应用CBCT评估隐形矫治技术远移上颌磨牙的临床疗效

Researches on the Effects of Upper Molars Distalization with Clear Aligner Treatment by Cone-beam Computed Tomography

目的:通过口腔锥形束计算机断层扫描系统(Cone-beam computed tomography,CBCT)对隐形矫治技术远移磨牙的疗效进行评估。方法:收集15例Invisalign隐形矫治技术远移上颌磨牙的病例,患者平均年龄27岁,均配合Ⅱ类颌间牵引。在治疗前及第一磨牙远移到位时拍摄CBCT影像,运用Dolphin软件生成CBCT转化头颅侧位片,分别测量治疗前后左右两侧上颌第一磨牙、第二磨牙和中切牙在矢状向和垂直向的移动情况,以及上下颌骨和软组织侧貌在矢状向和垂直向的变化情况,采用SPSS18.0软件进行相关统计学分析,评价磨牙远中移动效率和整体移动效率。结果:①隐形矫治远移磨牙使上颌第一磨牙牙冠远中移动(2.03±1.01)mm,牙根远中移动(1.13±1.02)mm,根尖平均压低0.35 mm,上颌第二磨牙牙冠远中移动(2.54±1.34)mm,牙根远中移动(1.66±0.82)mm,根尖平均压低0.80 mm。测量结果表明治疗前后磨牙矢状向远移、垂直向压低、远中倾斜差异均具有统计学意义(P<0.05);②治疗前后上颌中切牙的矢状向、垂直向移动距离,转矩角的差异均无统计学意义(P>0.05);③骨组织和侧貌软组织相关指标变化治疗前后差异亦无统计学意义(P>0.05);④第一磨牙和第二磨牙的远移表达率分别为85.2%、79.0%,实际远移距离与预期移动距离差异有统计学意义(P<0.05)。结论:隐形矫治技术可有效远移上颌磨牙,矫治效率较高。矫治期间支抗未见明显丧失,上下颌骨、面型在矢状向、垂直向变化无显著影响,副作用较小。

Objective To evaluate the therapeutic outcome of Upper Molars Distalization by Clear Aligner Treatment using cone-beam computed tomography.Methods Choose 15 patients with mean age of 27 years who were treated by Invisalign clear aligners and needed upper molar distalization.Class II elastics were used to reinforce the anchorage during the treatment.Cone-beam computed tomography images were obtained at the beginning of the treatment and after upper first molar distalization was accomplished.The sagittal and vertical movements of the maxillary first molars,the second molars,and the central incisors were measured before and after the treatment,and the sagittal and vertical changes of jaws and soft tissue profiles were also measured.SPSS18.0 was used for correlation analysis.The efficiency of molar distalization and bodily movement were calculated.Results①The crown of upper first molars was distalized(2.03±1.01)mm,the root of upper first molars was distalized(1.13±1.02)mm.The average intrusion was 0.35 mm.The crown of upper second molars was distalized(2.54±1.34)mm,the root of upper second molars was distalized(1.66±0.82)mm,the average intrusion was 0.80 mm.The sagittal distalization,vertical intrusion,distal tipping changed significantly(P<0.05).②Before and after treatment,the sagittal plane distalization,vertical-direction intrusion,distal tipping and buccal inclination of incisors did not show statistically significant changes(P>0.05).③There was no significant difference in the changes of jaws and soft tissue profiles before and after treatment(P>0.05).④The distalization expression rate of the first and second molars were 85.2%and 79.0%respectively.Conclusion Clear aligners can move maxillary molars with high efficiency.During molar distalization,there was no significant sagittal and vertical effects on anterior teeth,maxilla and maxillofacial.