Ortho - Lecture 13: Maxillary Expansion

Question 1

Transpalatal width of ________ or less is likely to require expansion

Answer 1

31 mm

Question 2

What are the 4 clinical characteristics that indicate transverse deficiency?

Answer 2

Crossbite
Crowding
Laterally flared posterior teeth
Dark spaces at corners of mouth

Question 3

What are the causes of a narrow palate?

Answer 3

Environmental factors
Genetic factors
Airway difficulties
Digit habits

Question 4

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

Answer 4

mouth

Question 5

Thumb sucking causes the _____________ to create an inward force, causing a narrow palate

Answer 5

buccinator

Question 6

What are the 3 methods for expansion?

Answer 6

Split removable plate w/ jackscrew or heavy midline spring
Lingual arch
Fixed palatal expander w/ jackscrew

Question 7

Early mixed or late mixed dentition?

Use quad helix (100 g force)
Jackscrews can accidentally be activated too rapidly and distort facial structures

Answer 7

Early mixed

Question 8

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

Answer 8

Late mixed

Question 9

Rapid, semi-rapid, or slow activation of jackscrews?

0.5 mm per day
10-20 lbs of pressure

Answer 9

Rapid

Question 10

Rapid, semi-rapid, or slow activation of jackscrews?

0.25 mm per day

Answer 10

Semi-rapid

Question 11

Rapid, semi-rapid, or slow activation of jackscrews?

1 mm per week
2 lbs of pressure

Answer 11

Slow

Question 12

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

Answer 12

Slow

Question 13

Separation of palatal suture is ____________

Answer 13

non-parallel

Question 14

Stresses on the palate are concentrated in the anterior and progress to the posterior.

What can this cause?

Answer 14

Diastemas

Question 15

What is a sign that palatal expansion is working?

Answer 15

Diastema

Question 16

Which has more attachments: anterior maxilla or posterior maxilla?

Answer 16

Posterior

Question 17

The effects of palatal expansion on the mandible are that the mandibular teeth are often ___________, and intermolar and intercanine distances ____________

Answer 17

upright; increase

Question 18

Expand the palate until _________ cusps of maxillary molars occlude with lingual inclines of ________ cusps of mandibular molars

Answer 18

lingual; buccal

Question 19

Retain for _______ months using the appliance

Answer 19

4-6

Question 20

When appliances aren’t enough, what are the tx options?

Answer 20

SARPE
Multiple piece Lefort I

Question 21

What does SARPE stand for?

Answer 21

Surgically assisted rapid palatal expansion

Question 22

When is SARPE definitely indicated?

Answer 22

> 7mm discrepancy

Question 23

< ______ mm discrepancies can be camouflaged by the orthodontist

Answer 23

< 5 mm

Question 24

SARPE or Lefort I?

More stable in the transverse

Answer 24

SARPE

Question 25

SARPE or Lefort I? Less risk of perio defects, relapse, and compromised blood supply

Answer 25

SARPE

Question 26

SARPE or Lefort I? Patients with arch length discrepancies and maxillary incisors in an acceptable vertical and sagittal position are ideal

Answer 26

SARPE

Question 27

SARPE or Lefort I? Extractions are not desired prior to surgery

Answer 27

SARPE

Question 28

SARPE or Lefort I? Requires alignment of teeth/tipping of roots prior to surgery and often times, extractions

Answer 28

Lefort I