Evaluation of the accuracy of a common regional registration method for three-dimensional reconstruction of edentulous jaw relation by a 7-axis three-dimensional measuring system

This study was to design a method to quantitatively evaluate three-dimensional (3D) reconstruction accuracy of spatial relationship of dental models based on a 7-axis contact 3D measuring system, and to evaluate the accuracy of a common regional registration method for edentulous jaw relation reconstruction. 3D surface data of edentulous dental casts with 10 positioning cylinders and wax occlusion rims of five patients were obtained using a dental scanner. The jaw relation was reconstructed using the common regional registration in the Geomagic software. Measurements were obtained for line length, vertical distance and horizontal distance between centric points from two sources with upper jaw model base plane as a reference plane. The statistical description of measurement data was done. $\bar{x}\pm s$ of line length, vertical distance and horizontal distance between the center points of each data set were 0.107±0.354, 0.076±0.576 and 0.108±0.530 mm, respectively. Data was analyzed using the paired samples t-test and one-way analysis of variance. Paired t-test results of each patient and one-way analysis of variance for the five patients showed no significant differences (P>0.05). Using the Faro Edge system and standardized positioning cylinders, quantitative evaluation of the 3D reconstruction accuracy of edentulous jaw relation was workable. And results of common regional registration method met clinical requirements.