REDUCING SCREW FOR TREATING FRACTURES OF LOWER JAW Russian patent published in 2019 - IPC A61B17/86 

FIELD: medicine.

SUBSTANCE: invention relates to medicine. Reducing screw for treating the lower jaw fractures comprises a rod, a threaded portion and a head. Rod of the reducing screw is made in the form of a smooth Kirschner spoke with a pointed end in the form of a trihedron, with diameter of 1.5 mm and length from 6 to 15 mm, within the limits of errors of the corresponding measuring instruments, including the rifled part. Rifled part is self-tapping at the end of the rod opposite to the pointed one. Rifled portion is made with a length corresponding to the thickness of the cortical bone of the lower jaw of the patient, with a metric thread with an outer diameter of 2 mm, with a thread depth of 0.5 mm and an apex angle of 60°, with thread pitch of 0.3 mm, within the limits of errors of corresponding measuring instruments. In the gum area, the rifled portion of the screw rod changes into a truncated cone, with height of 2–5 mm, with a polished lateral surface in contact with the gingival mucosa and protruding above its surface by 1 mm, within the limits of errors of the corresponding measuring devices. Diameter of the inner base of the truncated cone coincides with the outer diameter of the thread, and the diameter of the upper base of the cone in the entire range of height of the cone will match the maximum transverse dimension of the head of the screw which is made for the angular key. Upper base of the cone is connected to the head of the screw by means of the neck, which is made in the form of a circular groove, the depth of which provides the possibility of simultaneous fixation of rigid and elastic tie-rods.

EFFECT: invention provides reducing traumatism, simplifying and rapid insertion of the screw into the jawbone, as well as increasing the linear compression in the fracture line.

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