Abstract:Objective To explore the best way to make canine bodily movement distally by one step with the invisible bracketless appliances. Methods To simulate the force generated by the invisible bracketless appliance and analyze the stress distribution by the means of finite element method. Then to calculate the mean value of the main stress and Von Mises standard deviation when the canine effected by distal and mesial force (F) with different couples simultaneously and to analyze the stress distribution with different combinations of F and M ratio. Results The canine incline tends to be less by the combination of F and M with proper ratio. Conclusion When M/F=7.257.5, the canine looks more like bodily movement using the invisible bracketless appliances.