Abstract: Objective　To reconstruct 3D shape of edentulous jaw by using improved measurement system and to analyze the precision of this method.Methods　Standard edentulous jawmodels were measured with a improved measurement system by cut- ting and scanning layer-by-layer, and the 3D shape of the models was reconstructed by image processing with specialty software. Ten cubic plaster modes were reconstructed by the same way, data of every border before and after reconstruction were measured and analyzed.Results　Data of edentulous jawmodelswere obtained. The errors in ten cubic before and after reconstructionwere not significantly different(P>0·05), data measured in horizontal plane were not significantly different(P>0·05), and data measured in altitude directionwere significantly different(P<0·01), data measured after reconstructionwere less than before ,the error was (0·09±0·08) mm.Conclusion　The improved cutting and scanning measurement system can be fit for the 3D recon- struction of stomatognathic system with high precision.

Key words: three-dimensional reconstruction, edentulous jaw, reliability