Patent ID: 7936911

Claim:
A 3D planning and prediction method for optimizing facial skeleton symmetry in orthognathic surgery comprising steps of making a plaster dental cast according to an oral cavity of a patient, wherein the plaster dental cast has an upper jaw stone assembly and a lower jaw stone assembly; reconstructing jaw image assembly models in a computer by scanning the patient's facial structure using computer tomography, wherein the jaw image assembly models include an upper jaw image assembly and a lower jaw image assembly; performing registration between the jaw image assembly models and the plaster dental cast, wherein a coordinate relationship between the virtual jaw image assembly models and the substantial plaster dental cast is established in the computer by coordinate transformation for position synchronization; adjusting positions of the upper and lower jaw stone assemblies of the plaster dental cast to target positions according to a predetermined x-ray cephalometric plan; tracking movements of the upper and low jaw stone assemblies with a spatial tracking device to synchronously and correspondingly reappear the same movements of the upper and lower jaw image assemblies to obtain a relative variation between positions of the upper and lower jaw image assemblies; obtaining optimal symmetry planes of the upper and lower jaw image assemblies by a computer via an asymmetry quantifying process and thereby computing a variation of an included angle and a specific distance between the optimal symmetry planes of the upper and lower jaw image assemblies; determining whether a degree of overall symmetry is elevated by determining whether the included angle and the specific distance are shortened under a condition of compromising the x-ray cephalometric plan, and recording the included angle and the specific distance and proceeding to next step when the degree of overall symmetry is elevated, otherwise checking if any error occurs while adjusting positions of the upper and low jaw stone assemblies of the plaster dental cast according to the x-ray cephalometric plan and returning to the step of tracking movements of the upper and low jaw stone assemblies of the plaster dental cast; and making surgical occlusal splints according to the x-ray cephalometric plan and the recorded included angle and specific distance for surgical guiding.