Fig. 3
From: Quantitative analysis of facial symmetry by using three-dimensional technology
A Soft-tissue landmarks. Tr (Trichion): The point located below the hairline in the midline of the forehead. En (Endocanthion): The soft tissue point located at the inner commissure of each eye fissure. Ex (Exicanthion): The soft tissure point located at the outer commissure of each eye fissure. N: The nasion of soft tissue. Sn (Subnasale): The midpoint on the nasolabial soft tissure contour between the colunella crest and the upper lip. Ch (Cheilion): The point located at each labial commissure. Li (Labiale inferius): The midpoint of the vermilion line of the lower lip. B Constructed planes. P1 (The mirror symmetry plane): The plane across the points of Tr, N, Sn, Li. P2 (The transversal plane): The plane through left and right En and Ex. P3 (Subnasale): Through Sn, parallel to P2. P4 (Mouth corners): Through left Ch, parallel to P2. P5 (Lower mouth): Through Li, parallel to P2. P6 (Vertical left): Through left En and left Ch. P7 (Vertical right): Through right En and right Ch