Ortho - Lecture 13: Maxillary Expansion Flashcards
Transpalatal width of ________ or less is likely to require expansion
31 mm
What are the 4 clinical characteristics that indicate transverse deficiency?
Crossbite
Crowding
Laterally flared posterior teeth
Dark spaces at corners of mouth
What are the causes of a narrow palate?
Environmental factors
Genetic factors
Airway difficulties
Digit habits
Airway difficulties promote _________ breathing, which causes the tongue to be on the floor of the mouth. The result is no pressure from the tongue on the maxilla to expand it
mouth
Thumb sucking causes the _____________ to create an inward force, causing a narrow palate
buccinator
What are the 3 methods for expansion?
Split removable plate w/ jackscrew or heavy midline spring
Lingual arch
Fixed palatal expander w/ jackscrew
Early mixed or late mixed dentition?
Use quad helix (100 g force)
Jackscrews can accidentally be activated too rapidly and distort facial structures
Early mixed
Early mixed or late mixed dentition?
4 band RPE → severe anterior crowding and a tapered arch form
2 band RPE → in mixed dentition with mild crowding
Include as many teeth as possible
Late mixed
Rapid, semi-rapid, or slow activation of jackscrews?
0.5 mm per day
10-20 lbs of pressure
Rapid
Rapid, semi-rapid, or slow activation of jackscrews?
0.25 mm per day
Semi-rapid
Rapid, semi-rapid, or slow activation of jackscrews?
1 mm per week
2 lbs of pressure
Slow
Rapid, semi-rapid, or slow activation of jackscrews?
Can provide same ultimate result over 10-12 weeks as RPE with less trauma to teeth and bones
Slow
Separation of palatal suture is ____________
non-parallel
Stresses on the palate are concentrated in the anterior and progress to the posterior.
What can this cause?
Diastemas
What is a sign that palatal expansion is working?
Diastema
Which has more attachments: anterior maxilla or posterior maxilla?
Posterior
The effects of palatal expansion on the mandible are that the mandibular teeth are often ___________, and intermolar and intercanine distances ____________
upright; increase
Expand the palate until _________ cusps of maxillary molars occlude with lingual inclines of ________ cusps of mandibular molars
lingual; buccal
Retain for _______ months using the appliance
4-6
When appliances aren’t enough, what are the tx options?
SARPE
Multiple piece Lefort I
What does SARPE stand for?
Surgically assisted rapid palatal expansion
When is SARPE definitely indicated?
> 7mm discrepancy
< ______ mm discrepancies can be camouflaged by the orthodontist
< 5 mm
SARPE or Lefort I?
More stable in the transverse
SARPE
SARPE or Lefort I?
Less risk of perio defects, relapse, and compromised blood supply
SARPE
SARPE or Lefort I?
Patients with arch length discrepancies and maxillary incisors in an acceptable vertical and sagittal position are ideal
SARPE
SARPE or Lefort I?
Extractions are not desired prior to surgery
SARPE
SARPE or Lefort I?
Requires alignment of teeth/tipping of roots prior to surgery and often times, extractions
Lefort I
