[Development of 3-D reconstruction system of the craniofacial hard tissue based on 2-D digital radiograph].

Purpose: In this study, we used data from digital cephalometric radiograph to develop a 3-D craniofacial reconstruction system. The system was developed by Visual C++6.0, VTK on the platform of Windows XP, to increase the level of orthognathic diagnosis and treatment, and promote the communication between doctors and patients.

Methods: A model based on CT images was established as a standard model. Then the 3-D coordinate system was constructal and 64 feature points were set up as the initial feature points. The digital radiograph of the patient was adjusted to accord coordinate system of the model and regulated the feature points of the frontal and lateral cephalograms were regulated as the target feature points. Based on a certain deformation algorithm, deformed the standard model was deformed according to the feature points established in the digital radiograph, then the model of craniofacial hard tissue in patient was achieved.

Results: The 3-D model reflecting the actual surface construction of the craniofacial hard tissue was constructed. The 3-D image of the model constructed was lively and clear, which could be rotated and zoomed arbitrarily.

Conclusions: Separated deformation and then fusion, the hard tissue reconstruction break through convention. Occlusal relation essentially rebuilt is carried out. This system could be used in clinic for diagnosis and operation simulation.