REVIEWNavigation-aided reconstruction of medial orbital wall and floor contour in cranio-maxillofacial reconstruction
Introduction
A precise repositioning, or reconstruction, of the orbital walls, especially of the transition area between orbital floor and medial orbital wall, is a key procedure in orbital trauma management, and contributes to a high degree to the normal function and aesthetics of the midface.3., 14. In patients presenting with massive comminution, the reconstruction of the medial orbital floor is challenging. Computer-assisted planning has proved to be a very effective technique for re-establishing orbital symmetry.2., 4., 9., 11., 13., 18.
Section snippets
Material and methods
From January 1999 to July 2001, 20 patients with unilateral post-traumatic orbital deformities underwent computer-assisted surgical reconstruction of the orbit. Five patients presented with severe injuries to the orbit, including a massive destruction of the transitional area between the medial orbital wall and medial aspect of the orbital floor.
These five patients were operated on, using coronal and transconjunctival approaches. Intraoral incisions were performed additionally for those
Results
Intraoperative, pointer-based navigation was successfully carried out at the STN-workstation in five reconstructions of the medial aspect of the orbital floor/medial orbital wall for positioning of bone grafts. In the three zones of measurement, the post-operative CT scan demonstrated a maximum discrepancy of 2.7 mm between the simulated, intraoperatively identified and the achieved positions. The average discrepancy was 1.3 mm.
The mean orbital volumes for the unaffected orbits measured
Case report
A 20-year-old female patient suffered from a massive enophthalmus of the left orbit following a road accident. Reconstruction of a displaced zygomatic fracture and reconstruction of the outer orbital frame were performed 9 months later. The frontal view with the intruded and caudally displaced globe is shown in Fig. 5.
The virtual position of the bone grafts and amounts of intended corrections of the sagittal eye projection were drawn at the workstation (Figure 5, Figure 6).
Via a combined
Conclusions
The refinements in pre-operative planning for cranio-maxillofacial surgery procedures have lead to major improvements in clinical outcomes.1., 6., 7., 8., 12., 17. The surgeon becomes virtually familiar with the individual patient’s anatomy before the operation, and has the possibilities to adjust the grey scales of images and the projected reconstruction to the requirements needed.5., 16., 21., 22.
During surgery, navigation provides exact determination of transverse, cranio-caudal and
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