A Study of new development and design of the stock tray for edentulous patients

目的：应用三维激光扫描仪对上下颌无牙槽突牙槽骨进行三维测量。方法：从我科已有的牙列模型中选取140对(男60例，女80例)上下颌无牙颌模型。研究模型使用三维扫描仪(LPX-250，Roland DG)扫描。可以从任何角度对扫描的图像进行数字处理以进行评估。该分析软件允许在两点之间进行线性距离测量。上颌在左右Hamuler切迹处建立后方参考点，下颌在左右磨牙后垫中点建立后方参考点。无牙槽骨宽度以后参照点之间的距离为标准。在此基础上，通过前牙列与后方基准线之间的横截面建立前基准点，该基准线从后基准线中心垂直绘制。结果与讨论：三维激光扫描从研究病例放入扫描仪到数据记录的时间约为7分钟。无牙槽骨的宽度和长度均有绝对值。根据测量结果，上颌无牙颌牙列的宽度和长度分别为47.1、47.2、30.9、56.3 mm。男女数据比较，上颌宽、上颌长、下颌宽差异有统计学意义(p&lt；0.05)。上颌骨r=0.116，下颌骨r=0.239。这些结果不支持使用宽度和长度之间的相关性来进行无牙牙槽脊分类的基础。

I.Objectives :In order to facilitate three-dimensional measurements of maxillary and mandibular edentulous ridge, a three-dimensional laser scanner was applied.II.Methods :From the archived study casts in our department, 140 pairs of maxillary and mandibular edentulous study casts (60 males, 80 females) were selected. Study casts were scanned using a three-dimensional scanner (LPX-250,Roland DG). The scanned image can be digitally manipulated for the evaluation from any angles. The analysis software allows linear distance measurement between two points. The posterior reference points were established at right and left Hamuler notch for maxillae and the mid point of the right and left retro-molar pad for mandibles. The edentulous ridge width was determined as the distance between the posterior reference points. Furthermore, the anterior reference point was established by the cross section between anterior edentulous ridge and a reference line that was perpendicularly drawn from the center the posterior reference line. The length of the edentulous ridge was determined along the perpendicular line.III.Results and Discussion :The duration of a three-dimensional laser scanning was approximately 7 minutes from study case placement in the scanner to data recording. The width and length of the edentulous ridge were provided with absolute values. From our measurements, the width and length of maxillary and mandibular edentulous ridges were 47.1,47.2,30.9,56.3 mm, respectively. When male and female data were compared, the maxillary width and length, as well as mandibular width showed significant differences (p<0.05). However, the regression analysis between the width and length did not show significant correlation (maxilla r=0.116 ; mandible r=0.239). These results did not support the basis for edentulous ridge classification using the correlation between the width and length.