Topic 8: Malocclusion

Question 1

What is occlusion

Answer 1

normal position of teeth when jaws are closed

Question 2

what is malocclusion

Answer 2

misaligned teeth

Question 3

What are the consequences of malocclusion

Answer 3

Abnormal contact with other teeth or soft tissues = discomfort + pain
Accumulation of debris + foods, periodontal pockets, PD disease, tooth loss….
Chronic pain = changes in behavior
Difficulty in mastication

Question 4

how do you prevent malocclusion

Answer 4

Oral examination starting at initial puppy/kitten 1st visit!

AHT: during pre-consultation

Question 5

what can be done about a malocclusion if detected early

Answer 5

Can be treated with simple extraction / crown amputation or
Orthodontics tx (eg. braces, wire, buttons, elastics, acrylic plates)

Question 6

what happens if a malocclusion is not detected early

Answer 6

may result in permanent teeth malocclusions
that require extensive extractions
or multiple-procedure orthodontics. 


Question 7

describe the normal occlusion of dogs

Answer 7

Wild phenotype of domestic dogs and cats has interdigitating teeth cheek that create pinking shears effect.

Question 8

describe the pinking shears effect on canines

Answer 8

a mandibular tooth (canine) that interdigitates with the maxillary 3rd incisor and canine (fits in the diasthema) (canine interlock)

Question 9

describe the pinking shears effect on incisors

Answer 9

mandibular incisors that rest on the cingulae of the maxillary incissors

Question 10

what are the 4 points to evaluate occlusion in dogs

Answer 10

Scissor incisor relationship
The canine interlock
The PM interdigitation (“pinking shear” effect)
Head symmetry

Question 11

describe incisor scissor occlusion

Answer 11

scissor bite incisors. the mandibular incisors rest on the cingulae

Question 12

describe the proper canine interlock

Answer 12

Mandibular canine fits into diasthema between maxillary 3rd incisor and upper canine
Not touching each other
Creates an interlock situation that prevents one or the other jaw from overgrowing the other.

Question 13

what is a diasthema

Answer 13

space or gap between 2 teeth

Question 14

describe the normal canine PM interdigitation

Answer 14

Cusp tips of PM should point to the interdental space
Pinking shear effect
Buccal surface of the first 1st mandibular molar occludes with the palatal surface of maxillary PM4

Question 15

what is a cusp

Answer 15

raised points on the crowns of teeth

Question 16

What are the 3 dog head shapes

Answer 16

dolichocephalic
mesocephalic
brachycephalic

Question 17

what breed of dog has a dolichocephalic head

Answer 17

borzoi

Question 18

what breed of dog has a mesocephalic head

Answer 18

lab

Question 19

what breed of dog has a brachycephalic head

Answer 19

pug

Question 20

describe the head of a mesocephalic head

Answer 20

Mandible is shorter and less wide than maxilla
Scissor bite incisors
Maxillary incisors are rostral
Incisal tips of mandibular incisor contact cingulae of upper incisor

Question 21

what is the normal dentition for a mesocephalic head

Answer 21

Interdigitation of canine teeth- mandibular one into diastema b/n upper 3rd incisor and upper canine, not touching either
Premolars oppose interdental space opposite arcade
Maxillary 4th PM scissors with mandibular 1st molar

Question 22

how does cusp to cusp premolars happen

Answer 22

How does this happen?

Either mandibular prognathism (undershot) or brachygnathism (overshot)

Question 23

what does prognathic mean

Answer 23

longer

Question 24

what does brachygnathic mean

Answer 24

shorter

Question 25

describe the dentition of a brachycephalic breed

Answer 25

shorter maxilla- normal mandible Crowding and rotation upper teeth More prone to gingival hyperplasia due to open mouth breathing Also prone to missing teeth

Question 26

describe the dentition of a dolichocephalic breed

Answer 26

Have longer upper jaw | Larger interdental spaces

Question 27

what is a lance tooth

Answer 27

Or rostrally displaced maxillary canine(s) | One or both of the maxillary canine teeth deviating or pointing rostrally

Question 28

what is the result of a lance tooth

Answer 28

Result: closed diastema space between the max 3rd incisor and max canine tooth (crowding)

Question 29

what can lance tooth cause

Answer 29

periodontal disease occlusal problems area for plaque retention

Question 30

how does lance tooth occur?

Answer 30

genetic

Question 31

what breed commonly has lance tooth

Answer 31

sheltie

Question 32

describe an anterior crossbite

Answer 32

reverse scissor bite of one, two or all incisors | Displaced lingual to the lowers and the rest occlude normally

Question 33

what is an anterior corset considered a secondary condition to

Answer 33

Usually secondary to retained deciduous incisors

Question 34

what is a posterior caudal crossbite

Answer 34

Class 1 PM + M are lingual to lower ones (carnassial teeth are reversed)

Question 35

what is a level bite

Answer 35

where the incisor teeth meet exactly, surface to surface

Question 36

what can level bite cause

Answer 36

Cause abnormal wear of the incisal edges of these teeeth & even inflammation surrounding the roots

Question 37

what is the common teeth crowding in toy breeds

Answer 37

incissors

Question 38

what is the common teeth crowding in brachycephalic breeds

Answer 38

PM

Question 39

what is brachygnathia

Answer 39

excessive shortness of one or both jaws

Question 40

what is prognathism

Answer 40

abnormal profusion of one or both jaws

Question 41

what is a mandibular brachygnathic bite

Answer 41

Upper jaw extends significantly over the lower jaw | Also called overbite

Question 42

what is a mandibular prognathic bite

Answer 42

``` Also called underbite Mandibular premolars rostrally displaced Reverse scissor bite Lower incisors are rostral Mandibular canine touches 3rd incisor ```

Question 43

what is a narrow mandible

Answer 43

Lower canines impinge on: maxillary gingivae or hard palate …..instead of going into diasthema

Question 44

what is an open bite

Answer 44

the teeth do not meet properly and a space is created

Question 45

what is a wry bite

Answer 45

When one jaw quadrant grows differently from the other and symmetry is lost Felt to be caused by one sided prognathism or brachygnathism