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Maxillofacial Surgery
Facial Proportions (Ch 10)
Built from Facial Aesthetics — Concepts and Clinical Diagnosis
What’s inside
10 sections · 110 slides
Overview
- “
- What this covers
Proportion, beauty and the aim of examination
What proportion means, and what the clinician is really looking for
- What 'proportion' actually means
- Proportion is not the same as beauty
- So what is the clinician looking for?
- Faces drawn out of proportion
- A face with balanced vertical segments
- Where do the 'ideal' numbers come from?
- Why an evidence-based approach matters
- Two halves of the skull, two timetables
- Newborn and adult skull compared
- How much of the head is cranium, how much is face
- Do not miss the wood for the trees
Head height against standing height
The widest proportion of all, and the canons that tried to fix it
- A useful place to start
- Head and body do not grow at the same rate
- Head size against body size through growth
- The first canon: Polycleitos
- Doryphoros, the Spear-bearer
- Lysippos revises the rule to eight heads
- Apoxyomenos, the Scraper
- Apollo Belvedere
- Vitruvius puts proportion into writing
- The numbers Vitruvius gave
- Leonardo measures for himself
- The proportionate body inside a circle and a square
- Dürer's man of eight head-lengths
- The man of eight head-lengths
- Dürer allowed a range, not a rule
- Body types from one-seventh to one-tenth
- Modern measurement: Farkas
- 1/7.5
- Does anyone actually prefer it?
- What the raters actually chose
- Why this changes a treatment plan
Vertical facial proportions
Halves, thirds and quarters — the canons artists left us
- Three ways artists divided the face
- Landmarks you need before you measure
- Craniofacial bisection
- The head divided into halves at the eyes
- Vertical facial trisection
- The three vertical thirds
- Trisection drawn on the Vitruvian figure
- The face divided into equal thirds
- Finding the hairline when it has receded
- The lower third splits into thirds as well
- Craniofacial tetrasection
- The head in four bands
- The head divided into quarters
- The artist's facial grid
- Five eye widths across, seven eye widths tall
Do the canons survive measurement?
Farkas tested them on 103 healthy young adults
- These canons were art, not data
- Craniofacial bisection tested
- Facial trisection tested
- Craniofacial tetrasection tested
- How to hold a canon in your head
Measuring the lower face
Cephalometric ratios, modern norms and where the canon drifts
- Anterior face height ratio on a cephalogram
- How the lower face was divided
- What modern measurement found
- 31%
- Why a table of norms is worth having
- Anthropometric vertical facial measurements
- Trisection canon against measured thirds
- Lower face canon against measured lip and chin heights
- A second dataset, from the UK
How much lower face height do people accept?
Attractiveness research on the vertical dimension
- Silhouettes and the Eastman norm
- How much change before people want surgery?
- A short lower face is judged differently
- Where the acceptable band sits
When the lower face is too tall
Finding the segment at fault, and matching the operation to it
- Why vertical proportion matters at the chairside
- Two sources of an increased lower face height
- Total vertical maxillary excess
- Gum showing front and back
- Anterior vertical maxillary excess
- Excess tooth and gum only at the front
- A gummy smile is not always the jaw
- Excess gum tissue
- Three causes of a gummy smile, three operations
- Increased vertical chin height
- A chin that is too tall
- Always come back to the whole body
Transverse facial proportions
The rule of fifths, and what widens or narrows the face
- The rule of fifths
- The face divided into five equal widths
- The rule of sevenths
- When the ears fall outside the outer fifth
- Five equal fifths, and the seven-part variant
- The central fifth of the face
- Widths that should match across the face
- Why the alar base matters in surgery
- Norms differ between ethnic groups
- Normative values in young adults (age 18) for intercanthal and nasal alar base widths in three ethnic groups
- Telecanthus
- Orbital hypertelorism
- Two reasons the eyes look far apart
- Normally spaced eyes for comparison
- Both medial and lateral corners pushed apart
- Normal spacing, telecanthus and hypertelorism side by side
- Widely separated orbits in a craniofacial syndrome
- The medial fifths of the face
- Checking the width of the jaw
- A jaw that is too wide, or too narrow
- A widened lower jaw
- The lateral fifths of the face
Pulling it together
An order of examination, the numbers worth remembering, and the sources
- An order of examination
- 1/7.5–1/8
- Takeaways
- Where proportion analysis leads next
- “
- References
- References (continued)
- References (continued)
- Facial Aesthetics: Concepts and Clinical Diagnosis, 2nd Edition