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Tooth Fusion
Tooth fusion arises through union of two normally separated tooth germs, and depending upon the stage of development of the teeth at the time of union, it may be either complete or incomplete. On some occasions, two independent pulp chambers and root canals can be seen. However, fusion can also be the union of a normal tooth bud to a supernumerary tooth germ. In these cases, the number of teeth is fewer if the anomalous tooth is counted as one tooth. In geminated teeth, division is usually incomplete and results in a large tooth crown that has a single root and a single canal. Both gemination and fusion are prevalent in primary dentition, with incisors being more affected. Tooth gemination, in contrast to fusion, arises when two teeth develop from one tooth bud. When the anomalous tooth appears to be two separate teeth, it appears that the patient has an extra tooth, although they have a normal number of tooth roots. In contrast to fusion, concrescence is the roots of 2 or more t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deciduous Teeth
Deciduous teeth or primary teeth, also informally known as baby teeth, milk teeth, or temporary teeth,Illustrated Dental Embryology, Histology, and Anatomy, Bath-Balogh and Fehrenbach, Elsevier, 2011, page 255 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 back into the posterior region. B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dentistry
Dentistry, also known as dental medicine and oral medicine, is the branch of medicine focused on the teeth, gums, and mouth. It consists of the study, diagnosis, prevention, management, and treatment of diseases, disorders, and conditions of the mouth, most commonly focused on dentition (the development and arrangement of teeth) as well as the oral mucosa. Dentistry may also encompass other aspects of the craniofacial complex including the temporomandibular joint. The practitioner is called a dentist. The history of dentistry is almost as ancient as the history of humanity and civilization with the earliest evidence dating from 7000 BC to 5500 BC. Dentistry is thought to have been the first specialization in medicine which have gone on to develop its own accredited degree with its own specializations. Dentistry is often also understood to subsume the now largely defunct medical specialty of stomatology (the study of the mouth and its disorders and diseases) for which reas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amelogenesis Imperfecta
Amelogenesis imperfecta (AI) is a congenital disorder which presents with a rare abnormal formation of the enamel or external layer of the crown of teeth, unrelated to any systemic or generalized conditions. Enamel is composed mostly of mineral, that is formed and regulated by the proteins in it. Amelogenesis imperfecta is due to the malfunction of the proteins in the enamel (ameloblastin, enamelin, tuftelin and amelogenin) as a result of abnormal enamel formation via amelogenesis. People with amelogenesis imperfecta may have teeth with abnormal color: yellow, brown or grey; this disorder can affect any number of teeth of both dentitions. Enamel hypoplasia manifests in a variety of ways depending on the type of AI an individual has (see below), with pitting and plane-form defects common. The teeth have a higher risk for dental cavities and are hypersensitive to temperature changes as well as rapid attrition, excessive calculus deposition, and gingival hyperplasia.American Academy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dentinogenesis Imperfecta
Dentinogenesis imperfecta (DI) is a genetic disorder of tooth development. It is inherited in an autosomal dominant pattern, as a result of mutations on chromosome 4q21, in the dentine sialophosphoprotein gene (DSPP). It is one of the most frequently occurring autosomal dominant features in humans. Dentinogenesis imperfecta affects an estimated 1 in 6,000-8,000 people. This condition can cause teeth to be discolored (most often a blue-gray or yellow-brown color) and translucent, giving teeth an opalescent sheen. Teeth are also weaker than normal, making them prone to rapid wear, breakage, and loss. These problems can affect baby (primary/deciduous) teeth alone, or both baby teeth and adult (permanent) teeth, with the baby teeth usually more severely affected. Although genetic factors are the main contributor for the disease, any environmental or systemic upset that impedes calcification or metabolisation of calcium can also result in anomalous dentine. Classification Shield cl ... [...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 to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anodontia
Anodontia is a rare genetic disorder characterized by the congenital absence of all primary or permanent teeth. It is divided into two subsections, complete absence of teeth or only some absence of teeth. It is associated with the group of skin and nerve syndromes called the ectodermal dysplasias. Anodontia is usually part of a syndrome and seldom occurs as an isolated entity. There is usually no exact cause for anodontia. The defect results in the dental lamina obstruction during embryogenesis due to local, systemic and genetic factors. Congenital absence of permanent teeth can present as hypodontia, usually missing one or two permanent teeth, or oligodontia that is the congenital absence of six or more teeth. Congenital absence of all wisdom teeth, or third molars, is relatively common. Anodontia is the congenital absence of teeth and can occur in some or all teeth; whereas partial anodontia (or hypodontia), involves two dentitions or only teeth of the permanent dentition (Do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teeth
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 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 cartilaginous fish, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth Development
Tooth development or odontogenesis is the complex process by which teeth form from embryonic cells, grow, and erupt into the mouth. For human teeth to have a healthy oral environment, all parts of the tooth must develop during appropriate stages of fetal development. Primary (baby) teeth start to form between the sixth and eighth week of prenatal development, and permanent teeth begin to form in the twentieth week.Ten Cate's Oral Histology, Nanci, Elsevier, 2013, pages 70-94 If teeth do not start to develop at or near these times, they will not develop at all, resulting in hypodontia or anodontia. A significant amount of research has focused on determining the processes that initiate tooth development. It is widely accepted that there is a factor within the tissues of the first pharyngeal arch that is necessary for the development of teeth. Overview The tooth germ is an aggregation of cells that eventually forms a tooth.University of Texas Medical Branch. These cells are de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
