应用层析建模法建立数字化腭裂模型的研究

Preliminary study on the reconstruction of digital maxillary model of infants with cleft palate by destructive scanning

目的:通过层析建模法建立唇腭裂患者牙槽嵴的数字化模型,为唇腭裂患者的模型分析建立量化方法。方法:唇裂修复术前,于全麻下对8例完全性唇腭裂患者(单侧、双侧各4例)的上颌无牙颌制取模型,用层析建模法获得牙颌模型的断层图像,通过计算机逆向工程软件进行模型重建,并进行线距测量。将三维模型测量值和石膏模型数显游标直接测量值进行比较,检验其测量准确性。使用SPSS15.0软件包中的配对t检验分析2种测量方法的测量值。结果:层析建模法重建模型上设定测量参考点14个,可测出各标志点间的距离,模型可切割后测量和计算,三维测量值和石膏模型数显游标直接测量无显著性差异(P<0.05),测量误差0.22mm～0.4mm。结论:层析建模法重建唇腭裂三维腭裂模型分析方法可以量化分析唇腭裂患者牙槽嵴的形态改变,准确性符合临床要求。为术后腭裂修复效果的评估及患者术后上颌生长发育变化建立了量化的评价方法。

PURPOSE： This study was aimed to reconstruct a digital three-dimensional maxillary cast of infants with cleft lip and palate（CLP） by destructive scanning technique and to establish measuring system of detecting cleft palate.METHODS： Under general anesthesia,edentulous casts of 8 infants with CLP（4 bilateral CLP infants,4 unilateral CLP infants） was made.The sectional images of the casts were acquired by destructive scanning.Using reverse engineering software,the sectional images were reconstructed into three-dimensional digital models.The linear measurements were carried out on digital model.The validity was accessed via digital vernier caliper on plaster model directly.Two measurements were analyzed by paired t test with SPSS15.0 software package.RESULTS： By this method,14 reference landmarks were determined for measurements,the digital model was then segmented,measured,and calculated.There were no significant difference between measured results made by destructive scanning and by digital vernier caliper on plaster model directly.The measurement error of destructive scanning was 0.22mm to 0.4mm.CONCLUSIONS： The 3D analysis developed by destructive scanning is suitable for analyzing 3D morphologic changes in the edentulous maxilla of patients with CLP.This digital model system enables a quantification of morphological evaluation and growth and development effects in the maxilla of infants with CLP after palatoplasty.