Chapter 10

Question 1

1. What is sexual dimorphism? Give examples with regard to antlers, horns, and teeth.

Answer 1

• Sexual dimorphism is where only one member of the sex will exhibit a structure or physical characteristic
• Anters – deer, moose, & elk males only have antlers
• Horns – occurs in both sexes except for in Dorset sheep
• Teeth – horse canines in mares are often small and may not erupt

Question 2

What is meant by the rule of 7/11? How are the canine teeth of dogs and horses different?

Answer 2

Basic mammal has 11 teeth in each of four quadrants - 7 deciduous teeth in each quardrant (but some have less)

Dogs have deciduous canine teeth - horses don’t

Question 3

9. What distinguishes molars and premolars in general? What is the exception?

Question 4

What directional terms are used to describe the sides of various teeth? What is the meaning of dental occlusion and occlusal surface? What equine teeth are non-occlusal and why?

Answer 4

labial = lip side (incistors/canines), buccal = cheeck side (cheek teeth), lingual = tongue side (incisors, mandibular teeth), palatal = hard palate side of upper cheek teeth

chewing surface = occlusal surface

canine and wolf = non-occlusal

Question 5

What is the apical end of the tooth? What is the significance of so called temporary tuberosities (eruption bumps)? Why are they temporary?

Answer 5

end opposite of crown

unerupted permament teeth so long not room for them in mandible

teeth eventually grow out?

Question 6

Compare and contrast brachydont and hypsodont teeth. How do their crowns differ? What tooth is brachydont in horses? What is dental attrition and how does it sharpen teeth?

Answer 6

brachydont - eruption process stops shortly after eruption

hypsodont = eruption continous throughout life

hypsodont have clinical crown (exposed) and reserve crown (unerupted) - brachydont don’t have these

equine brachydont = wolf (canine in middle)

when teeth uneven and sharpen

Question 7

What is meant by cheek teeth? Which premolar doesn’t belong? What is PM or M number of CT 1, 3, 6? Compare and contrast the cheek teeth of horse and cattle. How does this relate to digestive systems?

Answer 7

cheek teeth = premolars and molars

wolf tooth

CT 1 = PM2, CT 6 = M3

cheek teeth better developed in horse - have to get it right the first time

Question 8

3. Compare llama dentition with ruminant dentition. What are the fighting teeth?

Answer 8

• Llama and ruminants both have dental pads but llamas have upper canines and I3 in addition to dental pad
• Llamas lower canines are differentiated from incisors; ruminants the canine is I4
• Fighting teeth are llamas upper canines and I3; often cut off

Question 9

4. What are the tusks of swine and elephants and how are these teeth similar to rodent incisors? Relate this to the pulp cavity.

Answer 9

• Tusks of swine are the canines
• Tusks of elephants are upper I2’s
• Similar to rodent incisors in that have continuous growth and eruption and also have wide open root which facilitates growth (increase in length) throughout life

Question 10

What is the significance of the infolded enamel? In what two ways does enamel infolding occur?

Answer 10

allows longer cutting edge to be rammed into small space of tooth

infolding occurs at periphery and from occlusal surface

Question 11

5. Differentiate between the cup and infundibulum; enamel spot and dental star. Which teeth have infundibula? What is the apparent reason for the formation of infundibula?

Answer 11

• Cup is the depression in the infundibulum and is often filled with black decaying material
• Enamal spot is the bottom of the cup and the dental star is a darker, secondary dentin filling the pulp cavity that is rostral to the enamel spot
• Incisor teeth have infundibula
• Formation of infundibula occurs as a mechanism to combat the wear and tear of grinding; enamel is harder than dentine and becomes sharper as it wears down aiding in the cutting and macerating of the plants

Question 12

6. What forms the ruminant corner teeth?

Answer 12

ask somebody

Question 13

10. Define caps, alveolus, deciduous teeth.

Answer 13

• Caps = A deciduous tooth remaining attached to its permanent replacement; affected teeth are Dp2, Dp3, Dp4
• Alveolus = the bony sockets of the incisive, mandible, and maxillary bones in which the roots of teeth are embedded
• Deciduous teeth = “baby teeth” that develop early in life to give the young animal a functional set of teeth; smaller and fewer in number than permanent dentition

Question 14

Full wear decidous mouth? full wear permanent mouth?

Answer 14

2 years, 5 years

Question 15

What 2 equine teeth numbers are most often not present in either gender? not deciduos? not present in most mares? problems with bits?

Answer 15

• 305, 405
• canines, wolf teeth, molars
• all the canines
• 105, 205

Question 16

11. What are the 2 major factors used in dental aging?

Answer 16

• Eruption dates (most reliable)
• Wear - are first “in wear” and when entire occlusal surface is worn down then the tooth is level

Question 17

12. Why are hypsodont teeth protected from abscess? What occurs instead?

Answer 17

• Hypsodont teeth are protected because enamel protects the unerupted portion of the tooth from bacterial penetration
• Alveolar periostitis (inflammation of the alveolar periostium) occurs instead

Question 18

13. Differentiate horns from antlers

Answer 18

Horns Antlers
Hollow Solid
Don’t shed Shed annually (rapid growth)
polled no polling
not branched branched

Question 19

What are cervids?

Answer 19

deer family

Question 20

14. What is meant by the term polled? What are some polled breeds? Why is polled a problem with goats?

Answer 20

• Polled is a term for horns that do not develop
• Polled breeds are Polled Hereford, Red Polled Ostland, Swedish Red Polled (cattle), Chengde Polled (goat), Polled Dorset (sheep)
• In goats polled is associated with hermaphroditism

Question 21

How could a breeder breed for polled goat kids without getting defects?

Answer 21

ask someone