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.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with teeth
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Study Pits Man v Machine in Piecing Together 425-Million Years Old Jigsaw
Other Sciences / Archaeology & Fossils
Nov 16, 2009 |
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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.
Dentistry, a high-tech version: Robots not far off, doctor says
Nov 24, 2009 |
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Robots may practice dentistry one day, but there will always be humans telling you to open wide, said a teacher on the cutting edge of tooth care.
Doctors create gum that helps promote tooth health
Nov 13, 2009 |
4 / 5 (4) |
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With the help of a gum chomping machine and years of careful chemistry, University of Kentucky researchers have developed a chewing gum that can help replace toothpaste and a toothbrush, thus improving the health of soldiers ...
What a grind: Bruxism at night likely a sign of stress by day
Nov 27, 2009 |
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You can practically track Steve Barkley's stress by the level of activity in his temporomandibular joint, or TMJ, the hinge joint that connects the lower jaw to the temporal bone of the skull and helps one chew, talk and ...
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Nature's fine designs: Scientists find modern lessons in ancient creations
Dec 04, 2009 |
4.5 / 5 (4) |
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(PhysOrg.com) -- Nature and its bottom-up processes for creating robust and responsive materials are inspiring new generations of synthetic materials and creative design.
Doctors Warn Against Holiday Heart Attack Spike
Dec 03, 2009 |
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(PhysOrg.com) -- Some studies indicate that death rates from heart attacks and stroke as well as non-heart-related causes spike during the holiday season.
Mathematical model of a simple circuit in a chicken brain raises fundamental questions
Dec 01, 2009 |
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(PhysOrg.com) -- The Web site Neuroanthropology asks visitors to complete this quote, "One of the difficulties in understanding the brain is ...". In addition to the typical facetious remarks, such as "so ...
Can cleft palate be healed before birth?
Dec 01, 2009 |
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In a study newly published in the journal Development, investigators at the USC School of Dentistry describe how to non-surgically reverse the onset of cleft palate in fetal mice - potentially one step in the journey to a b ...
New forensic technique gives clues about sharks from bite damage
Dec 01, 2009 |
5 / 5 (1) |
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Hit-and-run attacks by sharks can be solved with a new technique that identifies the culprits by the unique chomp they put on their victims, according to a University of Florida researcher and shark expert.
Rat pack: Scientists warming up to African rodent
Nov 28, 2009 |
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(AP) -- Naked mole rats don't get cancer. They shrug off brushes with acid and age so well, some are older than the college-aged researchers handling them.
Peptides control crystal growth with 'switches, throttles and brakes'
Nanotechnology / Bio & Medicine
Nov 23, 2009 |
4.8 / 5 (5) |
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(PhysOrg.com) -- By producing some of the highest resolution images of peptides attaching to mineral surfaces, scientists have a deeper understanding how biomolecules manipulate the growth crystals. This research ...
Consumers choose locally grown and environmentally friendly apples
Other Sciences / Social Sciences
Nov 23, 2009 |
1 / 5 (2) |
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When asked to compare apples to apples, consumers said they would pay more for locally grown apples than genetically modified (GMO) apples. But in a second questionnaire consumers preferred GMO apples - that is, when they ...
How green is your house? Recycling favorite activity among Brits says new survey
Nov 23, 2009 |
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Seventy percent of households always separate their rubbish for recycling, but only 2 percent buy their energy on a green tariff, according to the early findings of a major new annual household survey, called "Understanding ...
BoarCroc, RatCroc, DogCroc, DuckCroc and PancakeCroc
Other Sciences / Archaeology & Fossils
Nov 19, 2009 |
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A suite of five ancient crocs, including one with teeth like boar tusks and another with a snout like a duck's bill, have been discovered in the Sahara by National Geographic Explorer-in-Residence Paul Sereno. ...
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