The use of orthodontic traction to preserve healthy subgingival residual root is a classical method combining the treatment of restoration and orthodontics. Based on the target restoration space (TRS), by establishing a TRS digital model, the final traction position of the subgingival residual root can be preset. After evaluating the key parameters such as crown-to-root ratio and minimum crown height, clinicians can estimate the treatment time and exclude cases with bad preset position. The time of traction treatment can be effectively reduced, and the efficiency and efficacy of the entire treatment can also be improved.
