Lower Face Height Ratio: Subnasale, Stomion, and Menton

The lower face height ratio is the vertical third from subnasale to menton, and how that distance splits around your mouth. The upper segment runs from subnasale to stomion. The lower segment runs from stomion to menton. A common descriptive split puts roughly one third above the lip seal and two thirds below it. That is a planning guide, not a universal law. Dental height, lip length, chin height, jaw rotation, and soft tissue all feed the number.

On the surface, mark subnasale and soft tissue menton. The vertical distance between them is total lower face height. Mark stomion to split that distance into an upper lip segment and a lower lip to chin segment.

A classical descriptive split is about one third subnasale to stomion and two thirds stomion to menton. Convenient planning relation. Not a universal population mean. Not an attractiveness threshold.

Skeletal lower anterior facial height uses radiographic landmarks. Do not give it the same reference values as the surface ratio.

Jaw rotation, dentoalveolar height, lip length, chin height, and open or deep bite pattern all move the lower third. A long lower face can come from increased dental height or downward mandibular rotation, not just a tall chin.

A short lower face can travel with a deep bite and a more horizontal mandibular pattern. Surface geometry does not tell you which component caused it.

Soft tissue cephalometric norms built for orthognathic and cosmetic planning show that vertical relationships need defined samples and landmark systems (PMID 23099223).

An image manipulation study in an adult Asian male found that anterior vertical facial height and incisor inclination jointly influenced attractiveness ratings (PMID 34635397). Direct evidence that the vertical ratio is read with dental and profile context.

Faces treated to a divine proportion framework were not automatically perceived as divinely proportioned (PMID 21187759). Simple fractions are guides, not laws.

A cephalometric aging study in adults with normal occlusion found ongoing change, not a frozen adult face (PMID 34644780). Lip length, tooth display, and chin soft tissue can move the visible lower face split.

When you compare over time, match expression and note dental changes. A surface shift is not automatically skeletal growth.

Level frontal image. Relaxed lips. Teeth gently together. Full chin visible. Head pitch changes the vertical distances. A smile shortens the visible upper lip and wrecks the resting ratio.

Use a side image to check lip competence and chin posture. Compare only matched camera distance and height.

Solar scales the lower face against total facial height and also reads the stomion split, facial thirds, chin height, and mandibular pattern. It does not score the lower third from one fraction alone.

A neutral frontal capture supplies the main ratio. A usable side profile helps you see whether chin and lip position support the same result.

Lower face height splits the upper lip segment from the lower lip and chin. That is why you measure it. The classical split is a clear vocabulary, not a universal target.

Measure the full segment. Inspect its pieces. Read it with jaw rotation, dental pattern, chin height, and facial thirds.

Read it against the rest of the measurements series. Trait context: what facial dimorphism is.

Want this measurement read across your own facial structure? Run the Solar facial analysis.