CAJ | 학술논문

目的：：研究在数字化牙颌模型上确定牙合平面的两种方法的可重复性并比较其差异。方法：从北京大学口腔医院正畸科2004年7月至2008年8月治疗完成并具有完整临床资料的806例病例中，以Angle分类为分层因素，随机抽取48个病例，扫描其治疗后石膏模型生成数字化模型。在自行开发的软件中，由1名测量者以至少1周的间隔、重复5次在模型上确定标志点，拟合出1组解剖牙合平面和1组功能牙合平面；并由6名测量者分别定点，拟合出2组牙合平面。计算每个模型各组平面夹角的标准差，比较4组平面的可重复性并分析出现极端值的模型。结果：功能牙合平面和解剖牙合平面的可重复性在同一测量者差异无统计学意义(P>0.1)，在6名测量者间差异有统计学意义(P<0.001)，功能牙合平面的合并样本标准差小于解剖牙合平面，相差0.2°。同一测量者和6名测量者确定的功能牙合平面的可重复性差异没有统计学意义(P>0.1)，解剖牙合平面的可重复性差异有统计学意义(P<0.001)，同一测量者的合并样本标准差小于6名测量者，相差0.12°。结论：由一名测量者进行一批模型的测量时，功能牙合平面与解剖牙合平面的可重复性相同，均适合作为参考平面；由不同测量者进行大批量的测量时，功能牙合平面的可重复性好于解剖牙合平面，但差距较小。
목적：：연구재수자화아합모형상학정아합평면적량충방법적가중복성병비교기차이。방법：종북경대학구강의원정기과2004년7월지2008년8월치료완성병구유완정림상자료적806례병례중，이Angle분류위분층인소，수궤추취48개병례，소묘기치료후석고모형생성수자화모형。재자행개발적연건중，유1명측량자이지소1주적간격、중복5차재모형상학정표지점，의합출1조해부아합평면화1조공능아합평면；병유6명측량자분별정점，의합출2조아합평면。계산매개모형각조평면협각적표준차，비교4조평면적가중복성병분석출현겁단치적모형。결과：공능아합평면화해부아합평면적가중복성재동일측량자차이무통계학의의(P>0.1)，재6명측량자간차이유통계학의의(P<0.001)，공능아합평면적합병양본표준차소우해부아합평면，상차0.2°。동일측량자화6명측량자학정적공능아합평면적가중복성차이몰유통계학의의(P>0.1)，해부아합평면적가중복성차이유통계학의의(P<0.001)，동일측량자적합병양본표준차소우6명측량자，상차0.12°。결론：유일명측량자진행일비모형적측량시，공능아합평면여해부아합평면적가중복성상동，균괄합작위삼고평면；유불동측량자진행대비량적측량시，공능아합평면적가중복성호우해부아합평면，단차거교소。
Objective:To assess the repeatability ( intraobserver comparison ) and reproducibility ( inter-observer comparison) of two different methods for establishing the occlusal plane on digital dental models. Methods:With Angle’ s classification as a stratification factor,48 cases were randomly extracted from 806 ones which had integrated clinical data and had their orthodontic treatment from July 2004 to August 2008 in Department of Orthodontics,Peking University School and Hospital of Stomatology. Post-treatment plas-ter casts of 48 cases were scanned by Roland LPX-1200 3 D laser scanner to generate geometry data as re-search subjects. In a locally developed software package,one observer repeated 5 times at intervals of at least one week to localize prescriptive landmarks on each digital model to establish a group of functional occlusal planes and a group of anatomic occlusal planes, while 6 observers established two other groups of functional and anatomic occlusal planes independently. Standard deviations of dihedral angles of each group on each model were calculated and compared between the related groups. The models with the five largest standard deviations of each group were studied to explore possible factors that might influence the identification of the landmarks on the digital models. Results:Significant difference of intraobserver varia-bility was not detected between the functional occlusal plane and the anatomic occlusal plane ( P>0 . 1 ) , while that of interobserver variability was detected ( P<0 . 001 ) . The pooled experimental standard devia-tion the 6 observers established for the functional occlusal plane was 0 . 2 ° smaller than that of the anato-mic occlusal plane. The functional occlusal plane’ s variability of intraobserver and interobsever did not differ significantly (P>0. 1),while the anatomic occlusal plane’s variability of the intraobserver was sig-nificantly smaller than that of the interobserver (P<0. 001),with a 0. 12° difference value of the pooled experimental standard deviation. Conclusion: When one observer measures a number of digital models, both the functional and the anatomic occlusal planes are suitable as a conference plane with equal repeatability. When several observers measure a large number of digital models,the functional occlusal plane is more reproducible than the anatomic occlusal plane,but the difference is small.