Treatment prediction with three-dimensional computer tomographic skull models.

Orthodontic and surgical treatment planning in the conventional articulator is compared with three-dimensional computer tomographic (3D-CT) model surgery in an individually milled skull model. After computer tomography has been completed of the patient's skull that has a bimaxillary asymmetric disharmony, the data set is transferred to generate individually milled polyurethane foam models. The imprecisely delineated dental arches of the skull model are replaced by dental casts that allow the simulation of various orthodontic and surgical treatment procedures. Expected segment displacement, the best osteotomy lines, and the resulting skeletal and dental symmetry in relation to the orthodontic set up can be evaluated. Although the technique is both time-consuming and expensive compared with the traditional treatment planning through the articulator, we have included 3D-CT model surgery in our presurgical work-up of patients with severe dentofacial disharmonies. Especially in asymmetric cases, the individually milled skulls allow a higher precision of orthodontic and surgical treatment planning.