exam 3 Flashcards

1
Q

true or false

maxillary molar has higher ratio of trabecular to cortical bone

A

true

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2
Q

root resorption may result from

A

accumulate of catabolic cytokines in the pDL

Fatigue cracks or defects in cementum covering the dentin of the root.
Dental extrusion may result in prematuries and occlusal trauma

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3
Q

what is the heritability estimate for external apical root resorption

A

70%

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4
Q

pulp death can result from

A

application of heavy forces if apex of teeth is closed = Pulp Death

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5
Q

true or false

the anchorage value for mandibular molars is greater than for maxillary molars

A

true

more bone in mandible higher anchorage.

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6
Q

External apical root resorption (EARR)

A

the loss of root structure involving the apical region to the extent that it can be seen I. standard radiographs

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7
Q

in the context of bone modeling and remodeling

Cortical bone

A

has frontal resorption(catabolic modeling) within the PDL and remodeling sites ahead of the moving tooth (0.3-0.5mm/mo)

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8
Q

in the context of bone modeling and remodeling

Trabecular bone

A

resorption occurs on all sides of exposed trabeculae, resulting in high rate of movement…(.6-1mm/mo

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9
Q

true or false

mandibular molars move twice as fast as maxillary molar

A

false

maxillary molars move twice as fast as mandibular molars

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10
Q

Leading roots______ _____ bone and trailing roots resorb_______ bone

A

leading=trabecular bone

trailing roots= cortical bone

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11
Q

class 2 problems are more prevalent in

A

whites of norther European decent

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12
Q

in McNamara’s study he found class2 was mostly due to

A

Mandibular skeletal retrusion.

true maxillary protrusion was rare

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13
Q

true or false

early treatment is more effective than later treatment I chilndren

A

according to profit

false no difference

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14
Q

order of growth

A

width then length then finally height

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15
Q

what are the best appliance for control of vertical dimension

A

Bionators

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16
Q

Increase vertical dimension results in

A

elongation and increase activity of stomatognathic muscles

17
Q

Bionators to maintain vertical dimension are what size

A

3-4 mm of posterior opening

18
Q

Bionator to decrease the vertical dimension

A

5-6 mm of posterior opening

closes a skeletal open bit

19
Q

Bionator to increase the vertical dimension

A

4-5 mm of posterior opening for posterior eruption grooves to guide eruption(open the bite)

20
Q

Twin Block appliance

A

tooth born appliance
used in minimum to moderate crowding
early and mixed dentition or permanent dentition
Maxillary and or mandibular constriction

21
Q

Frankel appliance

A

tissue born appliance

22
Q

importance of the Hertwig shealth

A

I n developing tooth bud induces neural cells to form periodontal ligament

23
Q

When do supracrestal fibers form

A

as teeth erupt they ar made of collagen fibers inserted into cementum

24
Q

Biioelectric theory

A

Relates tooth movement in part to change in bone metabolism

states that metabolism is controlled by the electric signals produced when alveolar bone flexes and bends

25
Q

in bioelectric theory electric signals are

A

piezoelectric

26
Q

Arch integrity

A

important function of the supracrestal fiber network

27
Q

PDL is filled with _____ derived from where?

A

fluid derived from vascular system

acts as shock absorber

28
Q

osteoclasts are derived from

A

circulating preosteoclasts that are formed in the marrow

29
Q

osteoblasts are derived from

A

oerivascular cells

30
Q

what is the electric potential in osteoclastic vs osteogenic areas

A

Electric potential more negative in osteogenic areas

More positive+= osteoclastic+

31
Q

eruption mechanisms depend on

A

metabolic events = formation cross- linkage and shortening of collagen fibers