Real-time in situ three-dimensional integral videography and surgical navigation using augmented reality: a pilot study

To evaluate the feasibility and accuracy of a three-dimensional augmented reality system incorporating integral videography for imaging oral and maxillofacial regions, based on preoperative computed tomography data. Three-dimensional surface models of the jawbones, based on the computed tomography data, were used to create the integral videography images of a subject's maxillofacial area. The three-dimensional augmented reality system (integral videography display, computed tomography, a position tracker and a computer) was used to generate a three-dimensional overlay that was projected on the surgical site via a half-silvered mirror. Thereafter, a feasibility study was performed on a volunteer. The accuracy of this system was verified on a solid model while simulating bone resection. Positional registration was attained by identifying and tracking the patient/surgical instrument’s position. Thus, integral videography images of jawbones, teeth and the surgical tool were superimposed in the correct position. Stereoscopic images viewed from various angles were accurately displayed. Change in the viewing angle did not negatively affect the surgeon’s ability to simultaneously observe the three-dimensional images and the patient, without special glasses. The difference in three-dimensional position of each measuring point on the solid model and augmented reality navigation was almost negligible (<1 mm); this indicates that the system was highly accurate. This augmented reality system was highly accurate and effective for surgical navigation and for overlaying a three-dimensional computed tomography image on a patient’s surgical area, enabling the surgeon to understand the positional relationship between the preoperative image and the actual surgical site, with the naked eye. Projecting images of a surgical site onto a patient’s face may allow quicker, more precise dental surgery, scientists in Japan report. Dental and facial surgery is anatomically complex, with underlying structures and tissues often hidden from view. Surgeons can view an individual’s two-dimensional (2D) scans on computer monitors during surgery, but this is time-consuming. Hideyuki Suenaga and colleagues at the University of Tokyo have developed a way to superimpose 3D anatomical images directly onto a patient’s face during surgery. Their augmented reality system uses data from CT and MRI scans to generate a series of points mapped in 3D space. The image is then projected using lenses and mirrors that can be viewed at any angle without special glasses. The technology is accurate to within one millimeter and uses optical tracking to update when a patient moves.