改良Nance加前方牵引法用于矫治Ⅲ类骨性错畸形

The Application of Reformative Nance Bow with Reverse Headgear in ClassⅢ Malocclusion

目的:探讨应用改良Nance加前方牵引在矫治安氏Ⅲ类骨性错畸形的效果。方法:采用改良Nance加前方牵引技术矫治16例Ⅲ类错畸形病例,其中男性6例,女性10例,年龄7～12岁,平均9.5岁。16例患者均为近中磨牙关系,下颌不能后退至切对切,ANB(0°。治疗前后拍摄头颅定位侧位片,对16例Ⅲ类错畸形病例治疗前后X线头影测量数据进行统计分析。结果:SNA角增大,SNB角减少,ANB角增大。Ptm-A增加,表示A点前移,同时,UI-LI角减少,UI-NA角增加,表示上前牙唇向倾斜。结论:使用改良Nance加前方牵引治疗在矫治Ⅲ类错,特别在上颌发育不足或位置压缩方面效果良好,可使面中部发育不足得到改善,克服了以往活动矫治器配合前牵引固位较差,易脱落的缺点,是一种行之有效的治疗方法。

Objective： To investigate the effect of maxillary protration with reformative Nance bow in orthopedic treatment. Methods：A total of 16 patients （6 males and 10 females with an average age of 9.5 years） with Angle Ⅲ malocclusion were treated with protraction headgear attached to reformative Nance bow. Lateral cephalometric was taken respectively from 16 patients before and after treatment. Cephalometric analysis was carried out by using linear and angular measurements. The data was performed by statistial analysis. Results： SNA was increased, SNB was decreased. ANB and Ptm-A were increased which demonstrate A Point was protruded as well as UI-LI decreased and UI-NA was increased. Conclusion：Reformative Nance bow and maxillary protraction can effectively treating class Ⅲ malocclusion especially in hypoplastic maxillary and eonstringent position respects. Furthermore, the retention of reformatire Nance bow with protraction headyear was stronger than other removable appliance with it to against coming of appliance.