FORMA FEATURE / MOUTH & LIPSMouth width: measurements, ratios, and research
Mouth width is the distance between the corners of the relaxed mouth. It changes substantially with smiling. This page separates published measurements from interpretation, preference experiments, and community speculation.
What mouth width means
Measure corner to corner in a neutral frontal image. Compare with bigonial width (jaw corners) or alar width, but keep the denominator explicit.
Facial measurements only become comparable when the view, head position, soft-tissue landmarks, and endpoint definitions are held constant. A number copied from a profile photograph is not interchangeable with a value measured from a clinical scan or a front-facing portrait.
Official measurements, ratios & competing claims
Practical takeaway
Compare relaxed mouth width with jaw width.
The study’s mouth-to-jaw proportion offers a more explicit starting point than calling a mouth simply wide or narrow. Use nasal width as a second comparison.
What changes the answer
A wider jaw reduces the ratio even when the mouth stays unchanged. Lip fullness and smiling alter its apparent size, so compare neutral expressions.
Use these ranges to ask a better question about proportion—not to grade a face or choose a procedure by number alone. A qualified clinician still needs to examine function, tissue, skeletal structure, and your goals in person.
Connected facial features
Read or start mouth width discussions · Explore the interactive atlas