Adult dogs have 42 permanent teeth (20 upper and 22 lower teeth)
Puppies have 28 baby (deciduous) teeth (14 upper and 14 lower teeth)
Puppies should have 28 temporary teeth that erupt at about 3-4 weeks of age. They will eventually have 42 permanent adult teeth that begin to emerge at about 3-4 months of age. As puppies, there are 14 upper and 14 lower puppy teeth. Puppies do not have any of the molars or premolar 1.
There are 4 types of teeth with different functions:
Incisors – used for cutting and nibbling food, scooping, picking up objects and grooming. These are the front teeth situated directly in between the canines. In adults and puppies there are 6 upper and 6 lower all in a row; the centre two incisors are usually somewhat smaller and the others get larger as they move out and away from the centre.
Canines – used for holding and tearing food, slashing and tearing when fighting and as a cradle for the tongue. These are the large fangs. The lower canines lock in position in front of the upper canines. The canines are situated directly between the incisors and premolars. In adults and puppies there are two upper and two lower canines, one upper and lower on each side of the jaw.
Premolars – used for cutting, holding, shearing, carrying and breaking food into small pieces. These teeth are situated between the canines and molars. Puppies do not have P1 teeth, only P2, P3, and P4. Adults have 8 premolars on the top and 8 on the bottom, 4 on each side of the upper and lower jaws.
Molars – used for grinding food into small pieces. The molars are situated behind the premolars and are the last teeth in the back of the jaw. Puppies do not have molars. Adults have 4 molars on the top; two on each side of the upper jaw and 6 molars on the bottom, 3 on each side of the lower jaw.
Incisors 4-6 weeks 3-5 months
Canine 5-6 weeks 4-6 months
Premolars 6 weeks 4-5 months
Molars 5-7 months
In general, a puppy’s bottom jaw will continue to grow until they are approximately 9 months old, which means the bite is in transition until 9-11 months of age. It should be noted that the top jaw is also in transition and growing during this period. The bite can go either way, from scissors to underbite or from scissors to overbite, or from scissors to level bite. It is a general observation in some breeds that a puppy which starts off with an overbite, even if it corrects later on, can have a higher incidence of producing more puppies with overbites. Puppies with underbites almost never correct themselves.