【作者】 陈飞；

【导师】 赵士芳； 施洁珺；

【作者基本信息】 浙江大学 ， 口腔临床医学， 2010， 硕士

【摘要】 目的：探讨采用锥束CT (CBCT)分析微型种植钉支抗压低过长牙的三维治疗效果及发现牙根吸收情况的可行性,研究其进一步的临床应用方法。方法：回顾性研究2009年11月到2010年3月底正畸科需压低过长磨牙或前牙的6名患者,前后拍摄CBCT,用微型种植钉支抗压低过长牙齿。Surgicase软件测量三维压低效果,NNT软件观察牙根吸收。上颌磨牙测量第一磨牙(或第二磨牙)牙冠中央窝点(M-FH)、近中颊尖(MB1-FH)、远中颊尖(MB2-FH)、腭尖(MP-FH)到眼耳平面(FH平面)的距离,观察微型种植钉对上颌磨牙的压低效果。下颌前牙分别测量四颗下前牙切点到下颌平面(MP平面)的距离(LI-MP)以及下前牙长轴矢状分量与MP平面的角度(IR-MP),角度代表下颌前牙矢状向上的唇倾度。测量数据使用SPSS10.0统计学软件进行分析,采用配对t检验比较治疗前后改变量差异,检验水平设为0.05。结果：本研究中共6名患者14颗牙齿需要压低,其中下领前牙8颗,上颌磨牙6颗,治疗时间3月～5月。8颗下颌前牙均成功压低,上颌4颗磨牙压低效果明显,2颗磨牙仍在压低中。下颌前牙平均压低3.1mm(P<0.001),唇倾9.0°(P<0.01),上颌磨牙平均压低量分别为1.4mm (M-FH)、1.3mm (MB1-FH)、0.9m (MB2-FH)、1.3mm (MP-FH),无显著性差异。微型种植钉造成牙根吸收在前牙更加明显,7颗前后牙根吸收等级相差1,1颗前后等级相差2,磨牙牙根吸收情况前后变化不明显,8个牙根相差一个等级,10个牙根前后等级未变,基本上磨牙牙根吸收在轻中度范围。结论：CBCT可精确获得每颗牙及每个牙尖的测量数据,通过各个面来观察牙根吸收,敏感度高。微型种植钉可以为下颌前牙提供稳定的骨性支抗,牙根吸收变化比较明显。CBCT充分体现了其在正畸临床中的显著优势。本研究认为用CBCT来观察牙齿三维移动和根尖吸收,在临床应用不仅可行,而且其优于传统医学CT和二维影像。更多还原

【Abstract】 Objective:The purpose of this study was to use cone-beam computed tomography (CBCT) to evaluate the effectiveness and root resorption of micro-implant anchorage for intrusion of molar and anterior teeth.Methods:The study was comprised of 6 patients with excessive growth teeth from November 2009 to March 2010. CBCT and photos were taken immediately before and after intrusion. Three-dimensional CBCT images, measuring 9 and 12 in, were taken with a CBCT machine (NewTom 3G, Italy). All the patients was willingly to use micro-implant anchorage for intrusion. Landmark coordinates and linear and angular measurements were obtained with Surgicase software. Four linear parameters were measured (M-FH, MB1-FH, MB2-FH, MP-FH, LI-MP), one angular parameter was measured (IR-MP). The statistical analysis was performed with SPSS 10.0 (SPSS, Chicago, IL). Root resorption were obtained with NNT software.Results:The results showed that 12 excessive growth teeth were all corrected successfully. The treatment period of intrusion was from 3 to 5 months. The molar and anterior teeth were intruded for an average of 1.4 mm(M-FH) (P>0.05) and 3.1 mm(LI-MP)(P<.001), and the angular measurement was changed for an average of 9.0°(p<0.01). The root resorption was clinically significant, especially in the lower anterior teeth. Ten root resorption were unchanged, fifteen root resorption were changed by 1 level,and one root resorption was changed by 2 level.Conclusion:CBCT can measure every tooth and every tooth cusp precisely,also it can discover the root resorption easily. It was applicable to use the micro-implant as anchorage to intrude excessive growth anterior teeth, but it may induce root resorption.CBCT seems to be superior to conventional CT and cephalograms for orthodontic cases.更多还原