Sir:FigureLe Fort III advancement is often required for patients with severe midfacial hypoplasia to relieve upper airway obstruction, exorbitism, and malocclusion.1 Rare but serious complications of Le Fort III advancement include cerebrospinal fluid rhinorrhea, meningitis, meningoencephalocele, encephalocele, ocular trauma, and hemorrhage.1,2 Complications associated with dural tearing and fractures of the cribriform plate are most likely to occur at the nasofrontal osteotomy,1 and dental injury can occur at the pterygomaxillary osteotomy. Historically, careful preoperative inspection of computed tomographic images and reference to external anatomical landmarks was the only mechanism to prevent unfavorable osteotomies.2 Image-guided surgery platforms use patient references to register preoperative computed tomographic images to the patient's anatomy, and allow the surgeon to visualize and track instrument position in real time. Traditional osteotomies are performed with an osteotome or mechanical saw, both of which fail to discriminate between bone and critical soft-tissue structures. In contrast, piezoelectric surgery uses micrometric ultrasonic vibrations at frequencies that selectively cut only mineralized structures because of cessation of action on contact with nonmineralized tissues, thereby minimizing the risk of neural or vascular injury.3 We hypothesized that image guidance and a piezoelectric saw would be ideal for performing Le Fort III osteotomies and could prevent the well-described complications of this procedure. We confirm that we have adhered to the tenets of the Declaration of Helsinki. We present a 12-year-old girl with Crouzon syndrome who required Le Fort III advancement for treatment of obstructive sleep apnea, class III malocclusion, and midfacial hypoplasia. Using an intraoperative image guidance system (VectorVision; BrainLAB USA, Moorestone, N.J.), the three-dimensional computed tomographic scan of the patient's anatomy was referenced to the patient in real time (Fig. 1). The historically blind osteotomies from the nasofrontal suture to the skull base, and the lateral orbital wall to the pterygomaxillary junction, were visualized directly on the referenced computed tomographic scan. This prevented inadvertent entry through the cranial base, a well-described complication of this procedure.4 Once a safe extracranial trajectory was confirmed with image guidance, we made the osteotomies using a piezoelectric system (Synthes). Advancement was performed with an external distraction system. Of note, the patient also required a cranioplasty for residual skull defects from her cranial vault remodeling that had been performed in infancy. The patient tolerated the procedure well, and because of the intraoperative image guidance, no immediate postoperative computed tomographic scan was required. Operative time, including the bilateral cranioplasty, was 6.5 hours, which is comparable to historical controls.5 She was discharged to home on postoperative day 8 and has done well clinically. Follow-up computed tomographic scanning demonstrates maxillary advancement and no disruption of the cranial base (Fig. 2).Fig. 1: Intraoperative screen shot of the nasofrontal osteotomy using an image guidance system (BrainLAB VectorVision) in three-dimensional (above, left), axial (above, right), sagittal (below, left), and coronal (below, right) views demonstrating real-time three-dimensional intraoperative position localization and trajectory planning of the osteotomy.Fig. 2: Postoperative computed tomographic image demonstrating maxillary advancement without disruption of the cranial base.We report a combined application of intraoperative three-dimensional image guidance and piezoelectric surgery to more safely perform osteotomies in Le Fort III advancement. Nasofrontal and pterygomaxillary osteotomies, which were historically performed blindly and with instrumentation capable of neural and vascular injury, can be more controlled with these adjunctive tools. We suggest that real-time image guidance and ultrasonic bone saws minimize the potential morbidity and mortality of this procedure, reduce the need for immediate postoperative imaging, and do not extend operative time. Laurel S. Karian, B.A. University of Vermont College of Medicine, Burlington, Vt. Benjamin Z. Phillips, M.D., M.P.H. Clinton S. Morrison, M.D. Division of Plastic Surgery Petra M. Klinge, M.D., Ph.D. Department of Neurosurgery Stephen R. Sullivan, M.D., M.P.H. Helena O. Taylor, M.D., Ph.D. Division of Plastic Surgery, The Warren Alpert School of Brown University, Providence, R.I. DISCLOSURE The authors have no financial interest to declare in relation to the content of this article. PATIENT CONSENT The patient provided written consent for use of the images.