According to WebMD, a typical adult dog has 42 teeth, including incisors, canines, premolars and molars. Each jaw has six incisors in the front, one canine at each end of the incisors and eight premolars. The back of the top jaw has four molars, while the bottom jaw has six.
Most puppies are born toothless, but deciduous incisors start to show up at 2 to 3 weeks old. After two or three months, all of their 28 temporary teeth - incisors, canines and premolars - have erupted. Shortly after this, permanent teeth start coming in, and by age 7 or 8 months, a puppy has all of its adult teeth.