CBCT全牙列牙冠三维数字化模型的研究

摘要

目的:通过CBCT建立全牙列牙冠三维数字化模型,并检验该模型的准确性.方法:分别用8排螺旋CT和CBCT扫描10名青年志愿者的全牙列,然后用Mimics软件三维重建其相应的全牙列牙冠的三维数字化模型,并进行线距和角度测量;分别将螺旋CT/CBCT数字化模型测量值与上述10人石膏模型测量值进行统计分析,以P≤0.05为检验水准,用平均差和配对t检验评估螺旋CT/CBCT数字化模型的准确性.结果:CBCT全牙列数字化模型较螺旋CT数字化模型更精细.螺旋CT/CBCT数字化模型线距和角度测量值均与石膏模型无明显统计学差异(P>0.05);螺旋CT全牙列数字化模型线距和角度的最大均差分别为-0.13 mm和0.39°,其绝对值均大于CBCT全牙列数字化模型线距和角度的最大均差0.08mm和0.15°,表明CBCT数字化模型更准确.结论:CBCT全牙列数字化模型较螺旋CT数字化模型更精细、细腻,测量也更准确,可为口腔学术研究和临床诊断提供有效的影像学手段.%AIM : To construct a three dimensional ( 3D) digital model of full dentition crowns by CBCT and to test the accuracy of the modeL METHODS : We scanned ten young volunteers'dentition by CT and CBCT.Then the 3D digital models of full dentition crowns were reconstructed by Mimics.Linear and angular measurements were measured.Finally.all the measurements of CT/CBCT were compared with the measurements on the ten volunteersplaster casts.Validity of CT/CBCT was assessed by mean differences and paired Student t tests.A P value of P≤O.05 was used to assign statistical significance.RESULTS : The 3D digital models of CBCT were sharper than the models of CT.There is no significant difference between the 3D models of CT/CBCT and the plaster casts in linear and angular measurements (P＞0.05).The maximum mean differences in linear and angular measurement of CT models were -0.13mm and 0.39°, whose absolute value were bigger than 0.08mm and 0.15°of CBCT models , indicating that the CBCT models were more accurate than CT models.CONCLUSION: The 3D digital models of the full dentition crowns by CBCT were clearer,more detailed and accurate than the moclels by CT.CBCT would be an effective imaging method for aeademic research and clinical diagnosis in the oral field.