PhiltrumHow AI measures this feature and photo tips
The philtrum is the vertical groove between nose base and upper lip. Its length affects lower-third proportion and is a subtle but measurable signal in facial harmony analysis.
See this feature in action with our Face Analyser, Face Shape Analyzer, or Guess My Age.
Key Characteristics
- ✦Philtrum length relative to lip height
- ✦Definition of philtral columns
- ✦Upper lip volume below nose
- ✦Age-related philtrum lengthening
- ✦Profile lip-nose relationship
Analysis & Photo Tips
- 📸Closed mouth, neutral expression
- 📸Front-facing for length measurement
- 📸Profile for nose-lip projection
- 📸Avoid lip pursing that shortens philtrum
Related Features
Lips
Lips are key expressive features affecting smile scoring, perceived warmth, and lower-face proportion. Fullness, symmetry, and smile dynamics all feed into Smile Tracker's blendshape and landmark analysis.
Nose-to-Mouth Ratio
The nose-to-mouth ratio compares nasal width to mouth width and the vertical distance between nose base and upper lip. Balanced ratios contribute to lower-third harmony in facial proportion scoring.
Facial Thirds
Classical proportion divides the face into three equal vertical zones: upper (hairline to brows), middle (brows to nose base), and lower (nose base to chin). Deviations signal unique character and affect harmony scores.
FAQ — Philtrum
What is an ideal philtrum length?
Guides suggest philtrum length roughly equals lip height, though significant individual and ethnic variation exists.
Does philtrum length change with age?
Yes. Lip thinning and nasal tip changes can make the philtrum appear relatively longer over time.
Why does philtrum matter in AI analysis?
It contributes to lower-third vertical ratios used in facial proportion and harmony scoring.