Fig. 1

Diagram of facial swelling measurement. a The distance from the corner of the mouth to the earlobe on the extraction side. b The distance from the earlobe to the mandibular angle. c The distance from the external canthus to the mandibular angle. Calculating the facial measurement distance (X) according to formula X = [(a + b)/2 + c]/2, the X value was taken as the average value of facial measurements in millimeters in three times. And then calculating the facial swelling percentage = [postoperative facial measurement distance (X1)—preoperative facial measurement distance (X0)] / preoperative facial measurement distance (X0) * 100%