Navigation-guided en bloc resection and defect reconstruction of craniomaxillary bony tumours.

The aim of this study was to evaluate the validity of navigation-guided en bloc tumour resection and defect reconstruction in the treatment of craniomaxillary bony tumours. Three patients with ossifying fibroma and two patients with fibrous dysplasia were enrolled in this study. After preoperative planning and three-dimensional simulation, the osteotomy lines for resection were delineated and the normal anatomic structures for defect reconstruction were ascertained. With the guidance of an Accu-Navi navigation system, an en bloc tumour resection and simultaneous defect rehabilitation were performed. The system provided continuously updated information on the position and movement of surgical instruments in the operating field in relation to the preoperative imaging data set. The system error measured by the computer did not exceed 1mm. The osteotomy lines and reconstruction contour were checked by postoperative computed tomography, and good matching with the preoperative planning was achieved. Patients showed no signs of tumour recurrence or prosthesis infection during follow-up (range 12-35 months). Image-guided navigation makes radical bone tumour resection more reliable by implementing preoperative planning, showing the determined safety margins, preserving vital structures and guiding reconstruction.