口内数字印模与选择性压力印模下颌牙列缺损游离端黏膜形态差异分析

Study of the mucosal morphological difference of distal-extension of mandibular dentition defect impressions taken by intra-oral digital scanning and selective pressure impression technique

目的:比较口内数字印模与选择性压力印模技术制取的下颌牙列缺损模型游离端黏膜组织形态的差异。方法:纳入下颌Kennedy第一、二类牙列缺损患者17例,共23个游离端,分别使用口内数字印模和选择性压力印模为同一患者制取2个下颌模型。使用模型扫描仪获取选择性压力印模石膏模型的三维图像,作为参照模型。在Geomagic Control 2014软件中将同一患者的口内数字印模与选择性压力印模进行三维偏差分析,得到均方根误差,测量游离端牙槽嵴顶距末端基牙5、10、15 mm处的2.5 mm半径圆形区域形态差异。采用SPSS 20.0软件包对偏差进行统计学分析。结果:口内数字印模与选择性压力印模技术制取的游离端黏膜平均形态差异为(0.37±0.12)mm,最小形态差异为0.26 mm,最大形态差异为0.55 mm。区域形态差异与末端基牙距离呈正相关(P<0.05),其中,距末端基牙5 mm处区域形态差异为(0.14±0.11)mm,距末端基牙10 mm处区域形态差异为(0.22±0.13)mm,距末端基牙15 mm处区域形态差异为(0.39±0.16)mm。结论:在本研究条件下,口内数字印模与选择性压力印模对下颌游离端缺牙区黏膜组织形态差异整体为0.26~0.55 mm,形态差异大小与距离末端基牙的距离呈正相关趋势。

PURPOSE:To compare the mucosal morphological difference in distal-extension area of mandibular dentition defect taken by intra-oral digital scanning and selective pressure impression techniques.METHODS:Seventeen patients with Kennedy Class I and Class II dentition defect in lower jaw were included,including twenty-two distal-extensions.Intraoral digital scanning and functional impression technique were taken in each patients,respectively.Laboratory cast scanner was used to scan the plaster casts made from the selective pressure impression to obtain the three-dimensional data.All the data were stored in STL format.The 3D data collecting from intra-oral digital scanning and selective pressure impression from the same patient were compared by Geomagic Control 2014 software.Root mean square of 2.5mm diameter area was calculated in 5,10,15 mm from terminal tooth.Pearson's correlation test was used to analyze the correlation of the distance and morphological difference with SPSS 20.0 software package.RESULTS:Mean mucosal morphological difference of jaw distal-extension edentulous area taken by intra-oral digital scanning and selective pressure impression techniques was(0.37±0.12)mm.There was positive correlation between distance from terminal tooth and mucosal morphological difference(P<0.05).Morphological differences in 5,10,15 mm from terminal tooth were(0.14±0.11)mm,(0.22±0.13)mm and(0.39±0.16)mm,respectively.CONCLUSIONS:In this study,there was positive correlation between the length of distal-extension edentulous area and mucosal morphological difference,while the kind of ridge defect and mucos al thickness may also affect the morphological difference quantity.