Palate Expansion: 101
Section 1: What Is A Palate?
- The frontal part (⅔) the roof of your mouth comes from the maxilla which is called “its palatine process”
- The back part (⅓) comes from a separate small bone (the platine bone) that sits behind the Maxilla
Section 2: How Dentists Determine Projected Vs Recessed.
- Dentists will take a cephalometric X-ray (Side skull profile X-ray) which measures where the entire maxilla sits
- Dentists can also perform an: SNA Angle (angle showing the maxillas position → Normal: 80° - 84° | Recessed: Under 80° | Overly projected: 85°+ )
- They can also perform a: Wits (mm showing mandible and maxilla alignment to each other)
Section 2.1: How They Measure Projected/Recessed (Section A)
- They take a side profile of Skull
- Draw a vertical line straight down from a point between your eyes (This line is the nasion perpendicular plumb line hanging from between your eyebrows)
- They find A-point (deepest notch on the front of your maxilla)
- They will measure how far A-point is in front or behind your front teeth (protected vs recessed)
Section 2.2: Recessed vs Projected On X-Ray
- An Ideal (normal/balanced) = A-point sits about 0 to 1mm in front of the line (maxilla projected)
- Recessed = A-point falls more than 2mm behind the line → Maxilla sits 2-3mm further back than ideal.
- Over projected = A-point sits more than 1mm of normal range → Maxilla overprojected / sitting too far out.
Section 2.3: Wrap Up [/SPOILER]
- Ideal = A-point sits 0 - 1mm in front of the line
- Recessed = A-point sits more than 2mm behind the line
- Over Projected = A-Point sits more than 1mm ahead of the ideal range
Section 2.4: (Section B)
- Section B: Width measurement → How wide the maxilla and palate are.
- Normal Width = 36-39mm
- Too narrow = 31mm
- Clue: If the maxilla is 7.55mm narrower than your mandible = real bone problem, not crowded teeth.
Section 2.5: The Difference Between A and B
- Section A: Is your upper jaw recessed vs overly projected → measured on a vertical line between the eyes
- Section B: Maxilla being to narrow → measured by molar to molar
Section 3: Projection, Neutral, Recessed Table
| What's measured | Normal | Recessed | Well Projected |
| Maxilla Position A-point | 0 → 1mm | 2mm behind | 1mm ahead of normal |
| Palate Width | 36 → 39mm | < 31mm | 36-48mm |
| Upper Molar Width | 35 -39mm | < 31mm adult | 35-39mm (normal range) |
| Maxilla vs Mandible Width Gap | - 5 to 6 mm total measured across the dental arches - 1 to 6 mm depending on the specific skeletal landmark measured | 7.55mm | Maxilla curve matches well together with mandible curve |
Section 4: Cause Of Recession.
- Genetics
- Mouth breathing
- Thumbsucking/pacifier used past toddler age
- Tongue thrusting
- Cleft plate → Palate not fully fused
- Crouzen/Apert syndrome → causes midface undergrowth
- Crowding/loss of baby teeth to early
Section 5: How To Fix (Expanders).
Regular Expanders:
Regular Expanders:
- Hyrax → 3-7mm expansion | Stops working 16-18
- Haas → 3-7mm expansion | Stops working 15-17
- Bonded RPE → 3-6mm expansion | Stops working 16-18
- Quaded Helix → 2-5mm expansion | No age limit (Skeletal expansion limited after fusion)
Skeletal Expanders
- Marpe → 3-6mm expansion | Stops working 25-30
- MSE → 4-8-10mm expansion | Stops working 30-35
- MASPE → 4-10mm expansion | late 20s - mid 30s
- FME → 6-10mm expansion | Designed for after fusion
- Hybrid Hyrax → 4-7mm expansion | Stops working 25-30
Surgical Expanders
- EASE → 6-12mm exp | No age limit
- SARPE → 6-10mm expansion | No age limit
- Segmental Lefort 1 → 4-10mm expansion | No age limit
Aligner Expansion (Dental Only)
- Invisalign → 1-3mm expansion | No age limit
- Spark → 1-3mm expansion | No age limit
- Angel Aligner → 1-3mm expansion | No age limit
@zofatuz @jittletang42
[*]Semi-bad formatting
