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Permanent Teeth
Permanent teeth or adult teeth are the second set of teeth formed in diphyodont mammals. In humans and old world simians, there are thirty-two permanent teeth, consisting of six maxillary and six mandibular molars, four maxillary and four mandibular premolars, two maxillary and two mandibular canines, four maxillary and four mandibular incisors. Timeline The first permanent tooth usually appears in the mouth at around 5-6 years of age, and the mouth will then be in a transition time with both primary (or deciduous dentition) teeth and permanent teeth during the mixed dentition period until the last primary tooth is lost or shed. The first of the permanent teeth to erupt are the permanent first molars, right behind the last 'milk' molars of the primary dentition. These first permanent molars are important for the correct development of a permanent dentition. Up to thirteen years of age, 28 of the 32 permanent teeth will appear. The full permanent dentition is completed much l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth
A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tearing food, for defensive purposes, to intimidate other animals often including their own, or to carry prey or their young. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness that originate from the outermost 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 teeth of mammals have deep roots, and this pattern is also found in some fish, and in crocodilians. In most teleost fish, however, the teeth are attached to the outer surface of the bone, while in lizards they are attached to the inner surface of the jaw by one side. In cartila ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deciduous Dentition
Deciduous teeth or primary teeth, also informally known as baby teeth, milk teeth, or temporary teeth,Fehrenbach, MJ and Popowics, T. (2026). ''Illustrated Dental Embryology, Histology, and Anatomy'', 6th edition, Elsevier, page 287–296. are the first set of teeth in the growth and development of humans and other diphyodonts, which include most mammals but not elephants, kangaroos, or manatees, which are polyphyodonts. Deciduous teeth develop during the embryonic stage of development and erupt (break through the gums and become visible in the mouth) during infancy. They are usually lost and replaced by permanent teeth, but in the absence of their permanent replacements, they can remain functional for many years into adulthood. Development Formation Primary teeth start to form during the embryonic phase of human life. The development of primary teeth starts at the sixth week of tooth development as the dental lamina. This process starts at the midline and then spreads b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cleidocranial Dysostosis
Cleidocranial dysostosis (CCD), also called cleidocranial dysplasia, is a congenital disorder, birth defect that mostly affects the bones and teeth. The collarbones are typically either poorly developed or absent, which allows the shoulders to be brought close together. The front of the skull often does not close until later, and those affected are often shorter than average. Other symptoms may include a prominent forehead, wide set eyes, abnormal teeth, and a flat nose. Symptoms vary among people; however, cognitive function is typically unaffected. The condition is either heredity, inherited or occurs as a new mutation. It is inherited in an autosomal dominant manner. It is due to a defect in the RUNX2 gene which is involved in bone formation. Diagnosis is suspected based on symptoms and X-rays with confirmation by genetic testing. Other conditions that can produce similar symptoms include mandibuloacral dysplasia, pyknodysostosis, osteogenesis imperfecta, and Hajdu-Cheney synd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cleft Lip And Cleft Palate
A cleft lip contains an opening in the upper lip that may extend into the nose. The opening may be on one side, both sides, or in the middle. A cleft palate occurs when the palate (the roof of the mouth) contains an opening into the nose. The term orofacial cleft refers to either condition or to both occurring together. These disorders can result in feeding problems, speech problems, hearing problems, and frequent ear infections. Less than half the time the condition is associated with other disorders. Cleft lip and palate are the result of tissues of the face not joining properly during development. As such, they are a type of birth defect. The cause is unknown in most cases. Risk factors include smoking during pregnancy, diabetes, obesity, an older mother, and certain medications (such as some used to treat seizures). Cleft lip and cleft palate can often be diagnosed during pregnancy with an ultrasound exam. A cleft lip or palate can be successfully treated with surgery ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperdontia
Hyperdontia is the condition of having supernumerary teeth, or teeth that appear in addition to the regular number of teeth (32 in the average adult). They can appear in any area of the dental arch and can affect any dental organ. The opposite of hyperdontia is hypodontia, where there is a congenital lack of teeth, which is a condition seen more commonly than hyperdontia.Pathology of the Hard Dental Tissues The scientific definition of hyperdontia is "any tooth or odontogenic structure that is formed from tooth germ in excess of usual number for any given region of the dental arch."R. S. Omer, R. P. Anthonappa, and N. M. King, "Determination of the optimum time for surgical removal of unerupted anterior supernumerary teeth," Pediatric Dentistry, vol. 32, no. 1, pp. 14–20, 2010. The additional teeth, which may be few or many, can occur on any place in the dental arch. Their arrangement may be symmetrical or non-symmetrical. Signs and symptoms The presence of a supernumerary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wisdom Tooth
The third molar, commonly called wisdom tooth, is the most posterior of the three molars in each quadrant of the human dentition. The age at which wisdom teeth come through ( erupt) is variable, but this generally occurs between late teens and early twenties. Most adults have four wisdom teeth, one in each of the four quadrants, but it is possible to have none, fewer, or more, in which case the extras are called supernumerary teeth. Wisdom teeth may become stuck ( impacted) and not erupt fully, if there is not enough space for them to come through normally. Impacted wisdom teeth are still sometimes removed for orthodontic treatment, believing that they move the other teeth and cause crowding, though this is disputed. Impacted wisdom teeth may suffer from tooth decay if oral hygiene becomes more difficult. Wisdom teeth which are partially erupted through the gum may also cause inflammation and infection in the surrounding gum tissues, termed pericoronitis. More conservativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Dental Association
The American Dental Association (ADA) is an American professional dental association. Established in 1859 and with over 159,000 current members, ADA is the world's largest and oldest national dental association. The organization lobbies on behalf of the American dental profession and provides dental accreditation. The ADA publishes the '' Journal of the American Dental Association'' and ''JADA Foundational Science''. As part of its lobbying efforts, the ADA has sought to restrict non-dentists (such as dental hygienists and dental therapists) from providing basic dental care. The organization has played an important role in blocking the inclusion of dental coverage in Medicare. The ADA has expressed opposition to the opening of new dental schools or to increasing the number of dentists in the United States, even as the United States trains almost half as many dental students (relative to population) in the 2000s as it did in the 1980s. History The American Dental Associati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mouth
A mouth also referred to as the oral is the body orifice through which many animals ingest food and animal communication#Auditory, vocalize. The body cavity immediately behind the mouth opening, known as the oral cavity (or in Latin), is also the first part of the alimentary canal, which leads to the pharynx and the gullet. In tetrapod vertebrates, the mouth is bounded on the outside by the lips and cheeks — thus the oral cavity is also known as the buccal cavity (from Latin ', meaning "cheek") — and contains the tongue on the inside. Except for some groups like birds and lissamphibians, vertebrates usually have teeth in their mouths, although some fish species have pharyngeal teeth instead of oral teeth. Most bilaterian phylum, phyla, including arthropods, molluscs and chordates, have a two-opening gut tube with a mouth at one end and an anus at the other. Which end forms first in ontogeny is a criterion used to classify bilaterian animals into protostomes and deuterostomes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphyodont
A diphyodont is any animal with two sets of teeth, initially the ''deciduous'' set and consecutively the '' permanent'' set. Most mammals are diphyodonts—as to chew their food they need a strong, durable and complete set of teeth. Diphyodonts contrast with ''polyphyodonts'', whose teeth are constantly replaced. Diphyodonts also differ from '' monophyodonts'', which are animals who have only one set of teeth that does not change over a long period of growth. In diphyodonts, the number of teeth that are replaced varies from species to species. In humans, a set of twenty deciduous teeth, or "milk teeth", are replaced by a completely new set of thirty-two adult teeth. In some cases hypodontia or hyperdontia occurs, the latter in cleidocranial dysostosis and Gardner's syndrome. In the hare the anterior incisors are not replaced but the posterior smaller incisors are replaced. Not much is known about the developmental mechanisms regulating diphyodont replacement. The house shre ... [...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, anteaters and other animals in the order Edentata have none. Structure Adult humans normally have eight incisors, two of each type. The types of incisors 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. Typic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canine Tooth
In mammalian oral anatomy, the canine teeth, also called cuspids, dogteeth, eye teeth, vampire teeth, or fangs, are the relatively long, pointed teeth. In the context of the upper jaw, they are also known as '' fangs''. They can appear more flattened, however, causing them to resemble incisors and leading them to be called ''incisiform''. They developed and are used primarily for firmly holding food in order to tear it apart, and occasionally as weapons. They are often the largest teeth in a mammal's mouth. Individuals of most species that develop them normally have four, two in the upper jaw and two in the lower, separated within each jaw by incisors; humans and dogs are examples. In most species, canines are the anterior-most teeth in the maxillary bone. The four canines in humans are the two upper maxillary canines and the two lower mandibular canines. They are specially prominent in dogs (Canidae), hence the name. Details There are generally four canine teeth: two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
