Dental Formulae and Eruption times

Question 1

What does diphyodont mean?

Answer 1

Dogs and cats are diphyodont indicating that they have a set of deciduous teeth replaced
completely by a permanent set.

Question 2

How many deciduous teeth dogs have?

Answer 2

Dogs have 28 deciduous teeth.

2 x ( Id 3/3 Cd 1/1 Pd 3/3 M 0 )

Question 3

Discuss the deciduous teeth of the dog?

Answer 3

The first premolar has no deciduous precursor so in the deciduous dentition premolars are
therefore the 2nd, 3rd and 4th.

Question 4

When are deciduous teeth usually exfoliated?

Answer 4

The deciduous teeth are usually exfoliated about 14 days
before the crown of the permanent succedaneous teeth emerge. The roots of the deciduous
teeth resorb until the crowns only remain attached to the gingiva and is eventually lost
through masticatory activities.

Question 5

What are the approximate deciduous tooth eruption times in dogs?

Answer 5

Approximate deciduous tooth eruption times:
Incisors 3-4 weeks
Canines 3 weeks
Premolars 4-12 weeks

Question 6

How many permanent teeth do dogs have?

Answer 6

Dogs have 42 permanent teeth.
2 x ( I 3/3 C 1/1 P 4/4. M 2/3)

Question 7

Discuss the roots of canine permanent teeth?

Answer 7

Incisor and canine teeth have single roots. The first permanent premolar teeth in the maxilla
as well as the mandible are single rooted, and the last (third) mandibular molar tooth is
single rooted. All other premolars and molars in the mandible are double rooted The fourth maxillary premolar and the first and second maxillary molars are three-rooted
teeth. All the other maxillary premolars are double rooted. Supernumerary roots in premolar
teeth in dogs are not uncommon, underlining the benefit of radiography prior to extraction

Question 8

What are the approximate permanent adult tooth eruption times in dogs?

Answer 8

Approximate permanent tooth eruption times:
Incisors 3-4 months
Canines 4-6 months
Premolars 4-6 months
Molars. 5-7 month

Question 9

How many deciduous teeth do cats have?

Answer 9

Cats have 26 deciduous teeth:
2 x ( Id 3/3 Cd 1/1 Pd 3/2 M 0 )

The deciduous maxillary premolars are therefore the 2nd, 3rd and 4th.
The deciduous mandibular premolars are the 3rd and the 4th.

Question 10

What are the approximate deciduous eruption times for feline deciduous teeth?

Answer 10

Approximate deciduous tooth eruption times:
Incisors 2-3 weeks
Canines 3-4 weeks
Premolars 3-6 weeks

Question 11

How many permanent teeth do cats have?

Answer 11

Cats have 30 permanent teeth:
2 x ( I 3/3 C 1/1 P 3/2 M 1/1 )

Question 12

What are the approximate permanent tooth eruption times for cats?

Answer 12

Approximate permanent tooth eruption times:
Incisors 3-4 months
Canines 4-5 months
Premolars 4-6 months
Molars. 4-5 months.

Question 13

What happens to lagomorphs deciduous dentition?

Answer 13

most of their
deciduous dentition exfoliate in utero

Question 14

What type of dentition do lagomorphs have?

Answer 14

Lagomorphs are diphyodont even though they were previously considered monophyodont
(only have a single set) of constantly erupting teeth.

Question 15

How many deciduous teeth do lagomorphs have?

Answer 15

Lagomorphs have 16 deciduous teeth:
2 x ( Id 2/1 Cd 0/0 Pd 3/2 )

Question 16

How many permanent teeth do lagomorphs have?

Answer 16

Lagomorphs have 26-28 permanent teeth:
2 x ( I 2/1 C 0/0 P 3/2 M 2-3/3 )

Question 17

What does first number of the three-digit number indicate in the modern triadan system?

Answer 17

The quadrant that this tooth is located in

Question 18

How are quadrants in the triadan system assigned for permanent teeth?

Answer 18

To allocate this number the patient is viewed in a rostral caudal direction and the numbering
system for permanent dentition progresses in a clockwise fashion from the right maxilla.
* Teeth in the right maxilla have 1 as the first digit.
* Teeth in the left maxilla have 2 as the first digit.
* Teeth in the left mandible have 3 as the first digit.
* Teeth in the right mandible have a 4 as the first digit.

Question 19

How are quadrants in the triadan system assigned for deciduous teeth?

Answer 19

Deciduous teeth are numbered in the same pattern so deciduous teeth:
* The right maxilla have 5 as the first digit.
* The left maxilla has a 6 as the first digit.
* The left mandible has a 7 as the first digit.
* The right mandible has an 8 as the first digit.

Question 20

What is the rule of 4 and 9 in the triadan system?

Answer 20

Canine teeth are always number four (04) and the first molar tooth, is always number nine
(09).

Question 21

In the maxilla, the carnassial tooth is the fourth premolar. If we apply the rule of 4 and 9, the
maxillary carnassial tooth is therefore?

Answer 21

Always number eight e.g. the permanent right
maxillary fourth premolar (carnassial) would therefore be number 108 and the deciduous
right maxillary fourth premolar therefore number 508