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
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 ...
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.
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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.
Doctors create gum that helps promote tooth health
Nov 13, 2009 |
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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 ...
Teeth grinding linked to sleep apnea
Nov 02, 2009 |
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There is a high prevalence of nocturnal teeth grinding, or bruxism, in patients with obstructive sleep apnea (OSA), particularly in Caucasians. New research presented at CHEST 2009, the 75th annual international scientific ...
Exposure to alkaline substances can result in damaged teeth
Oct 27, 2009 |
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It has long been known that acids can erode tooth enamel but a new Swedish study from the Sahlgrenska Academy at the University of Gothenburg, Sweden, shows that strong alkaline substances can damage teeth too - substances ...
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.
Two-million-year-old evidence shows tool-making hominins inhabited grassland environments
Other Sciences / Archaeology & Fossils
Oct 21, 2009 |
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In an article published in the open-access, peer-reviewed journal PLoS ONE on October 21, 2009, Dr Thomas Plummer of Queens College at the City University of New York, Dr Richard Potts of the Smithsonian Institution Nation ...
Plesiosaur a victim of shark attack
Other Sciences / Archaeology & Fossils
Oct 06, 2009 |
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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 ...
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 ...
Open wide and say 'zap'
Aug 18, 2009 |
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A group of researchers in Australia and Taiwan has developed a new way to analyze the health of human teeth using lasers. As described in the latest issue of Optics Express,, by measuring how the surface of a tooth respon ...
Making crowns stick to teeth more effectively
Jul 20, 2009 |
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Dentists want those expensive crowns to stick to the teeth. But it doesn’t always happen because of contamination during the crown’s bonding.
How to manage erosion caused by everyday beverages
Jul 17, 2009 |
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Researchers have warned people to beware of the damage that acidic beverages have on teeth. Yet, for some, the damage and problems associated with drinking sodas, citric juices or certain tea may have already begun to take ...
Sugar substitute appears to prevent early-childhood cavities
Jul 06, 2009 |
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Children given an oral syrup containing the naturally occurring sweetener xylitol may be less likely to develop decay in their baby teeth, according to a report in the July issue of Archives of Pediatrics & Adolescent Me ...
From human bite to robot jaws
Jun 30, 2009 |
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The UK spends around £2.5 billion each year on dental materials to replace or strengthen teeth. The Chewing Robot is a new biologically inspired way to test dental materials and it will be shown to the public ...
