Three-dimensional accuracy of virtual planning in orthognathic surgery

Abstract

Introduction: This study aimed to assess the accuracy of virtual surgical planning (VSP) performed by Dolphin Imaging software (version 11.9; Dolphin Imaging and Management Solutions, Chatsworth, Calif).

Methods: Ten people requiring bimaxillary surgery and genioplasty were followed up prospectively. All patients had preoperative cone-beam computed tomography, plaster models, and photographs allowing for VSP. Interocclusal intermediate surgical splints were produced using a 3-dimensional (3D) printer. Postoperative images were acquired 15 days after surgery using cone-beam computed tomography. ITK-Snap (version 3.6; Cognitica, Philadelphia, Pa) allowed the segmentation of reliable 3D models. Geomagic Qualify 2013 (3D Systems, Rock Hill, SC) and MeshValmet (version 3.0) were used to identify the differences between VSP and actual surgical results through the root mean square values and the 3D translational displacement (3-axes) of the 3D centroid of each model.

Results: Discrepancies between the VSP and the actual result were found at the mandible (P = 0.013) and the chin (P = 0.013) when considering the root mean square values. In addition, 3D centroid differences were found in the transverse and sagittal direction of the right ramus (P = 0.034 and P = 0.005, respectively) and the sagittal aspect of the left ramus (P = 0.025). Considering 2 mm as a threshold of clinical relevance, almost all the bone fragments (maxilla, proximal, and distal mandibular segments) were accurately corrected by surgery, although not in the chin.

Conclusions: On the basis of the obtained values, it is possible to consider the Dolphin Imaging software as clinically acceptable for performing virtual orthognathic surgical planning.