- What is sexual dimorphism? Give examples with regard to antlers, horns, and teeth.
- 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
What is meant by the rule of 7/11? How are the canine teeth of dogs and horses different?
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
- What distinguishes molars and premolars in general? What is the exception?
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?
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
What is the apical end of the tooth? What is the significance of so called temporary tuberosities (eruption bumps)? Why are they temporary?
end opposite of crown
unerupted permament teeth so long not room for them in mandible
teeth eventually grow out?
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?
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
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?
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
- Compare llama dentition with ruminant dentition. What are the fighting teeth?
- 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
- What are the tusks of swine and elephants and how are these teeth similar to rodent incisors? Relate this to the pulp cavity.
- 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
What is the significance of the infolded enamel? In what two ways does enamel infolding occur?
allows longer cutting edge to be rammed into small space of tooth
infolding occurs at periphery and from occlusal surface
- 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?
- 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
- What forms the ruminant corner teeth?
ask somebody
- Define caps, alveolus, deciduous teeth.
- 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
Full wear decidous mouth? full wear permanent mouth?
2 years, 5 years
What 2 equine teeth numbers are most often not present in either gender? not deciduos? not present in most mares? problems with bits?
- 305, 405
- canines, wolf teeth, molars
- all the canines
- 105, 205
- What are the 2 major factors used in dental aging?
- Eruption dates (most reliable)
- Wear - are first “in wear” and when entire occlusal surface is worn down then the tooth is level
- Why are hypsodont teeth protected from abscess? What occurs instead?
- 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
- Differentiate horns from antlers
Horns Antlers
Hollow Solid
Don’t shed Shed annually (rapid growth)
polled no polling
not branched branched
What are cervids?
deer family
- What is meant by the term polled? What are some polled breeds? Why is polled a problem with goats?
- 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
How could a breeder breed for polled goat kids without getting defects?
ask someone
