Gonial anglewhat a photo can give, and how we take it.
Jaw taper (soft-tissue angle from the jaw angle to the chin, levelled to your pupils) and jaw definition (the shadow step across the jaw line) from your ¾ views, plus jaw:cheek width from the front — each with an error bar and a grade.
What we report
Jaw taper (soft-tissue angle from the jaw angle to the chin, levelled to your pupils) and jaw definition (the shadow step across the jaw line) from your ¾ views, plus jaw:cheek width from the front — each with an error bar and a grade.
Why not the clinical number itself
Gonion is a landmark on the mandibular BONE. In a photograph it is hidden under the masseter muscle and subcutaneous fat, so what a photo-based tool actually measures is the angle of the soft-tissue silhouette — the muscle-plus-fat envelope, not the jaw. It also swings by tens of degrees with a few degrees of head yaw. Gonial angle is a lateral-cephalogram or CBCT measurement (adult norms ≈118–128°) and cannot be recovered from a selfie.
Sources
- Lim et al. 2022 — bigonial breadth from 2D photogrammetry off by 9.3 mm vs calipers despite ICC 0.91 — doi.org/10.3389/fpubh.2021.813058
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