The Adam clasp is the most effective retention device for removable appliances because it engages the undercut areas of the tooth reliably, providing excellent mechanical retention. It is made from 0.36 or 0.38-inch stainless steel wire, which offers both flexibility and strength, ensuring the appliance stays securely in place during function. The Adam clasp is also simple to adjust and applies minimal pressure on the tooth, preserving tooth integrity while maintaining retention. Its design allows it to adapt to various tooth contours, making it versatile and effective in retaining removable orthodontic appliances.

Reference: Graber’s Orthodontics, 7th Edition.