Teeth

Question 1

Define a heterodont and give a species examples

Answer 1

Different types of teeth within the same jaw (Mammals -> cats, dogs etc.)

Question 2

Defines a homodont w/ spp example

Answer 2

All teeth are similar (fihs, amphibians, reptiles)

Question 3

Define a diphyodont

Answer 3

Two sets of teeth (seen in mammals)

Question 4

What is the difference between a hypsodont tooth and a brachydont tooth?

Answer 4

Hypsodont = high crowns (horses and ruminants)
Brachydont = Low crowns (dogs, pigs)

Question 5

In the modified triadan system, what are the permanent teeth quadrants labelled?

Answer 5

1, 2, 3 and 4. 
1 = Upper right
2= Upper Left
3 = Lower left
4 = Lower right

Question 6

Temporary teeth quadrants are labelled what?

Answer 6

5-8

Question 7

How many incisors are present in the Triadan system?

Answer 7

3 (01, 02, 03)

Question 8

How many canines are present in the Triadan system?

Answer 8

1 (04)

Question 9

How many premolars are present in the Triadan system?

Answer 9

4 (05, 06, 07, 08)

Question 10

How many molars are present in the Triadan system?

Answer 10

3 (09, 10, 11)

Question 11

The modified Tridan system is based on what animal? And how many teeth are there ins each quadrant?

Answer 11

Pig - 11

Question 12

What is the dental formula for a mare? Which teeth are missing?

Answer 12

3. 0.3.3 - Upper - missing canine and first pre-molar

3. 0.3.3 - Lower - missing canine and fire pre-molar

Question 13

What is the dental formula for a dog? Which teeth are missing?

Answer 13

Upper: 3.1.4.2 - missing lasy molar (4th pre-molar = carnasial tooth)
Lower: 3.1.4.3 - full set

Question 14

What is the dental formula for a cat? Which teeth are missing?

Answer 14

Upper: 3.1.3.1 - missing 1st premolar, x10 and x11 molar
Lower: 3.1.2.1 - missing 1st and 2nd premolar (x06, x05) and x10 and x11 molar

Question 15

Dental formula for a rabbit? Which teeth are missing?

Answer 15

Upper: 2.0.3.3 - missing= 3rd incisor, 1st premolar
Lower: 1.0.2.3 - missing = 2nd and 3rd incisor, 1st and 2nd pre-molar.

Question 16

Outline the embryological development of the tooth

Answer 16

1: Bud stage. Line of epithelial cells condenses along jaw margins, invaginate to form dental bud. Surrounded by proliferating mesenchymal cells
2: Cap stage. Bud infolds to form dental cap, neural crest derived mesenchyme forms dental papilla. Remains connected to epithelium via cord of cells, give off-shoots to form more buds.
3: Epithelial cells => ameloblasts => form enamel
4: Mesenchymal cells => odontoblasts =>form dentine
5: Bell stage. Mesenchyme around bud forms vascular dental sac (dental follice). Inner layer forms cementoblasts => cementum. Outer layer form osteoblasts => alveolar bone
6: Enamel organ comprises stellate reticulum plus ameloblasts and outer enamel epithelium
7: Dental sac differentiates into the periodontal ligament

Question 17

What forms the enamel in a developing tooth?

Answer 17

Ameloblasts

Question 18

What dorms the dentine in developing tooth?

Answer 18

Odontoblasts

Question 19

What do the osteoblasts form?

Answer 19

Alveolar bone

Question 20

What is the sensory nervous supply to the maxilla teeth?

Answer 20

Trigeminal V2 - Infraorbital nerve

Question 21

What is the sensory nervous supply to the mandibular teeth

Answer 21

Trigemnial V3 - Mandibular nerve

Question 22

What is the eruption times of deciduous teeth in horses?

Answer 22

Di 1= 6 days, Di 2= 6 weeks Di 3 = 6 months

3 Pre-Molars = 2 weeks

Question 23

What is the eruption time of permanent teeth in horses?

Answer 23

I1 = 2.5 years, I2 = 3.5 yrs, I3 = 4.5yrs
C = 4-5 years
PM1 (Wolf) = 6 months, PM2 = 2.5yrs PM3 = 3yrs, PM4 = 4 yrs
M1 = 1 year, M2 = 2 year, M3= 4 year

Question 24

What is Galvayne’s groove?

Answer 24

Appears on the lateral aspect of I3, appears at 10 years of age. At 15 year will be halfway down the tooth. 20 years is full developed.

Question 25

When do cattle’s incisors erupt?

Answer 25

2 years old