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tooth[to̳th] (pl. teeth)
Covering the root of the tooth and holding it in place in its alveolus (socket) in the jaw is a fibrous connective tissue called the periodontium. Its many strong fibers are embedded in the cementum and also the wall of the tooth socket. The periodontium not only helps hold the tooth in place but also acts to cushion it against the pressure caused by biting and chewing.
There are 20 primary teeth, called also deciduous teeth, baby teeth, or milk teeth, which are eventually replaced by 32 permanent teeth, evenly divided between the upper and lower jaws.
Teeth have different shapes because they have different functions. The incisors, in the front of the mouth, are shaped like a cone with a sharp flattened end, and cut the food. There are eight deciduous and permanent incisors, four upper and four lower. The canines (or cuspids) are at the corners of the mouth and are shaped like simple cones; they tear and shred food. There are four permanent canines; the two in the upper jaw are popularly known as the “eye teeth.” The premolars (or bicuspids) are next behind the cuspids and consist of two cones, or cusps, fused together; they tear, crush, and grind the food. There are eight permanent premolars. The molars are in the back of the mouth; they have between three and five cusps each, and their function is to crush and grind food. There are 12 permanent molars in all, three on each side of both the upper and lower jaw. The hindmost molar in each of these groups, and the last one to emerge, is popularly known as the wisdom tooth.
When the child is about 6, the first permanent molar comes in just behind the second molar of the primary teeth. About the same time, shedding of primary teeth begins. The permanent teeth form in the jaw even before the primary ones have erupted, with the incisors and the canines beginning to calcify during the first 6 months of life. Calcification of the others takes place shortly after. As the adult teeth calcify, the roots of the primary ones gradually disappear, or resorb, and are completely gone by the time the permanent teeth are ready to appear. Occasionally a primary tooth root does not resorb, and as a result the permanent tooth comes in outside its proper position. When this happens, it is necessary to remove the primary tooth and root.
The first teeth to be shed, about the sixth year, are the central incisors. The permanent incisors erupt shortly afterward. The lateral incisors are lost and replaced during the seventh to ninth years, and the canines in the ninth to twelfth years. The first premolars generally appear between the ages of 10 and 12, the second molars between 11 and 13, and the third molars, or wisdom teeth, between 17 and 22. It is not uncommon for the third molars to fail to erupt.
Occasionally there is a partial or total lack of either the primary or the permanent teeth (anodontia). In some cases this is inherited, and in others it may be related to endocrine gland disturbances.
teeth(tūth, tēth), [TA]
tooth(tooth) pl. teeth one of the hard, calcified structures set in the alveolar processes of the jaws for the biting and mastication of food.
tooth, pl. teeth (tūth, tēth) [TA]
Synonym(s): dens (1) [TA] .
tooth(tooth) (teth) plural.teeth
Everyone has two complete sets of teeth during his life. The 20 primary teeth are the first set of teeth a person develops. They exfoliate by age 14 and are replaced by the 32 permanent teeth. The permanent teeth include the following: incisors, canines (cuspids), premolars (bicuspids), and molars. On average, a child should have 6 teeth at 1 year, 12 teeth at 18 months, 16 teeth at 2 years, and 20 teeth at 12 years. Some children are born with a few erupted teeth; in other children the teeth may not appear until 16 months.
Health care professionals should assess patients’ teeth and gums during physical examinations, educate patients about routine dental hygiene (brushing, flossing, gum stimulation, use of oral rinses), and refer them to a dental professional for dental caries, eruption anomalies, or periodontal problems.See: dental plaque; periodontal disease
baby toothDeciduous tooth.
Popular treatments for hypersensitivity include topical varnishes, sealants, and topical fluoride applications. Other treatments include application of silver nitrate, formalin, glycerin, strontium chloride, potassium nitrate, calcium compounds, sodium citrate, and potassium oxalate.
The patient can reduce sensitivity by a regimen of plaque control, dentifrice with fluoride, self-applied fluoride, and control of diet.
milk toothDeciduous tooth.
primary toothDeciduous tooth.
secondary toothPermanent tooth.
- one of a series of structures found in the mouth of vertebrates associated with the biting, tearing and crushing of food. Each tooth is a hard structure consisting of a very hard external enamel layer of minerals bound by KERATIN. Underneath this is dentine which has a similar structure to the bone, but is harder, again due to mineral content. The dentine is perforated by fine channels containing processes of the odontoblasts (tooth cells). Centrally the pulp cavity contains blood capillaries and nerve endings. The root is covered by cement and embedded in the jaw bone. See Fig. 298 . See INCISORS, CANINES, PREMOLARS and MOLARS.
- any structure with the general appearance of a tooth, such as a dogfish tooth (denticle) which is a modified scale.
tooth, pl. teeth (tūth, tēth) [TA]
Synonym(s): dens (1) [TA] .
Patient discussion about tooth
Q. what exactly is a tooth fracture?A broken tooth? there is a tremendous amount of pain with this tooth.
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Q. do you know what are the pros and cons of the Sonic toothbrush from Oral B (electric tooth brush)? last night, my best friend raved about it for a whole hour. My dentist told me to use a soft brush (number 35) to clean my teeth and that the electric brushes are a bit over rated. My friend specifically told me about the Sonic product and told me that it also makes his teeth whiter. I wanted to know if anybody has any knowledge or experience from first hand about this product or any good information about it.
Q. what happens if a dentist fills a cavity with some caries left on the tooth? the cavity was deep ,close to the nerve. Didn’t make nerve exposure.?