Teeth

Question 1

Type of teeth?

Answer 1

4 quadrants with 8 teeth in each:
- 2 incisors, 1 canine, 2 premolars, 3 molars
all except molars preceded by baby teeth

Question 2

Crown vs Root

Answer 2

Crown
- anatomical crown (covered by enamel)
- clinical crown (visible above gingival)
Root
- alveolar bone (anchors tooth)
- cementum (covers root)
- periodontal ligament (link cementum bone)
- pulp chamber (blood and nerve supply)

Question 3

Stage 1 of Tooth Formation

Answer 3

Bud Stage
- tooth bud from oral epithelial cells
- cranial neurocrest cells –> aggregate under tooth bud

Question 4

Stage 2 of Tooth Formation

Answer 4

Cap Stage
- tooth bud form cup-shape – cells differentiate inside
- dental papilla (in indent)
- dental sac (under papilla)

Question 5

Stage 3 of Tooth Formation

Answer 5

Late Cap Stage
- outer enamel epithelium
- inner enamel epithelium (pre-ameloblasts)
- neural crest in dental papilla (odontoblast)

Question 6

Stage 4 of Tooth Formation

Answer 6

Bell Stage
- inner enamel epithelium –> ameloblasts –> enamel
- crest in dental papilla –> odontoblast –> dentin

Question 7

Stage 5 of Tooth Formation

Answer 7

Tooth Eruption
- dental sac = cementoblasts –> cementum
- dental sac = periodontal ligament

Question 8

Dentin

Answer 8

20% collagen + 80% hydroxyapaptite
- odontoblast –> pre-dentin –> dentin
- odontoblast apical process extend = dentinal tubule

Question 9

Ameloblasts

Answer 9

secretory stage = produce enamel matrix proteins
maturation stage = mineralize enamel rods
- each ameloblast produce one enamel rod

Question 10

Cementum

Answer 10

• cementoblasts in a lacunae –> cementum
• cellular vs acellular + cementocytes

Question 11

Periodontal Ligament

Answer 11

• LCT + DCT
• tooth attachment
• cells from dental sac
• Sharpey’s Fibers (type I collagen to anchor to cementum and alveolar bone)

Question 12

Pulp Cavity

Answer 12

LCT with vessels and nerves
- infection = pressure in cavity and on nerves