Abstract: A dual coil lingual arch (10) appliance for use in the field of orthodontics is disclosed. Molar teeth (36, 38) are displaced distally by means of a primary wire arch (14) while anterior teeth (40) are displaced forward by means of a secondary wire arch (20). The primary wire arch (14) may be attached to the molar teeth (36, 38) by means of a pair of molar bands (42, 44), and the secondary wire arch (20) is attached to the primary wire arch (14) at a pair of spring junctions (30, 32). Near the spring junctions (30, 32) the secondary wire arch (20) is wound around the primary wire arch (14) to form a pair of spring coils (24, 26). In use, after the primary wire arch (14) is anchored to the molar teeth (36, 38) the secondary wire arch is activated by a practitioner by the action of lengthening the spring coils (24, 26), whereas the pressure on the molar teeth ( 36, 38) is independently set by means of preforming the primary wire arch (14).

Abstract: A relator for use in mounting complementary maxillary and mandibular dental casts in desired occluded arrangement within a pair of shell-like bases includes a locator having edges, each with a profile configuration complementary to a predetermined profile configuration on a complementary shell-like base, and a platform between the edges, the edges being spaced from one another a distance corresponding to the location of the shell-like bases when the bases are engaged with the edges of the locator and the dental casts are resting upon the platform in the desired occluded arrangement.