Accuracy evaluation of CAD/CAM generated splints in orthognathic surgery: a cadaveric study
- PDF / 2,811,565 Bytes
- 9 Pages / 595.276 x 793.701 pts Page_size
- 50 Downloads / 164 Views
HEAD & FACE MEDICINE
RESEARCH
Open Access
Accuracy evaluation of CAD/CAM generated splints in orthognathic surgery: a cadaveric study Thomas Schouman2, Philippe Rouch3, Benoît Imholz1, Jean Fasel4, Delphine Courvoisier5 and Paolo Scolozzi1*
Abstract Introduction: To evaluate the accuracy of CAD/CAM generated splints in orthognathic surgery by comparing planned versus actual post-operative 3D images. Methods: Specific planning software (SimPlant® OMS Standalone 14.0) was used to perform a 3D virtual Le Fort I osteotomy in 10 fresh human cadaver heads. Stereolithographic splints were then generated and used during the surgical procedure to reposition the maxilla according to the planned position. Pre-operative planned and postoperative 3D CT scan images were fused and imported to dedicated software (MATLAB®) 7.11.) for calculating the translational and rotational (pitch, roll and yaw) differences between the two 3D images. Geometrical accuracy was estimated using the Root Mean Square Deviations (RMSD) and lower and upper limits of accuracy were computed using the Bland & Altman method, with 95 % confidence intervals around the limits. The accuracy cutoff was set at +/− 2 mm for translational and ≤ 4° for rotational measurements. Results: Overall accuracy between the two 3D images was within the accuracy cutoff for all values except for the antero-posterior positioning of the maxilla (2.17 mm). The translational and rotational differences due to the splint were all within the accuracy cutoff. However, the width of the limits of agreement (range between lower and upper limits) showed that rotational differences could be particularly large. Conclusion: This study demonstrated that maxillary repositioning can be accurately approximated and thus predicted by specific computational planning and CAD/CAM generated splints in orthognathic surgery. Further study should focus on the risk factors for inaccurate prediction. Keywords: Orthognathic surgery, Computer-assisted surgery, CAD/CAM splints
Introduction Treatment planning in orthognathic surgery is based on a combination of clinical, radiological and plaster casts analyses. These analyses allow for a simulation of the ideal repositioning of the skeletal pieces of the facial skeleton that should be reproduced during the surgery as closely as possible to the simulation. Usually, surgical intermediate and final occlusal acrylic splints made on plaster models mounted on a semi-adjustable articulator, after facebow transfer, are used to reproduce the planning during surgery. This method has numerous and inherent sources of * Correspondence: [email protected] 1 Department of Surgery, Service of Maxillofacial and Oral Surgery, University Hospital and Faculty of Medicine, Geneva, Switzerland Full list of author information is available at the end of the article
non-controllable errors. The succession of manipulations and the multiple stakeholders implied make this handmade planning reliability questionable [1–5]. The accuracy of this method cannot be estimated by makin
Data Loading...
