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Complex maxillofacial malformations continue to present challenges in analysis and correction beyond modern technology. The purpose of this paper is to present a virtual reality workbench for surgeons to perform virtual orthognathic surgical planning and soft-tissue prediction in three dimensions. A resulting surgical planning system, i.e.,(More)
PURPOSE This study incorporated 3 objectives: 1 ) to evaluate the physical location of the center of rotation as determined by a custom mathematical algorithm, 2 ) to identify and compare the geometric center of the condylar head in radiographs with the calculated center of rotation, and 3 ) to determine whether a correlation exists between jaw motion(More)
In the field of craniomaxillofacial (CMF) surgery, surgical planning can be performed on composite 3-D models that are generated by merging a computerized tomography scan with digital dental models. Digital dental models can be generated by scanning the surfaces of plaster dental models or dental impressions with a high-resolution laser scanner. During the(More)
PURPOSE The purpose of this study was to compare the accuracy of 4 methods for cephalometric tracing superimposition. They are the FH@Porion method, S-N@Sella method, least-squared averaged 5 landmarks (LS-5) method, and manual geometric method. MATERIALS AND METHODS Eight lateral cephalometric radiographs were used. Cephalometric tracing was performed by(More)
PURPOSE The purpose of this study was to determine the range of fixed trajectory curvilinear distraction devices required to correct a variety of severe mandibular deformities. MATERIALS AND METHODS Preoperative computed tomography (CT) scans from 18 patients with mandibular deformities were imported into a CT-based software program (Osteoplan).(More)
PURPOSE To test the hypothesis that facial symmetry affects both 2-dimensional (2D) and 3-dimensional (3D) cephalometric measurements. METHODS A baseline model of a preferred symmetrical face was first constructed. It consisted of a set of commonly used cephalometric landmarks. Seven cephalometric measurements were selected for testing. Each of them(More)
PURPOSE The goal of this study was to create a model for human mandibular movement prediction based on the geometry of the mandible. MATERIALS AND METHODS Ten nonpathologic individuals underwent motion tracking and sagittal radiographs. From the data, a mathematical algorithm for mandibular movement prediction was developed based on mandibular geometry.(More)
This paper proposes a nonlinear regression model to predict soft tissue deformation after maxillofacial surgery. The feature which served as input in the model is extracted with finite element model (FEM). The output in the model is the facial deformation calculated from the preoperative and postoperative 3D data. After finding the relevance between feature(More)
Distraction osteogenesis of the mandible has found an application in the treatment of patients with a variety of different mandibular deformities. Compared with the relatively simple unidirectional distraction of long bones as described by Ilizarov, the three-dimensional distraction of the mandible is extremely complex. Whereas experience with orthognathic(More)
The purpose of this study was to develop and test a new technique for recording natural head position (NHP) in 3 dimensions and transferring it into a three-dimensional computed tomography (CT) model. In this technique, a digital gyroscope was first attached to a human head using a bite-jig and a face-bow with a set of built-in fiducial markers. The(More)