An orthognathic bone joining or positioning implant method for performing an osteotomy and subsequent rejoining of one or more separated bone sections to the bone in a desired repositioning, wherein the implant is manufactured such that it provides a separating tool guidance contour for separating the bone sections after attaching a first attachment area to the bone, and provides a second or third attachment area for attaching the separated bone sections to the bone in the desire repositioning without detaching said first attachment area. The method utilizes tomographic imaging to produce a target 3D model of the bone showing the repositioned bone sections based on the original 3D model of the bone.