Registration-free workflow for electromagnetic and optical navigation in orbital and craniofacial surgery

Abstract

The accuracy of intra-operative navigation is largely dependent on the intra-operative registration procedure. Next to accuracy, important factors to consider for the registration procedure are invasiveness, time consumption, logistical demands, user-dependency, compatibility and radiation exposure. In this study, a workflow is presented that eliminates the need for a registration procedure altogether: registration-free navigation. In the workflow, the maxillary dental model is fused to the pre-operative imaging data using commercially available virtual planning software. A virtual Dynamic Reference Frame on a splint is designed on the patient’s fused maxillary dentition: during surgery, the splint containing the reference frame is positioned on the patient’s dentition. This alleviates the need for any registration procedure, since the position of the reference frame is known from the design. The accuracy of the workflow was evaluated in a cadaver set-up, and compared to bone-anchored fiducial, virtual splint and surface-based registration. The results showed that accuracy of the workflow was greatly dependent on tracking technique used: the workflow was the most accurate with electromagnetic tracking, but the least accurate with optical tracking. Although this method offers a time-efficient, non-invasive, radiation-free automatic alternative for registration, clinical implementation is hampered by the unexplained differences in accuracy between tracking techniques.

Computer-Aided Dynamics Intraoperative Navigation in Oral Medicine: A Review

“…Electromagnetic location tracking uses an electromagnetic eld and a reference point attached to the device on the patient's head and wired instruments used in the surgical area to locate and track the environment. Unlike optical positioning tracking, electromagnetic tracking and positioning do not have to worry about occlusion during surgery, but the accuracy of this system can be compromised if there is too much metal in the surgical area (Sukegawa et al 2018; Landaeta-Quinones et al 2018; Schreurs et al 2021a). Compared with CASN, CADIN can ensure real-time visualization and accurate positioning of key anatomical structures during surgery, providing a safe surgical boundary for the surgeon in real time, largely reducing the operating time and radiation exposure of the surgeon and patient, effectively avoiding medically induced injuries, and improving the safety and accuracy of surgery.…”

Marker‐free registration for intraoperative navigation using the transverse palatal rugae

“…8 Currently, several registration concepts exist in CMFS including headbands that can be easily displaced intraoperatively, fiducial markers, splints, or a combination of the two may be used in pointbased registration. [9][10][11][12] Besides to the splint-supported registration in the maxilla, which requires the presence of teeth, the presurgical insertion of osteosynthesis screws in the maxilla or forehead with subsequent 3D imaging allows intraoperative registration with high accuracy even in the edentulous maxilla. 13,14 However, this method requires invasive marker insertion and an additional pre-operative 3D imaging for marker detection.…”