development of the face Flashcards
what is the primary ossification centre of the maxilla?
infraorbital nerve
when are nasal pits formed?
4th week
when are lateral and medial nasal prominences formed?
5th week
when does medial nasal prominences fuse and when do they fuse with maxilla to form inter maxillary ligament?
week 6/7
what does the frontal nasal form?
fore head
bridge of nose
what does the medial nasal form?
philtrum and tip of nose
what does lateral nasal form?
alae of nose
what does maxillary form?
checks and lateral of upper lip
what is the major signalling molecule for the maxilla?
retinoic
is cartilage vascular or avascular?
avascular
what forms out layer cartilage and what name is given to outer layer?
chondroblasts and perichondrium
when chondroblasts are trapped as chondrocytes what are they found within?
lacunae
what week does meckels cartilage form?
week 6
where does bone lay in comparison to mockers cartilage?
alongside the cartilage- it is used as a template
what does the posterior part of meckels cartilage become?
malleus (ear) and spehenomalleor ligament
what does 2nd posterior part of meckels cartilage become?
disappears but capsule forms sphenomandibular cartilage
what does 3rd area of meckels cartilage become?
absorbed
what does anterior part of meckels cartilage become?
undergoes endochondral ossification
what kind of cartilage is primary cartilage?
hyaline
what is CCN2?
a growth factor that allows growth and development of mesenchymal tissues of the face
what is the 1st stage of CCN2 expression?
forms meckels cartilage
what is the 2nd stage of CCN2 expression?
released from MC and acts as a messanger molecule between chondrocytes and osteoblasts to form bone at surface
where does primary ossification occur in the mandible?
in-between mental and inscisive nerve
where does intraosseous formation occur first?
anteriorly and posteriorly up to where mandibular nerve splits into lingual and IAN. and then extends up to form ramus of mandible
when does primary ossification end?
10 weeks
what forms secondary cartilage?
endochrondral ossification
what type of cartilage is secondary cartilage?
fibrous
what are the areas of secondary cartilage of the mandible?
coronoid
condyle
symphyseal at chin
what is the last secondary cartilage to ossify?
condyle- 20 years
