Digital expression and interactive adjustment method of personalized orthodontic archwire for robotic bending

The robotic archwire bending technology has been used clinically to free orthodontic doctors from the heavy labor because of the improvement of the digital medical technology, and the digital expression of orthodontic archwire is necessary to realize the robotic archwire bending. Because of the differences between the human tooth arrangement and the difficulty of archwire shape design, it is difficult to realize the digital expression of orthodontic archwire. A method for the digital expression and interactive adjustment of personalized orthodontic archwire is presented in this paper. The straight section and the transitional section of the brackets are defined according to the reference points of the brackets. The transitional sections of the brackets are built by the mathematical model of Cubic Bezier curve. The process of handmade archwire bending, the method of discretization and combination are considered in the establishment of the mathematical model and model library about special function arch curve. The ways of the adjustment of the straight sections, the deformation of the transitional section shape, the selections of the position and type of special function arch curve are used in the study of the method for the digital expression and interactive adjustment of personalized orthodontic archwire. The interactive adjustment software is designed by the LABVIEW software. The archwire bending experiment is carried out, the error rate of the bent archwire ranged between 1.1% and 6.7% which proves the digital expression and interactive adjustment method of personalized orthodontic archwire for robotic bending is feasible and effective.