The present invention provides a virtual orthodontic treatment method, comprising, providing a virtual diagnostic setup model of teeth of at least one jaw of an individual, associating virtual orthodontic appliances with all teeth in the model to obtain a first composite model and repositioning teeth into an initial treatment state according to pre-defined appliances-dependent rules; in the initial treatment state, detaching one or more teeth from their corresponding one or more orthodontic appliances, repositioning one or more appliances, reassociating one or more appliances with the teeth, permitting the teeth to reposition according to the appliances-dependent rules to obtain an altered treatment state, yielding a better grade, according to one or more systems for grading an orthodontic model, as compared to the grade of initial treatment state.