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AU14 Orthodontics > Skeletal Changes > Flashcards

Flashcards in Skeletal Changes Deck (40)
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1
Q

The maxilla is attached to the cranium via what

A

numerous sutures

2
Q

What are the three major clinical problems of maxillary growth

A
maxillary hypoplasia (class III)
maxillary prognathism (classII)
transverse deficiency (posterior crossbite)
3
Q

This can be used to restrain maxillary growth

A

headgear

4
Q

What is the distribution of forces involving headgear retraining maxillary growth

A

500-1000g (orthopedic) distributed over large bone areas and number of teeth

5
Q

What is the force duration involving headgear retraining maxillary growth

A

12-16 hours/day

6
Q

What is the force frequency involving headgear retraining maxillary growth

A

intermittent, not continuous

7
Q

What are the common headgear variations

A

high-pull
cervical pull
combination

8
Q

Where are the intraoral components anchored involving maxillary protraction-face mask and reverse pull headgear

A

maxillary molars (sometimes premolars)

9
Q

These can be used for maxillary protraction to minimize unwanted dental movement

A

temporary implants or ankylosed teeth

10
Q

When is maxillary protraction-face mask and reverse pull headgear typically done

A

before the age 9-10 (when sutures close)

11
Q

How long does maxillary protraction-face mask and reverse pull headgear last

A

6-8/9-12 months

12
Q

How much skeletal movement can be achieved involving maxillary protraction-face mask and reverse pull headgear

A

generally not more than 3mm

13
Q

In which patients are you likely to see a maxillary transverse deficiency

A

in patients with class III, class II vertical problems and as an isolated problem

14
Q

This is a common treatment to correct maxillary transverse deficiency

A

palatal expansion

15
Q

This suture is targeted during palatal expansion

A

midpalatal suture

16
Q

How much expansion can you achieve with rapid palatal expansion

A

1mm/day; mostly in adolescents

takes 2-3 weeks

17
Q

Which is the most common type of palatal expanders

A

Jackscrew-type expanders

18
Q

What type of palatal expanders are used in preschool and preadolescent patients

A

W-arch
Quad helix
1mm/week
3-6 months

19
Q

This regarding the mid palatal suture increases with age, which increases the difficulty of suture expansion

A

interdigitation

20
Q

RPE is mostly done in adolescents and pre-adolescents, which produces what movements

A

50% skeletal

50% dental

21
Q

In adults, the mid palatal suture is either fused or highly interdigitated, a palatal expansion would produce what

A

mostly (if not entirely) dental movements

large movements may require surgically assisted RPE

22
Q

The mandible grows mainly at which two locations

A
the condyles (endochondral)
posterior and lateral surfaces (intramembraneous)
23
Q

What are the three common clinical problems of mandibular growth

A
mandibular hypoplasia/retrognathism (class II)
mandibular prognathism (class III)
transverse constriction (brodie bite)
24
Q

Functional appliances can accelerate mandibular growth, but may not what

A

increase the final size of the mandible

25
Q

This partly accounts for the inconsistent skeletal effect

A

the loading pattern

26
Q

What are the two common unwanted dental effects of functional appliances

A

lower incisor proclination

upper incisor retroclination

27
Q

Functional appliances may reduce what, which is acceptable for some patients

A

overjet

28
Q

Why is the retraining mandibular growth-chin cup headgear no longer used

A

it reduces mandibular protrusion primarily by increasing anterior face height rather than shortening its size

29
Q

This is the most common treatment for mandibular prognathism

A

mandibular surgical setback after the cessation of mandibular growth

30
Q

Why is widening of the mandible difficult to achieve

A

the symphisis fuses at 7-8 months in most humans

31
Q

Mandibular expansion appliances expand what

A

dento-alveolus but not basal bone

32
Q

Expansion of the mandible basal bone requires what

A

surgical procedure; distraction osteogenesis

33
Q

This is a surgically and mechanically induced bone regeneration process, which has been used commonly to lengthen limb and craniofacial bones

A

distraction osteogenesis

34
Q

How does distraction osteogenesis work

A

two bone fragments are gradually opened by the distractor to create a gap which induces new bone formation, consolidation, and remodeling

35
Q

This is a term used to describe the adaptation of the soft tissues which include the blood vessels, ligaments, muscles, and nerves, etc.

A

distraction histogenesis

36
Q

This is the interval between osteotomy operation and the start of distraction

A

latency

37
Q

This is the period that distractor activation takes place

A

distraction

38
Q

This is the post distraction period (appliance is still in place) to allow for new bone formation

A

consolidation

39
Q

This is the period that the regenerated bone continues to remodel (after appliance removal)

A

remodeling

40
Q

How much should you over-expand so consolidation can occur

A

30%