Craniofacial developmental disorders

Question 1

what gradient describes growth?

Answer 1

cephalocaudal gradient

Question 2

what are the 3 characteristics of growth?

Answer 2

indivudal variability
normal variation
pattern v timing

Question 3

what is the main trend seen in scammon’s curves (tissue systems)?

Answer 3

neural growth occurs very rapidly in early stages of first year of life and then tails off

Question 4

when is the pubertal growth spurt?

Answer 4

8-12 year

Question 5

what are the 4 types of growth in the craniofacial complex?

Answer 5

cranial vault
cranial base
nasomaxillary complex
mandible

Question 6

what are the 3 distinct regions (embryonic origins) of the skull?

Answer 6

desmocranium
chondrocranium
viscerocranium

Question 7

what is the chondrocranium?

Answer 7

cartilage based

Question 8

what is the viscerocranium?

Answer 8

facial tissues

Question 9

what is the desmocranium?

Answer 9

vault housing the brain

Question 10

what is the process of bone development from fibrous membrane?

Answer 10

intra-membranous ossification

Question 11

what happens prior to sutural growth?

Answer 11

fontanelle fusion

Question 12

what are the main skull sutures?

Answer 12

coronal
lambdoid
formator
posterior
parietal

Question 13

what happens to the sutures as the brain grows and bone moves apart ?

Answer 13

sutural infill

Question 14

how does the skull remodel to accommodate neural growth?

Answer 14

resorption on inside
deposition on outside

Question 15

what is hydrocephaly?

Answer 15

brain grows to an abnormally large size

Question 16

what is microcephaly?

Answer 16

problem in neural development

Question 17

what virus is associated with micrcephaly?

Answer 17

zeco virus

Question 18

what is craniosynostosis?

Answer 18

premature fusion of cranial sutures which prevent brain expanding skull normally

results in protrusion of eyeballs

Question 19

what is proptosis?

Answer 19

protrusion of eyes

Question 20

what is crouzon syndrome?

Answer 20

craniosynostosis

Question 21

what is apert syndrome?

Answer 21

coronal and lambdoid fusion - brain expands front and back instead of transversely

Question 22

what is turricephaly?

Answer 22

tall head with small length and width

Question 23

what is plagiocephaly?

Answer 23

saggital and coronal fusion

Question 24

what is trigonocephaly?

Answer 24

triangular forehead

Question 25

what type of ossification occurs in the cranial base?

Answer 25

endochondral

Question 26

what is synchondrosis?

Answer 26

a type of cartilaginous joint where hyaline cartilage completely joins together two bones

Question 27

where are centres of ossification in the chondrocranium?

Answer 27

either side of synchondrosis

Question 28

what is endochondral mechanism in the chondrocranium?

Answer 28

cartilage grows rapidly and replaced by bone

Question 29

how are ethmoid, sphenoid and basioccipital bones formed in the chondrocranium?

Answer 29

cartilage interposed between large sections of bone

Question 30

how is nasomaxillary complex formes?

Answer 30

begins at nasal cartilage in adult, becomes intramembranous ossification of maxilla, nasal and zygomatic apposition of bone at sutures bone remodelling

Question 31

when does bone remodelling occur?

Answer 31

after bones are formed

Question 32

what process allows face to grow downwards?

Answer 32

sutural growth of the circum-maxillary sutures

Question 33

how is mandible formed?

Answer 33

condyle endochondral activity periosteal activity

Question 34

what is a precursor of the mandible?

Answer 34

meckels cartilage

Question 35

when do condylar cartilage seperate?

Answer 35

early stages of foetal development before birth

Question 36

where do teeth develop?

Answer 36

alveolar process

Question 37

what are the components of the developing mandible?

Answer 37

condylar process coronoid process angular process alveolar process body chin unit

Question 38

what is the role of the condylar cartilage?

Answer 38

downward and forward transposition of mandible via cranial base bone deposition and resorption

Question 39

what is the complex growth rotation called?

Answer 39

Bjrok

Question 40

what is an environmental influence on growth?

Answer 40

orthodontic appliance

Question 41

what is a homebox gene?

Answer 41

master developmental control genes

Question 42

what is the role of homebox genes?

Answer 42

craniofacial shape and patterning patterning of the dentition

Question 43

what do homebox genes encode?

Answer 43

transcription factors

Question 44

what do homebox genes control?

Answer 44

epithelial/ mesenchymal interaction

Question 45

how do homebox genes work?

Answer 45

through neural crest cells

Question 46

where is the origin of facial mesenchyme?

Answer 46

neural crest

Question 47

what homebox genes are involved in tooth development?

Answer 47

MSX1 MSX2

Question 48

what is tooth development information expressed through?

Answer 48

mesenchymal growth factors - FGF, EGF, TGF, BPM

Question 49

what happens during week 4 NCC migration?

Answer 49

NCC migration populates branchial arches

Question 50

what are features of treacher collins syndrome?

Answer 50

down slanting fissures low set ears maxillary hypoplasia cleft

Question 51

what is missing in treacher collins syndrome?

Answer 51

condylar process zygomatic arches

Question 52

what is absent in hemifacial microsomia?

Answer 52

ramus

Question 53

why is the ramus absent in hemifacial microsomia?

Answer 53

haemorrhage of stapedial artery

Question 54

what are the types of cleft lip?

Answer 54

unilateral bilateral

Question 55

when does the primary palate fuse?

Answer 55

week 6 day 44

Question 56

when do the palatal shelves elevate?

Answer 56

week 7 day 54

Question 57

when does the secondary palate fuse?

Answer 57

week 8 day 58