目的:研究使用种植体支抗整体远中移动下颌牙列治疗骨性Ⅲ类错牙合畸形的疗效。方法:选择轻到中度骨性Ⅲ类错牙合患者20例,男性8例,女性12例,年龄16~38岁,平均(21.5±5.6)岁。采用直丝弓矫治技术,使用下颌外斜线区种植体支抗整体远中移动下颌牙列。患者在治疗前后拍摄X线头颅定位侧位片,对共计26个软硬组织测量项目进行测量分析。结果:矫治结束后患者磨牙关系均达到中性关系,侧貌改善。治疗后ANB角增大(0.80±1.02)°,P<0.05,Wits值增大(1.67±1.74) mm,P<0.05;L1NB距离减小(2.64±1.50) mm,P<0.05;下颌第一磨牙近中颊尖远中移动(3.26±1.95) mm,P<0.05;下颌第一磨牙近中根尖远中移动(0.79±1.27) mm, P<0.05;下颌第二磨牙近中颊尖远中移动(3.06±1.80) mm,P<0.05。下颌牙齿与下颌平面的夹角:L1/MP角度减小(6.37±8.53)°,L5/MP角度减小(10.59±8.50)°,L6/MP角度减小(11.48±7.22)°,L7/MP角度减小(15.72±7.16)°,差异均有统计学意义(P<0.05);下唇和审美平面距离减小(1.70±1.59) mm, P<0.05。结论:种植体支抗整体远中移动下颌牙列能够有效治疗恒牙期骨性Ⅲ类错牙合,侧貌改善良好;下颌牙齿发生有控制的倾斜移动。
Objective:To evaluate the clinical effect of distalizing mandibular dentition with micro-implant in patients with skeletal classⅢmalocclusion. Methods: In the study, 20 patients with skeletal class Ⅲmalocclusion were selected. They are consist of 8 males and 12 female with an age range from 16 to 38 years old and an average age of (21.5±5.6) years.They were treated with straight wire technique and the implant were inserted into the mandibular external oblique line to distlize the lower dentition to a class Ⅰmolar relationships.Cephalometrics films were taken before and after treatment. The changes of hard tissue and soft tissue were analyzed by evaluating 26 measurement measurements. Results: ClassⅠmolar relationships were achieved, and the profile were improved after treatment. ANB increased by(0.80±1.02)°,Wits increased by (1.67±1.74) mm,after treatment(P<0.05).The lower dentition were significantly retracted after treatment with L1-NB distance decreased by(2.64±1.50) mm, P<0.05; the mesial buccal cusp and mesial root of the lower first molars were retracted by (3.26±1.95) mm and (0.79±1.27) mm respectively (P<0.05); the mesial buccal cusp of the lower second molars were retracted by (3.06±1.80) mm (P<0.05). After treatment, mandibular teeth got uprighted distally. From incisors to molar, L1/MP, L5/MP, L6/MP, L7/MP angle decreased by(6.37±8.53)°, (10.59±8.50)°, (11.48±7.22)°, (15.72±7.16)°on average respectively (P<0.05), all of those changes had the statically significant effects. Soft tissue change after treatment, the distance from lower lip to esthetic plane were decreased by (1.70±1.59) mm on average (P<0.05). Conclusion: Distalizing mandibular dentition with micro-implant can get an satisfying result in patients with skeletal class Ⅲmalocclusion, the lower teeth were retracted by controlled tipping movement.