4. oral cavity - teeth

Question 1

What is meant by heterodont?

Answer 1

tooth shape differences along the tooth row- I, C, PM, M

Question 2

What is meant by diphyodont?

Answer 2

any animal with two successive sets of teeth, initially the “deciduous” set and consecutively the “permanent” set

Question 3

what is meant by homodont?

Answer 3

have all the same types of teeth, performing the same function

Question 4

What is meant by diastema?

Answer 4

a physiological gap between the incisors and the premolars

Question 5

name the main anatomy structures of a tooth

Answer 5

• Cementoenamel junction (CEJ)
• Alveolus bone socket (alveloli)
• Lamina dura
• periodontium (membrane)
• periodontal ligaments
• Pulp cavity
• dentin
• enamel
• cementum

Question 6

where is the cementoenamel junction (CEJ)?

Answer 6

the borderline between the crown and root(s)

Question 7

what is the Alveolus bone socket (alveloli)?

Answer 7

it anchors the tooth by its root into the socket

Question 8

what is the lamina dura?

Answer 8

the thin shell of dense bone lining the alveoli

Question 9

what is the pulp cavity?

Answer 9

It is the central space of the tooth containing pulp- soft tissue with nerves, vessels, lymphatics

Question 10

what is periodontium and what does it do?

Answer 10

it is a connective tissue that attaches the root to the bone via periodontal ligaments

Question 11

what 4 structures are included in periodontal tissues?

Answer 11

gingiva,
cementum,
alveolar bone,
periodontal ligament

Question 12

name the hard tissues in the teeth?

Answer 12

enamel
dentin
cementum

Question 13

what do cells in the gums adhere to at the gingival crevice/ sulcus

Answer 13

cells of the enamel adhere via a basement membrane

Question 14

what is meant by gums/gingiva?

Answer 14

oral mucosa that covers the tooth

Question 15

Name the 2 teeth types

Answer 15

brachydont
hypsodont

Question 16

Describe brachydont teeth

Answer 16

Smaller and low crowned suitable for feeding on soft diet, it has a true root

Question 17

describe hypsodont teeth

Answer 17

• Larger crowned teeth that can resist the wear and tear of feeding on a tough and fibrous diet as in ungulates
• Radicular: forms true root or aradicular root: no true root

Question 18

Aradicular hypsodont:

Answer 18

teeth with a long anatomic crown, erupt continuously and while errupting, remain open rooted

Question 19

what is enamel and what cell type is formed from

Answer 19

hardest substance in the body, formed from ameoblast

Question 20

in brachydont teeth what does the enamel cover?

Answer 20

only the crown

Question 21

in hypsodont teeth what does the enamel cover?

Answer 21

covers the entire body of the tooth, but not the root

Question 22

what is dentin and what cell type is it formed from?

Answer 22

the hard substance which forms the bulk of the tooth and surrounds the pulp cavity.
Formed by odontoblasts

Question 23

what us cementum and what does it cover in brachydont and hypsodont teeth?

Answer 23

thin bonelike layer
- brachydont: covers root only
- hypsodont: fills infundibula and covers entire tooth

Question 24

what are the 4 types of teeth?

Answer 24

incisors
canines
premolars
molars

Question 25

What Is the function of incisors?

Answer 25

adapted for grasping, pinching, scratching and nipping

Question 26

What Is the function of canines?

Answer 26

“weapons” for tearing flesh during hunting & fighting

Question 27

what is the function of premolars?

Answer 27

rostral cheek teeth which have deciduous precursors; molars do not. Shearing off food

Question 28

what is the function of molars?

Answer 28

flattened and triangular with jagged edges; function like serrated-edged blades. Shearing and grinding food.

Question 29

describe the vestibular surface of the tooth

Answer 29

Surface of the tooth facing the vestibule or lips (buccal and labial)

Question 30

describe the lingual surface of the tooth

Answer 30

Surface of the maxillary or mandibular tooth that faces the tongue or median plane of the mouth, and the caudal surfaces of the C, PM or M

Question 31

describe the palatal surface of the tooth

Answer 31

refers to the lingual surface of the maxillary teeth

Question 32

describe the coronal surface of the tooth

Answer 32

is used as a term relating toward the occlusal surface

Question 33

describe the medial surface of the tooth

Answer 33

Surfaces of the incisor teeth that are toward the middle or median plane of the mouth. Rostral surface of the canine, premolar and molar teeth

Question 34

describe the distal surface of the tooth

Answer 34

Surface of the incisor teeth that are away from the middle or median plane of the mouth. Caudal surfaces of the canine, premolar and molar teeth

Question 35

How many permanent teeth do pigs have? how many deciduous teeth do they have?

Answer 35

permanent- 44
deciduous- 28

Question 36

what is the dental formula for pigs permanent and deciduous teeth?

Answer 36

permanent
I-3 C-1 P-4 M-3
I-3 C-1 P-4 M-3

deciduous
I- 3 C-1 P-3
I- 3 C-1 P-3

Question 37

how many teeth do dogs have?

Answer 37

42

Question 38

which tooth are dogs missing?

Answer 38

upper M3

Question 39

which teeth are carnassial in dogs?

Answer 39

upper PM4
lower M1

Question 40

what is the dental formula of dog teeth?

Answer 40

I- 3 C-1 P-4 M-2
I-3 C-1 P-4 M-3

Question 41

describe the roots of dog teeth

Answer 41

• All incisors have a single root
  -The root of the canine is large; larger than the crown
• PM1s have a single root
• PMs and Ms have two roots:
  -Exception: Upper PM4 and the two upper molars have three roots
• Exception: Lower M3 has one root

Question 42

describe ruminant teeth?

Answer 42

-Dental pad, no upper incisors or canines
- Incisors and canines are brachydont
-Premolars and molars are hypsodont
- large diastema
-32 teeth

Question 43

how many teeth do horses have?

Answer 43

40 or 42 depending on whether they have vestigial world teeth

Question 44

describe horse teeth

Answer 44

• Slowly errupt
• Hypsodont crowned teeth have continuous wear
• Delayed development of roots
• Complicated folding of enamel: infundibulum
• Brachydont & in diastema
• Incisors: High crowns with single root
• Pre/molars form continuous surface
• PM2-PM4 and M1-M3 three roots in the upper jaw and two in the lower jaw

Question 45

what is meant by infundibulum

Answer 45

• An infundibulum is a cup or funnel-shaped invagination of enamel from the occlusal surface of equine incisor and maxillary cheek teeth
• Looks like a dark mark, because food gets packed inside and turns black as it decays
• Partly filled with cement, leaving small cavity but does not connect with the pulp cavity
• As the tooth continually erupts and wears down the appearance of the occlusal surface changes
  secondary dentin forms dental stars on worn surface of tooth
• Wear of the occlusal surface causes the cup to get smaller and eventually disappear from all lower incisors (at about 8 years of age) leaving the enamel spot in its place

Question 46

describe lagamorph teeth

Answer 46

• 2 small incisors (peg teeth) behind maxillary incisors
• 3 pairs of incisors: 2 upper, 1 lower
• enamel thicker on the facial aspect, thinner on lingual
• both incisors and cheek teeth are radicular hypsodont (long anatomic crown, erupt continuously and remain open rooted)
• no canine teeth
• have horizontal occlusion surface - transverse enamel folds for shredding & grinding tough fibrous food

Question 47

Describe the blood supply to teeth

Answer 47

• upper teeth: infraorbital artery
• lower teeth: inferior alveolar artery (IAA)

Question 48

describe the nerve supply to teeth

Answer 48

• trigeminal nerve supplies sensory innervation through its maxillary and mandibular division
• upper incisor teeth innervated by the infraorbital nerve
• mandibular teeth are innervated by inferioralveolar nerve

Question 49

which canal does the infraorbital nerve run in?

Answer 49

infraorbital canal

Question 50

which canal does the inferioralveolar nerve run in?

Answer 50

mandibular canal