There is, in essense, a stair-step order followed between the tip of the nose to the bottom of the chin with each main anatomical structure sitting just a little behind the one above it.
Those nose is the most forward projecting structure on the face and extends farther out than the upper lip.
The upper lip originates about half-way between the tip of the nose and the back of nasal wings (alae). It courses downward and slightly forward in a slightly concave curve.
The main part of the upper lip overhangs the lower lip, which faces downward. With the mouth at rest, the lips should fall together without the teeth showing.
Below the lower lip, there is a slight undercut that is often darkened by shadow.
The distance from the bottom of the nose (columella) to the bottom of the lower lip is approximately equal to the distance from the bottom of the lower lip to the bottom of the chin.
The chin sits behind the forward projection of the lower lip.