A novel method for fusion of intra-oral scans and cone-beam computed tomography scans for orthognathic surgery planning

Aim: To assess the feasibility of a new method to augment the three-dimensional virtual skull model with a detailed surface model of the dentition produced by intra-oral scanning, compared to the conventional triple scan procedure.

Materials & methods: In four patients who were planned for bimaxillary orthognathic surgery, the conventional triple scan procedure was carried out to create an augmented model. During scanning the patient wears a modified wax bite containing radio-opaque markers. An additional CBCT and laser scan of the wax bite and an intra-oral scan of the dentition were acquired. Surface-based and marker-based matching procedures were performed to integrate the intra-oral scans into the CBCT scan of the patient. The accuracy of the proposed method was assessed by measuring the distance between the occlusal surfaces of the registered intra-oral scans and the augmented model.

Results: Mean distances between the ios-dental cast registration and the augmented model were 0.30 mm (SD 0.20) and 0.27 mm (SD 0.20) for the upper and lower jaw, respectively.

Conclusion: Intra-oral scans provide an accurate representation of the dental arches compared to the AlgiNot-dental casts and can be fused with CBCT scans.