Nasofacial angle, and any profile angle taken against a plane
what a photo can give, and how we take it.
The angles a silhouette genuinely contains, each traced off your own outline and drawn on your photograph: the nasal root, the nose-to-lip corner, the lip-to-chin crease, the angle under your chin, and the brow → nose-base → chin line with which way it bends. Then chin–lip direction, forehead slope, the dorsum line, and nasal projection as a ratio of your own face. All carry error bands. None are in millimetres.
Also searched as nasofacial angle, facial profile analysis and profile angles.
What we report
The angles a silhouette genuinely contains, each traced off your own outline and drawn on your photograph: the nasal root, the nose-to-lip corner, the lip-to-chin crease, the angle under your chin, and the brow → nose-base → chin line with which way it bends. Then chin–lip direction, forehead slope, the dorsum line, and nasal projection as a ratio of your own face. All carry error bands. None are in millimetres.
Why not the clinical number itself
There are two kinds of profile angle, and only one of them is refusable.
A THREE-POINT angle has its vertex and both arms on the visible outline: the nasal root, the corner between the nose and the upper lip, the crease between lip and chin, the corner under the chin. That kind is measurable from a photograph. An angle between two chords does not depend on scale, and it does not depend on how the camera was rolled. Canthion measures those, traces them off your own silhouette against the wall, and draws them on the photograph so you can see which lines they came from.
An angle taken AGAINST A PLANE is a different object. The nasofacial angle is measured against the facial plane. The nasal tip's rotation is quoted against the true vertical. Anything in Frankfort horizontal is measured against a line through porion, which is inside the ear canal. A plane you cannot see cannot be recovered from one uncalibrated photograph: the camera distance is unknown (12–19% midface stretch at 8–12 inches, Derakhshan 2024), the yaw is unknown and foreshortens the profile, and Frankfort horizontal itself varies ±4.6° between individuals relative to true horizontal (Madsen 2008). Those stay refused. So does anything quoted in millimetres.
Sources
- Derakhshan et al. 2024, Laryngoscope — doi.org/10.1002/lary.30935
- Madsen, Sampson & Townsend 2008, Eur J Orthod — doi.org/10.1093/ejo/cjn031
- Naini et al. 2017 (mentolabial angle norms: SD ±20.7° in males) — doi.org/10.1186/s40902-017-0102-8
Ratios of near-coplanar frontal distances, angles relative to the interpupillary line, and skin appearance. Each comes with an error bar, and each is placed against a population you choose. Start an analysis or read the methodology.
The others people ask for
Same question, different measurement: what the clinical version needs, and what a photograph can give instead.
What is measured instead
How every bone-level measurement is taken here · methodology · glossary · all 35 insight pages