearance of orthodontic implant anchorage,better solved clinical anchorage selection problem.But for some high angle class II malocclusion,the use of traditional extra oral anchorage or implant anchorage,can improve patients face to a maximum degree?Whether the anchorage preparation in the concept of Tweed can be better in line with the orthodontist' operating concept by various applications of anchorage? These are our current concerns in clinic. 