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 tooth
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.
Museum: Galileo's fingers, tooth are found
Other Sciences / Archaeology & Fossils
Nov 21, 2009 |
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(AP) -- Two fingers and a tooth removed from Galileo Galilei's corpse in a Florentine basilica in the 18th century and given up for lost have been found again and will soon be put on display, an Italian museum ...
Form of Mercury in Older Dental Fillings Unlikely to be Toxic: Study
Chemistry / Analytical Chemistry
Nov 11, 2009 |
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(PhysOrg.com) -- Amid the on-going controversy over the safety of mercury-containing dental fillings, a University of Saskatchewan research team has shed new light on how the chemical forms of mercury at the surface of fillings ...
Hybrid composite for root canal treatment
Nov 03, 2009 |
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(PhysOrg.com) -- A dentist carrying out root canal treatment will need to use a variety of compounds. These do not always bond together properly and sometimes expensive follow-up treatment has to be performed. ...
Mummy's tooth yields DNA
Other Sciences / Archaeology & Fossils
Oct 22, 2009 |
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(PhysOrg.com) -- A four thousand year old Egyptian mummy's tooth has yielded its DNA to probing scientists.
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 ...
Healing power of aloe vera proves beneficial for teeth and gums, too
Jul 17, 2009 |
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The aloe vera plant has a long history of healing power. Its ability to heal burns and cuts and soothe pain has been documented as far back as the 10th century. Legend has it that Cleopatra used aloe vera to keep her skin ...
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 ...
New treatment for receding gums: No pain, lots of gain
Jul 01, 2009 |
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Tufts dental researchers conducted a three-year follow-up study that examined the stability of a treatment option for receding gums and found that complete root coverage — the goal of the surgery — had been maintained. This ...
OJ worse for teeth than whitening, researchers say
Jun 30, 2009 |
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With the increasing popularity of whitening one's teeth, researchers at the Eastman Institute for Oral Health, part of the University of Rochester Medical Center, set out to learn if there are negative effects on the tooth ...
Structural biology scores with protein snapshot
Jun 25, 2009 |
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In a landmark technical achievement, investigators in the Vanderbilt Center for Structural Biology have used nuclear magnetic resonance (NMR) methods to determine the structure of the largest membrane-spanning ...
Largest carnivorous dinosaur tooth in Spain described
Other Sciences / Archaeology & Fossils
Jun 22, 2009 |
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Researchers from the Teruel-Dinópolis Joint Palaeontology Foundation have compared an Allosauroidea tooth found in deposits in Riodeva, Teruel, with other similar samples. The palaeontologists have ...
53 million-year-old high Arctic mammals wintered in darkness
Space & Earth / Earth Sciences
Jun 01, 2009 |
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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 ...
