Automatic cutting path recognition of invisible aligners

Accurate recognition of cutting path is crucial for the manufacture of invisible aligners. Current methods for cutting path recognition suffers from low efficiency in the manual point selection and line drawing, or low robustness and high complexity in the automatic recognition. This paper proposes an accurate and rapid algorithm for the automatic recognition of cutting paths for invisible aligners. Based on curvature from the vertices of the mesh, the algorithm extracts the feature region for the cutting path. Initial cutting path is obtained via three-dimensional morphological operations and an improved skeleton extraction algorithm. The final cutting path is achieved by applying a conformal mapping algorithm to unfold initial cutting paths to a two-dimensional plane for smoothing, and then mapping two-dimensional smooth cutting path back to three-dimensional space. Experimental results on 80 digital dental models verify the accuracy and robustness of the proposed method.