What is the Triadan tooth numbering system?

The Triadan system is a standardized veterinary dental numbering system. Each quadrant is numbered 1–4 (right maxillary=1, left maxillary=2, left mandibular=3, right mandibular=4). Tooth positions within each quadrant are numbered sequentially from midline: incisors 01–03, canine 04, premolars 05–08, molars 09–11.

How many teeth do adult dogs and cats have?

Adult dogs have 42 permanent teeth. Adult cats have 30 permanent teeth. Puppies have 28 deciduous teeth and kittens have 26 deciduous teeth.

When do permanent teeth erupt in dogs and cats?

In dogs, permanent incisors erupt at 3–5 months, canines at 4–6 months, premolars at 4–6 months, and molars at 5–7 months. In cats, permanent incisors erupt at 3–4 months, canines at 4–5 months, premolars at 4–6 months, and molars at 4–5 months.

Clinical reference

Dental chart reference

Triadan tooth numbering, eruption ages, and dental anatomy for dogs and cats.

Dog dental formula: I 3/3, C 1/1, P 4/4, M 2/3 = 42 permanent teeth. Deciduous: I 3/3, C 1/1, P 3/3 = 28 teeth.

Right maxillary quadrant (100 series)

Tooth #	Name	Type	Eruption (months)
101	Right maxillary 1st incisor (central)	Incisor	4–5
102	Right maxillary 2nd incisor (intermediate)	Incisor	4–5
103	Right maxillary 3rd incisor (corner)	Incisor	4–5
104	Right maxillary canine	Canine	5–6
105	Right maxillary 1st premolar	Premolar	4–5
106	Right maxillary 2nd premolar	Premolar	4–5
107	Right maxillary 3rd premolar	Premolar	4–5
108	Right maxillary 4th premolar (carnassial)	Premolar	4–5
109	Right maxillary 1st molar	Molar	5–6
110	Right maxillary 2nd molar	Molar	6–7

Left maxillary quadrant (200 series)

Tooth #	Name	Type	Eruption (months)
201	Left maxillary 1st incisor	Incisor	4–5
202	Left maxillary 2nd incisor	Incisor	4–5
203	Left maxillary 3rd incisor	Incisor	4–5
204	Left maxillary canine	Canine	5–6
205	Left maxillary 1st premolar	Premolar	4–5
206	Left maxillary 2nd premolar	Premolar	4–5
207	Left maxillary 3rd premolar	Premolar	4–5
208	Left maxillary 4th premolar (carnassial)	Premolar	4–5
209	Left maxillary 1st molar	Molar	5–6
210	Left maxillary 2nd molar	Molar	6–7

Left mandibular quadrant (300 series)

Tooth #	Name	Type	Eruption (months)
301	Left mandibular 1st incisor	Incisor	4–5
302	Left mandibular 2nd incisor	Incisor	4–5
303	Left mandibular 3rd incisor	Incisor	4–5
304	Left mandibular canine	Canine	5–6
305	Left mandibular 1st premolar	Premolar	4–5
306	Left mandibular 2nd premolar	Premolar	4–5
307	Left mandibular 3rd premolar	Premolar	4–5
308	Left mandibular 4th premolar	Premolar	4–5
309	Left mandibular 1st molar (carnassial)	Molar	5–6
310	Left mandibular 2nd molar	Molar	6–7
311	Left mandibular 3rd molar	Molar	6–7

Right mandibular quadrant (400 series)

Tooth #	Name	Type	Eruption (months)
401	Right mandibular 1st incisor	Incisor	4–5
402	Right mandibular 2nd incisor	Incisor	4–5
403	Right mandibular 3rd incisor	Incisor	4–5
404	Right mandibular canine	Canine	5–6
405	Right mandibular 1st premolar	Premolar	4–5
406	Right mandibular 2nd premolar	Premolar	4–5
407	Right mandibular 3rd premolar	Premolar	4–5
408	Right mandibular 4th premolar	Premolar	4–5
409	Right mandibular 1st molar (carnassial)	Molar	5–6
410	Right mandibular 2nd molar	Molar	6–7
411	Right mandibular 3rd molar	Molar	6–7

Cat dental formula: I 3/3, C 1/1, P 3/2, M 1/1 = 30 permanent teeth. Deciduous: I 3/3, C 1/1, P 3/2 = 26 teeth.

Right maxillary quadrant (100 series)

Tooth #	Name	Type	Eruption (months)
101	Right maxillary 1st incisor	Incisor	3–4
102	Right maxillary 2nd incisor	Incisor	3–4
103	Right maxillary 3rd incisor	Incisor	3–4
104	Right maxillary canine	Canine	4–5
105	Right maxillary 2nd premolar	Premolar	4–5
106	Right maxillary 3rd premolar	Premolar	4–5
107	Right maxillary 4th premolar (carnassial)	Premolar	4–5
108	Right maxillary 1st molar	Molar	4–5

Left maxillary quadrant (200 series)

Tooth #	Name	Type	Eruption (months)
201	Left maxillary 1st incisor	Incisor	3–4
202	Left maxillary 2nd incisor	Incisor	3–4
203	Left maxillary 3rd incisor	Incisor	3–4
204	Left maxillary canine	Canine	4–5
205	Left maxillary 2nd premolar	Premolar	4–5
206	Left maxillary 3rd premolar	Premolar	4–5
207	Left maxillary 4th premolar (carnassial)	Premolar	4–5
208	Left maxillary 1st molar	Molar	4–5

Left mandibular quadrant (300 series)

Tooth #	Name	Type	Eruption (months)
301	Left mandibular 1st incisor	Incisor	3–4
302	Left mandibular 2nd incisor	Incisor	3–4
303	Left mandibular 3rd incisor	Incisor	3–4
304	Left mandibular canine	Canine	4–5
305	Left mandibular 2nd premolar	Premolar	4–5
306	Left mandibular 3rd premolar	Premolar	4–5
307	Left mandibular 4th premolar	Premolar	4–5
308	Left mandibular 1st molar (carnassial)	Molar	4–5

Right mandibular quadrant (400 series)

Tooth #	Name	Type	Eruption (months)
401	Right mandibular 1st incisor	Incisor	3–4
402	Right mandibular 2nd incisor	Incisor	3–4
403	Right mandibular 3rd incisor	Incisor	3–4
404	Right mandibular canine	Canine	4–5
405	Right mandibular 2nd premolar	Premolar	4–5
406	Right mandibular 3rd premolar	Premolar	4–5
407	Right mandibular 4th premolar	Premolar	4–5
408	Right mandibular 1st molar (carnassial)	Molar	4–5

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