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Flashcards in Extractions Deck (22)
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1
Q

What factors do we consider when deciding which teeth to extract?

A
  • Location and severity of crowding
  • Anchorage requirements
  • Prognosis of teeth
  • Position of teeth
  • Patient factors
2
Q

How severe does crowding have to be to consider extractions?

A

Moderate-severe

- Never say you will extract to correct mild crowding!!!!!!

3
Q

How does location of crowding affect where we extract?

A

Ideally extract as close to crowding as possible to limit amount of movement required and reduce risk of anchorage loss

4
Q

What does anchorage requirement determine?

A

Whether the 4 or 5 will be removed

5
Q

What will be the extraction pattern for: Class I moderate-severe crowding

A

44/44 for severe as it gives maximum space to correct crowding
OR
55/55 if moderate

6
Q

Why do we extract the same teeth in both arches in class I?

A

It prevents altering the molar relationship (We want it to remain class I)

7
Q

What will be the extraction pattern for: Class 2 div 1 with moderate crowding

A

44/55
Upper 4s removed to aid OJ reduction and correct canines into class I
Lower 5s to prevent retraction of lower labial segment and corrects molar relationship

8
Q

What will be the extraction pattern for: Class 3 with moderate crowding

A

55/44

Camouflages reverse OJ and retroclines LLS

9
Q

What will be the extraction pattern for: Class 2 with well aligned lower arch

A

Upper 4s only because it aligns labial segments but maintains the molar relationship

10
Q

When would you consider removing 6s?

A

Only if they are of poor prognosis e.g. hyper plastic or carious, developmental conditions

11
Q

Why is removing 6s not ideal?

A

The 6 is too posterior to provide space for crowding (which usually occurs anteriorly) and correction of incisal relationship

12
Q

Importance of timing in extraction of 6s

A
  • Ideally age 9-10 to allow spontaneous space closure with 7s
  • Not if the dentition is crowded though
13
Q

How would you approach extraction of 6s in a crowded dentition

A

Wait for 7s to erupt to prevent space loss (extracting early will result in teeth moving into extraction space) and prevent medial tipping of 7s

14
Q

How can radiographs indicate correct timing for removal of 7s

A

Calcification at the bifurcation of the unerupted 7s

15
Q

When would extraction of canines be indicated

A

Poor prognosis e.g. severely displaced or impacted that cannot be saved surgically or are resorbing roots of incisors
Caries not as important as it doesn’t commonly affected

16
Q

Indications for extraction of lower incisor

A
  • Moderate class III malocclusion to shorten the mandibular arch and retried lower incisors
  • Supplemental tooth
  • Excluded from the arch/ ectopic eruption
  • Macrodontia
  • trauma
17
Q

What happens when you remove 4 premolar units?

A

Always results in class I molar

18
Q

What happens with removal of 2 upper premolar units only?

A

Full unit class II molar relationship no matter what you started with

19
Q

What happens with removal of 2 lower premolar units only?

A

Full unit class III molar relationship no matter what you started with

20
Q

How can you restore aesthetics if canines

A

Modify crown of 4s to look like a canine or orthodontically rotate the 4 so the palatal cusp faces palatally

21
Q

What is an alternative to removing an incisor to overcome crowding

A

interdental stripping

22
Q

Indications for removal of an 8

A

Not important for orthodontic as too posterior and erupts too late
- Repeat pericoronitis or caries distal of the 7