Patent ID: 7125250

Claim:
A screw device for orthodontic treatment comprising: a screw-body part having a diameter with external threads extending a length wherein the screw-body part is tapered at a section away from a platform part and the tapered section of the screw-body part has a tapering angle of 2˜10 degrees, and the external threads of the screw-body part are slightly loosened at a portion away from the platform part and relatively concentrated at another portion near the platform part; the platform part axially aligned and integrally formed with the screw-body part, the platform part having: a flat top plane perpendicular to the screw-body part; a first mating structure formed on the flat top plane; and an outer periphery being a smooth surface without threads thereon; and a head part which is detachable from the platform part, the head part having: a flat cap; a second mating structure formed on a bottom side of the flat cap, said second mating structure being capable of engaging with the first mating structure so as to fix the head part on the platform part; and an accessory member formed on a top side of the flat cap for assisting orthodontic treatment and comprising a swirl-shaped structure of an arc-shaped wire wound at least 360 degrees; wherein the accessory member is exposed outside of the platform part when the second mating structure engages with the first mating structure.