A system for fabricating a customized appliance for the orthodontic treatment of teeth (10), comprising forming an appliance (20) comprising plural cavities each shaped to conform to the crown of a tooth (10) and customized extensions (22) which are chemically bonded to thermoformed aligners in a dental repositioning system. These extensions facilitate rigid and precise attachment of aligners to auxiliary devices such as TADs (Temporary Anchorage Devices) (12) or are used as a mechanism to strengthen the aligner in specific areas. This facilitates simultaneous wear of aligners and sectional braces for the treatment of dental malocclusions.
