Ricketts E-line, Steiner S-line, Holdaway H-linewhat a photo can give, and how we take it.
Chin–lip direction from your profile: a direction and a share of the nose-tip→chin distance, with its ±.
What we report
Chin–lip direction from your profile: a direction and a share of the nose-tip→chin distance, with its ±.
Why not the clinical number itself
Lip-to-line distances with norms of a few millimetres (E-line: upper lip −4 ± 2 mm). Requires a calibrated lateral in Frankfort horizontal; H-line additionally needs bony nasion and point B. Ethnic variation is also large — African, East Asian and South Asian populations show more anterior lips relative to Ricketts' original White sample, so applying the norm cross-ethnically 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 with an error bar, each against a population you choose. Start an analysis or read the methodology.
How every bone-level measurement is taken here · all insights