Abstract: In an orthodontic appliance fit into the mouth, at least either one of an orthodontic bracket or an arch wire is composed of a composite resin. A reinforcing member is provided at a slot of the bracket and exposed to an inner wall surface of the slot. The reinforcing member is extended into tie wings which are formed as being extended toward the gingival side of the slot and towards the occlusal side. The composite resin is a resin, e.g., a polymer alloy, in which two or more kinds of resin having contrary capacities, i.e., durability and adhesiveness, are blended. Further, a thermoplastic elastomer (TPE) is dispersed into a matrix resin to accomplish the strength and the solvent crack prevention, which are difficult to consist with each other. Dispersing TPE into the matrix resin is one kind of polymer alloying, and thus obtained resin is the composite resin.