Orthodontic systems and related methods are disclosed for designing andproviding improved or more effectivetooth moving systems for eliciting a desired tooth movement and/orrepositioning teeth into a desired arrangement. Methods andorthodontic systems of the invention include tooth attachments having improvedor optimized parameters selected or modified formore optimal and/or effective application of forces for a desired/selectedorthodontic movement. Attachments of the presentinvention can be customized to a particular patient (e.g., patient-customized), a particular movement, and/or a sub-group or sub-setof patients, and configured to engage an orthodontic tooth positioningappliance worn by a patient, where engagement betweenthe attachment and orthodontic appliance results in application of arepositioning force or series/system of forces to the toothhaving the attachment and will generally elicit a tooth movement.
