ICP innit

Question 1

three growth periods in post-natal growth

Answer 1

0-6 years primary dentition (deciduous)
6-12 years mixed dentition
12-18 years permanent dentition

Question 2

primary dentition

Answer 2

6-9 months
- lower a’s -> lower b’s and upper a’s -> upper b’s
1-1.5 years
- lower first molars d’s -> upper first molars d’s
1.5-1.75 years
- lower canines c’s -> upper canines c’s
1.75-2 years
- lower second molars e’s -> upper second molars e’s

Question 3

generally for tooth growth periods

Answer 3

lower then upper

anterior then posterior

Question 4

mixed dentition

Answer 4

6 years
- first permanent molar 6’s
6-9 years
- lower 1’s -> lower 2’s and upper 1’s -> upper 2’s
9-11 years
- lower canines 3’s -> upper canines 3’s
10-12 years
- lower first molars 4’s -> upper first molars 4’s + lower second molars 5’s -> upper second molars 5’s
12 years
- second permanent molar 7’s

Question 5

permanent dentition

Answer 5

17-21 years

- third permanent molar 8’s

Question 6

clinical crown

Answer 6

from top of enamel to gum line

Question 7

anatomical crown

Answer 7

from top of enamel to cervical line

Question 8

what is enamel made up of

Answer 8

calcium hydroxyapatite arranged as crystalline units from enamel-dentine junction called enamel prisms/ rods

Question 9

cell that produces enamel

Answer 9

ameloblasts

lost when erupted, do not regenerate

Question 10

decussation

Answer 10

emanel prisms/ rods cross over so it is harder to fracture

Question 11

difference between deciduous and permanent teeth

Answer 11

deciduous teeth have thinner enamel
deciduous teeth have less scalloped enamel-dentine junction as they form faster
deciduous teeth have higher pulp horns

Question 12

amelogenesis

Answer 12

process of enamel formation

Question 13

odontogenesis

Answer 13

formation and development of teeth

Question 14

what is dentine made up of

Answer 14

collagen fibres (I) and dentinal tubules which contain fluid

Question 15

formation of dentine

Answer 15

predentine formed by odontoblasts (line pulp border) unmineralised
primary dentine is until root formation is complete
secondary dentine reduces pulp chamber and root canal size
tertiary dentine is protective, responds to stimuli

Question 16

tertiary reactionary dentine

Answer 16

original odontoblast function in response to weak stimuli/ injury

Question 17

tertiary reparative dentine

Answer 17

newly recruited odontoblasts begin depositing dentine in response to severe injury

Question 18

sclerotic dentine

Answer 18

dentinal tubles are occluded with calcified material

Question 19

what is pulp made up of

Answer 19

fibroblasts maintain pulp matrix with collagen fibres and ground substances

Question 20

where do vessels and nerves enter tooth

Answer 20

apical foramen

accessory canals

Question 21

what covers dentine of roots

Answer 21

cementum - mineralised, avascularised connective tissue

periodontal ligaments insert into it

Question 22

tooth supporting structures

Answer 22

cementum
alveolar bone (lamina dura is compact part where periodontal ligament attaches)
periodontal ligament
gingiva

Question 23

alveolar bone

Answer 23

mineralised connective tissue part of maxilla and mandible

Question 24

what is periodontal ligament made up of

Answer 24

collagen I and III, cementoblasts (cementum), fibroblasts (fibres) and osteoblasts (bone)

Question 25

Sharpey’s fibres

Answer 25

ends of periodontal ligaments that insert into lamina dura of periodontal ligament and cementum
act as shock absorber against masticatory forces

Question 26

what are gingiva covered in

Answer 26

keratin to protect against abrasive forces during mastication

Question 27

root completion

Answer 27

1-1.5 years after eruption for primary teeth

<2 - >3 years after eruption for permanent teeth