9. Expansion Flashcards
Describe a apical base to dental arch width
tangents of the posterior buccal surfaces are parallel to one another
Describe dental posterior cross-bite
- Apical base is wider than the dental arch
- Tangents of posterior buccal surfaces converge occlusally
Treatment for dental posterior cross-bite is
tipping or dental expansion
Describe skeletal posterior cross-bite
- Basal bone is narrower than dental arch
- Tangents of posterior buccal surfaces diverge occlsally
Treatment for skeletal posterior cross-bite
- Dental expansion is contraindicated
- Skeletal expansion in growing patients
- Surgically assisted RPE in non-growing adult
What are the different posterior unilateral and bilateral cross bites
Unilateral
- True cross-bite
- Edge-to-Edge bite (with functional shift )
Bilateral
- Buccal cross-bite
- Lingual cross-bite
- Complete buccal cross-bite
- Complete lingual cross-bite
Indications for orthopedic sutural expansion
- Cleft patient
- Class III patient with facemask
- Class II with constricted maxilla
- Naso-respiratory issues
One turn of the hyrex RPE is _ mm expansion
1/4 mm
Rapid expansion= 1 turn how often
-Slow expansion= 1 turn how often
- 1 turn a day
- 1 or 2 turns a week
Slow expansion is done with what appliance
schwartz
Describe the Haas RPE
- Max rigidity (due to acrylic)
- Max true sutural expansion
- Max long term stability
- Superior nasal expansion
- OH issue
Describe Shwartz appliance
- Retainer + expansion screw
- Best for mandible
- Slow expansion
- Compliance plays major role
Dentition to use quad helix in
primary and early mixed dentition
What are the differences between a skeletal shift and functional shift
Skeletal=asymmetry of the skeletal midline
Functional- Skeletal midline is only shifted when teeth are in occlusion (no asymmetry in rest position)
