Ricketts E-line, Steiner S-line, Holdaway H-line
what a photo can give, and how we take it.
Where your lips sit between your nose tip and your chin, read off your own profile: a direction, and a share of the nose-tip→chin distance, with its ±.
Also searched as Ricketts E-line, E-line lips, lip protrusion and Steiner S-line.
What we report
Where your lips sit between your nose tip and your chin, read off your own profile: a direction, and a share of the nose-tip→chin distance, with its ±.
Why not the clinical number itself
These are lip-to-line distances with norms of a few millimetres (E-line: upper lip −4 ± 2 mm). They require a calibrated lateral in Frankfort horizontal, and the H-line additionally needs bony nasion and point B. Ethnic variation is large. African, East Asian and South Asian populations show more anterior lips than Ricketts' original White sample, so applying the norm across ethnicities systematically labels normal lips as protrusive.
Sources
- Ricketts 1960, Am J Orthod 46:330 — pubmed.ncbi.nlm.nih.gov/13741421/
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