Simulated patient for orthognathic surgery

Abstract

Orthognathic surgery corrects a wide range of minor and major facial and jaw irregularities. This surgery will improve the patients' ability to chew, speak and breathe. In many cases, a better appearance will also result. With the recent advances in virtual reality (VR) and three-dimensional (3D) medical imaging technology, orthognathic surgery simulations typically requires costly volumetric data acquisition modalities such CT or MRI imaging for patient modeling. The authors present an approach for constructing 3D hard and soft tissue models of a patient based on colour portraits and conventional radiographs. This allows patient modeling to be done efficiently on low-cost platforms. Specifically, we extend the techniques developed by the author (H.S.H Ip and Lijin Yin, 1996) to hard tissue modeling. The extended technique employs a user-assisted approach to obtain the 3D coordinates of the feature points of the human face and jaw respectively from conventional photographs and radiographs. Then the displacement vectors of the feature points are computed by correspondence matching and interpolation against a generic head model and jaw bone model. The resulting combined hard and soft tissue models can be used for orthognathic surgical planning on a low-cost, PC based platform.