Computer-Aided Mandibular Reconstruction With Vascularized Iliac Crest Bone Flap and Simultaneous Implant Surgery
The intention of oral rehabilitation in patients with mandibular defects is an early prosthetic treatment with maximum possible functionality and high accuracy. The present study describes a new computer-aided technique for mandibular reconstruction using a free vascularized iliac flap and simultaneous insertion of dental implants into the flap while it is still pedicled at the donor site. Based on preoperative computerized tomography data of the facial skeleton and the iliac crest donor site, a surgical guide transferred the virtual plan including information on the transplant dimensions and shape as well as the position of the dental implants into real-time surgery. Using postoperative computerized tomography scans, the actual situation were compared with the preoperative simulation. A mean difference of 0.75 mm (SD ± 0.72) for the flap shape and 0.70 mm (SD ± 0.44) for the implant position analysis was determined. A calculation of the closest point distance showed a surface deviation of <2 mm for the shape analysis in 93.3% of the values and <1 mm for implant position in 75.2% of the values. The mean angular deviation was 3.65°. Virtual surgical planning is a suitable method for mandibular reconstruction with vascularized iliac crest flaps and simultaneous implant surgery. It can be used to restore the anatomy of the mandible with a high accuracy and can help to shorten subsequent dental rehabilitation.

Figure 1 . The best fitting part of the left iliac crest in terms of shape and interface with the affected left mandible was selected virtually prior to surgery. Figure 2. Virtual implant positioning using STL files of 3 bone level implants (Straumann, Basel, Switzerland). Figure 3. Three-dimensional design of the surgical guide generated from the optimally constructed virtual transplant data and located on the left iliac crest. Figure 4. Comparison of the actual postoperative iliac bone flap shape with its preoperative planned shape. Figure 5. Comparison of actual postoperative position of the implants with their preoperative planned positions. (a) Overview of the implants in the flap; (b) Detail view with color gradient.

Figure 6 . The surgical guide is temporarily fixed on the external side of the left iliac crest using osteosynthesis screws. The arrow indicates the deep circumflex iliac artery on the medial side of the iliac crest. Figure 7. The precision-cut and osteotomized left iliac crest bone flap. Figure 8. Insertion of the 3 endosseous dental implants in the iliac crest bone flap while it is still pedicled. Figure 9. Positioning and fixation of the iliac crest bone flap for reconstruction of the left mandible. The arrow points to the anastomosis of the deep circumflex iliac vessel to the left cervical vessels. Figure 10. (a) and (b) The postoperative lateral cephalogram shows the iliac crest bone flap including the dental implants (a). The frontal view of the left side of the face shows a timely healing phase with decreasing swelling 1 week after surgery (b).

(a) and (b) The surface deviation analysis for shape of the iliac crest bone flap (a) and implant position (b). The calculation showed a surface deviation of <2 mm (red line) in 93.3% of values for the shape analysis of the iliac flap and of <1 mm (red line) in 75.2% of values for implant position. ED indicates element distribution.
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