Fig. 3From: Quantification of three-dimensional facial asymmetry for diagnosis and postoperative evaluation of orthognathic surgeryCalculation of facial asymmetry index on ANS. The differences of distances between 2 reference points—frontozygomatic suture point (Z point) and porion (Po)—and ANS were measured. The sum of the square value of each difference was obtained, and we defined the root value of the sum was defined as facial asymmetry index on the midsagottal landmarks. If ANS was on the true midsagittal plane, the facial asymmetry index indicated 0Back to article page