An orthodontic appliance and system are provided for adjusting the relative positions of mandibular and maxillary arches. The orthodontic appliance includes a telescoping assembly comprising a plurality of telescoping members, and at least a first end member supportably retaining at least a portion of a spring member. The end member is adapted to slidably receive an end of a first telescoping member for selectively interconnection and disconnection therebetween. When interconnected, the spring member extends into an open end of the first telescoping member and is operative to apply spring-force to a second telescoping member. A plurality of interchangeable end members may be provided for use with the telescoping assembly, wherein the different end members have different spring-force delivery attributes. The orthodontic appliance may be installed utilizing an attachment device selectively interconnectable to and disconnectable from orthodontic archwires.
