Three-dimensional dental model constructed from an average dental form

Introduction The purposes of this study were (1) to discover a simple method for computing an average dental form, (2) to evaluate the validity of the new computing method, and (3) to build an average digital dental model based on the resulting average dental form. Methods Dental casts of 51 adults were scanned, and 3-dimensional virtual models were reconstructed by using specialized software. Fifty-two anatomic landmarks were plotted on each model to obtain a configuration representing that model. The averaging method was a simplified approach of the generalized partial Procrustes analysis (GPPA); called multiple partial Procrustes analysis (MPPA), it was used to superimpose the 51 sample configurations. For the evaluation method, the GPPA was performed to estimate the population mean form. This mean form was compared with the average forms obtained from the proposed method by using the Procrustes distance as the measure of difference. Construction of the average dental model was based on an average form obtained from the proposed method, and a 3-dimensional dental mesh model was reconstructed. Results The average forms from the proposed method showed no significant differences compared with the one from the GPPA. The Procrustes distances were about 0.01 mm, which can safely be considered insignificant. Conclusions The proposed averaging method, which is simpler than the traditional GPPA approach, was found to be feasible for computing average dental forms. The average dental model constructed in this study might serve as a guide for treatment planning in orthodontic and prosthodontic dentistry.