2. Are youless than 14years old? Ifso, chancesare you havehad at leastone loosetooth.
3. Having loose teeth when you are young is normal.In fact, after spending the first three years of your lifegetting a set of teeth, you then spend the next tenyears slowly losing them one by one.
4. 1. How many years does it take to grow your first set of teeth? a) 3 years b) 4 years c) 6 years d) 7 years
5. Do youhave a loosetooth, or haveyou lost onelately? Ifso, this topicwill interestyou.
6. Teetharen’t organslike our heartor brain –they aren’tthere andready to workas soon as weare born.
7. 2. Which one is different? – Heart – Lung – Brain – Tooth
8. Although asbabies we have thebeginnings of ourfirst teeth, theyaren’t visible untilwe are about six orseven months old.Once the teethbegin toappear, mostchildren get all ofthem by the timethey are three yearsold.
9. These are called primaryteeth, and there are twentyof them in all. These teeth arealso known as baby teeth. Aswe get older, one byone, these teeth begin toloosen and eventually fallout. The first primary toothusually falls out when a childabout five or six years old.
10. 3. How many baby teeth should a person have? – 16 – 20 – 28 – 24
11. Primaryteeth fall outbecause theyare pushed outby thesecondaryteeth, whichare beneaththem in thegums.
12. 4. What makes the baby teeth fall out? – They get old and decay. – They have no root and fall out. – They are pushed out by the adult teeth. – They must be pulled.5. In the above question, who is they? – Baby teeth – Adult teeth – Your Tongue – The Class
13. Secondary teeth are also calledpermanent teeth. Slowly, thepermanent teeth grow in and pushthe baby teeth out, and by agefourteen most children have all theirpermanent teeth. There are twenty-eight teeth in a permanent set. Thatis eight more than in the first set ofprimary teeth.
14. By age twenty, four more permanent teeth willhave grown in at the back of the mouth. These lastfour are called wisdom teeth. They don’t make ussmarter, though. In fact, they sometimes causeproblems and have to be extracted by a dentist.
15. 6. Draw and Label
16. The part ofthe tooth thatyou can seeabove the gumsis called thecrown.
17. The crown ofeach tooth iscovered with avery hard, shinymaterial calledenamel. Enamelis the hardestsubstance in yourwhole body. It isthe tooth’sshield, protectingit from beingcracked by hardthings you eat.
18. 7. What part of the tooth can you see and what is it made? – You see the Tierra and it is made of bone. – You see the Root and it is made of Hairs. – You see the Head and it is made of bone. – You see the Crown and it is made of Enamel.
19. The nextlayer of atooth is calleddentin. Itmakes up thelargest part ofthe tooth andis similar tobone.
20. The pulp contains the tooth’s nerves andblood vessels. The nerves inside the pulpallow us to feel pain by sending pain messagesto the brain.
21. The root is covered bycementum, which is a kindof glue. This cementumconnects the root of eachtooth to thejawbone, keeping eachtooth in place.
22. 8. Draw and Label the Parts
23. 9. Why do primary teeth fall out? –The root breaks off the jawbone. –They are pushed out by the permanent teeth. –The enamel begins to crack. –The cementum begins to dissolve.
24. 10. What does the word enamel mean in this passage? – The layer of the tooth next to the root. – The part of the tooth that sends messages to the brain. – The part of the tooth that connects to the jawbone. – The very hard shiny coating on a tooth.
25. 11. Why do you think it is important to take care of your secondary teeth? – Secondary teeth are the last teeth a person gets. – Secondary teeth will fall out in about seven years. – Secondary teeth have nerves that connect them to the brain. – To make sure there is room for the wisdom teeth.