Jaw width
Bigonial : bizygomatic width
How wide the jaw is at its back corners compared with the widest part of the face, which is usually across the cheekbones.
Also searched as bigonial width, bizygomatic to bigonial width, wide jaw and jaw to cheekbone ratio.
How to read it
the lower face tapers markedly relative to the cheekbones for the reference group.
jaw width relative to cheek width sits close to the reference mean (~0.70–0.75).
the lower face is comparatively wide relative to the cheekbones for the reference group.
Both landmarks sit on the soft-tissue outline, not on bone. Bigonial breadth from a 2D photo differs from direct measurement by 9.3 mm on average (Lim 2022), despite repeating well from photo to photo. What the camera sees is the masseter and fat envelope over the bone, and that outline shifts with yaw. The gonial angle itself is therefore given as its photographic equivalent (jaw taper & definition) rather than in degrees.
Reference values by population
| Reference population | Female (mean ± SD) | Male (mean ± SD) | n | Source |
|---|---|---|---|---|
| North American White | 0.698 ± 0.053 | 0.698 ± 0.049 | 2326 | Farkas 1994/2005 (NA White young adults) prov. |
| East Asian | 0.728 ± 0.053 | 0.731 ± 0.05 | 618 | Farkas 2005 (Chinese/Japanese/Vietnamese/Thai pooled); Jayaratne 2012 (Southern Chinese, n=103) prov. |
| South Asian | 0.711 ± 0.054 | 0.721 ± 0.053 | 210 | Farkas 2005 (Indian); Metgudmath 2022 prov. |
| African / African diaspora | 0.705 ± 0.053 | 0.707 ± 0.051 | 300 | Farkas 2005 (African-American, Zulu, Angolan) prov. |
| Middle Eastern | 0.707 ± 0.053 | 0.71 ± 0.051 | 348 | Farkas 2005 (Turkish, Iranian, Egyptian); Al-Sebaei 2015 (Saudi, n=168) prov. |
| Hispanic / Latino | 0.71 ± 0.053 | 0.714 ± 0.051 | 120 | Farkas 2005 (Mexican-American) prov. |
| Not specified — show pooled | 0.71 ± 0.059 | 0.714 ± 0.057 | 3922 | Unweighted pool of the six groups above prov. |
Where these numbers come from
Transcribed from the cited anthropometric literature; SDs of ratios are propagated conservatively (independence assumed). Entries marked prov. await line-by-line audit against the primary tables. See the norm provenance note.
Why every value has an error bar
Every value Canthion reports carries a 1σ uncertainty propagated from MediaPipe Face Mesh's published accuracy (3.96% of inter-ocular distance mean absolute error per landmark, Kartynnik 2019). On a typical photo with 300 px between the pupils, that is about 12 px of wander on every point. Small ratios and angles inherit it, so their intervals are wide. A number without an interval is a number pretending to be more precise than it is.
References
- Farkas, Katic & Forrest (2005). International Anthropometric Study of Facial Morphology in Various Ethnic Groups/Races. J Craniofac Surg 16(4):615–646. doi.org/10.1097/01.SCS.0000171847.58031.9E
- Lim, Abdul Shakor & Shaharudin (2022). Reliability and Accuracy of 2D Photogrammetry: A Comparison With Direct Measurement. Front Public Health 9:813058. doi.org/10.3389/fpubh.2021.813058
Common questions
What is jaw width?
How wide the jaw is at its back corners compared with the widest part of the face, which is usually across the cheekbones. Lower values = tapered lower face; higher = squarer.
How is jaw width measured from a photo?
It is computed from the face-mesh landmarks (go_R, go_L, zy_R, zy_L): dist(go_R, go_L) / dist(zy_R, zy_L). Every value carries a 1σ error bar propagated from the landmark detector's published accuracy, with a floor of ± 0.04, so a small difference inside the interval is not a difference.
What is a normal jaw width?
Reference means and standard deviations from the anthropometric literature, by population. North American White: 0.698 ± 0.053 for women, 0.698 ± 0.049 for men; East Asian: 0.728 ± 0.053 for women, 0.731 ± 0.05 for men; South Asian: 0.711 ± 0.054 for women, 0.721 ± 0.053 for men; African / African diaspora: 0.705 ± 0.053 for women, 0.707 ± 0.051 for men. This value is provisional and awaits line-by-line audit against the primary tables. Your own value is placed on the distribution you choose, as a percentile with its error bar.
What does a low or high jaw width mean?
Below the mean: the lower face tapers markedly relative to the cheekbones for the reference group. Above the mean: the lower face is comparatively wide relative to the cheekbones for the reference group.
How reliable is jaw width from a photograph?
Both landmarks sit on the soft-tissue outline, not on bone. Bigonial breadth from a 2D photo differs from direct measurement by 9.3 mm on average (Lim 2022), despite repeating well from photo to photo. What the camera sees is the masseter and fat envelope over the bone, and that outline shifts with yaw. The gonial angle itself is therefore given as its photographic equivalent (jaw taper & definition) rather than in degrees.
Jaw width against cheekbone width is what separates square, oval and heart in the face-shape read.
Related measurements
The rest of the jaw set, then the nearest measurements elsewhere on the face. Every one is computed on the same photograph, in the same run, with its own error bar.
Also: how bone-level measurements are taken from a photo · methodology · glossary · all 35 insight pages