Daniel Zweifel1, Marius Gustav Bredell2, Martin Lanzer3, Claudio Rostetter4, Martin Rücker5, Stephan Studer3. 1. Consultant, Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Zurich, Zurich, Switzerland. Electronic address: daniel.zweifel@hin.ch. 2. Private Practitioner, Winterthur, Switzerland. 3. Consultant, Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Zurich, Zurich, Switzerland. 4. Resident, Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Zurich, Zurich, Switzerland. 5. Professor, Head of Department, Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Zurich, Zurich, Switzerland.
Abstract
PURPOSE: Dental rehabilitation in patients receiving free flap reconstructive surgery on the mandible or maxilla is an important part of bringing patients back to normality in both a physical and psychological way. It is therefore important to be able to do this in the fastest way possible. Virtual preplanned reconstructions of jaws with implants placed simultaneously are a good way to expedite this process and have the advantage of allowing true backward planning to achieve bone placement where it prosthetically needs to be. Thus, the precise transfer of the virtually preplanned implant position to the intraoperative situation is crucial for prosthetic rehabilitation. PATIENTS AND METHODS: We compared a control group of patients (4 patients with 15 implants) with preplanned fibular reconstructions of the mandible with implants incorporated in the planning and a trial group of patients (4 patients with 13 implants) with an additional intraoperative splint for the verification of the implants' angulation. The preoperative planning and postoperative computed tomography scans were compared. RESULTS: The average positioning error at bone level was 0.9 mm in the trial group and 1.3 mm in the control group. The average angulation error in the buccolingual plane was 2.9° in the trial group and 5.5° in the control group; axially, the difference was 6.3° in the trial group and 4.1° in the control group. CONCLUSIONS: The use of digitally backward-planned fibula cutting guides with direct dental implant positioning is feasible, and the precision found is comparable with that of standard splint-guided implant placement in the general population. Although the axial angulation error has more to do with anatomic variance and positioning of the bony cutting guide, the trial population clearly profited from the additional splint in the important buccolingual angulation. Overall, we showed a high level of precision over all implants in both groups.
PURPOSE: Dental rehabilitation in patients receiving free flap reconstructive surgery on the mandible or maxilla is an important part of bringing patients back to normality in both a physical and psychological way. It is therefore important to be able to do this in the fastest way possible. Virtual preplanned reconstructions of jaws with implants placed simultaneously are a good way to expedite this process and have the advantage of allowing true backward planning to achieve bone placement where it prosthetically needs to be. Thus, the precise transfer of the virtually preplanned implant position to the intraoperative situation is crucial for prosthetic rehabilitation. PATIENTS AND METHODS: We compared a control group of patients (4 patients with 15 implants) with preplanned fibular reconstructions of the mandible with implants incorporated in the planning and a trial group of patients (4 patients with 13 implants) with an additional intraoperative splint for the verification of the implants' angulation. The preoperative planning and postoperative computed tomography scans were compared. RESULTS: The average positioning error at bone level was 0.9 mm in the trial group and 1.3 mm in the control group. The average angulation error in the buccolingual plane was 2.9° in the trial group and 5.5° in the control group; axially, the difference was 6.3° in the trial group and 4.1° in the control group. CONCLUSIONS: The use of digitally backward-planned fibula cutting guides with direct dental implant positioning is feasible, and the precision found is comparable with that of standard splint-guided implant placement in the general population. Although the axial angulation error has more to do with anatomic variance and positioning of the bony cutting guide, the trial population clearly profited from the additional splint in the important buccolingual angulation. Overall, we showed a high level of precision over all implants in both groups.