Optimization spring coil design for orthodontic tooth movement

Orthodontic tooth movement is achieved by the remodeling of alveolar bone in response to mechanical loading by using spring coil. Spring coil design was made of round stainless steel wire and usually it was custom-made design. In the previous study, the orthodontic force on 30 gram is required to move maxillary incisor during experimental tooth movement in rat. In this study, optimization new design of spring coil is developed to fulfill the requirement of orthodontic force. The design variable of new spring coil design is set on variation of angle aperture (5° ≤ α ≤ 10°), hook length (10 mm ≤ l ≤ 20 mm) and hook diameter (0.012 inch ≤ D ≤ 0.014 inch). From the result, it can be produced the optimum designs which 8.9° of angle aperture; 12 mm of hook length and 0.014 inch of hook diameter for fulfilling the requirement of orthodontic force on 30 gram force.