Virtual 3D planning and prediction accuracy in two bimaxillary face transplantations in Helsinki.

[BACKGROUND] The aim of this study was to describe the 3D planning process used in our two composite face transplantations and to analyze the accuracy of a virtual transplantation in predicting the end-result of face transplantation.

[METHODS] The study material consists of two bimaxillary composite face transplantations performed in the Helsinki University Hospital in 2016 and 2018. Computed tomography (CT) scans of the recipient and donor were used to define the osteotomy lines and perform the virtual face transplantation and to 3D print customized osteotomy guides for recipient and donor. Differences between cephalometric linear and angular measurements of the virtually simulated and the actual postoperative face transplantation were calculated.

[RESULTS] No changes to the planned osteotomy lines were needed during surgery. The differences in skeletal linear and angular measurements of the virtually simulated predictions and the actual postoperative face transplantations of the two patients varied between 0.1-5.6 mm and 0.7°-4°. The postoperative skeletal relationship between maxilla and mandible in both patients were almost identical in comparison to the predictions.

[CONCLUSIONS] 3D planning is feasible and provides close to accurate bone reconstruction in face transplantation. Preoperative virtual transplantation assists planning and improves the outcome in bimaxillary face transplantation.