Appliances are made using a dental mold representing a patient's dental
configuration. In particular, thermoformable plastic positioning
appliances which fit over the patient's teeth may be formed over a
three-dimensional mold of the patient's dentition. An apparatus and
methods which employ a manipulable or reconfigurable mold to model
patient dentition and gingiva at each stage of treatment. The apparatus
and methods are particularly useful for performing midcourse corrections
during orthodontic procedures using a plurality of such appliances in
sequence.