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Bicuspids
The premolars, also called premolar teeth, or bicuspids, are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant in the permanent set of teeth, making eight premolars total in the mouth. They have at least two cusps. Premolars can be considered transitional teeth during chewing, or mastication. They have properties of both the canines, that lie anterior and molars that lie posterior, and so food can be transferred from the canines to the premolars and finally to the molars for grinding, instead of directly from the canines to the molars. Human anatomy The premolars in humans are the maxillary first premolar, maxillary second premolar, mandibular first premolar, and the mandibular second premolar. Premolar teeth by definition are permanent teeth distal to the canines, preceded by deciduous molars. Morphology There is always one large buccal cusp, especially so in the mandibular first premolar. The lower second p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cusp (dentistry)
A cusp is a pointed, projecting, or elevated feature. In animals, it is usually used to refer to raised points on the crowns of teeth. The concept is also used with regard to the leaflets of the four heart valves. The mitral valve, which has two cusps, is also known as the bicuspid valve, and the tricuspid valve has three cusps. In humans A cusp is an occlusal or incisal eminence on a tooth. Canine teeth, otherwise known as cuspids, each possess a single cusp, while premolars, otherwise known as bicuspids, possess two each. Molars normally possess either four or five cusps. In certain populations the maxillary molars, especially first molars, will possess a fifth cusp situated on the mesiolingual cusp known as the Cusp of Carabelli. Buccal Cusp- One other variation of the upper first premolar is the 'Uto-Aztecan' upper premolar. It is a bulge on the buccal cusp that is only found in Native American Indians, with highest frequencies of occurrence in Arizona. The name is no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dentes Premolares
The premolars, also called premolar Tooth (human), teeth, or bicuspids, are transitional teeth located between the Canine tooth, canine and Molar (tooth), molar teeth. In humans, there are two premolars per dental terminology#Quadrant, quadrant in the permanent teeth, permanent set of teeth, making eight premolars total in the mouth. They have at least two Cusp (dentistry), cusps. Premolars can be considered transitional teeth during chewing, or mastication. They have properties of both the canines, that lie anterior and molars that lie Posterior (anatomy), posterior, and so food can be transferred from the canines to the premolars and finally to the molars for grinding, instead of directly from the canines to the molars. Human anatomy The premolars in humans are the maxillary first premolar, maxillary second premolar, mandibular first premolar, and the mandibular second premolar. Premolar teeth by definition are permanent teeth Anatomical terms of location#Proximal and distal, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mandibular First Premolar
The mandibular first premolar is the tooth located laterally (away from the midline of the face) from both the mandibular canines of the mouth but mesial (toward the midline of the face) from both mandibular second premolars. The function of this premolar is similar to that of canines in regard to tearing being the principal action during mastication, commonly known as chewing. Mandibular first premolars have two cusps. The one large and sharp is located on the buccal side (closest to the cheek) of the tooth. Since the lingual cusp (located nearer the tongue) is small and nonfunctional (which refers to a cusp not active in chewing), the mandibular first premolar resembles a small canine. There are no deciduous (baby) mandibular premolars. Instead, the teeth that precede the permanent mandibular premolars are the deciduous mandibular molars. Sometimes, premolars are referred to as bicuspids. Even though the terms are synonymous, "bicuspid" refers to having two functional cusps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mandibular Second Premolar
The mandibular second premolar is the tooth located distally (away from the midline of the face) from both the mandibular first premolars of the mouth but mesial (toward the midline of the face) from both mandibular first molars. The function of this premolar is assist the mandibular first molar during mastication, commonly known as chewing. Mandibular second premolars have three cusps. There is one large cusp on the buccal side (closest to the cheek) of the tooth. The lingual cusps (located nearer the tongue) are well developed and functional (which refers to cusps assisting during chewing). Therefore, whereas the mandibular first premolar resembles a small canine, the mandibular second premolar is more alike to the first molar. There are no deciduous (baby) mandibular premolars. Instead, the teeth that precede the permanent mandibular premolars are the deciduous mandibular molars. Anatomy: The mandibular second premolar most commonly has three cusps but can have two as we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth (human)
The human teeth function to mechanically break down items of food by cutting and crushing them in preparation for swallowing and digesting. As such, they are considered part of the human digestive system. Humans have four types of teeth: incisors, canines, premolars, and molars, which each have a specific function. The incisors cut the food, the canines tear the food and the molars and premolars crush the food. The roots of teeth are embedded in the maxilla (upper jaw) or the mandible (lower jaw) and are covered by gums. Teeth are made of multiple tissues of varying density and hardness. Humans, like most other mammals, are diphyodont, meaning that they develop two sets of teeth. The first set, deciduous teeth, also called "primary teeth", "baby teeth", or "milk teeth", normally eventually contains 20 teeth. Primary teeth typically start to appear (" erupt") around six months of age and this may be distracting and/or painful for the infant. However, some babies are born with o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinodont
In anthropology, Sinodonty and Sundadonty are two patterns of features widely found in the dentitions of different populations in East Asia and Southeast Asia. These two patterns were identified by anthropologist Christy G. Turner II as being within the greater "Mongoloid dental complex". The combining forms ''Sino-'' and ''Sunda-'' refer to China and Sundaland, respectively, while refers to teeth. Proto-sundadonty hypothesis Tsunehiko Hanihara (1993) believed that the dental features of Aboriginal Australians have the characteristic of high frequencies of "''evolutionarily conservative characteristics,''" which he called the "proto-sundadont" pattern, as he believed that the dental pattern of Aboriginal Australians was ancestral to that of Southeast Asians.Hanihara, Tsunehiko. (1993). Craniofacial Features of Southeast Asians and Jomonese: A Reconsideration of Their Microevolution Since the Late Pleistocene. ''Anthropological Science, 101''(1). Page 26. Retrieved March 8, 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steve Jones (biologist)
John Stephen Jones (born 24 March 1944) is a British geneticist and from 1995 to 1999 and 2008 to June 2010 was Head of the Department of Genetics, Evolution and Environment at University College London.UCL GEE News GEE marks the transfer of headship His studies are conducted in the . He is also a television presenter and a prize-winning author on the subject of , especially . He is a popular contemporary writer on evolution. In 1996 his w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incisor
Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, whereas armadillos have none. Structure Adult humans normally have eight incisors, two of each type. The types of incisor are: * maxillary central incisor (upper jaw, closest to the center of the lips) * maxillary lateral incisor (upper jaw, beside the maxillary central incisor) * mandibular central incisor (lower jaw, closest to the center of the lips) * mandibular lateral incisor (lower jaw, beside the mandibular central incisor) Children with a full set of deciduous teeth (primary teeth) also have eight incisors, named the same way as in permanent teeth. Young children may have from zero to eight incisors depending on the stage of their tooth eruption and tooth development. Typically, the mandibular central incisors erupt first, followed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Claud Bramblett
Claud is a given name. Notable people with the name include: *Claud Allister (1888–1970), English actor *Claud Beelman (1883–1963), American architect * Claud Irvine Boswell (1742–1824), Scottish judge *Claud Thomas Bourchier (1831–1877), English recipient of the Victoria Cross * Claud E. Cleeton (1907–1997), physicist notable for his work on the microwave spectroscopy of ammonia *Claud Cockburn (1904–1981), radical English journalist controversial for communist sympathies * Claud Derrick, former Major League Baseball shortstop *Claud Lovat Fraser (1890–1921), English Artist, designer and author *Claud Hamilton, 1st Lord Paisley (1543–1621), Scottish politician *Claud Hamilton, 2nd Baron Hamilton of Strabane (1606–1638), the third son of James Hamilton *Claud Hamilton, 4th Earl of Abercorn, PC (1659–1691), Scottish and Irish peer and Jacobite *Claud Heathcote-Drummond-Willoughby (1872–1950), British Conservative Party politician * Alfred Claud Hollis (1874–19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gentry Steele
Gentry (from Old French ''genterie'', from ''gentil'', "high-born, noble") are "well-born, genteel and well-bred people" of high social class, especially in the past. Word similar to gentle imple and decentfamilies ''Gentry'', in its widest connotation, refers to people of good social position connected to landed estates (see manorialism), upper levels of the clergy, and "gentle" families of long descent who in some cases never obtained the official right to bear a coat of arms. The gentry largely consisted of landowners who could live entirely from rental income, or at least had a country estate; some were gentleman farmers. In the United Kingdom, the term ''gentry'' refers to the landed gentry: the majority of the land-owning social class who typically had a coat of arms, but did not have a peerage. The adjective "patrician" ("of or like a person of high social rank") describes in comparison other analogous traditional social elite strata based in cities, such as free c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hominoidea
Apes (collectively Hominoidea ) are a clade of Old World simians native to sub-Saharan Africa and Southeast Asia (though they were more widespread in Africa, most of Asia, and as well as Europe in prehistory), which together with its sister group Cercopithecidae form the catarrhine clade, cladistically making them monkeys (though this is the subject of much debate). Apes do not have tails due to a mutation of the TBXT gene. In traditional and non-scientific use, the term "ape" can include tailless primates taxonomically considered Cercopithecidae (such as the Barbary ape and black ape), and is thus not equivalent to the scientific taxon Hominoidea. There are two extant branches of the superfamily Hominoidea: the gibbons, or lesser apes; and the hominids, or great apes. * The family Hylobatidae, the lesser apes, include four genera and a total of 20 species of gibbon, including the lar gibbon and the siamang, all native to Asia. They are highly arboreal and bipedal on the gro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cercopithecoidea
Old World monkey is the common English name for a family of primates known taxonomically as the Cercopithecidae (). Twenty-four genera and 138 species are recognized, making it the largest primate family. Old World monkey genera include baboons (genus '' Papio''), red colobus (genus '' Piliocolobus'') and macaques (genus '' Macaca''). Common names for other Old World monkeys include the talapoin, guenon, colobus, douc (douc langur, genus ''Pygathrix''), vervet, gelada, mangabey (a group of genera), langur, mandrill, surili (''Presbytis''), patas, and proboscis monkey. Phylogenetically, they are more closely related to apes than to New World monkeys. They diverged from a common ancestor of New World monkeys around 45 to 55 million years ago. The smallest Old World monkey is the talapoin, with a head and body 34–37 cm in length, and weighing between 0.7 and 1.3 kg. The largest is the male mandrill, around 70 cm in length, and weighing up to 50 kg. Old ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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