Abstract: A system for fabricating a customized appliance for the orthodontic treatment of teeth, comprising forming an appliance comprising plural cavities each shaped to conform to the crown of a tooth and customized extensions 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) 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.