Second, in many studies BTA was conventionally injected 0.5-1cm away from the incision, along the margin at an interval of 1cm, with a volume of 5-10U for every injection point. If the incision was located in the forehead, a full treatment of the frontalis was also feasible (with dosage ranging from 20-50U). The lateral supraorbital rim should be avoided to prevent lid ptosis.