Navigational Maxillofacial Surgery Using Virtual Models

Abstract

Ablative tumor surgery and orbital and midface reconstruction, as much as orthognathic surgery, requires detailed planning using computed tomography (CT) or magnetic resonance imaging (MRI). These techniques also allow simulation of complex surgeries preoperatively. Proper reconstruction depends on reliable information to choose the correct type of grafts and to predict the outcome. This study evaluates the benefit and indications of computer-assisted surgery in the treatment of 107 patients who underwent craniomaxillofacial surgery. Based on a CT or MRI data set, an optical navigation system was used for preoperative planning, intraoperative navigation, and postoperative control. Surgery could be preoperatively planned and intraoperatively navigated. Preoperatively, it required that soft and hard tissues were measured using the mirrored data set of the unaffected side; the size and location of the graft were chosen virtually. Intraoperatively contours of transplanted tissues were navigated to the preoperatively simulated reconstructive result. Computer-assisted treatment was successfully completed in all 107 cases. Preoperatively outlined safety margins could be exactly controlled during tumor resection. Reconstruction was designed and performed precisely as virtually planned. Image-guided treatment improves preoperative planning by visualizing the individual anatomy, outlining the intended reconstructive outcome, and by objectifying the effect of adjuvant therapy. Intraoperative navigation makes tumor and reconstructive surgery more reliable by showing the safety margins, saving vital structures, and leading the reconstruction to preoperatively planned objectives.

Computer‐assisted therapy in orbital and mid‐facial reconstructions

“…On the other hand, intraoperative navigation involves no additional radiation exposure and can be done without interrupting the surgical procedure. In addition, intraoperative navigation permits more detailed direct or indirect visualization of the bony structures and, to a degree, of soft-tissue structures during each phase of the operation (4,6,16).…”

“…The second step is the navigational surgery. The third step consists of post-therapeutic control (6,7).…”

Use of Occlusal Splint for Noninvasive Fixation of a Reference Frame in Orbital Navigation Surgery

“…Recently, optical tracking navigation has been applied to oral and maxillofacial surgery [1][2][3]. When prepping for navigation surgery, a reference frame must be fixed to the patient's head with a Mayfield clamp, bone anchor, headset, or headband [2,3].…”

“…When prepping for navigation surgery, a reference frame must be fixed to the patient's head with a Mayfield clamp, bone anchor, headset, or headband [2,3]. Fixation of the clamp or bone anchor with a screw or head pins is invasive (Fig.…”

Evaluation of two dental registration-splint techniques for surgical navigation in cranio-maxillofacial surgery

“…(Eggers et al, 2006) The structures established pre-operatively by means of a CBCT or an MDCT are transferred to the patient during registration. Gellrich et al, 2002;Schmelzeisen et al, 2002;Marmulla et al, 2004b;Schmelzeisen et al, 2004;Hohlweg-Majert et al, 2005) Registration can be subdivided into distinct groups. One differentiates between marker-based (Altobelli et al, 1993;Hassfeld et al, 1995;Howard et al, 1995;Schramm et al, 1999;Luebbers et al, 2008) and marker-free (Troitzsch et al, 2003;Marmulla et al, 2004a;Hoffmann et al, 2005;Marmulla et al, 2005b) registration techniques.…”