Side profile analysis: convexity, angles, and the E-line

Side profile analysis measures the face seen from the side — the overall curve from forehead to chin (facial convexity), the way the lips sit against a line from nose to chin (the E-line), and the angles the nose makes with the forehead and lip. These are the measurements orthodontists and surgeons use to describe a profile.

Facial convexity: straight, convex, concave

Facial convexity describes the overall shape of the profile through three points — the brow region (glabella), the base of the nose (subnasale), and the chin (pogonion). The angle those points make classifies the profile:

• Straight. The three points fall roughly in line, giving a flat, balanced profile.
• Convex. The middle steps forward relative to the chin — often a more prominent nose or a set-back chin — so the profile bows outward.
• Concave. The chin sits forward and the middle is flatter, so the profile curves inward.

Convexity is a description, not a verdict. All three types appear on faces that read as balanced, and the classification simply names where the profile sits along a continuum.

Ricketts' E-line

The E-line, or esthetic line, was described by orthodontist Robert Ricketts. It is a straight line drawn in profile from the tip of the nose to the most forward point of the chin, and it is used to describe the position of the lips. In many adults the lips sit slightly behind this line, with the lower lip usually a little closer to it than the upper. Lips well ahead of the E-line suggest a more protrusive profile; lips well behind it suggest a flatter one. The ideal relationship varies with age and ancestry, so the E-line is a reference for describing a profile rather than a fixed target.

Nasofrontal and nasolabial angles

Two angles anchor the nose within the profile:

• Nasofrontal angle. The angle where the forehead meets the bridge of the nose, commonly cited as roughly 115–135°. It describes how sharply or smoothly the nose emerges from the brow.
• Nasolabial angle. The angle between the base of the nose and the upper lip, commonly cited as roughly 90–110° and often a little larger in women than men. It describes how the nose tip relates to the lip and is a routine measurement in rhinoplasty planning.

Forehead slope and chin projection in profile

Two more features complete the profile. Forehead slope — how far the forehead recedes from vertical — sets the top of the convexity line and changes how prominent the brow and nose appear. Chin projection, seen in profile, determines how far the chin extends toward the E-line; a recessed chin makes the same nose look larger and the profile more convex, while a projecting chin flattens it. Because the nose, lips, and chin are read against each other, changing one changes how all of them appear.

Why the side profile matters in orthodontics and rhinoplasty

The profile is where the balance between the nose, lips, jaw, and chin is easiest to see and measure. Orthodontists assess convexity and the E-line to judge how the bite and jaws relate to the soft-tissue profile, and rhinoplasty consultations rely on the nasofrontal and nasolabial angles and the nose–lip–chin relationship to plan how a change to the nose will read against the rest of the face. In both fields the profile is a planning tool, and the measurements are references for discussion rather than promises of an outcome.

How Refrakt captures a true profile

A profile is only as accurate as the geometry it is measured from, and a phone side-photo is a poor source:

1. No perspective distortion. A phone held close enlarges whatever is nearest the lens — usually the nose — and flattens the rest. Refrakt's 3D scan reconstructs the face in three dimensions, so the profile reflects real projection.
2. Controlled pose. Camera height and head tilt change apparent nose and chin projection. The scan is levelled to a consistent orientation before any angle is measured.
3. Angles from geometry. Convexity, the E-line relationship, and the nasofrontal and nasolabial angles are computed from located landmarks rather than traced on a single photo.

Why the profile reads as one connected line

The reason profile analysis uses reference lines rather than isolated features is that the eye reads the profile as a single continuous edge from forehead to chin. A change to any point along that edge shifts how every other point is perceived: a stronger chin makes the nose look smaller, a flatter forehead makes the brow and nose look more prominent, and a fuller lip changes its relationship to the E-line without the nose or chin moving at all. This is why surgeons and orthodontists plan against the whole profile — altering one feature in isolation can throw the rest of the line out of balance even when that feature, measured alone, looks improved.

It is also why the classifications on this page are descriptions rather than grades. Straight, convex, and concave profiles each sit within a range that reads as balanced, and the "right" profile for a given face depends on the other features it is paired with. The measurements give a shared vocabulary for a consultation; they do not rank one profile above another.

Profile measurements

Commonly cited profile measurements and typical adult ranges. Figures are population averages that vary with sex, ancestry, age, and method:

Frequently asked questions