METHOD AND DEVICE FOR RECONSTRUCTION OF THE LOWER JAW Russian patent published in 2021 - IPC A61B17/24 A61B17/56 A61F2/28 

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to oncology, maxillofacial, plastic surgery, and can be used when performing resection of the lower jaw with restoration of the temporomandibular joint. The bone margins of the defect are prepared in the area of ​​the zygomatic and temporal bones. After contact of all attachment points of the endoprosthesis with the bony edges of the zygomatic and temporal bones, holes are formed in the bone tissue for screwing in titanium mini-screws with a diameter of 2.0 mm. The peroneal flap is simulated to fit. templates are used, which are created on the basis of computed tomography data of the lower extremities. The templates are fixed on the anterior surface of the bone fragment. Bone blocks are formed. Bone fragments on the vascular pedicle are placed and fixed in the bed of the jaw component of the endoprosthesis. The jaw component is transferred to the defect area and the two-component endoprosthesis is assembled. The articular head of the mandible frame is inserted into the capsule of the articular part of the endoprosthesis in the area of ​​the zygomatic arch. Reconstruction of the temporomandibular joint is performed. The distal end of the articular component is fixed to the surface using mini-screws with a diameter of 2 mm and a length of 5.5 mm, also to the temporal bone through holes with a diameter of 2.05 mm in the supporting surface of the articular element of the endoprosthesis. The frame of the lower jaw with the bone blocks of the peroneal flap fixed in it is fixed in the area of ​​the sawdust of the lower jaw. The vascular pedicle of the peroneal flap is brought out into the upper third of the neck and microvascular anastomoses are applied to the facial vessels. A device for endoprosthetics of the lower jaw in the form of an L-shaped frame, repeating the outlines of the patient's healthy jaw, was made using 3D printing from Ti64ELI titanium alloy metal powder according to models obtained from computed tomography data. The jaw component replaces the resected part of the lower jaw from the head to the area of ​​resection, includes an attachment area to the unresected part of the lower jaw bone, a bed for placing a bone graft, and a leg with an articular head. The stock forms a J-shaped cross-sectional profile made in the form of a 1.1 mm thick mesh plate formed by rhombic holes 2 - 1.2 mm in size and 0.5 mm wide bridges. Around the perimeter of the plate, an edging with a height of 2.5 to 4 mm is made for attaching the frame to the jaw and bone blocks of the graft to the frame. In the mesh formed by the holes, supporting elements with a diameter of 4 mm and a hole in the center with a diameter of 2.05 mm are made. Bone blocks from the patient's fibula are located in the jaw component in this way: two of them are oriented along the body of the mandible and one along the branch of the reconstructed mandible. The attachment area has a J-shaped profile and wraps around the anterior and lower parts of the lower jaw in the area of ​​its sawdust. The leg, replacing the upper part of the branch of the lower jaw with the condylar process, is a beam made in the form of a body of revolution, expanding towards the base and tapering closer to the articular head, ending with an articular head in the form of an ellipsoid. At the junction of the bed with the leg, an end stop is made for attaching the bone block of the graft located in the region of the branch of the lower jaw. Its profile repeats the profile of the end of the graft abutting against it. On the surface of the stop there is a mesh structure with pore sizes from 0.3 to 1 mm. The articular element consists of an articular capsule and a support base. The capsule is a parallelepiped with rounded side edges. A cavity is made from the lower end of the capsule, into which the articular head of the jaw component is placed. The hole and cavity shapes are chosen so that after the articular head is inserted into it, its movement is ensured. A dovetail seat is made from the upper end of the capsule for connection to the base, containing holes for holding fastening screws. The support base is a rectangular body with a thickness of 4 to 14 mm with rounded edges, passing into an L-shaped spatial frame, and a support surface on the base of the skull support surface. To attach the component to the base of the skull using mini-screws with a diameter of 2 mm and a length of 5.5 mm, holes with a diameter of 2.05 mm are made at the base of the supporting surface. The supporting surface of the base on the skull bone is made according to the model obtained from the computed tomography data, repeats the contours of the bone in the place of their conjugation. The component of the zygomatic arch has the shape of a bone, one end is oriented to the supporting surface of the base, and the other is placed on the temporal process of the zygomatic bone, in section it has an O-shape. The surfaces of the endoprosthesis adjacent to the bones are made in the form of a mesh structure with pores from 0.3 to 1 mm.

EFFECT: method provides for the restoration of the functions of the temporomandibular joint and a reduction in the number of postoperative complications associated with the development of inflammatory processes and the dislocation of reconstructive material due to the use of a two-component endoprosthesis.

2 cl, 3 dwg, 1 ex