Facial Analysis Glossary
Definitions for terms used in Smile Tracker — from Duchenne smiles to blendshapes and facial landmarks.
Duchenne Smile
A genuine smile involving simultaneous activation of the zygomatic major (mouth) and orbicularis oculi (eyes).
Smile Score
Smile Tracker's 0–100 metric rating smile warmth, symmetry, and Duchenne authenticity.
Blendshape
A parametric facial deformation model that quantifies expression components like smile, brow raise, and eye squint.
Facial Landmark
A detected point on the face used for geometric measurement — jaw, eyes, nose, mouth, and brow contours.
Canthal Tilt
The angle of the eye axis from inner to outer corner — positive if outer corner is higher.
Facial Thirds
Classical proportion dividing the face into three equal vertical zones: forehead, midface, and lower face.
Facial Proportion
The geometric harmony of facial features measured via landmark ratios and symmetry.
Facial Symmetry
The degree to which left and right facial features mirror each other.
Golden Ratio
Approximately 1.618:1 — a mathematical proportion cited in classical facial beauty frameworks.
Orbicularis Oculi
The circular muscle around the eye responsible for eye crinkling during genuine smiles.
Smize
Smiling with the eyes — a technique popularised by Tyra Banks for model photography.
Fox Eyes
An aesthetic ideal of elongated, lifted outer eye corners with feline intensity.
Hunter Eyes
Deep-set eyes with positive tilt and minimal upper sclera — an online aesthetic term.
Deep-Set Eyes
Eyes positioned further back in the orbital socket behind a prominent brow bone.
Hooded Eyes
Eye shape where a skin fold drapes over the crease, partially hiding the mobile lid.
Monolid
Eye shape without a visible supratarsal crease — smooth lid from lash to brow.
Eye Shape
Classification of eye geometry — almond, round, hooded, upturned, and others.
Face Shape
Classification of face outline geometry — oval, round, square, heart, oblong, diamond, triangle.
Jawline
The lower face contour from ear to chin, defining face shape angles and definition.
Youthful Energy Score
Smile Tracker's vitality metric combining skin, under-eye, expression, and structural youth signals.
Gummy Smile
Smile showing excessive gum tissue above the upper teeth — typically >3mm visible.
Social Smile
A polite, voluntary smile using mouth muscles without full eye engagement.
Interpupillary Distance
The distance between the centres of the pupils, used in eye spacing analysis.
Philtrum
The vertical groove between the nose base and upper lip.
Tear Trough
The groove between lower eyelid and cheek, often showing hollowing or dark circles with age.
Zygomatic Major
The primary cheek muscle pulling lip corners upward during smiling.
Age Estimation
AI prediction of apparent age from facial photo analysis.
Open-Mouth Smile
Smile with visible teeth and separated lips.
Closed-Mouth Smile
Smile with lips together and elevated corners — no teeth visible.
Put terms into practice with Smile Analyzer, Face Analyser, or Guess My Age.