[Safety of closed traction appliance in the treatment of impacted anterior teeth and its effect on pulp blood flow and masticatory function].

Both closed traction and open traction correction can effectively treat the impacted anterior teeth, and the two methods have no significant effects on root length, surrounding bone density and pulp blood flow. Although the treatment time of closed traction is slightly longer, it is more beneficial to improve patients' masticatory ability, and has high aesthetics and safety, which is worthy of clinical promotion.