Development of Orofacial Structures Flashcards
Neurocranium derived from, gives rise to
Derived from mesenchyme
Gives rise to bones that enclose the brain
Viscerocranium derived from, gives rise to
Derived from mesenchyme
Gives rise to bones that comprise the facial skeleton
Intramembranous ossification
Mesenchymal origin w/o cartilage formation
Osteoblasts deposit osteoid
Endochondral ossification
Pre-existing cartilaginous model
Primary ossification center, chondrocyte hypertrophy
Craniosynostosis
Premature fusion of cranial sutures
Scaphocephaly
Sagittal suture
Long, narrow, wedge shaped cranium- most common
Brachycephaly
Entire coronal suture
High, tower-like cranium
Plagiocephaly
One side of coronal suture
Twisted and asymmetric
Trigonocephaly
Frontal/metopic suture
Derivatives of frontal and lateral nasal prominences
Frontal- forehead, dorsum/apex of nose
Lateral- alae of nose
Derivatives of medial nasal prominence
Nasal septum
Ethmoid bone
Cribriform plate
Derivatives of maxillary/mandibular prominences
Maxillary- upper cheek, upper lip
Mandibular- chin, lower lip, cheek
Formation of lower jaw and lip
First parts of face to form
Oropharyngeal membrane disintegrates, merging of medial ends of mandibular prominences
Incomplete fusion results in chin dimple
Maxillary prominence forming into lip, maxilla, secondary palate
Maxillary prominences grow medially, merge laterally with mandibular prominences
Nasal placodes
Bilateral oval thickenings of surface ectoderm on inferolateral portion of frontonasal prominence
Proliferation causes horse-shoe shaped elevations
These result in primordial nares and nasal prominences
Auricular primordia
Six auricular hillocks form around first pharyngeal groove
Development of mandible pushes ears from neck to side of head
Which signaling molecule is responsible for development of mandibular processes and removing webbing from the hands/feet
BMP
Primordial chonae
Connection between nasopharynx and nasal cavity
Formation of primary palate
Fusion of medial nasal prominences forms median palatine process
Located b/w maxillary prominences
Forms premaxillary part of maxilla
Secondary palate formation
Develops from lateral palatine processes
Mesenchymal projections extending from internal aspects of maxillary prominences
Nasal septum
Downward growth of internal parts of merged medial nasal prominences
Fuses with lateral palatine processes from anterior to posterior
Choanal atresia
Associated with bony abnormalities of the pterygoid plates and midfacial growth abnormalities
Presents as upper airway obstruction, noisy breathing, or cyanosis that worsens during feeding and improves with crying
Can be part of Treacher-Collins, CHARGE, Kallman, or VACTERL syndromes
Anterior 2/3rds tongue growth is induced by
Mesenchyme from pharyngeal arch 1
What induces the pharyngeal parts of the tongue- the copula and hypopharyngeal eminence
Copula- PA2
Hypopharyngeal eminence- PA3/4
Hypopharyngeal eminence overgrows copula, terminal sulcus is where fusion of oral and pharyngeal parts occurs
