15. Retention Flashcards Preview

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Flashcards in 15. Retention Deck (25)
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1
Q

What are the three things we want to balance to prevent an ortho case from relapsing

A

teeth
bone
muscle

2
Q

Define retention

A

holding of teeth in ideal esthetic and functional positions

3
Q

Causes of relapse are

A
  • Unfavorable growth pattern may return
  • Incorrect placement of teeth relative to basal bone (esp. lower anterior teeth too far anterior)
  • Incorrect arch form relative to muscle function
  • Lack of normal proximal contacts (tipping)
  • Incorrect relationship inclined planes
  • Continuation causative factors (i.e habits)
  • Perio factors move teeth to move teeth to former positions
  • Tooth size discrepancies
  • Eruption of third moalrs
  • Local hereditary characteristics (Growth factors in cell metabolism/ local tissue conditions may cause relapse tendency forever)
  • Individual variations (chewing, speaking, lip/tongue/cheek)
4
Q

Over-extension is resisted by _ and over contraction is resisted by _

A

cheeks and lips… tongue

5
Q

(overjet/overbites) have the tendency to return

A

overbite

6
Q

Periapical fibers in perio membrane rearrange how often

A

8-10 weeks

7
Q

Alveolar crest (supra-alveolar) elastic fibers rearrange how often

A

1 yr

8
Q

The teeth should be held in their position until what happens

A

fibrous tissue rearranged and bone fully calcifies

9
Q

What are the limits of labial movement for the mandibular incisors

A

2 mm

10
Q

What is the limit of lateral movement of the mandibular canines

A

0 mm

11
Q

What is the limit of lateral movement of the mandibular 1st PM

A

1-2 mm

12
Q

What is the limit of lateral movement of the mandibular 2nd PM

A

2-3 mm

13
Q

What is the limit of lateral movement of the mandibular 1st molar

A

2-3 mm

14
Q

What are the different intra-alveolar fiber bundles between the root and cortical plate

A
  • Crestal
  • Horizontal
  • Oblique
  • Apical
15
Q

What is an example of hereditary characteristics that can cause relapse tendency forever

A

maxillary laterals in class II division 2

16
Q

Most ortho cases have (no retention/limiteds retentio/semi-permenant/permenant retention)

A

limited retention

17
Q

What are the different requirements of retainers

A
  • Restrain teeth in current (moved) positions
  • Allow functional forces to act freely
  • Hygenic (smooth, polished and no porosities)
  • Inconspicuous and strong
18
Q

What are the different types of retainers

A

Removable
-Hawley and variations

Fixed
-Mandibular cuspid to cuspid (like a splint)

Headgear
-May be worn with retainers above in skeletal discrepancies till the end of growth

19
Q

Impressions for retainers should be made (before/after) the removal of fixed appliances

A

before

20
Q

How long should the patient wear their retainer full time

A

1 month after braces removed

21
Q

After the first month post-treatment how many hours should the retainer be worn for and for how long

A

18 hrs…3 months

22
Q

Describe the retainer schedule

A
Full time --> 1 month 
18 hrs --> 3 months
12 hr --> 3 months 
8 hrs --> 3 months 
Alternate Nights --> 3 months 
2-3 nights/week --> forever
23
Q

Why are corrected anterior and posterior cross bites no retention

A

become open bites

24
Q

Teeth separated with regainers to allow the eruption of blocked teeth is an example of (no retention/ limited retention/semi-premanent retention)

A

no retention

25
Q

Examples of permanent/semi-permanent retention is

A

spacing (congenitally missing teeth)