about sets of teeth easy paragraph
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Around the 8th week after conception, oval-shaped tooth buds consisting of cells form in the embryo. These buds begin to harden about the 16th week. Although teeth aren't visible at birth, both the primary and permanent teeth are forming below the gums. The crown, or the hard enamel-covered part that's visible in the mouth, develops first. After the crown is formed, the root begins to develop.
Between the ages of 6 months and 1 year, the deciduous teeth begin to push through the gums. This process is called eruption or teething. At this point, the crown is complete and the root is almost fully formed. By the time a child is 3 years old, he or she has a set of 20 deciduous teeth, 10 in the lower and 10 in the upper jaw. Each jaw has four incisors, two canines, and four molars. The molars' purpose is to grind food, and the incisors and canine teeth are used to bite into and tear food.
The primary teeth help the permanent teeth erupt in their normal positions; most of the permanent teeth form close to the roots of the primary teeth. When a primary tooth is preparing to fall out, its root begins to dissolve. This root has completely dissolved by the time the permanent tooth below it is ready to erupt.
Kids start to lose their primary teeth, or baby teeth, at about 6 years old. This begins a phase of permanent tooth development that lasts over the next 15 years, as the jaw steadily grows into its adult form. From ages 6 to 9, the incisors and first molars start to come in. Between ages 10 and 12, the first and second premolars, as well as the canines, erupt. From 11 to 13, the second molars come in. The wisdom teeth (third molars) erupt between the ages of 17 and 21.
Sometimes there isn't room in a person's mouth for all the permanent teeth. If this happens, the wisdom teeth may get stuck, or impacted, beneath the gum and may need to be removed. Overcrowding of the teeth is one of the reasons kids get braces.
Your teeth are one of the strongest parts of your body. They’re made from proteins such as collagen, and minerals such as calcium. In addition to helping you chew through even the toughest foods, they also help you speak clearly.
Most adults have 32 teeth, called permanent or secondary teeth:
8 incisors
4 canines, also called cuspids
8 premolars, also called bicuspids
12 molars, including 4 wisdom teeth
Children have just 20 teeth, called primary, temporary, or milk teeth. They include the same 10 teeth in the upper and lower jaw:
4 incisors
2 canines
4 molars
Primary teeth start to erupt through the gums when a baby is about 6 months old. The lower incisors are usually the first primary teeth to come in. Most kids have all 20 of their primary teeth by age 3.
Children tend to lose their primary teeth between the ages of 6 and 12. They’re then replaced by permanent teeth. Molars are usually the first permanent teeth to come in. Most people have all of their permanent teeth in place by age 21.