What is Tooth?
[[File:06-10-06smile.jpg|thumb|250px|{{center|Healthy human teeth}}]] A '''tooth''' is one of the hard, white things in the [[mouth]]. '''Teeth''' (plural) are used to help the [[mastication]] process by chewing food. ''Chew'' means to break up and crush food so it can be swallowed (pushed down into the [[stomach]]). Most [[vertebrate]]s have teeth. [[Bird]]s are the biggest group that do not. Many [[invertebrate]]s have [[mouthparts]] which, to some extent, act like teeth. Different animals have different kinds of teeth because they eat different foods. Some animals use teeth as a weapon. [[Human]] [[adult]]s usually have 32 teeth.<ref name=COCC>{{cite web |url=http://www.colgate.com/en/us/oc/oral-health/basics/mouth-and-teeth-anatomy/article/sw-281474979043251 |title=How many teeth do we have? |author=Tina Callison |website= |publisher=Colgate Oral Care Center |accessdate=10 January 2016 |archive-date=10 January 2016 |archive-url=https://web.archive.org/web/20160110185332/http://www.colgate.com/en/us/oc/oral-health/basics/mouth-and-teeth-anatomy/article/sw-281474979043251 |url-status=dead }}</ref> Human [[children]] usually have 20 teeth.<ref name=COCC/> == Natal teeth == Some human babies are born with teeth. '''Natal teeth''' are teeth that are present at birth.<ref name=USNLM>{{cite web |url=https://www.nlm.nih.gov/medlineplus/ency/article/003268.htm |title=Natal teeth |author= |website= |publisher=U.S. National Library of Medicine |accessdate=10 January 2016}}</ref> These are different from '''neonatal teeth''' which are teeth that emerge during the first month of life.<ref name=USNLM/> Natal teeth are not common. They occur in about 1 out of every 2–3 [[thousand]] births.<ref name=USNLM/> They are usually found on the [[lower jaw]]. Natal teeth are usually not well attached and may easily [[wikt:wobble|wobble]].<ref name=USNLM/> == Teeth eruption == '''Deciduous teeth''' or milk teeth or temporary teeth are the first set of teeth for most [[mammal]]s. Humans have 20 of them.<ref name=COCC/> The first