Lecture 36: Mammalian Dental Anatomy Flashcards
1
Q
What is the relationship between mammalian teeth and endothermy
A
Mammalian teeth permit mammals to process a very diverse array of foods and to do so efficiently, this is critical for maintaining large supply to energy to counter high energy requirements of endothermy
2
Q
Mesial
A
Towards anterior portion of mouth
3
Q
Distal
A
Towards posterior portion of mouth
4
Q
lingual
A
Towards tongue
5
Q
Palatal
A
Towards palate
6
Q
Buccal
A
Towards check
7
Q
Labial
A
Towards lips
8
Q
What are the three specializations of mammalian teeth
A
Thecodonty, heterodonty, diphyodonty
9
Q
What is thecodonty
A
Teeth are anchored within bony sockets of the jaws (maxillary, pre maxilla, mandible)
10
Q
What is heterodonty
A
Differentiation of teeth in different parts of the mouth into distinct functional units
11
Q
What is diphyodonty
A
Two different sets of dentition (milk and permanent)
12
Q
What is the crown part of mammal tooth
A
Extends from gum line into oral cavity- usually covered by enamel
13
Q
What is the root part of the mammal tooth
A
Extends from gum line into the alveolus, coated with cementum
14
Q
What are the crown and root primarily made of
A
Dentine
15
Q
What is the pulp cavity
A
Hollow cavity filled with pulp
16
Q
What does pulp of the tooth contain.
A
Soft tissue that contain nerves and blood vessels of tooth
17
Q
What anchors teeth within alveolus
A
Periodontal ligaments
18
Q
What kind of receptors do periodontal ligaments contain
A
Stretch receptors important for chewing
19
Q
What are the steps of diphyodonty- process of tooth replacement
A
- Periodic thickening of dental lamina, ectoderm inside labiogingival will produce dental buds which give rise to individual teeth.
- If bud is destined for deciduous tooth an additional bud for permanent tooth develops
- As deciduous tooth erupts the primordium of the permanent tooth is already located on lingual side of deciduous tooth
- Crown of permanent tooth is forming and resorption for the root of deciduous tooth occurs
- Permanent tooth ready to breakthrough and deciduous tooth fully reabsorbed
- Permanent molar erupts pushing deciduous out of alveolus
20
Q
When does eruption of temporary incisors 1-3 occur in dogs
A
4-6 weeks
21
Q
When does the eruption of permanent incisors 1-3 occur in dogs
A
Incisors 1+2: 3-5 months
Incisor3: 4-5 months
22
Q
When does eruption of temporary canine occur in dogs
A
3-5 weeks
23
Q
When does eruption of permanent canine occur
A
5-7 months
24
Q
When does eruption of permanent premolar 1 occur in dogs
A
4-5 months
25
When does eruption of temporary premolar 2-4 occur in dogs
5-6 weeks
26
When does eruption of permanent premolars 2-4 occur in dogs
Premolars 2+3: 5-6 months
Premolar 4: 4-5 months
27
When does permanent eruption of molars 1-3 occur in dogs
Molars 1+2: 5-6 months
Molars 3: 6-7 months
28
When does the eruption of temporary of feline incisors 1-3 occur
3-4 weeks
29
When does the permanent eruption of feline incisors 1-3 occur
3.5-5.5 months
30
When does the temporary eruption of temporary canines in felines occur
3-4 weeks
31
When does the permanent eruption of canines in felines occur
5.5-6.5 months
32
When does the temporary eruption of premolars 2-4 occur in felines
5-6 weeks
33
When does the permanent eruption of premolars 2-4 occur in felines
4-5 months
34
When does the permanent eruption of molar 1 occur in kittens
5-6 months
35
What are the four basic tooth types of mammals
Incisors, canines, premolars, and molars
36
Where are incisors and what are they used for
Anterior dentition and usually used for gripping but also initiating cracks
37
Where are premolars and what are they used for
Cheek teeth usually used for fracturing
38
Where are molars and what are they used for
Cheek teeth, usually used for fracturing
39
What are some advantages of mammalian heterodonty
Increased efficiency and specialization
40
Do mammals have precise of imprecise occlusion
Precise
41
What are the three different crown shapes
Bruno don’t, lophodont, Selendont
42
Bunodont teeth
Rounded cusps
43
Lophodont teeth
Cusps connected by ridges, ridges can run either bucco-lingual or mesic-dorsally
44
Selendont teeth
Molar cusps elongate to form ridges
Long mesio-distal crescent shaped molar cusps
45
Brachydonty
Low crowned teeth, usually with longer roots
46
Hypsodonty
High crowned teeth, usually with long crowns
47
What does cementum cover in brachydont vs hypsodont teeth
Cementum only covers root in brachydont teeth but in hypsodont teeth cementum is surrounding enamel
48
Why is root formation delayed in hypsodont mammals
So that crown continues to grow out of alveolus and can increase amount of exogenous grit in diet
49
What is the primitive dental formula for mammals
3-1-4-3
50
What are the 1st, 2nd, and 3rd numbers in triadan numbering system
1st- quadrant
2nd and 3rd- describe the position in the mouth, always begin with central incisor and progress medial to distal
51
Incisors are always what numbers
01, 02, 03
52
Canines are always what number
04
53
Premolars are always what numbers
05, 08
54
First molar is always what number
09
55
What are food specialists
Adapted to rely on very limited range of foods
56
What are food generalists
Adapted to rely on wide range of foods
57
What teeth are important for capturing and gripping prey
Large caniniform incisors and very large canines
58
What teeth are responsible for shearing motion in carnivores
Carnassial teeth- upper P4 and lower m1 are enlarged
59
Do carnivores gain or lose molars as an adaption for processing meat
Loss/reduction of molars
60
What are the swine adaptions for an omnivorous diet (what crown shape)
Bunodont teeth and the wear of teeth creates pits/bowls which opposing cusps fit
61
What must herbivores rely on to breakdown structural carbohydrates forming plant cell walls
Symbiotic microbes that ferment carbohydrates in herbivore food into energy rich byproducts- volatile fatty acids
62
What is the primary energy source in herbivores
Volatile fatty acids
63
What are the characteristics in a browsing diet
Less homogenous, increased chemical defense, reduced protein digestibility, less exogenous grit diet
64
What are the characteristics of a grazing diet
Relatively homogenous, less chemical defense, increased protein digestibility, more exogenous grit in diet
65
What are some adaptions for grazing and browsing in cows
Lack upper incisors and canines, lower canines have a very incisor like shape (4th incisor-I4), large space between anterior and cheek teeth
66
Do goats/browers have a wide or narrow dental pad and what does it allow for
Narrower dental pad that allows for finer control of what food is being consumed
67
Do cows/grazers have a narrow or wide dental pad and what does it allow for
Wide dental pad that allows for cropping of more grass with each bite
68
What crown shape do ruminant cheek teeth have
Selendont and hypsodont
69
Cheek teeth ___ in size distally
Increase
70
Upper cheek teeth are ___ than lower ones
Wider
71
At what age does enamel still surround the crown in cows
Newborn calf
72
At what age in cows has incisor 1 been replaced, but others haven’t and the distal border of I1 has been slightly worn down with dentine exposed
2 years
73
At what age in cows are I1-3 present I4 still deciduous
3.5 years
74
At what age in cows are the lingual edges of occlusal surface of I1 and I2 smooth- teeth are level
8 years
75
What crown type are horse incisors
Hypsodont
76
Pattern of incisor wear is very important for ____ in horses
Estimating age
77
What crown type are cheek teeth in horses
Selendont
78
Where do dental cavities form
Enamel and dentine of tooth
79
What species are dental cavities most common
Horses, often extracted
80
Where can you gain access to maxillary teeth in horse for extraction
Via maxillary sinus
81
What is gum disease
Bacterial infection of gum surrounding the tooth, leading to placque accumulation
82
Gingivitis
Only gingiva but no damage to ligaments and bone
83
Periodontitis
Tissue damage includes ligaments and bones
84
When do temporary incisors 1-3 erupt in cattle
Birth-2 weeks
85
When does permanent incisor 1 in cattle
18-24 months
86
When does permanent incisor 2 erupt in cattle
24-30 months
87
When does permanent incisor 3 erupt in cattle
36-42 months
88
When does temporary incisor 4/canine erupt in cattle
Birth- 2 weeks
89
When does permanent incisor/canine erupt in cattle
42-48 months
90
When do temporary premolars 2-4 erupt in cattle
Birth-1 week
91
When does permanent premolar 2 erupt in cattle
24-30 months
92
When does permanent premolar 3 erupt in cattle
18-30 months
93
When does permanent premolar 4 erupt in cattle
20-36 months
94
When does molar 1 erupt in cattle
6 months
95
When does molar 2 erupt in cattle
12-18 months
96
When does molar 3 erupt in cattle
24-30 months
97
When does temporary incisor 1 erupt in horses
6 days
98
When does temporary incisor 2 erupt in horses
6 weeks
99
When does temporary incisor 3 erupt in horses
6 months
100
When does temporary incisor 3 become in wear in horses
1yr
101
When do temporary incisors 1+2 level out in horses
2yrs
102
When does permanent incisor 1 erupt in horses
2.5 years
103
When does permanent incisor 3 erupt in horses
3.5 years
104
When does permanent incisor 3 erupt in horse
4.5 years
105
When are all cusps present in horses
5yrs
106
When is incisor 1 cup gone in horse
6yrs
107
When is incisor cup 2 gone in horses
7yrs
108
When is incisor cup 3 gone in horses
8yrs
109
At what age does galvayne’s groove appear in horses
10 yrs
