Principles of Bone Grafting

Question 1

osteoinduction

Answer 1

new bone formation from differentiation of osteoprogenitor cells into osteoblasts

Question 2

osteoprogenitor cells are derived from what cells?

Answer 2

mesenchymal

Question 3

differentiation of osteoprogenitor cells are influenced by what?

Answer 3

bone inductive proteins from the bone matrix

Question 4

what must be stimulated to differentiate into the osteoblasts by transplanted growth factors and cytokines?

Answer 4

host cells

Question 5

what initiates osteoinduction?

Answer 5

BMP (bone morphogenic protien)

Question 6

BMP (bone morphogenic protien) is a member of what?

Answer 6

cytokine family of growth factors

Question 7

BMP (bone morphogenic protien) acts on what?

Answer 7

progenitor cells to induce differentiation into osteoblasts

Question 8

BMP (bone morphogenic protien) is higher in what type of bone?

Answer 8

higher in cortical bone than cancellous

Question 9

osteoconduction

Answer 9

formation of new bone from either host-derived or transplanted osteoprogenitor cells along a biologic frameowkr

Question 10

osteoconduction provides what?

Answer 10

only passive framework or “scaffolding”

Question 11

T/F: osteoconductive cells can produce bone

Answer 11

false, can’t… just conducts bone forming cells from host into/around the scaffolding

Question 12

osteogenesis

Answer 12

formation of new bone from osteoprogenitor cells

Question 13

osteogenesis have what type of properties?

Answer 13

osteoinductive and conductive

Question 14

what type of graft posses osteogenesis, osteoconductive and osteoinductive properties?

Answer 14

autogenic grafts

Question 15

phase 1 of two-phase theory of osteogenesis

Answer 15

transplanted cellular bone produces new osteoid

Question 16

the amount of bone regenerated during phase 1 depends on what?

Answer 16

the amount of transplanted bone cells that survive

Question 17

T/F: considerable amount of cell death occurs during grafting procedures and phase 1 may not lead to an impressive amount of regeneration

Answer 17

true

Question 18

which phase determines the quantity of bone that the graft will form?

Answer 18

phase 1

Question 19

cells in phase 1 is most active within what?

Answer 19

4 weeks

Question 20

phase 2 of two-phase theory of osteogenesis

Answer 20

angiogenesis and fibroblastic proliferation from the graft bed begin after grafting, and osteogenesis from host connective tissue soon begins

Question 21

initial woven bone in phase 2 is resorbed and replaced by what?

Answer 21

lamellar bone

Question 22

as the initial graft is resorbed, what is released from the matrix?

Answer 22

bone morphogenic proteins (BMP)

Question 23

phase 2 determines what?

Answer 23

quality

Question 24

when does phase 2 begin and peak?

Answer 24

begins at 2 weeks and peaks around 6 weeks

Question 25

T/F: remodeling process continues indefinitely

Answer 25

true

Question 26

types of grafts

Answer 26

1. autograft 2. allograft 3. xenograft 4. alloplast 5. recombinate graft

Question 27

what is the golden standard of grafts?

Answer 27

autografts

Question 28

which type of graft is most frequently used in OMFS?

Answer 28

autografts

Question 29

autografts

Answer 29

composed of tissues from the same individual

Question 30

T/F: autografts have osteogenic properties (possibly but not always)

Answer 30

true

Question 31

advantage of autografts

Answer 31

biocompatability

Question 32

disadvantage of autografts

Answer 32

1. second surgical site 2. requirement of anesthesia 3. scarring

Question 33

source of autografts

Answer 33

1. chin and other intraoral sites 2. anterior iliac crest 3. posterior iliac crest 4. anterior tibia 5. calvarium 6. rib 7. pedicle grafts

Question 34

which autograft sources may not have osteogenic potential if primarily cortical bone is harvested?

Answer 34

1. chin and other intraoral sites 2. calvarium 3. rib

Question 35

what can be harvested with cartilage for TMJ reconstruction?

Answer 35

rib

Question 36

source of pedicle grafts

Answer 36

1. fibula | 2. radial forearm

Question 37

free flap is indicated when autografts are sourced from where?

Answer 37

1. fibula 2. radial forearm 3. iliac 4. scapula

Question 38

T/F: allografts/homografts are osteoconductive

Answer 38

true

Question 39

allografts/homografts are sourced from where?

Answer 39

cadaver bone

Question 40

allografts/homografts carries what?

Answer 40

inductive proteins in some cases

Question 41

allografts/homografts are replaced by what?

Answer 41

patient's own bone

Question 42

advantages of allografts/homografts

Answer 42

1. no donor site morbidity | 2. readily available

Question 43

disadvantages of allografts/homografts

Answer 43

1. no viable cells for phase 1 osteogenesis 2. longer consolidation period 3. encapsulation 4. disease transmission 5. graft/host reaction 6. patient acceptance

Question 44

xenograft

Answer 44

grafts transplanted between individuals of different species

Question 45

T/F: xenografts are osteoconductive

Answer 45

true

Question 46

advantages of xenografts

Answer 46

1. no donor site morbidity 2. carrier for inductive proteins (possible) 3. limitless quantity

Question 47

disadvantages of xenografts

Answer 47

1. expensive 2. longer consolidation period 3. disease transmission 4. patient acceptance

Question 48

recombinate grafts

Answer 48

recominate bone morphogenic proteins

Question 49

which recombinate BMPs are FDA approved?

Answer 49

BMP-2 and BMP-7

Question 50

BMP-2 has been approved for what?

Answer 50

1. sinus floor augmentation | 2. grafting of mandibular defects

Question 51

T/F: recominate grafts can be done in children/skeletally immature patients

Answer 51

false, it's not

Question 52

disadvantage of recombinate graft

Answer 52

1. expensive | 2. may cause swelling, sterility, oncogenesis?

Question 53

common application of grafting in OMFS

Answer 53

1. reconstruction of socket following tooth ext 2. particulate grafting of small defects or sinus floor to improve implant site 3. onlay grafting using intraoral donor for improving implant site 4. onlay grafting with ICBG for larger defects to improve implant site 5. grafting of alveolar cleft in children with cleft lip/palate 6. grafting of facial contour defects associated with trauma 7. costochondral grafting for replacement of TMJ 8. grafting of continuity defects resulting from pathology or trauma