Changes

==Introduction==

==Introduction==

The modified Triadan system provides a '''consistent method of numbering teeth''' across different animal species.  

The modified Triadan system provides a '''consistent method of numbering [[:Category:Teeth - Anatomy & Physiology|teeth]]''' across different animal species.  

The system is based on the permanent dentition of the pig, which has 11 teeth in each quadrant - three incisors, one canine, four premolars and three molars. The grand total is 44 teeth.

The system is based on the permanent [[Dental Formula - Pig|dentition of the pig]], which has 11 teeth in each quadrant - three incisors, one canine, four premolars and three molars. The grand total is 44 teeth.

==Quadrant==

==Quadrant==

The first digit of the Triadan numbering system refers to the '''quadrant''': right maxilla, left maxilla, left mandible, right mandible.

The first digit of the Triadan numbering system refers to the '''quadrant''': right [[Maxilla|maxilla]], left maxilla, left [[Mandible|mandible]], right mandible.

The quadrants are '''numbered 1-4''' starting with the right maxilla and ending with the right mandible in a clockwise direction as viewed from the front of the animal.

The quadrants are '''numbered 1-4''' starting with the right maxilla and ending with the right mandible in a clockwise direction as viewed from the front of the animal.

For deciduous dentition, '''numbers 5-9''' are used in the same way.

For deciduous dentition, '''numbers 5-8''' are used in the same way.

==Tooth position==

==Tooth Position==

The second and third digits refer to the '''tooth position''' within the quadrant, with the sequence always starting at the '''midline'''.

The second and third digits refer to the '''tooth position''' within the quadrant, with the sequence always starting at the '''midline'''.

Certain rules should be followed in species that have fewer teeth, such as cats, rabbits and horses.

Certain rules should be followed in species that have fewer teeth, such as [[Dental Formula - Cat|cats]], [[Dental Formula - Rabbit|rabbits]] and [[Dental Formula - Horse|horses]].

'''The central incisor is always 01''' and the following incisors are 02 and 03.

'''The central incisor is always 01''' and the following incisors are 02 and 03.

The '''carnassials''' of carnivores can be used as landmarks to help number the teeth, as the upper carnassials are always the last premolars (108 and 208) and the lower carnassials are always the first molars (309 and 409).

The '''carnassials''' of carnivores can be used as landmarks to help number the teeth, as the upper carnassials are always the last premolars (108 and 208) and the lower carnassials are always the first molars (309 and 409).

The numbers of the other teeth can then be determined from there.

The numbers of the other teeth can then be determined.

==Examples==

==Examples==

The mandibular right first molar is 409.

The mandibular right first molar is 409.

'''In the cat''': the second mandibular left premolar is 308. (1 tooth forward from the lower left carnassial which is always 09).

'''In the cat''': the "second" mandibular left premolar is 308. (1 tooth forward from the lower left carnassial which is always 09).

The first maxillary right premolar is 106. (the largest cheek tooth in the cat maxilla is the fourth premolar 108, 2 teeth rostrally from this is the first premolar 106. There is no 105 in the cat)

The "first" maxillary right premolar is 106. (the largest cheek tooth in the cat maxilla is the fourth premolar 108, 2 teeth rostrally from this is the first premolar 106. There is no 105 in the cat)

'''In the rabbit''': the second incisor in the left maxilla (the peg tooth) is 202. There is no third incisor or canine in the rabbit maxilla, so these numbers are missing.

'''In the rabbit''': the second incisor in the left maxilla (the peg tooth) is 202. There is no third incisor or canine in the rabbit maxilla, so these numbers are missing.

Johnston, N. [http://www.rvc.ac.uk/review/dentistry/index.htm Veterinary Dentistry interactive programme]

Johnston, N. [http://www.rvc.ac.uk/review/dentistry/index.htm Veterinary Dentistry interactive programme]

[[Category:To Do - Helen]]

 

[[Category:To Do - Review]]

 

 

 

 

 

[[Category:Teeth - Anatomy & Physiology]]

[[Category:Oral Examination]]

[[Category:Waltham reviewed]]