Ch. 14: Lagomorph, Rodent, and Ferret Dentistry

Question 1

What species are included in the order Lagomorpha?

Answer 1

Domestic rabbit, hare, and cottontail

Question 2

Adult rabbits have how many teeth?

Answer 2

Between 26 and 28 teeth

Question 3

What does the term rodent mean?

Answer 3

To gnaw

Question 4

What order is the largest order of the class mammalia?

Answer 4

Order Rodentia

Question 5

What species are included as pets in the order rodentia?

Answer 5

Rat, mouse, guinea pig, hamster, gerbil, chinchilla, gopher, squirrel, and prairie dog

Question 6

Most adult rodents have how many teeth?

Answer 6

Between 12 and 22 teeth

Question 7

What order and family do ferrets belong to?

Answer 7

Order Carnivora and Family Mustelidae

Question 8

How many teeth do adult ferrets have?

Answer 8

34 teeth

Question 9

All lagomorphs are herbivores, but some may be _____?

Answer 9

Omnivores

Question 10

Lagomorphs and rodents have a dental formula that features variations in tooth size and shape. What is this dentition called?

Answer 10

Heterodont dentition

Question 11

Lagomorphs and rodents have canines, but they are included as an incisor.

True or False?

Answer 11

False; they do not have any canines (They have a diastema (toothless area between the incisors and cheek teeth))

Question 12

Ferret dentition is similar to a cats dentition.

True or False? And in what ways?

Answer 12

True; they have all 4 kinds of teeth and are also carnivores

Question 13

How do lagomorph incisors differ from rodent incisors?

Answer 13

Lagomorphs have an extra set of smaller maxillary incisor teeth behind the rostral maxillary incisors

Question 14

What are the extra maxillary incisors on a lagomorph known as?

Answer 14

Peg teeth

Question 15

Describe a lagomorph dentition. What is special about them?

Answer 15

The special feature of lagomorph teeth is that they continuously grow and erupt as the teeth undergo normal wear. They have crowns visible intraorally and also reverse crowns submerged below the gingival margin. These teeth never form roots

Question 16

What is the term for definition that has continuously growing and erupting teeth throughout an animals life?

Answer 16

Aradicular hypsodont teeth aka elodont

Question 17

What is the term for a tooth that has a true distinction between crown and root and does no longer grow once fully erupted?

Answer 17

Brachyodont teeth; found in humans, cats, and dogs

Question 18

Guinea pigs and chinchillas have all aradicular hypsodont teeth for both the incisors and the cheek teeth.

True or False?

Answer 18

True

Question 19

Mice and rats have all brachyodont teeth.

True or False?

Answer 19

False; the incisors are aradicular hypsodont and the cheek teeth are brachyodont teeth

Question 20

What shape are the maxillary first molar teeth in ferrets?

Answer 20

Hourglass shaped

Question 21

Ferrets have aradicular hypsodont teeth.

True or False?

Answer 21

False; they are carnivores and have similar teeth to a cat. Cat and ferret teeth are not continuously growing (aradicular) and are all brachyodont teeth

Question 22

What layers of teeth form the layers of lagomorph and rodent teeth?

Answer 22

They have enamel on the front and lateral sides but only cementum and dentin on the palatal/lingual surfaces

Question 23

Does cementum and dentin wear faster than enamel?

Answer 23

Yes; this results in a chiseled edge of the teeth in lagomorphs and rodents

Question 24

The enamel of incisors in most rodents takes on a yellow-orange color. Which rodent doesn’t have a yellow-orange color to its incisors?

Answer 24

The guinea pig

Question 25

The word apices is the plural form of what word?

Answer 25

Apex

Question 26

In rats and mice, how far do the roots of the mandibular incisors reach?

Answer 26

They are distal to the roots of the last cheek tooth

Question 27

In rabbits and chinchillas, how far do the roots of the mandibular incisors reach?

Answer 27

They are located near the mesial surfaces of the first cheek tooth

Question 28

In lagomorphs and rodents, the highest point of the chisel tip of the maxillar cheek teeth is on the labial side. How are the teeth angled?

Answer 28

Dorsally toward the soft tissue of the hard palate

Question 29

In lagomorphs and rodents, the chisel point of the mandibular cheek teeth are on what aspect of the tooth?

Answer 29

Lingual side

Question 30

The maxillary cheek teeth are wider apart from the midline than the mandibular teeth. True or False?

Answer 30

True; this is called anisognathic

Question 31

Which species of lagomorph/rodent has the steepest angle of the cheek teeth?

Answer 31

A guinea pig has the steepest angulation while chinchillas have a level occlusal plane

Question 32

It is thought to believe that the plexus of a tooth allows for continuously growing teeth to move coronally as they grown. This adaptation of hypsodont teeth is thought to explain how ________ allows for continued eruption.

Answer 32

The periodontal ligament (PDL)

Question 33

What is the dental formula of a rabbit?

Answer 33

2 X (2/1 I, 0/0 C, 3/2 P, 2-3/3 M) = 26-28 total

Question 34

What is the dental formula of a hare?

Answer 34

2 X (2/1 I, 0/0 C, 3/2 P, 3/3 M) = 28 total

Question 35

What is the dental formula of a guinea pig and chinchilla?

Answer 35

2 X (1/1 I, 0/0 C, 1/1 P, 3/3 M) = 20 total

Question 36

What is the dental formula of a degu?

Answer 36

2 X (1/1 I, 0/0 C, 1/1 P, 3/3 M) = 20 total

Question 37

What is the dental formula of a rat?

Answer 37

2 X (1/1 I, 0/0 C, 0/0 P, 2-3/2-3 M) = 12-16 total

Question 38

What is the dental formula of a hamster?

Answer 38

2 X (1/1 I, 0/0 C, 0/0 P, 2-3/2-3) = 12-16 total

Question 39

What is the dental formula of a gerbil?

Answer 39

2 X (1/1 I, 0/0 C, 0/0 P, 3/3 M) = 16 total

Question 40

What is the dental formula of a squirrel?

Answer 40

2 X (1/1 I, 0/0 C, 1-2/1 P, 3/3 M) = 20-22 total

Question 41

What is the dental formula of a ferret?

Answer 41

2 X (3/3 I, 1/1 C, 3/3 P, 1/2 M) = 34 total

Question 42

What forms of anesthesia are available for these animals?

Answer 42

Injectable and inhalant

Question 43

Due to the odor of the inhalant anesthetic, these animals may do what?

Answer 43

Hold their breath

Question 44

What IV catheter gauge can be used as an ET tube for smaller rodents (stylet removed)?

Answer 44

12-14 gauge

Question 45

What instruments are needed for a dental procedure on these animals?

Answer 45

Towel, anesthesia, otoscope, IV catheter, umbilical tape, cotton-tipped applicators, explorers/probes, hand pieces, mouth gags, cheek retractors, burs, files/rasps (floats), tooth cutters, luxators and elevators, extraction forceps, bone substitutes, antibiotic impregnated beads, paper points, calcium hydroxide, and restoratives

Question 46

What are the most common types of burs used?

Answer 46

Diamond, carbide round, carbide tapered fissure, and white stone points

Question 47

Rasp instruments cut/file on push and pull strokes. Files cut on what stroke?

Answer 47

On pull stroke

Question 48

What are burs used for?

Answer 48

Removal of hard tissue

Question 49

What are luxators and elevators used for?

Answer 49

Used to work circumferentially around a tooth in the PDL space to aid in the tooth's removal

Question 50

What tool can also be used for a luxator/elevator function in lagomorphs and rodents?

Answer 50

Hypodermic needles (18-22 gauge) (Curved and bent)

Question 51

What instrument is used for extraction of cheek teeth?

Answer 51

90-degree angled Halstead mosquito forceps or angled root tip forceps

Question 52

What are examples of restorative temporary filling materials?

Answer 52

Reinforced zinc oxide-eugenol cements, or glass ionomer

Question 53

Antibiotic-impregnated beads may be placed for treatment of refractory infections. What are examples of different antibiotics?

Answer 53

Polymethylmethacrylate (releases heat so not recommended) (non absorbable), gentamicin, and calcium phosphate (absorbable)

Question 54

What is rostral gingivitis in lagomorphs and rodents most commonly caused by?

Answer 54

Trauma caused by rough edges on watering devices, and food bowls

Question 55

What are the treatments for rostral gingivitis?

Answer 55

Removal of watering/feeding devices. However, if the situation warrants, the lesion can be treated with multiple coats of tincture of myrrh and benzoin or topical antibiotic ointments

Question 56

Where is periodontitis generally found in lagomorphs & rodents?

Answer 56

In the cheek teeth of animals with brachyodont teeth, such as mice and rats

Question 57

What species frequently suffer from periodontitis?

Answer 57

Chinchillas

Question 58

What may be the cause of periodontitis in lagomorphs and rodents?

Answer 58

Tooth elongation and/or tooth resorption in aradicular hypsodont cheek teeth of rabbits, chinchillas, and guinea pigs

Question 59

What are the treatment options for periodontitis?

Answer 59

Dental cleaning or extractions

Question 60

Where is enamel hypomineralization/hypoplasia typically seen?

Answer 60

On the incisors

Question 61

What does enamel hypomineralization/hypoplasia look like?

Answer 61

Chalky white or brown discoloration on the labial surface of the tooth

Question 62

What are possible causes of enamel hypomineralization/hypoplasia?

Answer 62

Nutritional imbalance, infection, or inflammation that temporarily decreases enamel production

Question 63

What is the treatment for enamel hypomineralization/hypoplasia?

Answer 63

Correction of the initiating cause

Question 64

What may result with long-term enamel defects?

Answer 64

Trauma to and subsequent death of ameloblasts

Question 65

What is the only time an animal with enamel hypomineralization needs to have direct treatment?

Answer 65

If the weakened area of the tooth results in tooth fracture

Question 66

True caries lesions are generally found in only which teeth of rodents?

Answer 66

Cheek teeth of rodents with brachyodont teeth and occlusal surfaces of the crown but many are found on the root surfaces

Question 67

Caries in rodents are uncommon. True or False?

Answer 67

True; but are difficult to find if they are present

Question 68

Why are caries difficult to detect in rodents?

Answer 68

Because they mostly occur in cheek teeth which are difficult to examine

Question 69

What is the most common treatment for caries in rodents?

Answer 69

Extraction Removal of diseased dental structure with a bur and glass ionomer restorations have also been used

Question 70

What are the two categories of malocclusions in exotic animals?

Answer 70

Traumatic and atraumatic

Question 71

How is a traumatic malocclusion characterized?

Answer 71

Traumatic injuries to the teeth can result in broken crowns, which may cause overgrowth (elongation) of the opposing tooth because of the lack of normal attrition

Question 72

What are the treatment options for traumatic malocclusions?

Answer 72

Periodic odontoplasty and exam (determine if pulp is exposed), if pulp is exposed but is still vital, pulp therapy can be performed, if pulp isn't vital the tooth may need extracted

Question 73

How is an atraumatic malocclusion characterized?

Answer 73

Caused by hereditary factors or by nutritional factors

Question 74

Atraumatic malocclusions are found in what three basic forms?

Answer 74

Short maxillary diastema, genetics or nutritional mandibular abnormalities, and improper wear

Question 75

Diastema definition

Answer 75

A space separating teeth of different function (ex. space between incisors, canines and cheek teeth)