An apparatus and a related pair of elements and methods are for aligning or positioning teeth. The apparatus is configured to be worn in a mouth of a wearer and further configured to be supported on the teeth of the wearer, and has elements arranged to be distributed along a set of the teeth and at least one engager member for engaging the elements for moving one or more of the teeth. In such embodiments, at least one pair of the elements can be engaged such that when in use, at least one part of one of the elements in the pair bears against at least one part of the other of the elements in the pair.