微钛钉种植体支抗单侧推磨牙向后的临床应用

The clinical effects of unilateral distalization of upper molars in Class Ⅱ,malocclusion by micro-implant anchorage.

目的:探讨运用微钛钉种植体支抗单侧推磨牙向后的临床及应用要点。方法:选择安氏Ⅱ类亚类错7例,男2例,女5例,年龄15～30岁,平均18.7岁。轻中度拥挤,拥挤度平均在4～5mm,或伴上中线偏移,侧貌面下1/3无明显前突者。采用单侧颊侧植入微钛钉种植体,推磨牙向后,推力250g。疗程3～5个月,平均4个月。通过临床评价和矫治前后的照片、模型和头颅侧位片分析其治疗的有效性。结果:7例患者有效地应用微钛钉种植体支抗单侧推磨牙向后,非拔牙矫治纠正了单侧磨牙Ⅱ类远中关系、轻中度拥挤或中线偏移,取得较好的临床疗效。远移侧上颌第一磨牙远中平均移动4.2mm,平均移动速度(1.25±0.25)mm/月,有一定程度的颊向移动,水平旋转和垂直压低。上中切牙长轴倾斜度、下颌平面及面下1/3高度不变。结论:微钛钉种植体支抗单侧推磨牙向后,发挥了绝对强支抗作用,有效地远中移动上颌磨牙。矫治过程中,需注意诊断、设计、生物力学的考虑以及临床应用要点。

Objective： To study the clinical effects of unilateral distalization upper molars in class Ⅱ malocclusion by micro-implant anchorage.Method： 7 Class Ⅱ, subdivision malocclusion patients with Ⅰ - Ⅱ ° Crowding or midline shifting （5 females and 2 males） were selected as the subjects,aged from 15 to 30 years old （18.7 on average） ,All the patients were treated with non-extraction treatment by distalizing the unilateral upper molar with micro-implant anchorage. The micro- implant was embedded in buccal alveolar bone between maxillary second premolar and maxillary first molar, and then the Ni-Ti coil spring was set maxillary second premolar and maxillary first molar. The duration for distalization of upper molars was from 3 to 5 months （about 4 months on average） .This study had measured the change in velocity, distance and position of the maxillary first molar, which evaluated molar moving form character to test anchorage intensity. Casting Model and Cephalometric analysis were used. All results were analyzed by statistics. Result： The upper molar was bodily distalized by 4.2 mm on the side with （1.25±0.25） mm / M. The horizontal circumvolving angle,the intrusion and buccally move of the first molar were of statistics significance. The upper incisor position remained stable throughout treatment. The lower incisor position remained unchanged as well as the mandible plane and the lower facial height. Conclusion： The results of this study have shown that the micro-implant placed in the maxillary interradicular bone provided absolute anchorage for unilateral or bilateral distalization of maxillary molar. It is an effective and reliable method for distalizing maxillary molars without the loss of anchorage. This treatment requires minimal patient compliance and also shortens the whole treatment period and is easy to insert and remove. However, it should be cautious for applying the micro-implant anchorage to distalize the maxillary molar because of its side effects.