Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Ortho > Biomechanics 1 > Flashcards

Biomechanics 1 Flashcards

1
Q

first step in tx

A

PATHOLOGY should be controlled first

then ortho problems
- so treated in priority order

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

biomechanics - genreal

A

principles that reveal how to accomplish tooth movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

application of force –>

A

tissue response –> orthodontic movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

principles of bio of tooth movement

A
  • if prolonged pressure is applies to a tooth movement will occur
  • bone is selectively removed in some areas and added in others
  • tooth moves through the bone carrying its attachment apparatus with it
  • tooth movement is primarily a periodontal ligament phenomenom (so need this healthy structure for movement)
  • like no pdl ankylossis is incapable of movement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is necessary for tooth movement? - clincial level

A

prolonged application of force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

graph of movement at tissue level

A

1-3 days – displacement

2-10 weeks delay / long phase

then accelarates up to acceleration and linear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

describe the initial strain / primary displacement

A
  1. initial reaction following force
  2. immediate movement within the viscoelastic pdl cradle
  3. fluid movement
  4. magnitude depends on root length/ bone height/ age/ pdl elasticity
  5. areas of pressure and tension are created
  6. pressure : pdl fibers and bone are compressed
  7. tension pdl is stretched
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

pressure

A

pdl fibers and bone is compressed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

tension

A

pdl is stretched

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

time needed for movement

A

minimal of 6 hours for movement

more efficient movement with longer duration of force applied

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

dleay / lag phase general

A

Chain of reaction to allow within a few weeks of 2 -10 weeks to see the clinical movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

tooth closer to bone?

A

pressure vs farther away = areas of tension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

delay / lag phase details

A

no movement but intense remodeling action around the tooth

relative force dependent (force applied per unit area)
- whats the ‘clincial root value’

partial or absolute occlusion of pdl blood vessels

structureal and biomechanical changes

bone remodeling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

bone remodeling occurs

A

delay / lag phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

force determines

A

how long the delay / lag force lasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

partial occlusion

A

lower relative forces

blood vesels adaps to new environmnet

localized angiogenesisi to bypass occluded areas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

absolute occlusion

A

higher forces

first time force is applied

complete occlusion of blood flow

temporary necrosis of immediate area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

acceleration and linera phase - timing

A

LIGHT CONTINUOUS FORCES allow constant responsive state in tissues and more effective ortho movement

this is a response to adaption at bone/ pdl changes - directly affected by force magnitude - higher forces may show lag phase

rapid tooth displacement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

frontal resorption

A

light forces distributed in large areas

  • right in front of root surface

transient ischemia

oxygenated is limited but still present (partial occlusion)

adaption and initiation of frontal resorption by pdl osteoclasts

movement occurs within 3-4 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

when does frontal resoprtion occur? by?

A

3-4 days by pdl osteoclasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

when does frontal resoprtion occur? by?

A

3-4 days by pdl osteoclasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

undermining resopriton details

A

larger forces applied

complete vascular occlusoin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

tooth movement in undermining resorption

A

12-15 days after bone remodeling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

pressure areas - more detailed

A

bone resorption from osteoclasts coming from the PDL

FRONTAL RESORPTION

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

tension areas - more detailed

A

bone apposition by osteoblats coming from the PDL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

osteogenesis

A

bone formed in soft tissue where it was never there before

intramembranous and endochondral

embryonic development

ORTHO HAS NOTHING TO DO WITH THIS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

BONE MODELING

A

bone formation on existin bone tissue

over extended areas for significant periods of time

growth and development

change in shape of structure or translation of surface

osteoclasts and osteoblsts act at different sites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

which is a reparative mechanism?

A

bone remodeling with 4 different stages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

4 stages of bone remodeling

A
  1. activation
  2. resorption
  3. reversion
  4. formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

light force

A

tooth contiues to mvoe with frontal resopriton

31
Q

heavy force

A

repeated hyalinization - frontal resoprtion cycles

32
Q

center or mass or gravity

A

point through which an applied force must pass for a FREE OBJECT to move linearly without rotation

point of balance

33
Q

center of resistance

A

point through which if an applied force must pass for a RESTRICTED BODY to move linearly movement without rotation

in teeth - CR depends on the root length , morphology, and attachemnt levels

1/4 to 1/3 distance from CEJ to apec

34
Q

Center of resistence in teeth

A

in teeth - CR depends on the root length , morphology, and attachemnt levels

1/4 to 1/3 distance from CEJ to apec

usually around fircation in molars *

35
Q

force in general

A

mass multiplied by acceleration

vectors with magnitude (size) and direction

direction – line of action, sense and point of origin

36
Q

resultant?

A

multiple vectors can be added

37
Q

pure translation of tooth?

A

if forces passes through CR directly – produce pure translation

38
Q

ortho forces are applied where

+ implication

A

on teh CROWN LEVEL

- so will generate rotation as well

39
Q

center of rotation

A

a point about which a body appears to have rotated, as determined from its initial and final positions

it can be located ANYWHERE on or off the tooth

40
Q

center of resistance is where

A

always on the root

41
Q

removable appliances produce

A

SINGLE FORCES

42
Q

fixed appliances may produce

A

single forces and or couples

- more precise outcomes

43
Q

types of tooth movement and result

A

tipping

translation

root movement

rotation

result from the application of moments and forces (moment/force) ratio

44
Q

describe tipping

A

greater movement of the crown

center of rotation is apical to center of resistance – apex is staying more steady

can be controlled or uncontrolled depending on location of Center of rotation

45
Q

uncontrolled tipping

A

simplest movement

single force

non uniform stresses are generted

greatest stress at CROWN AND APEX

moment/ force ratio 0:1 to 5:1

46
Q

0:1 to 5:1 ration

A

moment / force ratio

within the uncontrolled tipping

47
Q

in uncontrolled tipping where is the center of rotation adn resistenc e

A

center of rotation located between C of resistance and apex

tip and apex move in OPPOITE DIRECTOIN

48
Q

controlled tipping

A

very desirable - minimal stress at apex - less chances of root resorption

moment/ force ratio 7:1

force AND COUPLE

system of forces

center of rotation AT APEX – only major movement is at the crown

49
Q

where is movement occuring in controlled tipping

A

movement at the CROWN

– the center of rotation at the apex moves very little

50
Q

movement that allows for closure of space

A

translation

51
Q

translation - basic

A

bodily movement

52
Q

translation

A

single force at center of resistance

system of forces – force NOT passing through C resistance and couple

moment / force ratio 10: 1

53
Q

translaiton ratio and movement

A

10: 1

root and corwn moving in same distance in same HORIZONTAL DIRECTION

center of rotation at infinity

a lot of control

54
Q

root movement general

A

toque movement

55
Q

root movement moment/ force ratio

A

12:1

56
Q

root movement changes what

A

the tooths axial incliniation - want the root position to change

57
Q

greater stress where with root movement

A

greatest stress at apex level (may cause undermininig resorption and slow the movement)

so greater stress at the apical level

58
Q

greater stress where with root movement

A

greatest stress at apex level (may cause undermininig resorption and slow the movement)

so greater stress at the apical level

59
Q

movement in root movement

A

root moves while crown stays stationary – center of rotation at the INCISAL EDGE OR BRACKET

60
Q

ROTATION

A

pure rotation requires a couple

if single force is sued, C of rotation is outside the tooth

no net force acts at center of resistance

need two forces opposing

61
Q

rotation movement

A

single force not passing through center of resistnace

c of roation outside of tooth

62
Q

pure rotation

A

couple acts on tooth

center of rotation is located at center of resistance
- like on either sife of the tooth

63
Q

when does Crot = CR

A

pure rotation

64
Q

anchorage

A

resistance to unwanted tooth movemet

65
Q

teeth move differently because

A

due to variations in their root surface – more root surface more resistance to movement

66
Q

more root SA?

A

harder to move – more resistance

67
Q

friction? - very general

A

opposes movement as well

68
Q

friction - more detialed

A

it is resistance to the direction of movement, when moving a solid object tangentially against one another

69
Q

sliding mechanics

A

teeth slide on the wire

the higher the diameter the wire , the higher the friction, the greater the anchorage

70
Q

relationship between wire and friction

A

higher diameter of wire – the higher the friction – the greater the anchorage

71
Q

anchorage

A

resistance to unwanted tooth movement

72
Q

examples of intraoral anchorage

A

TPA

lingual arch

73
Q

TPA

A

transpalatal arch

connects the maxillary 1st molars and creates an anchor u nit of 6 roots

74
Q

minimum force needed for movement

A

6 hours a day

Ortho (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions