Anatomy – Sample

Dental Formula

Puppy

2 x (Id 3/3, Cd 1/1, Pd 3/3) = 28 or 2 x (Id33, Cd11, Pd33) = 28

This translates that on each side of the mouth the puppy has three incisors in the front of the top jaw (maxilla) and three incisors in the front of the lower jaw (mandible), followed by one canine top and one canine bottom, followed by three premolars top and three premolars in the bottom, making a total of 28 deciduous teeth if you count both the left and right sides of the mouth.

Kitten

2 x (Id 3/3, Cd 1/1, Pd 3/2) = 26 or 2 x (Id33, Cd11, Pd32) = 26

This translates that for each side of the mouth the kitten has three incisors in the front of the top jaw (maxilla) and three incisors in the front of the lower jaw (mandible), followed by one canine top and one canine bottom, followed by three premolars top and two premolars on the bottom, making a total of 26 deciduous teeth if you count both the left and right sides of the mouth.

Adult dog

2 x (I 3/3, C 1/1, P 4/4 M 2/3) = 42 or 2 x (I33, C11, P44 M23) = 42

This translates that for each side of the mouth the dog has three incisors in the front of the top jaw (maxilla) and three incisors in the front of the lower jaw (mandible), followed by one canine top and one canine bottom, followed by four premolars top and bottom, followed by two molars in the top and three molars in the bottom, making a total of 42 permanent teeth if you count both the left and right sides of the mouth.

Adult cat

2 x (I 3/3, C 1/1, P 3/2, M 1/1) = 30 or 2 x (I33, C11, P32, M11) = 30

This translates that for each side of the mouth the cat has three incisors in the front of the top jaw (maxilla) and three incisors in the front of the lower jaw (mandible), followed by one canine top and one canine bottom, followed by three premolars top and two premolars on the bottom, followed by one molar top and bottom, making a total of 30 permanent teeth if you count both the left and right sides of the mouth.

Modified Triadan system

With the use of computers and veterinarians discussing dental nomenclature, both verbally and in publications, an easier system was needed. This has been termed, the Modified Triadan system, in which each tooth has a designated number.

Firstly, the arcades are assigned a number. For a puppy and kitten with deciduous teeth – ‘5’ is used for the upper right arcade, ‘6’ for the upper left arcade, ‘7’ for the lower left arcade and ‘8’ for the lower right arcade. In the adult dog and cat with adult teeth – ‘1’ is used for the upper right arcade, ‘2’ for the upper left arcade, ‘3’ for the lower left arcade and ‘4’ for the lower right arcade.

In the dog, each adult tooth is assigned a number commencing with ‘1’ from the midline of each arcade and working caudally– the incisors are ‘1’, ‘2’, and ‘3’, the canine ‘4’, the premolars ‘5’, ‘6’, ’7’, ‘8’, and the molars ‘9’, ‘10’, and ‘11’. When a tooth has a single number, it is often written with a ‘0’ in front of it, thus a canine would be ‘04’ rather than just ‘4’. The teeth and the arcade are then joined, so that each tooth has a three digit number assigned to it. Thus the canine teeth will always end in a 4 and the first molars will always end in a 9, this has been termed, ‘the rule of 4s and 9s’. Thus, the upper left second incisor tooth is tooth 202, the upper right fourth premolar is tooth 108, and the lower right first molar is tooth 409, and so on. In the puppy, the incisors are numbered ‘1’, ‘2’, ‘3’, the canine ‘4’ and the three premolar ‘6’, ‘7’ and ‘8’.

In the cat, each adult incisor and canine tooth is assigned a number commencing with ‘1’ from the midline to ‘4’ for the canine. The molars are numbered ‘9’ and the subsequent premolars numbered towards the mesial aspect – ‘8’, ‘7’, ‘6’ in the maxilla and ‘8’ and ‘7’ in the mandible. In the kitten, the incisors are numbered ‘1’, ‘2’, ‘3’, the canine ‘4’, the three maxillary premolars ‘6’, ‘7’ and ‘8’ and the two mandibular premolars ‘7’ and ‘8’.

Adult Canine Chart

An open mouth view of the dog with teeth identified by the anatomical and Modified Triadan System of nomenclature. Canine dental chart from Vet Dental Charts.

FelineAdultchart

An open mouth view of the cat with teeth identified by the anatomical and Modified Triadan System of nomenclature. Feline dental chart from Vet Dental Charts.