Medical research

Stopping tooth decay before it starts—without killing bacteria

Oral bacteria are ready to spring into action the moment a dental hygienist finishes scraping plaque off a patient's teeth. Eating sugar or other carbohydrates causes the bacteria to quickly rebuild this tough and sticky ...

Dentistry

Complexity of human tooth enamel revealed at atomic level

Scientists used a combination of advanced microscopy and chemical detection techniques to uncover the structural makeup of human tooth enamel at unprecedented atomic resolution, revealing lattice patterns and unexpected irregularities. ...

Health

Tooth loss more prevalent in adults with chronic disease

(HealthDay)—Adults with severe chronic disease or with fair or poor general health have a higher prevalence of edentulism and severe tooth loss, according to research published in the May 29 issue of the U.S. Centers for ...

page 1 from 33

Tooth

Teeth (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.

This text uses material from Wikipedia, licensed under CC BY-SA