Accuracy Evaluation of Computed Tomography–Derived Stereolithographic Surgical Guides in Zygomatic Implant Placement in Human Cadavers
Presurgical planning is essential to achieve esthetic and functional implants. For implant planning and placement, the association of computer-aided design (CAD) and computer-aided manufacturing (CAM) techniques furnishes some advantages regarding tridimensional determination of the patient's anatomy and fabrication of both anatomic models and surgical guides. The goal of this clinical study was to determine the angular deviations between planned and placed zygomatic implants using stereolithographic surgical guides in human cadavers. A total of 16 zygomatic implants were placed, 4 in each cadaver, with the use of stereolithographic (SLA) surgical guides generated by computed tomography (CT). A new CT scan was made after implant insertion. The angle between the long axis of the planned and actual implants was calculated. The mean angular deviation of the long axis between the planned and placed implants was 8.06 ± 6.40 (mean ± SD) for the anterior-posterior view, and 11.20 ± 9.75 (mean ± SD) for the caudal-cranial view. Use of the zygomatic implant, in the context of this protocol, should probably be reevaluated because some large deviations were noted. An implant insertion guiding system is needed because this last step is carried out manually. It is recommended that the sinus slot technique should be used together with the CT-based drilling guide to enhance final results. Further research to enhance the precision of zygomatic implant placement should be undertaken.Abstract
The 3-dimensional computed tomography (CT) planning system. Axial, transversal, panoramic, and tridimensional CT slices are possible. Clinically relevant covisualization can be obtained.
Drill guides to every corresponding drill were made to perfectly adapt into the cylindrical guide.
Figure 3. Preoperative and postoperative computed tomography (CT) scans in an anterior-posterior view were aligned while the superposition of anatomic markers was observed. Figure 4. Preoperative and postoperative CT scan superposition in a caudal-cranial view. Figure 5. Superposition of the planned and placed implants in a caudal-cranial view (cadaver 4). Figure 6. Superposition of the planned and placed implants in an anterior-posterior view (cadaver 1).
Figure 7. Good clinical results. Left side of cadaver 1. Figure 8. Good clinical results. Left side of cadaver 1.
Figure 9. Poor clinical results. One implant emerged in the infratemporal fossa of cadaver 3. Figure 10. Poor clinical results. One implant emerged inside the orbital cavity of cadaver 3.
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