a hard crown above the gum line, which is attached to two or four roots by a portion called the neck. The roots are covered with a very thin layer of bone, and they keep the tooth embedded in the bones of the jaw. The exposed exterior of the tooth is covered with tough enamel. Under the enamel is a thick layer of dentin, and in the center is the pulp, which contains blood vessels and nerves.
- Tooth and nail syndrome
A genetic disorder characterized by the absence of several teeth at birth and abnormalities of the nails. The disorder is also known as hypodontia and nail dysgenesis or Witkop syndrome (TNS). It was first described by Dr. Carl Witkop in 1965. The tooth and nail defects in the syndrome are highly variable. The number and […]
- Primary teeth
The first teeth which are shed and replaced by permanent teeth. The first primary tooth comes in at about 6 months of age and the 20th and last primary tooth erupts at around 2 1/2 years of age. The primary teeth are replaced beginning usually at about age 6. Also called baby teeth, milk teeth, […]
- Tooth erosion
The gradual loss of the normally hard surface of the tooth due to chemical, not bacterial, processes.
- Tooth numbering
(1) is the patient’s upper right molar and follows around the upper arch to the upper left third molar (16), descending to the lower left third molar (17) and follows around the lower arch to the lower right third molar (32). The Universal/National System is used primarily in the United States whereas the International Standards […]
- Tooth root
The lower two-thirds of a tooth. The roots are normally buried in bone, and they serve to anchor the tooth in position. The roots are covered with a thin layer of bone, and they are inserted into sockets in the bone of the jaw.