A defined jaw is part bone and part body composition.
- The gonial angle — where the jaw turns up toward the ear — and the length of the ramus set your structural potential. A sharper angle (roughly 115–125°) tends to read as more defined.
- Soft-tissue coverage decides how much of that structure is visible. This is where most real-world change happens.
What actually moves the needle:
- 1.Body fat. A modest 3–5% reduction often uncovers a jawline that was always there.
- 2.Posture. Forward-head position blurs the mandibular border, especially in photos; chin tucks and neck training help.
- 3.Grooming. A crisp cheek line and neckline create the *impression* of a sharper jaw as soft tissue reduces.
What about "mewing" and jaw exercises? Evidence for changing adult bone is weak; the reliable levers are the three above.