The accuracy of image-guided navigation for maxillary positioning in bimaxillary surgery.

The aim of our study was to evaluate the accuracy of image-guided maxillary positioning in sagittal, vertical, and mediolateral direction. Between May 2011 and July 2012, 17 patients (11 males, 6 females) underwent bimaxillary surgery with the use of intraoperative surgical navigation. During Le Fort I osteotomy, the Kolibri navigation system was used to measure movement of the maxilla at the edge of the upper central upper incisor in sagittal (buccal surface), vertical (incisor edge), and mediolateral (dental midline) direction. Six weeks after surgery, a postoperative CBCT scan was taken and registered to the preoperative cone-beam computed tomography scan to identify the actual surgical movement of the maxilla. Student 2-tailed paired t test was used to evaluate differences between the measured result from navigation system and actual surgical movement of the maxilla, which were 0.44 ± 0.35 mm (P = 0.82) in the sagittal, 0.50 ± 0.35 mm (P = 0.85) in the vertical, and 0.56 ± 0.36 mm (P = 0.81) in the mediolateral direction. Our finding demonstrates that intraoperative computer navigation is a promising tool for measuring the surgical change of the maxilla in bimaxillary surgery.