Man has two sets of teeth: a first (primary), or baby set, and a second, or permanent, set. In a full set of teeth, there are four types, and each type has a special job. The “incisors”, in the center of the mouth, cut food. The “cuspid on either side of the incisors, tear food. The “bicuspids”, just behind the cuspids, tear and crush food. The “molars”, in the back of the mouth, grind food.
There are 20 teeth in the first set, 10 in each jaw. They begin to form about 30 weeks before birth. In most children the first teeth to appear are the lower incisors. They usually appear when a child is about six months old. Between the sixth and thirtieth month, the rest of the primary teeth appear. The primary teeth in each jaw are the four incisors, two cuspids, and four molars.
Of the 32 teeth in the permanent set, 28 usually erupt between the sixth and fourteenth years. The other four, the third molars, or wisdom teeth, erupt between the seventeenth and twenty-first years.
The permanent teeth are four incisors, two cuspids, four bicuspids, and six molars in each jaw. The twelve permanent molars do not replace the primary teeth. As the jaws become longer, they grow behind the primary teeth. The bicuspids in the permanent set replace the molars in the first set.
The first molars, which are often called the six-year molars, usually are the first to erupt. They are the largest and among the most important teeth. Their position in the jaw helps determine the shape of the lower part of the face and the position of the other permanent teeth. They come in right behind the primary molars and often are mistakenly thought of as primary teeth.
How Many Sets Of Teeth Do You Get In Your Life?
There are 32 permanent teeth in all.