About 20 days: Dogs begin to teether.
4 ~ 6 weeks old: canine deciduous incisors are long.
At the age of 2 months, the dog's primary teeth are long, white, thin and pointed.
2 ~ 4 months old: the dog replaces the first deciduous incisor.
5 ~ 6 months: the dog begins to change the second and third deciduous incisors and canine teeth.
After 8 months of age: all dogs have changed their permanent teeth, but it is not excluded that some dogs will change their permanent teeth in the future, even when they are 2 years old.
L-year-old: The dog's permanent teeth are long, white and bright, and the front teeth are pointed.
1.5 years old: the first mandibular incisors of dogs wear to the level of small peaks, which is called peak wear.
2.5 years old: the peak wear of the second mandibular incisors in dogs.
3.5 years old: The dog's first maxillary incisor has lost its peak.
4.5 years old: The dog's second maxillary incisor is worn at its peak.
5 years old: The dog's mandibular third incisors are slightly worn, and the worn surfaces of the first and second mandibular incisors are rectangular.
6 years old: The dog's third mandibular incisors are sharp and dull.
7-year-old: The first mandibular incisors of dogs are worn to the root, and the worn surface is vertical oval.
8-year-old: The dog's first incisor with worn mandible leans forward.
10 years old: The worn surfaces of the second mandibular incisors and the first maxillary incisors of dogs are vertical ellipses.