| abstract |
(57) Summary A system (10) and method by which an orthodontic appliance (25) is automatically designed and manufactured from a patient's (14) digital lower jaw and tooth shape data (26) is preferably of a patient's mouth. From the model (20), a scan is performed to generate a two-dimensional or three-dimensional image and the patient's tooth and jaw contours and selected points thereon are digitized. A computer (30) draws an arch line from the individual patient data scanned to calculate the finishing tooth position, and then preferably an appliance (25) including the arch line and bracket is designed to move the tooth to the calculated position. The lower teeth are placed on the gum on the arch defined by the lower jaw and modified to best fit the tooth tips on a smooth curve. The crown long axis of the tooth is extracted and optimally tilted in a treatment to place all lower teeth, except the canines, in-plane to accommodate the occlusal teeth. The overlap for upper incisors and canine ridges is calculated. Each bracket has a base and archwire support, and the blades of the cutter (39) are used to cut the archwire groove into a blank clamped to the tiltable holder at a custom bevel, depth, position and curvature. . The holder and blade are moved by commands from the computer (30c). The archwire is automatically formed by the wire bender (40) into an optimal smooth bow and optimal low profile bracket design. Preferably, the bow equation starts with a cubic spline equation and is transformed into a form of a series of circle segments for machine control instructions of a numerical former. Designed at the same time as the numerically controlled machine (41), each placement jig that is automatically created to position and orient the appliance at a connection point on the tooth has a surface that is custom shaped to the contour of the tooth. ing. The bracket, wire, and jig making machines (38-41) are driven by commands derived from digitized tooth and jaw geometry data and digital representations of tooth finish positions and appliance designs. |