Method for forming jigs for custom placement of orthodontic appliances on teeth

A method of forming jigs to place a custom orthodontic appliance for connection to teeth of a patient, the method comprising the steps of:

• forming a custom orthodontic appliance by:
• digitizing tooth shape data of external surfaces of crowns of teeth of a patient,
• defining appliance connection points on surfaces of the teeth in relation the digitized tooth shape data,
• establishing appliance geometry based on the tooth shape data to move the teeth to desired finish positions when connected to the teeth at the connection points, and
• fabricating a custom appliance in accordance with the established appliance geometry;
• and
• forming jigs for locating the appliance at the connection points by:
• calculating, from the digitized tooth shape data and defined connection points, jig geometry defining a jig locating surface that conforms to a unique portion of the external surface of the crown of a tooth, and defining an appliance engaging surface having the same location relative to the jig locating surface as the unique portion of the external surface has to the connection point on the tooth,
• generating a machine control signal carrying machine control instructions for producing a jig in accordance with the calculated jig geometry, and
• operating the machine in response to the control signal to form a jig that, when fit on the tooth, will position and orient an appliance engaged thereby at the connection point of the tooth for connection thereto.