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The first 25 slides, exactly as they appear. The full deck has 134 content slides.
Maxillofacial Surgery
The Chin
Built from Facial Aesthetics — Concepts and Clinical Diagnosis
What’s inside
13 sections · 134 slides
Overview
- What this topic covers
Why the chin matters
A feature unique to humans that carries more social meaning than almost any other.
- “
- A feature only humans have
- Ancient hominid skull beside a modern human skull
- The chin sets the character of the lower face
- Strong chin, weak chin
- How chin surgery began
- Adding height to the toolkit
Anatomy and the words we use
Two layers of tissue, and a vocabulary built from Greek and Latin roots.
- Where the chin begins and ends
- Names for the same two layers
- The word roots behind every label
- Name the cause, not just the look
The chin that sits too far forward
Progenia: one appearance, three completely different causes.
- Excess and deficiency, in two directions
- Progenia in plain words
- Three roads to a forward chin
- Normal chin compared with two causes of chin excess
- When the bone itself juts too far forward
- When a thick pad does the projecting
- A normal chin carried forward on a big jaw
- A short face pattern pushes the chin out
- How a growing jaw rotates
- Which way the growing jaw rotates
- The jaw swinging shut lifts the chin forward
- Posturing the jaw forward
- The chin that only looks prominent
The chin that sits too far back
Retrogenia splits the same three ways, and the split decides the operation.
- Retrogenia in plain words
- Three roads to a receding chin
- Normal chin compared with two causes of chin deficiency
- When the bone does not come far enough forward
- When the pad is too thin
- A normal chin on a small or set-back jaw
- A long face pattern pulls the chin back
- Backward growth rotation
- The jaw swinging open drops the chin back
- The chin that only looks weak
- Why the cause changes the operation
- A set-back jaw carrying an oversized bony chin
- When two causes sit together
- A chin that is too tall
Sorting chin deformities
A classification built to point straight at the operation.
- A classification built for planning
- The five things that can be wrong
- The skeletal group
- Types of skeletal chin excess
- Types of skeletal chin deficiency
- Big one way, small the other
- A thick pad over an underdeveloped chin
- A thin chin pad with a bunched mentalis
- When the pad slides off the bone
- A chin pad that has dropped
- Rotation, size and position as causes
Examining the patient
Get the head, the jaw and the lips right before you measure anything.
- The chin is its own aesthetic unit
- The order of a chin examination
- Natural head position
- Do not let the jaw cheat
- Getting the lips truly relaxed
Judging the chin from the side
Reference lines for soft tissue pogonion, and why no single one fits everyone.
- Why the side view decides so much
- No single analysis fits every face
- Skeletal causes of altered projection
- Soft tissue and positional causes
- Vertical planes you can drop
- Angles, lips and aesthetic planes
- The zero-degree meridian line
- Reading the zero meridian
- Updating the zero meridian
- Subnasale perpendicular to Frankfort Horizontal
- A true vertical through nasion
- Why some analyses start at the nose base
- Front and back limits for the chin
- Reading the Bass analysis
- Measuring the chin from the eye
- Angle of facial profile convexity
- The facial angle
- A line touching both lips
- Reading the chin from the upper lip
- The chin should not overtake the lower lip
- Why the lower lip limits genioplasty
- Advancing a chin behind a retrusive lower lip
- Rosen's compromise
- Men, women and how much chin
- Measuring chin prominence as an angle
- What people actually notice
- 4 mm
Measuring the bony chin
Cephalometric landmarks for hard tissue pogonion, and what they leave out.
- The nasion perpendicular
- The facial angle on the radiograph
- Three measurements from the jaw angle
- Gonion distances in young Caucasian adults
- Reading those three numbers
- Effective chin: pogonion against the NB line
- Balancing chin against the lower front teeth
- The A-Pog line
- A line from nose tip to upper lip
- Bone numbers are never the whole story
- Craniofacial parts that shift the chin indirectly
- Seven parameters that move the chin indirectly
The soft tissue chin pad
The layer that every bony measurement quietly depends on.
- How thick is a normal chin pad?
- Feel before you plan
- Reducing bone under a thick pad backfires
- Same chin position, three different folds
- The fold can matter more than the projection
- What a smile does to a thin chin pad
- Assess the chin in movement, not just at rest
- A smile that pulls the chin down
- The horizontal smile and chin ptosis
The mentalis muscle
The small muscle that controls chin pad position and central lower lip posture.
- The muscle that runs the chin
- Where the mentalis actually starts
- Reading the attachment on a real patient
- Which way the fibres run
- What happens when the mentalis contracts
- How mentalis lifts the lip without touching it
- The cleft chin
- An overworked mentalis in a lip-apart patient
- Overactive and underactive mentalis
- The chin can drift back after treatment
- How reduction genioplasty can drop the chin
- Two ways surgery can drop the chin
- What a damaged mentalis costs the patient
- Reduction is the harder operation
Chin height and chin width
The vertical and transverse planes, and how much variation goes unnoticed.
- Dividing up the lower face
- Leonardo's chin proportion
- Mandibular anterior dental height
- Mandibular anterior dental height, normal values
- How much chin height do people notice?
- The band that goes unnoticed
- Chin width and the light reflection
Bringing it together
What to carry away into the clinic.
- Two operations, two risk profiles
- Take-home points, part one
- Take-home points, part two
- References
- References (continued)
- References (continued)
- References (continued)
- References (continued)
- References (continued)
- Facial Aesthetics: Concepts and Clinical Diagnosis, 2nd Edition