module 6 review

Question 1

fibroblast

Answer 1

1) mesenchymally derived
2) produce ECM

Question 2

osteoblast

Answer 2

1) mesenchymal in origin
2) makes osteoid

Question 3

osteoclast

Answer 3

1) hematopoetic stem cell population
2) dissolve mineral and organic matrix

Question 4

response of periodontium

Answer 4

1) normal function is high and intermittent force
- eating food
2) less than 1 sec - PDL incompressible (shock absorber) and piezoelectric signal
3) 1-2 sec - PDL fluid compresses and tooth moves in PDL space
4) 3-5 sec - PDL fluid expressed, PDL compresses, immediate pain
5) PDL can resist short duration light and heavy forces

Question 5

piezoelectric theory

Answer 5

1) bone deforms and produces this current when minerals are stressed
2) helps general maintenance of the skeleton
3) changes in the local bone metabolism in that area when alveolar bone is flexed

Question 6

bioelectric theory

Answer 6

1) NOT the main theory of how teeth and roots move through bone under orthodontic forces
2) it is pressure tension theory

Question 7

pressure tension theory

Answer 7

1) osteoblasts respond to tension
2) osteoclasts respond to pressure
3) tooth movement occurs after 2-3 days
3) differentiation of osteoclasts in PDL
4) frontal resorption
5) direct bone resorption
6) heavy orthodontic force
- undermining resorption
- blood flow in PDL is shut off
- peripheral osteoclast comes from adjacent bone marrow
- delayed tooth movement

Question 8

light pressure

Answer 8

1) cyclic AMP is very important in tooth differentiation

Question 9

tooth movement light forces

Answer 9

1) tipping 35-60 g
2) bodily 70-120
3) uprighting 50-100
4) intrusion 10-20 *
5) extrusion 35-60

Question 10

heavy pressure

Answer 10

1) occluding blood vessel within PDL in 3-5 sec
2) minutes blood flow cut off
3) 3-5 days cell differentiation in adjacent narrow spaces
4) 7-14 days undermining resorption removes lamina dura PDL
- tooth movement occurs

Question 11

what inhibits tooth movement

Answer 11

1) steroids
2) aspirin and ibuprofen
3) bisphosphonate
4) chemical inhibitors of cAMP

Question 12

root resorption

Answer 12

1) most commonly upper lateral incisor
2) increased orthodontic duration increases root resorption
3) multifactorial etiology
40 invisalign causes less root resorption
- 0.25 mm is max movement, so that is why

Question 13

orthodontic retention

Answer 13

1) bone remodeling 6 mo
2) gingival fiber remodel 232 days
3) PDL settle 90 days
4) lower incisor teeth can move due to later mandibular growth in males