Dental clasps are removable secured to teeth in part by wire ears engaging the natural undercut of the teeth and in part by engagement with buttons adhered to the teeth. Clasps are modified for the above purpose and also form combinations to engage different areas of teeth to correct various occlusions....http://www.google.co.uk/patents/US5145364?utm_source=gb-gplus-sharePatent US5145364 - Removable orthodontic appliance
