The Adam's clasp is a component of removable orthodontic appliances, not fixed ones. Fixed orthodontic appliances consist of bands, brackets, and arch wires that are cemented or bonded to the teeth and remain in place until professionally removed. Adam's clasp is used to engage and retain removable devices, such as retainers or expansion plates, allowing for easy insertion and removal by the patient. Thus, it does not belong to the fixed orthodontic system, which relies on permanently attached hardware for controlled tooth movement.

Reference: Graber’s Orthodontics, 7th Edition.