Table 2.

Definitions of the landmarks

Region	Landmarks	Description
Along the lips	Cph (L), Cph (R)	The highest point of the Cupid’s bow (left, right)
	Ls	The lowest point of the middle area of the Cupid’s bow
	Ch (L), Ch(R)	The most lateral point of vermilion border (left, right)
	Li	The lowest point of vermilion border
	L1, L4, R1, R4	Midpoints of curved vermilion border
Around the lips	1–9 B′	Perioral points which are counterparts of each point along the lip border, being apart by the same distance Soft tissue B point
Around the nostril	Al (L), Al (R)	Most lateral point of the alar contour (left, right)
	Pn	Most anterior point of the nose
	Sn	Midpoint of the nasolabial angle at the columellar base
	Ac (L), Ac (R)	Labial insertion of each alar base