Mandibular and maxillary arch expander having polygonal or ovoid rod and tube expanding elements

Abstract

An orthodontic appliance for expanding the mandibular or maxillary arch comprises a first forward orthodontic band; a second forward orthodontic band; a first spring-loaded rod and tube assembly between said first and second forward orthodontic bands; a first rear orthodontic band and a second rear orthodontic band; a second spring-loaded rod and tube assembly connecting said first forward and first rear orthodontic bands; and a third spring-loaded rod and tube assembly connecting said second forward and second rear orthodontic bands. Where both a maxillary and mandibular arch expander are used, they can be connected by a Herbst-type telescoping connector. The telescoping assembly has a first end connected to one of said forward and rear bands of said mandibular arch expander and a second end connected to the other of said forward and rear bands of said maxillary arch expander. The telescoping assembly includes a tube assembly and a rod slidably received in the tube assembly. In each of the various tube and rod assemblies (i.e. of the maxillary arch expander, the mandibular arch expander, and of the Herbst-type appliance), the tube of rod and tube assemblies defines a channel which slidably receives the rod of the rod and tube assemblies. The tube and rod have complementary cross-sectional shapes; the cross-sectional shape being polygonal or ovoid. The cross-sectional shape, for example, can be square, a circle truncated on one or two sides, or round.