Abstract: The disclosed &bgr; titanium alloys contain alloying elements of molybdenum between 10.0 and 12.0 weight percent, aluminum between 2.8 and 4.0 weight percent, chromium and vanadium between 0.0 and 2.0 weight percent, and niobium between 0.0 and 4.0 weight percent. Orthodontic arch wires and appliances of nickel-free &bgr; titanium alloys having pseudo-elastic properties associated with stress-induced martensitic transformation. These arch wires and appliances were found to possess a high strain recovery up to 3.5% strain of deformation, a lower stiffness yielding relatively constant force for tooth movement and improved formability over that of pseudo-elastic nitinol. Eyeglasses having parts made of such materials can be welded. Stents made of this material avoid problems which a certain percentage of the population have when nickel is included within alloys used in the human body. Other medical devices which are used in the body also have this benefit.