Potential new method of design for reconstruction of complicated mandibular defects: a virtual deformable mandibular model

The treatment of complicated mandibular defects, including misshaped and missing bones, is challenging, and the success of reconstruction depends to a large extent on the formulation of a precise surgical plan. There is still no ideal preoperative method of design for reconstruction to deal with large, cross-midline, mandibular, segmental defects. We have built a virtual deformable mandibular model (VDMM) with 3-dimensional animation software. Sixteen handles were set on the model, and these could be easily controlled with a computer mouse to change the morphology of the deformable mandibular model. The computed tomographic (CT) data from 10 normal skulls was used to validate the adjustability of the VDMM. According to the positions of the mandibular fossa of the temporomandibular joint, the maxillary dental arch, and the craniomaxillofacial profile, the model could be adjusted to an ideal contour, which was coordinated with the skull. The VDMM was then adjusted further according to the morphology of the original mandible. A 3-dimensional comparison was made between the model of the deformed mandible and the original mandible. Using 16 control handles, the VDMM could be adjusted to a new outline, which was similar in shape to the original mandible. Within 3 mm deviation either way, the absolute mean distribution of deviation between the contour of the deformed model and the original mandible was 92.5%. The VDMM might be useful for preoperative design of reconstruction of complicated mandibular defects.