Purpose <p>Computed tomography (CT) imaging is utilized during virtual surgical planning (VSP) in orthognathic surgery to simulate the surgical scenario, thereby aiding the actual surgery. Various surgical strategies exist to enhance accuracy in Le Fort I osteotomy, but an ideal planning and treatment approach has not yet been defined. The purpose of this study was to assess the accuracy of markerless Augmented Reality (AR), utilizing the iterative closest point algorithm for real-time tracking without 3D-printed surgical guides, wafers, or physical markers. The study explores the integration of VSP and an intraoperative markerless AR-assisted system for Le Fort I osteotomy in orthognathic surgery.</p> Methods <p>Six patients were enrolled in the study. We conducted a markerless AR-assisted orthognathic surgery utilizing VSP containing a virtual plate model. To assess accuracy, the postoperative 3-dimensional reconstructed CT image was compared to the VSP.</p> Results <p>Distance maps visualizing the distances between VSP and the postoperative CT scan revealed an accuracy with a standard deviation (SD) of 0.81&#xa0;mm (81.0% within 1&#xa0;mm) in terms of the maxillary position.</p> Conclusions <p>This approach facilitated the movement and positioning of the maxillary bone along with fixation and setting of titanium plates. The simulation of the surgical procedure made the process more straightforward, enabling us to perform the actual surgery with greater precision. The markerless AR-assisted surgery shows potential in orthognathic surgery, aiding surgeons to prepare and execute surgical procedures more accurately. The future studies anticipate the integration of artificial intelligence, robotic technology, and AR for further improvements in orthognathic surgery.</p>