Molar (tooth) Totally Explained

Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone".

Human molars

Adult humans have twelve molars, in four groups of three at the back of the mouth. The third (rearmost) molar in each group is called a wisdom tooth. It is the last tooth to appear, breaking through the surface of the gum at about the age of twenty, although this varies by ethnicity.
The types of molars in the human mouth are:

Molars among species

Molars differ considerably from one species to another, so there are many terms describing them:

Tribosphenic: This kind is found in insectivores and young platypuses (adults have no teeth). Upper molars look like three-pointed mountain ranges; lowers look like two peaks and a third off to the side.

Quadrate: This kind is found in humans and various other species. Four cusps are arranged in a rectangle; there may be a fifth.

Bunodont: The cusps, instead of being sharp peaks, are rounded hills. The entire tooth is covered in enamel, and is most common among omnivores such as the pig, the bear and humans.

Hypsodont: There is a lot of enamel and dentine above the gumline and the top of the pulp. This kind of molar is found in mammals that wear their teeth a lot, such as the horse.

Zalambdodont: The tooth has two ridges that meet at an angle, forming the letter lambda.

Dilambdodont: Like zalambdodont, but there are two lambdas on one tooth.

Lophodont: The tooth has a few ridges perpendicular to the jaw.

Selenodont: The tooth has a crescent-shaped ridge or ridges.

Loxodont: The tooth has several parallel oblique ridges on its surface. The elephant Loxodonta is named for this feature.

Tribosphenic molar

The molar design that's considered one of the most important characteristics of mammals is a three-cusped shape called a tribosphenic molar. This design of molar has two important features: the trigonoid, or shearing end, and the talinoid, or crushing heel. With the exception of Jurassic mammal Shuotherium, the talinoid is posterior the triginoid.
The tribosphenic design appears in all species of mammals. In monotremes, it seems to have developed independently, rather than from common ancestry with marsupials and placentals.

Additional images

Image:Teeth_molar47_46resection_crown_premolar45.jpg|Molar 47 (left), molar 46 and premolar 45(right) Image:Illu mouth.jpg|Mouth (oral cavity) Image:Gray157.png|Left maxilla. Outer surface. Image:Gray187.png|Base of skull. Inferior surface. Image:Gray1003.png|The permanent teeth, viewed from the right.

External results

Click here for more details on Molar Tooth

External Link Exchanges

Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:

<a href="http://molar__tooth.totallyexplained.com">Molar (tooth) Totally Explained</a>

Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned.