Tooth
hideTeeth (singular tooth) are small whitish structures found in the jaws (or mouths) of many vertebrates that are used to tear, scrape, and chew food. Some animals, particularly carnivores, also use teeth for hunting or defense. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of tissues of varying density and hardness.
Teeth are among the most distinctive (and long-lasting) features of mammal species. Paleontologists use teeth to identify fossil species and determine their relationships. The shape of the animal's teeth are related to its diet. For example, plant matter is hard to digest, so herbivores have many molars for chewing. Carnivores, on the other hand, need canines to kill prey and to tear meat.
Mammals are diphyodont, meaning that they develop two sets of teeth. In humans, the first set (the "baby," "milk," "primary" or "deciduous" set) normally starts to appear at about six months of age, although some babies are born with one or more visible teeth, known as neonatal teeth. Normal tooth eruption at about six months is known as teething and can be painful.
Some animals develop only one set of teeth (monophyodont) while others develop many sets (polyphyodont). Sharks, for example, grow a new set of teeth every two weeks to replace worn teeth. Rodent incisors grow and wear away continually through gnawing, maintaining relatively constant length. Many rodents such as voles (but not mice) and guinea pigs, as well as rabbits, have continuously growing molars in addition to incisors.
For more information about Tooth, read the full article at
Wikipedia.
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News tagged with teeth
53 million-year-old high Arctic mammals wintered in darkness
Space & Earth / Earth Sciences
Jun 01, 2009 |
4.8 / 5 (17) |
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(PhysOrg.com) -- Ancestors of tapirs and ancient cousins of rhinos living above the Arctic Circle 53 million years ago endured six months of darkness each year in a far milder climate than today that featured ...
Researchers Crack the Mystery of Resilient Teeth
Apr 17, 2009 |
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(PhysOrg.com) -- After years of biting and chewing, how are human teeth able to remain intact and functional? A team of researchers from The George Washington University and other international scholars have ...
Tiny juvenile dinosaur fossil sheds light on evolution of plant eaters
Other Sciences / Archaeology & Fossils
Oct 24, 2008 |
4 / 5 (13) |
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One of the smallest dinosaur skulls ever discovered has been identified and described by a team of scientists from London, Cambridge and Chicago. The skull would have been only 45 millimeters (less than two ...
Floss your teeth -- on the double!
Aug 06, 2008 |
4.5 / 5 (10) |
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In dental offices all over the world, patients are often told they are not flossing enough or instructed to floss more. As the old saying goes, you only need to floss the teeth you want to keep. After all, not flossing regularly ...
Teeth are the windows to your health
Nov 19, 2008 |
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(PhysOrg.com) -- The phrase, “the eyes are the windows to the soul,” is attributed to several authors and philosophers. But the phrase, “your teeth are the windows to your health,” can be attributed to Mohamed Bassiouny, ...
Dino tooth sheds new light on ancient riddle
Other Sciences / Archaeology & Fossils
Jun 29, 2009 |
4.9 / 5 (8) |
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Microscopic analysis of scratches on dinosaur teeth has helped scientists unravel an ancient riddle of what a major group of dinosaurs ate- and exactly how they did it!
Plesiosaur a victim of shark attack
Other Sciences / Archaeology & Fossils
Oct 06, 2009 |
4.4 / 5 (8) |
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(PhysOrg.com) -- An 85 million-year-old plesiosaur fossil has been found with over 80 shark's teeth, suggesting the animal was the victim of sharks in a feeding frenzy. The find is perhaps the most spectacular example of ...
Scientists discover why teeth form in a single row
Feb 26, 2009 |
4.7 / 5 (7) |
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(PhysOrg.com) -- A system of opposing genetic forces determines why mammals develop a single row of teeth, while sharks sport several, according to a study published today in the journal Science. When comple ...
Study of baby teeth yields new findings on nuclear fallout
Oct 21, 2009 |
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Joan Ketterer still recalls the button her son Edward got for donating his baby teeth to what was then a ground-breaking study looking at the effect of nuclear fallout on children born in the St. Louis-area in the 1960s.
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Study Pits Man v Machine in Piecing Together 425-Million Years Old Jigsaw
Other Sciences / Archaeology & Fossils
Nov 16, 2009 |
3.9 / 5 (8) |
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(PhysOrg.com) -- A new study pitting academic expertise against a computer in recreating a 425 million-year old jigsaw puzzle has discovered that there is no substitute for wisdom born out of experience.
Evidence from dirty teeth: Ancient Peruvians ate well
Other Sciences / Archaeology & Fossils
Dec 01, 2008 |
4.7 / 5 (6) |
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Starch grains preserved on human teeth reveal that ancient Peruvians ate a variety of cultivated crops including squash, beans, peanuts and the fruit of cultivated pacay trees.
Flying by the skin of our teeth
Aug 19, 2009 |
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It's been a mystery: how can our teeth withstand such an enormous amount of pressure, over many years, when tooth enamel is only about as strong as glass? A new study by Prof. Herzl Chai of Tel Aviv University's School of ...
Little teeth suggest big jump in primate timeline
Other Sciences / Archaeology & Fossils
Aug 04, 2008 |
4.2 / 5 (5) |
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Tiny fossilized teeth excavated from an Indian open-pit coal mine could be the oldest Asian remains ever found of anthropoids, the primate lineage of today's monkeys, apes and humans, say researchers from Duke University ...
Genetic discovery could lead to advances in dental treatment
Feb 23, 2009 |
5 / 5 (4) |
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Researchers have identified the gene that ultimately controls the production of tooth enamel, a significant advance that could some day lead to the repair of damaged enamel, a new concept in cavity prevention, and restoration ...
Fossil bone bed helps reconstruct life along California's ancient coastline
Other Sciences / Archaeology & Fossils
Jun 08, 2009 |
4.8 / 5 (4) |
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In the famed Sharktooth Hill Bone Bed near Bakersfield, Calif., shark teeth as big as a hand and weighing a pound each, intermixed with copious bones from extinct seals and whales, seem to tell of a 15-million-year-old ...
