craniofacial embryology Flashcards
cranial neural crest cells form
- dentin
- pulp
- cementum
- pdl
- nerve supply
- not enamel or blood supply!
neural plate invaginates to form what
neural tube
fusion of the neural folds forms what
neural crest cells (and epidermis)
steps to formation of neural crest cells
1) induction
2) delamination
3) migration
4) differentiation
defects in NC cells lead to
craniofacial birth defects
development of the oral cavity begins when
3 weeks
contact between oral ECTOderm and foregut ENDOderm
oropharyngeal membrane
when does the oropharyngeal membrane distintegrate
4th week
when does the branchial arches begin to form
late 3rd week
1st branchial arch
maxillary process and mandibular arch
1st branchial groove
EAM (ear canal)
ectoderm of 1st groove
tympanic membrane
2nd groove
palatine tonsil
3rd groove
parathyroid gland
folding of branchial arch forms
cervical sinus
primary palate forms from what
2 medial nasal processes and frontonasal process
function of primary palate
separates developing oral and nasal cavities
what forms the secondary palate
3 palatal processes (which come from maxillary processes)
=> 2 lateral fuse with 1 medial
improper fusion of the palates results in
cleft palate
improper fusion of the neural tube (not fully enclosed)
spina infibida
cncc are considered ____ structures
transient embryonic structures
cncc come from __ edges of the neural tube and migrate ___
lateral, centrally
epithelial-mesenchymal transition
epithelial become mesenchymal cells
2nd brachial arch
hyoid arch and neck
found in the frontonasal area and invaginates to make “nasa pit”
nasal/olfactory placode
fusion of the 2 medial nasal processes and the frontonasal process
intermaxillary segment
what gives rise to the primary palate
intermaxillary segment
improperly fusion of the medial and lateral nasal processes and maxillary process
cleft lip
improper fusion of the medial and lateral palatine processes
cleft palate
formation of the tongue
brachial arch 1 (oral) and 3 (pharyngeal)
epiglottis and adjacent regions
brachial arch 4
anterior 2/3 of the tongue
oral part
posterior 1/3 of the tongue
pharyngeal part
anterior to the terminal sulcus (junction bw oral and pharyngeal parts)
circumvallate papillae
bone forming on top of a template
endochondral ossification
bone arrives DE NOVO (new) by
intramembranous ossification
membranous ossification
mesenchyme => osteoblasts
bones of the cranial vault (skull) are formed by
intramembranous ossification
bones of the endocranium (base of the skull) are formed by
endochondral ossification
body of mandible is formed by
intramembranous ossification
ramus and condyle of mandible is formed by
endochondral ossification
1st sign of mandible
meckel’s cartilage
*mandible does NOT arise from meckels
where does meckels cartilage come from
1st branchial arch
cleft palate is ___ common than cleft lip +/- palate
less common
defect in upper wall of oral cavity
orofacial cleft
cleft l/p is more common in which races
chinese, japanese, koreans
majority of clp are
non-syndromic (only cleft affected and nothing else in the body)
defect of TCOF1 gene
treacher collins syndrome
- TCOF1 gene: encdoes nucleolar (treacle) protein
- not enough neural crest cells! (apoptosis)
birth defect where sutures are fused
craniosynostosis
connecting medium between sutures (during synchondrosis)
hyaline cartilage
palate formation comes from
medial and lateral palatal processes
palate ossification comes from
1) premaxillary
2) maxillary
3) palatine
ossification centers meet to form
secondary palate
what contributes to the primary TMJ joint
meckels cartilage
