ABSTRACT
The purpose of this study was to develop a principal component analysis-based adaptive minimum Euclidean distances (PAMED) approach to establish an optimal object reference frame for symmetrical alignment of the dental arch during computer-aided surgical simulation (CASS). It was compared with our triangular methods and the standard principal component analysis (PCA) method. Thirty sets of maxillary digital models were used. Midsagittal and occlusal planes were ranked by three experienced evaluators based on their clinical judgment. The results showed that for the midsagittal plane, all three evaluators ranked "ideal" for all 30 models with the PAMED method, 28 with the triangular method, and at least 11 with the PCA method. For the occlusal plane, one evaluator ranked all 30 models "ideal" with both the PAMED and the PCA methods while the other two evaluators ranked all 30 models "ideal" with the triangular method. However, the differences among the three methods were minimal. In conclusion, our PAMED method is the most reliable and consistent approach for establishing the object reference frame for the dental arch in orthognathic surgical planning. The triangular method should be used with caution because it can be affected by dental arch asymmetry. The standard PCA method is not recommended.
Subject(s)
Computer Simulation , Dental Arch/anatomy & histology , Orthognathic Surgical Procedures/methods , Surgery, Computer-Assisted/methods , Humans , Models, Dental , Principal Component AnalysisABSTRACT
The success of craniomaxillofacial (CMF) surgery depends not only on the surgical techniques, but also on an accurate surgical plan. The adoption of computer-aided surgical simulation (CASS) has created a paradigm shift in surgical planning. However, planning an orthognathic operation using CASS differs fundamentally from planning using traditional methods. With this in mind, the Surgical Planning Laboratory of Houston Methodist Research Institute has developed a CASS protocol designed specifically for orthognathic surgery. The purpose of this article is to present an algorithm using virtual tools for planning a double-jaw orthognathic operation. This paper will serve as an operation manual for surgeons wanting to incorporate CASS into their clinical practice.
Subject(s)
Algorithms , Computer Simulation , Maxillofacial Abnormalities/surgery , Orthognathic Surgical Procedures , Patient Care Planning , Anatomic Landmarks , Cephalometry , Dental Impression Technique , Humans , Models, Anatomic , Surgery, Computer-Assisted , Tomography, X-Ray ComputedABSTRACT
Three-dimensional (3D) cephalometry is not as simple as just adding a 'third' dimension to a traditional two-dimensional cephalometric analysis. There are more complex issues in 3D analysis. These include how reference frames are created, how size, position, orientation and shape are measured, and how symmetry is assessed. The main purpose of this article is to present the geometric principles of 3D cephalometry. In addition, the Gateno-Xia cephalometric analysis is presented; this is the first 3D cephalometric analysis to observe these principles.
