安氏Ⅱ类1分类拔牙矫治患者的X线头影测量研究

Cephalometric Appraisal of Extraction Treatment Patients in Gass Ⅱ Division 1 Malocclusion

目的 对安氏Ⅱ类1分类拔牙矫治患者进行治疗前后的X线头影测量研究,以了解该类患者矫治后的牙颌面结构变化。方法 对20例安氏Ⅱ类1分类患者酌情拔除4颗双尖牙或2颗上颌双尖牙,方丝弓矫治器矫治。对治疗前后的头颅定位侧位片进行测量、统计及分析。结果 上中切牙倾斜度（UI-NA）减小15.44度。上中切牙突度UI-NA（mm）减小4.72mm。前牙覆盖减小6.22mm。下颌基骨（Go-Po）生长5.11mm。后面高（ANS-Me）及前面高（S-Go）各增加了4.94mm和5.0mm。下颌平面角无明显改变。结论 安氏Ⅱ类1分类患者矫治后深覆盖的改善主要是上前牙的内收及下颌骨的向前生长和向前移动。Ⅱ类的矫治使得下颌骨的长度得到明显增加。

Objective The purpose of this study was to evaluate dentofacial changes in class Ⅱ division 1 malocclusion with extraction treatment. Methods Twenty class Ⅱ division 1 malocclusion patients (7 males and 13 females) were extracted four promolars in maxillary and mandibular or two promolars in maxillary. The cephalograms were compared before and after treatment of Edgewise appliance. Results After treatment, UI-NA reduced by 15.44° ( P < 0.001) , UI-NA mm reduced by 4.72mm ( P < 0.01) overjet reduced by 6.22mm. Go-Po increased by 5.11 mm, S-Go increased by 5mm and ANS-Me increased by 4.94mm( P < 0.05 ) . Conclusion The improvement of cover was a result of upper incisor changes mainly and partly from mandibular growth and forward movement. Mandibular gained a significant growth during treatment.