Embryology
How long is the preimplantation period?
1 week
How many branchial arches are there?
6
Where is the location of the base of the tongue in adulthood?
pharynx
During which stage is the tooth germ created?
cap stage
What is a cementocyte?
What marks the fusion of the right and left mandibular processess?
mandibular symphysis
What causes commisural lip pits?
failure of fusion between max and mand processes at corners of the mouth
What forms first, primary or secondary palate?
primary
What does the tooth germ consist of?
enamel orgen, dental papilla, dental sac
What is the cell that is from undifferentiated mesenchyme that causes resorption of collagen fibers
fibroclast
What does the maxillary process give rise to?
Midface (zygomatic bones, cheeks, sides of upperlip, secondary palate, maxillary canines, premolars and molars)
Another name for the intermaxillary segment?
premaxilla, or primary palate
The secondary palate is derived from which embryonic process?
maxillary
What is predentin?
dentin matrix, not fully mineralized dentin
When does the basement membrane disintegrate in tooth development?
after odontoblasts lay down dentin matrix
What is mesenchyme?
type of connective tissue that forms many features of the head and neck, derived from neural crest cells that migrate to mesodermal layer
Where is meckel cartilage located and what does it become?
located on each side of developing mandibular arch, disappears as the bony mandible forms (primordium as the bony mandible)
what is odontogenesis
tooth development
What structure is responsible for initiating root development?
the cervical loop
What is nasymth membrane?
residue on newly erupted teeth that leaves stained residue that can be polished off.
How many layers does the embryonic disc have during the 3rd week of prenatal development? What are they called?
Trilaminar disc (3 layers). ectoderm, mesoderm, endoderm.
The bridge of the nose is derived from what frontonasal process?
median nasal process
What is the terminal sulcus? What does it mark?
Intraoral landmark marking the line of fusion between the base and body of the tongue
When does HERS disintegrate?
when the root is completely formed
What is the last job that ameloblasts perform?
Secretion of the dental cuticle