Jaw & chin measurement
Chin Recession (vs. Nasion)
How far the chin sits in front of or behind a vertical line through the nasion, drawn perpendicular to the Frankfort horizontal (the “zero meridian”). A chin in line with or ahead of the nasion reads as well projected; a chin at or behind the eye socket is severely recessed.
At a glance
- Ideal
- > −4.0 mm
- Unit
- millimetres
- Weight in the overall score
- 3
- Area
- Jaw & chin
How it is measured
(Pog − N) along the Frankfort horizontal
- Pog Pogonion — The most forward point of the chin.
- N Nasion — The deepest point of the dip between the forehead and the bridge of the nose.
- Or Orbitale — The lowest point of the bony eye-socket rim, just below the lower eyelid.
- Po Tragion (porion) — The top of the tragus — the small flap in front of the ear canal. With orbitale it defines the Frankfort horizontal.
A chin at or behind the orbital rim (orbitale) is always Tier 4.
Ideal range and tiers
Each value falls into a tier (T1 = ideal). Comfortably inside T1 the rating is 10, easing to 9.5 at the edges of the ideal range; beyond it the rating falls with the deviation — fastest in the first tiers outside the ideal — down to −20 (below 0 where the original tier sheet takes points away) at the far end of the worst tier.
| Tier | Range | Rating |
|---|---|---|
| T1 In line or ahead | > −4.0 mm | 9.5–10 |
| T2 Slightly behind | −10.0 to −4.0 mm | 5.8–9.5 |
| T3 Moderate recession | −18.0 to −10.0 mm | 2.8–5.8 |
| T4 Severe recession | < −18.0 mm | −20 to 2.8 |
Differences between populations
Optional population norms move this range by the difference reported between groups measured the same way:
- Middle Eastern: men −4.5 mm, women −3.5 mm.
Individual faces vary far more within any group than between groups; these are averages, not targets.
Related measurements
References
- Gonzalez-Ulloa M, Stevens E. The role of chin correction in profileplasty. Plast Reconstr Surg. 1968;41(5):477–486.