Puppies do not have molars until they reach 12 weeks of age. Before this time, puppies only have incisors, canines, and premolars, which grow in temporarily. Sometimes as early as 8 weeks, puppies will lose this initial set of teeth, which are then replaced by 42 adult teeth by the time they are 6 months old. This set will include the molars. Your 6-month-old puppy will have 10 molars, four of which are in the upper jaw, and six of which are in the lower jaw.