Abstract: Appliances and related methods use a resilient retention member that is retained in a recess within a body that is optionally made from a suitably translucent ceramic material. The retention member, optionally in combination with one or more side walls of the recess, provides two or more regions for accommodating a protrusion. The protrusion, in turn, is part of a sliding door which can be opened or closed depending on the equilibrium position of the protrusion with respect to the two or more regions. Based on the engagement between the protrusion and the retention member, these appliances can provide discrete opened and closed door positions to facilitate archwire ligation.

Abstract: A catheter assembly having first and second shaft members that provide stearability for the catheter assembly. The first shaft member has a plurality of longitudinally spaced apart first ring members that are interconnected with a longitudinally extended first spine member. The second shaft member is positioned within the first shaft member and is connected to a distal end portion of the first shaft member. The second shaft member has a plurality of longitudinally spaced apart second ring members that are interconnected with a longitudinally extending second spine member. Alternatively, the second shaft member includes a plurality of protrusions extending radially outward from the longitudinally extending second spine member. The second shaft member is operable to move at least portions of the first ring members longitudinally relative to each other to bend the first shaft member.