Clinical and experimental evaluation of an augmented reality system in cranio-maxillofacial surgery

Abstract An augmented reality tool for computer-assisted surgery named X-Scope allows for visual tracking of real anatomical structures in superposition with volume rendered CT or MRI scans and thus can be used for navigated translocation of bony segments. In a feasibility study X-Scope was used in orthognatic surgery to control the translocation of the maxilla after Le Fort I osteotomy within a bimaxillary procedure. The achieved situation was compared with the computer-based preoperative planning by means of cephalometric analysis on lateral and frontal cephalograms. In addition to the clinical feasibility study, an experimental evaluation of system accuracy was performed. The technique could be successfully applied in 5 patients. The maxillary positioning using X-Scope was accomplished with accuracy within a range of 1 mm. The tool was used in all cases in addition to the usual intra-operative splints. A stand-alone application without conventional control mechanism seems to be not reasonable yet. The final analysis of data obtained from the accuracy study is not completed yet. The preliminary results indicate a deviation of the X-Scope system not significantly greater then the deviation of the navigation system itself with a given registration method. Augmented reality tools like X-Scope may be helpful for control of maxillary translocation in orthognathic surgery. The application to other types of interventions in cranio-maxillofacial surgery associated with movement of bony segments as Le Fort III osteotomy, fronto-orbital advancement, and cranial vault reshaping or reconstruction may be considered as well.