Orthodontics: Computer-aided diagnosis and treatment planning

The purpose of this article is to introduce the outline of our newly developed computer-aided three-dimensional dental cast analyzing system with laser scanning, and its preliminary clinical applications. The system is composed of a scanning device and a personal computer as a scanning controller and a post processor. The scanning device is composed of a laser beam emitter, two sets of linear CCD cameras and a table which is rotatable by two-degree-of-freedom. The rotating is controlled precisely by a personal computer. The dental cast is projected and scanned with a laser beam. Triangulation is applied to determine the location of each point. Generation of three-dimensional graphics of the dental cast takes approximately 40 minutes. About 170, 000 sets of X, Y, Z coordinates are store for one dental cast. Besides the conventional linear and angular measurements of the dental cast, we are also able to demonstrate the size of the top surface area of each molar. The advantage of this system is that it facilitates the otherwise complicated and time-consuming mock surgery necessary for treatment planning in orthognathic surgery.