عرض مصدر Tooth

{{About|the structure found in many animals|the teeth of humans|Human tooth|other uses}}
{{pp-semi|small=yes}}
[[File:Close up - chimpanzee teeth.png|thumb|right|200px|A [[chimpanzee]] displaying its teeth]]

A '''tooth''' (plural '''teeth''') is a small, [[calcification|calcified]], whitish structure found in the [[jaw]]s (or [[mouth]]s) of many [[vertebrate]]s and used to [[Mastication|break down]] [[food]]. Some animals, particularly [[carnivore]]s, also use teeth for hunting or for defensive purposes. The roots of teeth are covered by [[gingiva|gums]]. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness. The cellular tissues that ultimately become teeth originate from the embryonic germ layer, the [[ectoderm]].

The general structure of teeth is similar across the vertebrates, although there is considerable variation in their form and position. The [[Mammal tooth|teeth of mammals]] have deep roots, and this pattern is also found in some fish, and in [[crocodilian]]s. In most [[teleost]] fish, however, the teeth are attached to the outer surface of the bone, while in [[lizard]]s they are attached to the inner surface of the jaw by one side. In [[cartilaginous fish]], such as sharks, the teeth are attached by tough [[ligament]]s to the hoops of [[cartilage]] that form the jaw.<ref name=VB>{{cite book |author=Romer, Alfred Sherwood|author2=Parsons, Thomas S.|year=1977 |title=The Vertebrate Body |publisher=Holt-Saunders International |location= Philadelphia, PA|pages= 300–310|isbn= 0-03-910284-X}}</ref>

Some animals develop only one set of teeth (monophyodont) while others develop many sets (polyphyodont). [[Shark]]s, for example, grow a new set of teeth every two weeks to replace worn teeth. [[Rodent]] incisors grow and wear away continually through gnawing, which helps maintain relatively constant length. The industry of the [[beaver]] is due in part to this qualification. Many rodents such as [[vole]]s  and [[guinea pig]]s, but not [[mouse|mice]], as well as [[leporidae]] like [[rabbit]]s, have continuously growing molars in addition to incisors.<ref>{{cite journal |vauthors=Tummers M, Thesleff I |title=Root or crown: a developmental choice orchestrated by the differential regulation of the epithelial stem cell niche in the tooth of two rodent species |journal=Development |volume=130 |issue=6 |pages=1049–57 |date=March 2003 |pmid=12571097 |doi=10.1242/dev.00332 |url=}}</ref><ref>{{cite journal |author=Hunt AM |title=A description of the molar teeth and investing tissues of normal guinea pigs |journal=J. Dent. Res. |volume=38 |issue=2 |pages=216–31 |year=1959 |pmid=13641521 |doi= 10.1177/00220345590380020301|url=http://jdr.sagepub.com/cgi/pmidlookup?view=long&pmid=13641521}}</ref>

Teeth are not always attached to the jaw, as they are in mammals. In many [[reptile]]s and fish, teeth are attached to the [[palate]] or to the floor of the mouth, forming additional rows inside those on the jaws proper. Some teleosts even have teeth in the [[pharynx]]. While not true teeth in the usual sense, the [[dermal denticle]]s of sharks are almost identical in structure, and are likely to have the same evolutionary origin. Indeed, teeth appear to have first evolved in sharks, and are not found in the more primitive [[jawless fish]] - while [[lamprey]]s do have tooth-like structures on the tongue, these are in fact, composed of [[keratin]], not of dentine or enamel, and bear no relationship to true teeth.<ref name=VB/> Though "modern" teeth-like structures with [[dentine]] and [[tooth enamel|enamel]] have been found in late [[conodont]]s, they are now supposed to have evolved independently of later vertebrates' teeth.<ref>{{cite journal|last=McCOLLUM|first=MELANIE|author2=SHARPE, PAUL T. |title=Evolution and development of teeth|journal=Journal of Anatomy|date=July 2001|volume=199|issue=1-2|pages=153–159|doi=10.1046/j.1469-7580.2001.19910153.x}}</ref><ref>[http://www.nature.com/news/fossil-scans-reveal-origins-of-teeth-1.13964 nature.com, ''Fossil scans reveal origins of teeth'', 16 October 2013]</ref>

Living [[amphibian]]s typically have small teeth, or none at all, since they commonly feed only on soft foods. In reptiles, teeth are generally simple and conical in shape, although there is some variation between species, most notably the venom-injecting [[fang]]s of [[snake]]s. The pattern of incisors, canines, premolars and molars is found only in mammals, and to varying extents, in their [[mammal-like reptiles|evolutionary ancestors]]. The numbers of these types of teeth varies greatly between species; [[zoology|zoologists]] use a standardised [[dental formula]] to describe the precise pattern in any given group.<ref name=VB/>

== Origin ==
The genes governing tooth development in mammals are [[homologous gene|homologous]] to these involved in the development of fish scales.<ref>{{Cite journal| first1 = P. T.| title = Fish scale development: Hair today, teeth and scales yesterday?| journal = Current Biology| volume = 11| last1 = Sharpe| issue = 18| pages = R751–R752| year = 2001| pmid = 11566120| doi = 10.1016/S0960-9822(01)00438-9    }}</ref> Study of a tooth plate of a fossil of the extinct fish ''[[Romundina stellina]]'' showed that the teeth and scales were made of the same tissues, also found in mammal teeth, lending support to the theory that teeth evolved as a modification of scales.<ref>{{cite news |title=First-known teeth belonged to fierce fish |author=Jennifer Viegas |url=http://www.abc.net.au/science/articles/2015/06/24/4261003.htm |publisher=[[Australian Broadcasting Corporation|ABC]] Science|date=June 24, 2015 |accessdate=June 28, 2015}}</ref>

== Mammals ==
{{Main|Mammal tooth}}

Teeth are among the most distinctive (and long-lasting) features of [[mammal]] species. [[Paleontology|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 [[herbivore]]s have many [[Molar (tooth)|molars]] for [[mastication|chewing]] and grinding. [[Carnivore]]s, on the other hand, need [[canine (tooth)|canines]] to kill prey and to tear meat.

[[Mammals]] in general are [[diphyodont]], meaning that they develop two sets of teeth. In [[humans]], the first set (the "baby," "milk," "primary" or "[[deciduous teeth|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.  [[Kangaroos]], [[elephant]]s and [[manatees]] are unusual among mammals because they are [[polyphyodont]]s.

=== Aardvark ===

In [[Aardvark]]s, teeth lack enamel and have many pulp tubules, hence the name of the order [[Tubulidentata]].

=== Canines ===
{{Main|Canine tooth}}

In [[dog]]s, the teeth are less likely than humans to form [[dental caries|dental cavities]] because of the very high [[pH]] of dog saliva, which prevents enamel from demineralizing.<ref>{{cite journal | pmc = 2777300 | pmid=20190984 | volume=50 | title=Dental caries in the dog | year=2009 | journal=Can. Vet. J. | pages=1301–4 | last1 = Hale | first1 = FA}}</ref>

=== Cetaceans ===

Like human teeth, [[whale]] teeth have polyp-like protrusions located on the root surface of the tooth. These polyps are made of cementum in both species, but in human teeth the protrusions are located on the outside of the root, while in whales the nodule is located on the inside of the pulp chamber. While the roots of human teeth are made of cementum on the outer surface, whales have cementum on the entire surface of the tooth with a very small layer of enamel at the tip. This small enamel layer is only seen in older whales where the cementum has been worn away to show the underlying enamel.<ref>{{cite web|title=Common Characteristics Of Whale Teeth|url=http://www.antiquescrimshaw.org|accessdate=18 July 2014}}</ref>

The toothed whale is a [[suborder]] of the [[cetacean]]s characterized by having teeth.  The teeth differ considerably among the species. They may be numerous, with some [[dolphin]]s bearing over 100 teeth in their jaws.  On the other hand, the [[narwhal]]s have a giant unicorn-like tusk, which is a tooth containing millions of sensory pathways and used for sensing during feeding, navigation and mating. It is the most neurologically complex tooth known.  [[Beaked whales]] are almost toothless, with only bizarre teeth found in males.  These teeth may be used for feeding but also for demonstrating aggression and showmanship.

=== Primates ===
{{Main|Human tooth|Dental anatomy}}
In [[human]]s, there are usually 20 primary ("baby") teeth and 28 to 32 permanent teeth, the last four being third molars or "[[wisdom teeth]]", each of which may or may not grow in. Among primary teeth, 10 usually are found in the [[maxilla]] (upper jaw) and the other 10 in the [[human mandible|mandible]] (lower jaw). Among permanent teeth, 16 are found in the maxilla and the other 16 in the mandible. Most of the teeth have distinguishing features.

=== Horse ===
{{Main|Horse teeth}}

An adult [[horse]] has between 36 and 44 teeth. The enamel and dentin layers of horse teeth are intertwined.<ref>{{cite web|title=Gummed Out: Young Horses Lose Many Teeth, Vet Says|url=http://portlanddentalpc.com/gummed-out.htm|accessdate=6 July 2014}}</ref> All horses have 12 premolars, 12 molars, and 12 incisors.<ref name=Pence2002>{{Cite journal |date=2002 |author=Patricia Pence |title=Equine Dentistry: A Practical Guide |place=Baltimore |publisher=Lippincott Williams & Wilkins |isbn=0-683-30403-8 |url=https://books.google.com/?id=o4KVGceXBNIC&printsec=frontcover&dq=%22Equine+dentistry%22&cd=1#v=onepage&q&f=false}}</ref>  Generally, all male equines also have four [[canine teeth]] (called tushes) between the molars and incisors.  However, few female horses (less than 28%) have canines, and those that do usually have only one or two, which many times are only partially erupted.<ref name=Cirelli>{{Cite journal |date= |author=Al Cirelli |title=Equine Dentition |place=Nevada |publisher=University of Nevada |url=http://www.unce.unr.edu/publications/files/ag/2000/sp0008.pdf |accessdate=7 June 2010}}</ref>  A few horses have one to four [[wolf teeth]], which are [[vestigial]] premolars, with most of those having only one or two. They are equally common in male and female horses and much more likely to be on the upper jaw.  If present these can cause problems as they can interfere with the horse's [[bit (horse)|bit]] contact. Therefore, wolf teeth are commonly removed.<ref name=Pence2002/>

[[Horse teeth]] can be used to estimate the animal's age.  Between birth and five years, age can be closely estimated by observing the eruption pattern on milk teeth and then permanent teeth.  By age five, all permanent teeth have usually erupted. The horse is then said to have a "full" mouth.  After the age of five, age can only be conjectured by study of the wear patterns on the incisors, shape, the angle at which the incisors meet, and other factors. The wear of teeth may also be affected by diet, natural abnormalities, and [[Cribbing (horse)|cribbing]].  Two horses of the same age may have different wear patterns.

A horse's incisors, premolars, and molars, once fully developed, continue to erupt as the grinding surface is worn down through chewing. A young adult horse will have teeth which are 4.5-5&nbsp;inches long, with the majority of the crown remaining below the gumline in the dental socket. The rest of the tooth will slowly emerge from the jaw, erupting about 1/8" each year, as the horse ages. When the animal reaches old age, the crowns of the teeth are very short and the teeth are often lost altogether. Very old horses, if lacking molars, may need to have their [[fodder]] ground up and soaked in water to create a soft mush for them to eat in order to obtain adequate nutrition.

=== Proboscideans ===
[[File:Mammoth ivory hg.jpg|thumb|Section through the ivory tusk of a mammoth]]

[[Elephant]]s' [[tusk]]s are specialized incisors for digging food up and fighting.  Some of elephant teeth are similar to those in [[manatee]]s, and it is notable that elephants are believed to have undergone an [[Aquatic animal|aquatic]] phase in their evolution.

Elephants have four [[Molar (tooth)|molar]]s, one on each side of the upper and lower jaw. Until age 40, these are replaced by larger molars. The new molars shift forward from the back of the [[jaw]] as the old wear down. The final set of molars last for about twenty years.<ref>Bram, L. et al. MCMLXXXIII. ''Elephants.'' Funk & Wagnalls New Encyclopedia, Volume 9, p. 183. ISBN 0-8343-0051-6</ref>

=== Rabbit ===

[[Rabbit]]s and other [[lagomorph]]s usually shed their deciduous teeth before (or very shortly after) their birth, and are usually born with their permanent teeth.<ref>[http://www.peteducation.com/article.cfm?cls=18&cat=1798&articleid=3078 Dental Anatomy & Care for Rabbits and Rodents<!-- Bot generated title -->]</ref>  The teeth of rabbits complement their diet, which consist of a wide range of vegetation.  Since many of the foods are abrasive enough to cause attrition, rabbit teeth grow continuously throughout life.<ref>Brown, Susan. [http://www.rabbit.org/chapters/san-diego/health/dental_disease.html Rabbit Dental Diseases], hosted on the [http://www.rabbit.org/chapters/san-diego/ San Diego Chapter of the House Rabbit Society].  Page accessed April 9, 2007.</ref>  Rabbits have a total of 6 incisors, three upper premolars, three upper molars, two lower premolars, and two lower molars on each side.  There are no canines.  Three to four millimeters of tooth is worn away by incisors every week, whereas the posterior teeth require a month to wear away the same amount.<ref>Ryšavy, Robin. [http://www.mohrskc.org/hrswebpg23.html The Missouri House Rabbit Society], hosted by the [http://www.mohrskc.org/index.html Kansas City Missouri House Rabbit Society]. Page accessed April 9, 2007.</ref>

The incisors and cheek teeth of rabbits are called aradicular hypsodont teeth.  This is sometimes referred to as an elodent dentition.  These teeth grow or erupt continuously.  The growth or eruption is held in balance by dental abrasion from chewing a diet high in fiber.

=== Rodents ===

[[Rodent]]s' incisors grow continuously throughout their lives or are aradicular.  Unlike humans whose [[ameloblasts]] die after [[tooth development]], rodents continually produce [[Tooth enamel|enamel]] and must wear down their teeth by gnawing on various materials.<ref>Caceci, Thomas. ''Veterinary Histology'' with subtitle "Digestive System: Oral Cavity" found [http://education.vetmed.vt.edu/Curriculum/VM8054/Labs/Lab17/Lab17.htm here].</ref>  These teeth are used for cutting wood, biting through the skin of fruit, or for defense.  The teeth have enamel on the outside and exposed [[dentin]] on the inside, so they self-sharpen during [[gnawing]].  On the other hand, continually growing molars are found in some rodent species, such as the [[sibling vole]] and the [[guinea pig]].<ref>Tummers M and Thesleff I. Root or crown: a developmental choice orchestrated by the differential regulation of the [[epithelial]] [[stem cell]] niche in the tooth of two rodent species. Development (2003). 130(6):1049-57.</ref><ref>AM Hunt. A description of the molar teeth and investing tissues of normal guinea pigs. J Dent Res. (1959) 38(2):216-31.</ref>  There is variation in the dentition of the rodents, but generally, rodents lack canines and premolars, and have a space between their incisors and molars, called the [[Diastema (dentistry)|diastema]] region.

=== Manatee ===

[[Manatees]] are polyphyodont with mandibular molars developing separately from the jaw and are encased in a bony shell separated by soft tissue.

=== Walrus ===

[[Walrus]] tusks are canine teeth that grow continuously throughout life.<ref>[http://www.uic.edu/classes/orla/orla312/CANINES.htm The Permanent Canine Teeth], hosted on the University of Illinois at Chicago website. Page accessed February 5, 2007.</ref>

== Fish ==
[[File:Surfacing great white shark.jpg|thumb|[[Shark tooth|Teeth]] of [[Great White Shark]]]]
{{See also|Pharyngeal teeth|Shark tooth}}

[[Fish]], such as [[shark]]s, may go through many teeth in their lifetime.  The multiple replacement of teeth is known as [[polyphyodont]]ia.

A class of prehistoric shark are called [[cladodont]]s for their strange forked teeth.

== Reptiles ==

The teeth of [[reptiles]] are replaced constantly during their life.  Juvenile [[crocodilians]] replace teeth with larger ones at a rate as high as one new tooth per socket every month.  Once adult, tooth replacement rates can slow to two years and even longer.  Overall, crocodilians may use 3,000 teeth from birth to death.  New teeth are created within old teeth.

==Invertebrates==
[[File:Svømmende blodigle.JPG|thumb|right|The [[European medicinal leech]] has three jaws with numerous sharp teeth which function like little saws for incising a host.]]

True teeth are unique to vertebrates,<ref name="kardong">{{cite book|last=Kardong|first=Kenneth V.|title=Vertebrates: comparative anatomy, function, evolution|year=1995|publisher=McGraw-Hill|isbn=0-697-21991-7|pages=55, 57}}</ref> although many invertebrates have [[Analogy (biology)|analogous structures]] often referred to as teeth. The [[organism]]s with the simplest [[genome]] bearing such tooth-like structures are perhaps the parasitic [[worm]]s of the family [[Ancylostomatidae]].<ref>{{cite web|url = http://www.nematode.net/Species.Summaries/Ancylostoma.duodenale/index.php|archiveurl = https://web.archive.org/web/20080516010133/http://www.nematode.net/Species.Summaries/Ancylostoma.duodenale/index.php|archivedate = 2008-05-16|title = Ancylostoma duodenale|publisher = Nematode.net Genome Sequencing Center |accessdate = 2009-10-27}}</ref> For example, the hookworm ''[[Necator americanus]]'' has two [[Anatomical terms of location|dorsal]] and two [[Anatomical terms of location|ventral]] cutting plates or teeth around the anterior margin of the [[Cheek|buccal]] capsule. It also has a pair of subdorsal and a pair of subventral teeth located close to the rear.<ref>Roberts, Larry S., and John Janovy, Jr. Foundations of Parasitology. Seventh ed. Singapore: McGraw-Hill, 2006.</ref>

Historically the [[European medicinal leech]], another invertebrate parasite, has been used in medicine to remove blood from patients.<ref name=Payton1981>{{cite book | author= Brian Payton | title = Neurobiology of the Leech |editor1=Kenneth Muller |editor2=John Nicholls |editor3=Gunther Stent |publisher = Cold Spring Harbor Laboratory | location = New York | year = 1981 | isbn = 0-87969-146-8 |pages=27–34}}</ref> They have three jaws (tripartite) that look like little saws, and on them are about 100 sharp teeth used to incise the host. The incision leaves a mark that is an inverted Y inside of a circle. After piercing the skin and injecting [[anticoagulant]]s ([[hirudin]]) and [[anaesthetic]]s, they suck out blood, consuming up to ten times their body weight in a single meal.<ref name=wells>{{cite journal|vauthors=Wells MD, Manktelow RT, Boyd JB, Bowen V |title=The medical leech: an old treatment revisited|journal=[[Microsurgery (journal)|Microsurgery]]|volume=14|issue=3|pages=183–6|year=1993 |pmid=8479316|doi=10.1002/micr.1920140309}}</ref>

In some species of [[Bryozoa]], the first part of the stomach forms a muscular [[gizzard]] lined with [[chitin]]ous teeth that crush armoured prey such as [[diatom]]s. Wave-like [[peristalsis|peristaltic]] contractions then move the food through the stomach for digestion.<ref>{{cite book | author=Ruppert, E.E., Fox, R.S., and Barnes, R.D. | title=Invertebrate Zoology | chapter=Lophoporata| publisher=Brooks / Cole | edition=7 | isbn=0-03-025982-7 | year=2004 | pages=829–845}}</ref>

[[File:Radula docoglosse.JPG|thumb|right|The limpet rasps algae from rocks using teeth with the strongest known [[tensile strength]] of any biological material]]

[[Mollusc]]s have a structure called a [[radula]] which bears a ribbon of [[chitin]]ous teeth. However, these teeth are histologically and developmentally different from vertebrate teeth, and are unlikely to be [[Homology (biology)|homologous]]. For example, vertebrate teeth develop from a [[neural crest]] mesenchyme-derived [[dental papilla]], and the neural crest is specific to vertebrates, as are tissues such as [[Tooth enamel|enamel]].<ref name="kardong"/>

The [[radula]] is used by molluscs for feeding, and is sometimes compared rather inaccurately to a [[tongue]]. It is a minutely toothed, [[chitin]]ous ribbon, typically used for scraping or cutting food before the food enters the [[oesophagus]]. The radula is unique to molluscs, and is found in every class of mollusc apart from [[Bivalvia|bivalves]].

Within the [[gastropods]], the radula is used in feeding by both [[herbivore|herbivorous]] and [[carnivore|carnivorous]] [[snail]]s and [[slug]]s. The arrangement of teeth (also known as denticles) on the radula ribbon varies considerably from one group to another as shown in the diagram on the left.

Predatory marine snails such as the [[Naticidae]] use the radula plus an acidic secretion to bore through the shell of other molluscs. Other predatory marine [[snails]], such as the [[Conidae]], use a [[Cone snail#Harpoon and venoms|specialized radula tooth as a poisoned harpoon]]. Predatory [[pulmonate]] land [[slug]]s, such as the [[ghost slug]], use elongated razor-sharp teeth on the radula to seize and devour [[earthworms]]. Predatory cephalopods, such as [[squid]], use the radula for cutting prey.

In most of the more ancient lineages of gastropods, the radula is used to graze by scraping [[diatom]]s and other microscopic [[alga]]e off rock surfaces and other substrates. [[Limpet]]s scrape [[algae]] from rocks using radula equipped with exceptionally hard rasping teeth.<ref name="Barber">{{citation |url=http://rsif.royalsocietypublishing.org/content/12/105/20141326 |title=Extreme strength observed in limpet teeth |author=Barber, Lu, Pugno |doi=10.1098/rsif.2014.1326 |date=18 February 2015 |publisher=Royal Society |journal=Interface |volume=Vol. 12 |number=105 |pages=20141326}}</ref> These teeth have the strongest known [[tensile strength]] of any biological material, outperforming [[spider silk]].<ref name=Barber/> The mineral protein of the limpet teeth can withstand a [[stress (mechanics)|tensile stress]] of 4.9 GPa, compared to 4 GPa of spider silk and 0.5 GPa of [[human teeth]].<ref>{{cite web | url =http://www.independent.co.uk/news/science/limpet-teeth-just-how-strong-is-it-10054520.html|title=The strongest materials in the world: Limpet teeth beats record resistance of spider silk |publisher=''[[The Independent]]''|author=Zachary Davies Boren|date=18 February 2015| accessdate = 20 February 2015}}</ref>

{{clear}}

== Fossilization and [[taphonomy]] ==
Because teeth are very resistant, often preserved when bones are not,<ref>Taphonomy: A Process Approach
By Ronald E. Martin
Edition: illustrated
Published by Cambridge University Press, 1999
ISBN 0-521-59833-8, ISBN 978-0-521-59833-0
508 pages</ref> and reflect the diet of the host organism, they are very valuable to archaeologists and palaeontologists.  Early fish such as the [[thelodonts]] had scales composed of dentine and an enamel-like compound, suggesting that the origin of teeth was scales which were retained in the mouth.  Fish as early as the late [[Cambrian]] had dentine in their exoskeleton, which may have functioned in defense or for sensing their environment.<ref name=Smith2007>Teaford, Mark F and Smith, Moya Meredith, 2007. ''Development, Function and Evolution of Teeth'', Cambridge University Press. ISBN 0-521-03372-1, ISBN 978-0-521-03372-5, Chapter 5.</ref>  Dentine can be as hard as the rest of teeth, and is composed of collagen fibres, reinforced with [[hydroxyapatite]].<ref name=Smith2007/>

Decalcification removes the enamel from teeth and leaves only the organic interior intact, which comprises dentine and cementine.<ref name=Fisher1981>{{Cite journal
 | last = Fisher | first = Daniel C
 | year = 1981
 | title = Taphonomic Interpretation of Enamel-Less Teeth in the Shotgun Local Fauna (Paleocene, Wyoming)
 | journal = Museum of Paleontology Contributions, the University of Michigan
 | volume = 25
 | issue = 13
 | pages = 259–275
 | id = {{hdl|2027.42/48503}}
 | postscript = <!-- Bot inserted parameter. Either remove it; or change its value to "." for the cite to end in a ".", as necessary. -->
}}</ref> Enamel is quickly decalcified in acids,<ref name=f-j/> perhaps by dissolution by plant acids or via diagenetic solutions, or in the stomachs of vertebrate predators.<ref name=Fisher1981/>  Enamel can be lost by abrasion or spalling,<ref name=Fisher1981/> and is lost before dentine or bone are destroyed by the fossilisation process.<ref name=f-j>{{Cite journal| first1 = Y.| first2 = B.| first3 = P.| first4 = S.| first5 = L.| title = Morphological taphonomic transformations of fossil bones in continental environments, and repercussions on their chemical composition| journal = Archaeometry| volume = 44| pages = 353–361| last1 = Fernandez-Jalvo| year = 2002| doi = 10.1111/1475-4754.t01-1-00068| last2 =  Sanchez-Chillon| last3 =  Andrews| last4 =  Fernandez-Lopez| last5 =  Alcala Martinez}}</ref>  In such a case, the 'skeleton' of the teeth would consist of the dentine, with a hollow pulp cavity.<ref name=Fisher1981/>
The organic part of dentine, conversely, is destroyed by alkalis.<ref name=f-j/>

== See also ==
{{Portal|Dentistry}}
* [[Animal tooth development]]

== References ==
{{Reflist|2}}
{{commons|tooth}}

== External links ==
* {{Cite NSRW|wstitle=Teeth}}

{{Authority control}}

[[Category:Articles with inconsistent citation formats]]
[[Category:Animal anatomy]]
[[Category:Teeth| ]]
[[Category:Speech organs]]

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