Computer-assisted orthognathic surgery: feasibility study using multiple CAD/CAM surgical splints.

OBJECTIVE: We present a virtual planning protocol incorporating a patented 3-surgical splint technique for orthognathic surgery. The purpose of this investigation was to demonstrate the feasibility and validity of the method in vivo.

MATERIALS AND METHODS: The protocol consisted of (1) computed tomography (CT) or cone-beam computed tomography (CBCT) maxillofacial imaging, optical scan of articulated dental study models, segmentation, and fusion; (2) diagnosis and virtual treatment planning; (3) computed-assisted design and manufacture (CAD/CAM) of the surgical splints; and (4) intraoperative surgical transfer. Validation of the accuracy of the technique was investigated by applying the protocol to 8 adult class III patients treated with bimaxillary osteotomies. The virtual plan was compared with the postoperative surgical result using image fusion of CT/CBCT dataset by analysis of measurements between hard and soft tissue landmarks relative to reference planes.

RESULTS: The virtual planning approach showed clinically acceptable precision for the position of the maxilla (<0.23 mm) and condyle (<0.19 mm), marginal precision for the mandible (<0.33 mm), and low precision for the soft tissue (<2.52 mm).

CONCLUSIONS: Virtual diagnosis, planning, and use of a patented CAD/CAM surgical splint technique provides a reliable method that may offer an alternate approach to the use of arbitrary splints and 2-dimensional planning.