Kamis, 02 Februari 2017

upper wisdom tooth growing sideways

announcer: how teeth grow brought to you by the u.s. department of health and human services national institutes of health. did you know tha... thumbnail 1 summary
upper wisdom tooth growing sideways

announcer: how teeth grow brought to you by the u.s. department of health and human services national institutes of health. did you know that when most babies areborn they don't have any teeth showing? our primary, or baby teeth, are alreadygrowing even before we're born. but our first primary tooth usuallydoesn't poke through our gums until we're around 6 or 7 months old. by the time most of us are 3 years old,all of our primary teeth have come into our mouths where we can see them, or at least we can see parts of them.


there are also parts of our primaryteeth that we can't see. imagine you had x-ray vision. here's what those primary teeth would look like. notice they have pointy roots. our primary teeth are very importantand we need to take good care of them. but did you know they aren't the onlyteeth we have. we also have these, our permanent teeth growing under the gums.only their tops, or crowns, are formed. their roots will develop later. our baby teeth are space holders for the permanent teeth.


as we grow, our permanent teeth will slowlycome into our mouth and replace our primary teeth. when we are about 6 years old, we getour first permanent molars in the back of our mouth. notice that a primarytooth isn't lost before these molars come into our mouth. about the same time, the frontpermanent teeth start to come in. you've probably seen a friend with aloose tooth or a tooth missing. primary teeth get loose and fall outbecause the roots dissolve. that's why when primary teeth fall out;their roots are short and stubby. by the time most people are 14 years old,the second molars and the


other permanent teeth have pokedthrough and are showing in the mouth. all the primary keep have been replaced. the last molars, our wisdom teeth,come in if there is room for them. this video is from open wide and trek inside, a curriculum supplement for grades 1 and 2. produced by the bscs for the nationalinstitute of dental and craniofacial research and the office of science educationat the national institutes of health.

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