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Edentulism is the condition of being toothless to at least some degree; in organisms (such as humans) that naturally have dentition, it is the result of tooth loss. Loss of some teeth results in partial edentulism, whereas loss of all teeth results in complete edentulism. Persons who have lost teeth are (either partially or completely) edentulous (edentate), whereas those who have not lost teeth can be called dentate by comparison. For example, a scientific study may include a partially edentulous group and a healthy dentate control group. Organisms that never possessed teeth can also be described as edentulous, such as members of the former zoological classification order of ''Edentata'', which included anteaters and sloths, all of which possess no anterior teeth and either no or poorly developed posterior teeth. In naturally dentate species, edentulism is more than just the simple presence or absence of teeth; it is biochemically complex, because the teeth, jaws, and oral mucosa are not static objects; they are dynamic (changing over time). Processes such as bone remodeling (loss and gain of bone tissue) in the jaws and inflammation of soft tissue in response to the oral microbiota are clinically important for edentulous people. For example, bone resorption in the jaw is frequently how the teeth were able to detach in the first place; the jaw in an edentulous area undergoes further resorption even after the teeth are gone; and insertion of dental implants can elicit new bone formation, leading to osseointegration. Meanwhile, bacteria and yeasts of the oral cavity and the immune system of their host create an immensely complicated and constantly changing interplay that presents clinically as gingivitis, caries, stomatitis, and other periodontal pathology. ==Signs and symptoms== For people, the relevance and functionality of teeth can be easily taken for granted, but a closer examination of their considerable significance will demonstrate how they are actually very important. Among other things, teeth serve to: *support the lips and cheeks, providing for a fuller, more aesthetically pleasing appearance *maintain an individual's vertical dimension of occlusion *along with the tongue and lips, allow for the proper pronunciation of various sounds *preserve and maintain the height of the alveolar ridge *cut, grind, and otherwise chew food 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「edentulism」の詳細全文を読む スポンサード リンク
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